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软件工程实践二：Spring Boot 知识回顾

news 2025/9/15 5:53:51

文章目录

      • 一、创建项目（Spring Boot 向导）
      • 二、项目最小代码示例
      • 三、运行与验证
      • 四、标准目录结构与说明
      • 五、Maven 依赖最小示例（仅供参考）
      • 六、常用配置（application.yml 示例）
      • 七、返回 JSON 与统一异常
      • 八、@Value 配置读取示例
      • 九、日志引入与配置（SLF4J + Logback）
      • 十、@ConfigurationProperties 批量绑定与校验
      • 十一、GET 参数处理与示例
      • 十二、POST 参数上传与示例
      • 十三、过滤器 Filter 与案例
      • 十四、拦截器 HandlerInterceptor 与案例
      • 十五、PUT 参数上传与示例
      • 十六、20 个 GET/POST 接口样例

原文链接：https://blog.ybyq.wang/archives/1099.html

一、创建项目（Spring Boot 向导）

2025-09-10T01:45:26.png

步骤说明：

  • 打开 IDEA → New Project → 选择 Spring Boot；服务地址保持默认。
  • Project Metadata：
    • Group：如 com.example
    • Artifact/Name：如 demo
    • Packaging：jar（默认）
    • Java：17（或本机已安装的 LTS 版本）
  • Build system：Maven（不要选 Gradle）
  • Dependencies：搜索并仅勾选 Spring Web。
  • Finish → 等待 Maven 下载依赖与索引完成。

提示：若看不到 Spring Boot(Initializr)，确保安装了 IntelliJ 的 Spring 插件，或使用 File > New > Project... 再选择。

二、项目最小代码示例

  1. 主启动类（IDE 已生成，检查包名与类名）
package com.example.demo;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplication
public class DemoApplication {public static void main(String[] args) {SpringApplication.run(DemoApplication.class, args);}
}
  1. Hello 控制器（新增）
package com.example.demo.controller;import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import java.util.Date;
import java.util.Map;@RestController
@RequestMapping("/api")
public class HelloController {@GetMapping("/hello")public Map<String, Object> hello() {return Map.of("msg", "hello","time", new Date());}
}
  1. 应用配置（可选）
# src/main/resources/application.yml
server:# 如需修改端口，取消注释并调整值# port: 8080

三、运行与验证

  • 在 DemoApplication 类左侧点击绿色运行箭头，或使用菜单 Run。
  • 控制台看到 Started DemoApplication ... 表示启动成功。
  • 浏览器/工具访问：http://localhost:8080/api/hello
    • 期望响应示例：
{"msg":"hello","time":"2025-01-01T00:00:00Z"}

常见问题：

  • 端口占用：在 application.yml 配置 server.port: 8081。
  • 依赖未下载：检查网络代理或尝试 Reload All Maven Projects。
  • JDK 不匹配：Project Structure > Project/Modules 指定与向导一致的 Java 版本。

四、标准目录结构与说明

 demo/                      ← 工程根目录├─ pom.xml  ← 构建脚本（Maven）├─ src│  ├─ main│  │  ├─ java│  │  │  └─ com│  │  │     └─ example│  │  │        └─ demo│  │  │           ├─ DemoApplication.java      ← 启动类│  │  │           └─ controller│  │  │              └─ HelloController.java   ← Web 控制器│  │  └─ resources│  │     ├─ application.yml                    ← 应用配置│  │     └─ static/ templates/                 ← 静态资源/模板(可选)│  └─ test│     └─ java│        └─ com.example.demo│           └─ DemoApplicationTests.java       ← 测试类
  • DemoApplication：应用入口，@SpringBootApplication 聚合配置并触发自动装配。
  • controller：放置 @RestController、@Controller 等 Web 层类。
  • resources：
    • application.yml|yaml：端口、数据源、日志级别等配置。
    • static/：静态文件（css/js/img）。
    • templates/：模板引擎（如 Thymeleaf）页面，需相应依赖时使用。
  • test：单元/集成测试。

五、Maven 依赖最小示例（仅供参考）

Maven pom.xml 关键片段：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>3.5.4</version><relativePath/></parent><groupId>com.example</groupId><artifactId>demo</artifactId><version>0.0.1-SNAPSHOT</version><name>demo</name><description>Demo project for Spring Boot</description><properties><java.version>17</java.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build>
</project>

六、常用配置（application.yml 示例）

spring:application:name: demojackson:time-zone: Asia/Shanghaidate-format: yyyy-MM-dd HH:mm:ssserver:port: 8080# servlet:#   context-path: /apilogging:level:root: INFOcom.example.demo: DEBUG# 多环境（profiles），开发/生产差异化配置（任选其一：此处或独立 profile 文件）
# spring:
#   profiles:
#     active: dev
  • 多环境配置（Profiles）示例：
# application-dev.yml（开发环境）
logging:level:com.example.demo: DEBUG

# application-prod.yml（生产环境）
logging:level:root: INFO

  • 运行时指定环境：

    • 在 application.yml 写：
      spring:profiles:active: dev
    • 或启动参数：--spring.profiles.active=prod

  • 全局 CORS（跨域）配置（如需前端跨域访问）：

package com.example.demo.config;import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;@Configuration
public class WebCorsConfig implements WebMvcConfigurer {@Overridepublic void addCorsMappings(CorsRegistry registry) {registry.addMapping("/**").allowedOrigins("http://localhost:3000").allowedMethods("GET", "POST", "PUT", "DELETE", "OPTIONS").allowCredentials(true);}
}
  • 全局异常处理（将错误转换为统一 JSON 响应）：
package com.example.demo.common;import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;import java.util.Map;@RestControllerAdvice
public class GlobalExceptionHandler {@ExceptionHandler(Exception.class)public Map<String, Object> handle(Exception ex) {return Map.of("success", false,"error", ex.getClass().getSimpleName(),"message", ex.getMessage());}
}

七、返回 JSON 与统一异常

  • 案例 1：路径参数 + 查询参数 + JSON 返回
package com.example.demo.controller;import org.springframework.web.bind.annotation.*;import java.util.Map;@RestController
@RequestMapping("/api/users")
public class UserController {@GetMapping("/{id}")public Map<String, Object> getUser(@PathVariable Long id,@RequestParam(defaultValue = "false") boolean detail) {return Map.of("id", id,"name", "Alice","detail", detail);}public record CreateUserRequest(String name, Integer age) {}@PostMappingpublic Map<String, Object> create(@RequestBody CreateUserRequest req) {long generatedId = System.currentTimeMillis();return Map.of("id", generatedId,"name", req.name(),"age", req.age());}
}
  • 案例 2：触发异常并由全局异常处理返回统一结构

将下述方法加入 UserController 以体验统一异常响应：

@GetMapping("/error")
public Map<String, Object> error() {throw new IllegalStateException("示例异常");
}
  • 测试命令示例：
# 获取用户（携带查询参数 detail）
curl "http://localhost:8080/api/users/1?detail=true"# 创建用户（POST JSON）
curl -X POST "http://localhost:8080/api/users" \-H "Content-Type: application/json" \-d "{\"name\":\"Bob\",\"age\":20}"# 触发错误，查看统一异常返回
curl "http://localhost:8080/api/users/error"

八、@Value 配置读取示例

  1. 在 application.yml 定义配置：
app:name: demo-apptimeout: 5s            # 可自动转换为 Durationwhite-list:- 127.0.0.1- 10.0.0.1db:host: 127.0.0.1port: 3306
  1. 使用 @Value 读取（支持默认值与基础类型转换）：
package com.example.demo.config;import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;import java.time.Duration;@Component
public class AppValueExample {@Value("${app.name}")private String appName;// 默认值示例：若未配置则为 3s@Value("${app.timeout:3s}")private Duration timeout;// 读取列表元素（带默认值）@Value("${app.white-list[0]:127.0.0.1}")private String firstWhiteIp;// 读取嵌套对象字段（带默认值）@Value("${app.db.host:localhost}")private String dbHost;@Value("${app.db.port:3306}")private Integer dbPort;public String getAppName() { return appName; }public Duration getTimeout() { return timeout; }public String getFirstWhiteIp() { return firstWhiteIp; }public String getDbHost() { return dbHost; }public Integer getDbPort() { return dbPort; }
}

说明：

  • 默认值语法：${key:defaultValue}，当 key 不存在时使用 defaultValue。
  • 类型转换：Duration/int/boolean 等常见类型由 Spring 自动转换（如 5s -> Duration.ofSeconds(5)）。
  • 列表索引：${list[0]} 访问第一个元素。
  • 建议：若配置项较多/需要分组，优先使用 @ConfigurationProperties 进行批量绑定与校验。

九、日志引入与配置（SLF4J + Logback）

  • 默认：spring-boot-starter-logging 已内置，提供 SLF4J API + Logback 实现。
  • 使用：在类中注入并使用 SLF4J Logger。
package com.example.demo.controller;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import java.util.Date;
import java.util.Map;@RestController
@RequestMapping("/api")
public class HelloControllerWithLog {private static final Logger log = LoggerFactory.getLogger(HelloControllerWithLog.class);@GetMapping("/hello2")public Map<String, Object> hello() {log.info("hello endpoint called at {}", new Date());log.debug("debug details...");return Map.of("msg", "hello", "time", new Date());}
}
  • 最小 application.yml 配置：
logging:level:root: INFOcom.example.demo: DEBUGfile:name: logs/app.log           # 输出到文件（会自动创建文件夹）logback:rollingpolicy:               # 基于 Logback 的滚动策略（无需 xml）max-file-size: 10MBmax-history: 7total-size-cap: 1GB

  • 常用说明：

    • logging.level.<包名>：设置指定包日志级别。
    • logging.file.name：直接指定日志文件；或使用 logging.file.path 指定目录（文件名默认为 spring.log）。
    • logging.logback.rollingpolicy.*：文件按大小/历史保留自动滚动。
    • 自定义输出格式可用：logging.pattern.console / logging.pattern.file。

  • 进阶（可选）：使用 logback-spring.xml 进行更细粒度控制，或切换 Log4j2：

    • 切换 Log4j2：在 pom.xml 引入 spring-boot-starter-log4j2 并排除默认 logging 依赖。

十、@ConfigurationProperties 批量绑定与校验

  • 配置（支持嵌套对象、列表、Map、时长等类型）：
app:name: demo-apptimeout: 5swhite-list:- 127.0.0.1- 10.0.0.1db:host: 127.0.0.1port: 3306
  • 属性类（开启校验，演示嵌套绑定与默认值）：
package com.example.demo.config;import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.convert.DurationUnit;import java.time.Duration;
import java.time.temporal.ChronoUnit;
import java.util.List;@ConfigurationProperties(prefix = "app")
public class AppProperties {private String name;@DurationUnit(ChronoUnit.SECONDS)private Duration timeout = Duration.ofSeconds(3);private List<String> whiteList;private Database db = new Database();public static class Database {private String host;private int port = 3306;public String getHost() { return host; }public void setHost(String host) { this.host = host; }public int getPort() { return port; }public void setPort(int port) { this.port = port; }}public String getName() { return name; }public void setName(String name) { this.name = name; }public Duration getTimeout() { return timeout; }public void setTimeout(Duration timeout) { this.timeout = timeout; }public List<String> getWhiteList() { return whiteList; }public void setWhiteList(List<String> whiteList) { this.whiteList = whiteList; }public Database getDb() { return db; }public void setDb(Database db) { this.db = db; }
}

  • 启用方式（三选一）：

    • 在启动类上开启扫描（推荐）：
    import org.springframework.boot.context.properties.ConfigurationPropertiesScan;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.SpringApplication;@SpringBootApplication
@ConfigurationPropertiesScan // 扫描同包及子包的 @ConfigurationProperties 类
public class DemoApplication {public static void main(String[] args) {SpringApplication.run(DemoApplication.class, args);}
}
    • 或在配置类上显式启用：
    import org.springframework.boot.context.properties.EnableConfigurationProperties;@EnableConfigurationProperties(AppProperties.class)
public class PropertiesConfig {}
    • 或直接把属性类声明为 Bean：
    import org.springframework.context.annotation.Bean;@org.springframework.context.annotation.Configuration
public class PropertiesConfig2 {@Beanpublic AppProperties appProperties() { return new AppProperties(); }
}

    也可在属性类上加 @Component 直接让其被扫描成 Bean（需保证包路径可被扫描）。

  • 校验依赖（若使用 @Validated/约束注解，请确保已引入）：

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-validation</artifactId>
</dependency>

十一、GET 参数处理与示例

GET 适用于通过查询参数与路径变量传递轻量数据；GET 不能上传文件（multipart/form-data）。

package com.example.demo.controller;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.util.MultiValueMap;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;import java.time.Duration;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.util.List;
import java.util.Map;@RestController
@RequestMapping("/api/get")
public class GetParamController {private static final Logger log = LoggerFactory.getLogger(GetParamController.class);// 1) 简单类型 + 默认值@GetMapping("/simple")public Map<String, Object> simple(@RequestParam String name,@RequestParam(defaultValue = "18") Integer age,@RequestParam(defaultValue = "false") boolean active) {log.info("GET simple: name={}, age={}, active={}", name, age, active);return Map.of("name", name, "age", age, "active", active);}// 2) 列表参数（重复 key：?tags=a&tags=b）@GetMapping("/list")public Map<String, Object> list(@RequestParam(required = false) List<String> tags) {log.info("GET list: tags={}", tags);return Map.of("tags", tags);}// 3) 所有查询参数（平铺）@GetMapping("/all")public Map<String, Object> all(@RequestParam Map<String, String> params) {log.info("GET all params: {}", params);return Map.of("params", params);}// 4) 所有查询参数（允许一个 key 多个值）@GetMapping("/all-multi")public Map<String, Object> allMulti(@RequestParam MultiValueMap<String, String> params) {log.info("GET all multi params: {}", params);return Map.of("params", params);}// 5) DTO 绑定（GET 默认使用 @ModelAttribute 绑定查询参数）public static class QueryDto {private String keyword;private Integer page;private Boolean highlight;public String getKeyword() { return keyword; }public void setKeyword(String keyword) { this.keyword = keyword; }public Integer getPage() { return page; }public void setPage(Integer page) { this.page = page; }public Boolean getHighlight() { return highlight; }public void setHighlight(Boolean highlight) { this.highlight = highlight; }}@GetMapping("/dto")public Map<String, Object> dto(@ModelAttribute QueryDto q) {log.info("GET dto: keyword={}, page={}, highlight={}", q.getKeyword(), q.getPage(), q.getHighlight());return Map.of("q", Map.of("keyword", q.getKeyword(),"page", q.getPage(),"highlight", q.getHighlight()));}// 6) 路径参数 + 查询参数@GetMapping("/users/{id}")public Map<String, Object> user(@PathVariable Long id, @RequestParam(defaultValue = "false") boolean verbose) {log.info("GET user: id={}, verbose={}", id, verbose);return Map.of("id", id, "verbose", verbose);}// 7) 日期/时间/Duration（注意：Duration 推荐使用 ISO-8601，如 PT30S）@GetMapping("/time")public Map<String, Object> time(@RequestParam @DateTimeFormat(iso = DateTimeFormat.ISO.DATE) LocalDate day,@RequestParam @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) LocalDateTime at,@RequestParam(required = false) Duration timeout) {log.info("GET time: day={}, at={}, timeout={}", day, at, timeout);return Map.of("day", day,"at", at,"timeoutSeconds", timeout != null ? timeout.getSeconds() : null);}
}

提示：

  • GET 不支持文件上传；文件请使用 POST multipart/form-data。
  • List<String> 通过重复 key 传递最稳妥（如 ?tags=a&tags=b）。
  • Duration 在查询参数中推荐使用 ISO-8601 表达（如 PT30S、PT5M）。

十二、POST 参数上传与示例

常见 POST 载荷类型：application/json、application/x-www-form-urlencoded、multipart/form-data、text/plain、application/octet-stream。

package com.example.demo.controller;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;import java.io.IOException;
import java.util.List;
import java.util.Map;@RestController
@RequestMapping("/api/post")
public class PostParamController {private static final Logger log = LoggerFactory.getLogger(PostParamController.class);// 1) application/json：JSON 体绑定到 DTOpublic static class CreateUserRequest {private String name;private Integer age;private List<String> tags;public String getName() { return name; }public void setName(String name) { this.name = name; }public Integer getAge() { return age; }public void setAge(Integer age) { this.age = age; }public List<String> getTags() { return tags; }public void setTags(List<String> tags) { this.tags = tags; }}@PostMapping(value = "/json", consumes = "application/json")public Map<String, Object> json(@RequestBody CreateUserRequest req) {log.info("POST json: name={}, age={}, tags={}", req.getName(), req.getAge(), req.getTags());return Map.of("ok", true,"data", Map.of("name", req.getName(),"age", req.getAge(),"tags", req.getTags()));}// 2) application/x-www-form-urlencoded：表单键值@PostMapping(value = "/form", consumes = "application/x-www-form-urlencoded")public Map<String, Object> form(@RequestParam String name,@RequestParam Integer age,@RequestParam(required = false) List<String> tags) {log.info("POST form: name={}, age={}, tags={}", name, age, tags);return Map.of("name", name, "age", age, "tags", tags);}// 3) multipart/form-data：单文件 + 其他字段@PostMapping(value = "/file", consumes = "multipart/form-data")public Map<String, Object> uploadFile(@RequestParam("file") MultipartFile file,@RequestParam(required = false) String desc) throws IOException {log.info("POST file: name={}, size={}, desc={}", file.getOriginalFilename(), file.getSize(), desc);return Map.of("filename", file.getOriginalFilename(),"size", file.getSize(),"desc", desc);}// 4) multipart/form-data：多文件@PostMapping(value = "/files", consumes = "multipart/form-data")public Map<String, Object> uploadFiles(@RequestParam("files") List<MultipartFile> files) {var names = files.stream().map(MultipartFile::getOriginalFilename).toList();var sizes = files.stream().map(MultipartFile::getSize).toList();log.info("POST files: count={}, names={}", files.size(), names);return Map.of("count", files.size(),"names", names,"sizes", sizes);}// 5) multipart/form-data：混合 JSON + 文件（JSON 放在 part 中）public static class Meta {private String title;private Integer count;public String getTitle() { return title; }public void setTitle(String title) { this.title = title; }public Integer getCount() { return count; }public void setCount(Integer count) { this.count = count; }}@PostMapping(value = "/mixed", consumes = "multipart/form-data")public Map<String, Object> mixed(@RequestPart("meta") Meta meta,@RequestPart("file") MultipartFile file) {log.info("POST mixed: meta.title={}, meta.count={}, file={}", meta.getTitle(), meta.getCount(), file.getOriginalFilename());return Map.of("meta", Map.of("title", meta.getTitle(), "count", meta.getCount()),"file", Map.of("name", file.getOriginalFilename(), "size", file.getSize()));}// 6) text/plain：纯文本@PostMapping(value = "/text", consumes = "text/plain")public Map<String, Object> text(@RequestBody String body) {log.info("POST text: len={}", body != null ? body.length() : 0);return Map.of("length", body != null ? body.length() : 0, "body", body);}// 7) application/octet-stream：二进制流@PostMapping(value = "/binary", consumes = "application/octet-stream")public Map<String, Object> binary(@RequestBody byte[] data) {log.info("POST binary: size={}", data != null ? data.length : 0);return Map.of("size", data != null ? data.length : 0);}
}

示例请求（curl）：

# 1) JSON
curl -X POST "http://localhost:8080/api/post/json" \-H "Content-Type: application/json" \-d '{"name":"Alice","age":20,"tags":["java","spring"]}'# 2) x-www-form-urlencoded（数组用重复 key）
curl -X POST "http://localhost:8080/api/post/form" \-H "Content-Type: application/x-www-form-urlencoded" \-d "name=Bob&age=22&tags=java&tags=spring"# 3) 单文件上传（multipart）
curl -X POST "http://localhost:8080/api/post/file" \-F "file=@/path/to/a.png" \-F "desc=头像"# 4) 多文件上传（同名字段）
curl -X POST "http://localhost:8080/api/post/files" \-F "files=@/path/to/a.png" \-F "files=@/path/to/b.jpg"# 5) 混合 JSON + 文件（给 JSON part 设置类型）
curl -X POST "http://localhost:8080/api/post/mixed" \-F 'meta={"title":"doc","count":2};type=application/json' \-F "file=@/path/to/a.pdf"# 6) 纯文本
curl -X POST "http://localhost:8080/api/post/text" \-H "Content-Type: text/plain" \--data-binary "hello world"# 7) 二进制流
curl -X POST "http://localhost:8080/api/post/binary" \-H "Content-Type: application/octet-stream" \--data-binary @/path/to/file.bin

提示：

  • 表单数组使用重复 key：tags=a&tags=b；或后端声明 String[]/List<String> 显式绑定。
  • 混合 JSON + 文件时，JSON part 的 Content-Type 必须是 application/json 才能被 @RequestPart 解析。
  • 大文件上传请调整 spring.servlet.multipart.max-file-size 与 max-request-size。

十三、过滤器 Filter 与案例

过滤器位于最前层（Servlet 容器级），可用于日志、鉴权、跨域预处理等。执行顺序：Filter → Servlet/DispatcherServlet → Interceptor → Controller。

package com.example.demo.filter;import jakarta.servlet.*;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;import java.io.IOException;
import java.time.Duration;
import java.time.Instant;/*** 基础日志过滤器：记录请求方法、URI、耗时与状态码*/
@Component
@Order(Ordered.HIGHEST_PRECEDENCE) // 越小越先执行
public class RequestLoggingFilter implements Filter {private static final Logger log = LoggerFactory.getLogger(RequestLoggingFilter.class);@Overridepublic void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {HttpServletRequest req = (HttpServletRequest) request;HttpServletResponse resp = (HttpServletResponse) response;Instant start = Instant.now();String method = req.getMethod();String uri = req.getRequestURI();try {chain.doFilter(request, response);} finally {long ms = Duration.between(start, Instant.now()).toMillis();log.info("[REQ] {} {} -> status={}, {}ms", method, uri, resp.getStatus(), ms);}}
}
  • 测试（与前文 GET/POST 控制器配合）：
# 不带 token 访问受保护的 API（期望 401）
curl -i "http://localhost:8080/api/post/json" \-H "Content-Type: application/json" \-d '{"name":"Alice","age":20}'# 携带错误 token（期望 403）
curl -i "http://localhost:8080/api/post/json" \-H "X-Auth-Token: wrong" \-H "Content-Type: application/json" \-d '{"name":"Alice","age":20}'# 携带正确 token（期望 200）
curl -i "http://localhost:8080/api/post/json" \-H "X-Auth-Token: demo-token" \-H "Content-Type: application/json" \-d '{"name":"Alice","age":20}'# 被排除的健康检查路径（无需 token，期望 200）
curl -i "http://localhost:8080/health"

提示：

  • 全局跨域建议使用 Spring WebMvcConfigurer 的 CORS 配置（见前文）。Filter 中处理 CORS 需注意 OPTIONS 预检放行。
  • 引入 Spring Security 时，其过滤器链可能优先于或穿插业务 Filter；鉴权逻辑推荐迁移到 Security 中。

十四、拦截器 HandlerInterceptor 与案例

拦截器运行在 Spring MVC 层（DispatcherServlet 之后、Controller 之前/之后），适合做登录鉴权、上下文注入、审计日志等。顺序：Filter → Interceptor → Controller → 异常处理（Advice）。

package com.example.demo.interceptor;import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.lang.Nullable;
import org.springframework.web.servlet.HandlerInterceptor;import java.time.Duration;
import java.time.Instant;/*** 日志拦截器：记录方法、URI、耗时*/
public class LoggingInterceptor implements HandlerInterceptor {private static final Logger log = LoggerFactory.getLogger(LoggingInterceptor.class);private static final String ATTR_START = "__start_time";@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {request.setAttribute(ATTR_START, Instant.now());return true;}@Overridepublic void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) {Object startObj = request.getAttribute(ATTR_START);long ms = 0;if (startObj instanceof Instant start) {ms = Duration.between(start, Instant.now()).toMillis();}String method = request.getMethod();String uri = request.getRequestURI();int status = response.getStatus();if (ex == null) {log.info("[INTCP] {} {} -> status={}, {}ms", method, uri, status, ms);} else {log.warn("[INTCP] {} {} -> status={}, {}ms, ex={}", method, uri, status, ms, ex.toString());}}
}
  • 鉴权拦截器（读取 Header 并写入请求属性）：
package com.example.demo.interceptor;import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.HandlerInterceptor;/*** 简易 Token 校验：要求 Header: X-Auth-Token=demo-token* 校验通过后写入 request attribute: userId*/
public class AuthInterceptor implements HandlerInterceptor {@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {String token = request.getHeader("X-Auth-Token");if (token == null || token.isBlank()) {response.setStatus(401);response.setContentType("application/json;charset=UTF-8");response.getWriter().write("{\"success\":false,\"message\":\"Missing X-Auth-Token\"}");return false;}if (!"demo-token".equals(token)) {response.setStatus(403);response.setContentType("application/json;charset=UTF-8");response.getWriter().write("{\"success\":false,\"message\":\"Invalid token\"}");return false;}// 通过：写入请求属性，供 Controller 使用request.setAttribute("userId", "demo-user");return true;}
}
  • 注册拦截器（路径包含/排除、顺序）：
package com.example.demo.config;import com.example.demo.interceptor.AuthInterceptor;
import com.example.demo.interceptor.LoggingInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;@Configuration
public class WebMvcConfig implements WebMvcConfigurer {@Overridepublic void addInterceptors(InterceptorRegistry registry) {// 日志拦截器：对所有请求生效，最先执行registry.addInterceptor(new LoggingInterceptor()).addPathPatterns("/**").order(1);// 鉴权拦截器：仅拦截 /api/**，排除无需登录的接口registry.addInterceptor(new AuthInterceptor()).addPathPatterns("/api/**").excludePathPatterns("/health","/actuator/**","/public/**","/api/get/**").order(2);}
}
  • 在控制器中读取拦截器写入的属性：
package com.example.demo.controller;import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import java.util.Map;@RestController
@RequestMapping("/api/me")
public class MeController {@GetMappingpublic Map<String, Object> me(@RequestAttribute(value = "userId", required = false) String userId) {return Map.of("authenticated", userId != null,"userId", userId);}
}
  • 测试命令（与前文 POST 接口一起验证鉴权）：
# 1) 未带 token 访问受保护接口（期望 401）
curl -i "http://localhost:8080/api/post/json" \-H "Content-Type: application/json" \-d '{"name":"Alice","age":20}'# 2) 错误 token（期望 403）
curl -i "http://localhost:8080/api/post/json" \-H "X-Auth-Token: wrong" \-H "Content-Type: application/json" \-d '{"name":"Alice","age":20}'# 3) 正确 token（期望 200）
curl -i "http://localhost:8080/api/post/json" \-H "X-Auth-Token: demo-token" \-H "Content-Type: application/json" \-d '{"name":"Alice","age":20}'# 4) 访问 /api/me（展示拦截器写入的 userId）
curl -i "http://localhost:8080/api/me" -H "X-Auth-Token: demo-token"# 5) 被排除的路径（无需 token）
curl -i "http://localhost:8080/health"

提示：

  • Interceptor 可访问 handler（方法/控制器信息），适合做基于注解的鉴权、审计。
  • 异常被抛出后将交由 @RestControllerAdvice 处理；如在 preHandle 已写响应并返回 false，后续链路不会继续。
  • 若引入 Spring Security，建议把登录鉴权放入 Security 过滤器链与授权机制中，拦截器更多用于业务级横切逻辑。

十五、PUT 参数上传与示例

PUT 常用于“更新”语义，通常与资源标识（如路径变量 id）配合；相较于 POST，PUT 更强调幂等性（同样的请求重复提交结果一致）。以下示例涵盖 JSON、x-www-form-urlencoded、multipart、text/plain 与二进制流。

package com.example.demo.controller;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;import java.io.IOException;
import java.util.List;
import java.util.Map;@RestController
@RequestMapping("/api/put")
public class PutParamController {private static final Logger log = LoggerFactory.getLogger(PutParamController.class);// 1) application/json：JSON 体绑定到 DTOpublic static class UpdateUserRequest {private String name;private Integer age;private List<String> tags;public String getName() { return name; }public void setName(String name) { this.name = name; }public Integer getAge() { return age; }public void setAge(Integer age) { this.age = age; }public List<String> getTags() { return tags; }public void setTags(List<String> tags) { this.tags = tags; }}@PutMapping(value = "/json", consumes = "application/json")public Map<String, Object> json(@RequestBody UpdateUserRequest req) {log.info("PUT json: name={}, age={}, tags={}", req.getName(), req.getAge(), req.getTags());return Map.of("ok", true,"data", Map.of("name", req.getName(),"age", req.getAge(),"tags", req.getTags()));}// 2) application/x-www-form-urlencoded：表单键值@PutMapping(value = "/form", consumes = "application/x-www-form-urlencoded")public Map<String, Object> form(@RequestParam String name,@RequestParam Integer age,@RequestParam(required = false) List<String> tags) {log.info("PUT form: name={}, age={}, tags={}", name, age, tags);return Map.of("name", name, "age", age, "tags", tags);}// 3) multipart/form-data：单文件 + 其他字段@PutMapping(value = "/file", consumes = "multipart/form-data")public Map<String, Object> uploadFile(@RequestParam("file") MultipartFile file,@RequestParam(required = false) String desc) throws IOException {log.info("PUT file: name={}, size={}, desc={}", file.getOriginalFilename(), file.getSize(), desc);return Map.of("filename", file.getOriginalFilename(),"size", file.getSize(),"desc", desc);}// 4) multipart/form-data：混合 JSON + 文件（JSON 放在 part 中）public static class Meta {private String title;private Integer count;public String getTitle() { return title; }public void setTitle(String title) { this.title = title; }public Integer getCount() { return count; }public void setCount(Integer count) { this.count = count; }}@PutMapping(value = "/mixed", consumes = "multipart/form-data")public Map<String, Object> mixed(@RequestPart("meta") Meta meta,@RequestPart("file") MultipartFile file) {log.info("PUT mixed: meta.title={}, meta.count={}, file={}", meta.getTitle(), meta.getCount(), file.getOriginalFilename());return Map.of("meta", Map.of("title", meta.getTitle(), "count", meta.getCount()),"file", Map.of("name", file.getOriginalFilename(), "size", file.getSize()));}// 5) text/plain：纯文本@PutMapping(value = "/text", consumes = "text/plain")public Map<String, Object> text(@RequestBody String body) {log.info("PUT text: len={}", body != null ? body.length() : 0);return Map.of("length", body != null ? body.length() : 0, "body", body);}// 6) application/octet-stream：二进制流@PutMapping(value = "/binary", consumes = "application/octet-stream")public Map<String, Object> binary(@RequestBody byte[] data) {log.info("PUT binary: size={}", data != null ? data.length : 0);return Map.of("size", data != null ? data.length : 0);}// 7) 路径变量 + JSON：典型“更新某个资源”@PutMapping(value = "/users/{id}", consumes = "application/json")public Map<String, Object> updateUser(@PathVariable Long id, @RequestBody UpdateUserRequest req) {log.info("PUT users/{}: name={}, age={}, tags={}", id, req.getName(), req.getAge(), req.getTags());return Map.of("id", id,"updated", true,"data", Map.of("name", req.getName(), "age", req.getAge(), "tags", req.getTags()));}
}

示例请求（curl）：

# 1) JSON
curl -X PUT "http://localhost:8080/api/put/json" \-H "Content-Type: application/json" \-d '{"name":"Alice","age":21,"tags":["java","spring"]}'# 2) x-www-form-urlencoded（数组用重复 key）
curl -X PUT "http://localhost:8080/api/put/form" \-H "Content-Type: application/x-www-form-urlencoded" \-d "name=Bob&age=22&tags=java&tags=spring"# 3) 单文件上传（multipart）
curl -X PUT "http://localhost:8080/api/put/file" \-F "file=@/path/to/a.png" \-F "desc=头像"# 4) 混合 JSON + 文件（给 JSON part 设置类型）
curl -X PUT "http://localhost:8080/api/put/mixed" \-F 'meta={"title":"doc","count":2};type=application/json' \-F "file=@/path/to/a.pdf"# 5) 纯文本
curl -X PUT "http://localhost:8080/api/put/text" \-H "Content-Type: text/plain" \--data-binary "hello world"# 6) 二进制流
curl -X PUT "http://localhost:8080/api/put/binary" \-H "Content-Type: application/octet-stream" \--data-binary @/path/to/file.bin# 7) 路径变量 + JSON（更新指定 id）
curl -X PUT "http://localhost:8080/api/put/users/100" \-H "Content-Type: application/json" \-d '{"name":"Carol","age":23,"tags":["k8s"]}'

注意：

  • 幂等性：PUT 语义倾向幂等，更新相同资源应返回相同结果；可配合 If-Match/ETag 做并发控制。
  • 鉴权：若启用了拦截器/过滤器鉴权，PUT 同样需要携带头 X-Auth-Token: demo-token 才能通过。
  • 表单/文件：multipart 与 x-www-form-urlencoded 对 PUT 同样适用；部分代理/网关可能对 PUT 有限制，需在网关放行并正确转发请求体。
  • 安全：开启 Spring Security 时，PUT 默认受 CSRF 保护；如为纯 API 服务可关闭 CSRF 或在请求中附带 CSRF token。

十六、20 个 GET/POST 接口样例

覆盖探活、版本、分页、详情、搜索、请求头/IP、速率限制、时间时区、登录、下单/支付、上传、表单、文本、数值计算等多样场景。每个接口提供功能说明、示例请求与“结果样式”。

  • 约定：若启用拦截器/安全，请携带 X-Auth-Token: demo-token。
  1. GET /api/sample/ping — 健康探活
  • 功能：返回服务运行状态与时间戳
  • 示例请求：
curl "http://localhost:8080/api/sample/ping"
  • 结果样式：
{"ok":true,"ts":1735700000000}
  1. GET /api/sample/version — 版本信息
  • 功能：返回应用名称、版本与构建
curl "http://localhost:8080/api/sample/version"

{"app":"demo","version":"1.0.0","build":"local"}
  1. GET /api/sample/users — 用户分页
  • 参数：page(默认1), size(默认10), keyword(可选)
curl "http://localhost:8080/api/sample/users?page=1&size=2&keyword=ali"

{"page":1,"size":2,"keyword":"ali","items":[{"id":1,"name":"Alice","age":20},{"id":2,"name":"Bob","age":22}]}
  1. GET /api/sample/users/{id} — 用户详情
curl "http://localhost:8080/api/sample/users/1001"

{"id":1001,"name":"User-1001","age":19}
  1. GET /api/sample/search — 关键字+标签搜索
  • 参数：q、tags(多值)
curl "http://localhost:8080/api/sample/search?q=phone&tags=android&tags=5g"

{"q":"phone","tags":["android","5g"],"results":["r1","r2"]}
  1. GET /api/sample/headers — 请求头读取
  • 功能：读取 X-Trace-Id 与 User-Agent
curl -H "X-Trace-Id: abc-123" -H "User-Agent: curl/8.0" "http://localhost:8080/api/sample/headers"

{"traceId":"abc-123","userAgent":"curl/8.0"}
  1. GET /api/sample/ip — 客户端 IP/UA
curl -H "User-Agent: demo" "http://localhost:8080/api/sample/ip"

{"ip":"127.0.0.1","userAgent":"demo"}
  1. GET /api/sample/rate-limit — 速率限制信息
  • 功能：返回窗口、配额与剩余；同时在响应头设置 X-RateLimit-*
curl "http://localhost:8080/api/sample/rate-limit"

{"window":"1m","limit":100,"remaining":40}
  1. GET /api/sample/echo — 回显 message
curl "http://localhost:8080/api/sample/echo?message=hello"

{"message":"hello","ts":1735700000000}
  1. GET /api/sample/time — 当前时间（可选时区）
  • 参数：tz(如 Asia/Shanghai)，非法时区自动回退系统默认
curl "http://localhost:8080/api/sample/time?tz=Asia/Shanghai"

{"now":"2025-01-01T08:00:00+08:00[Asia/Shanghai]","zone":"Asia/Shanghai","epochMs":1735700000000}
  1. POST /api/sample/users — 创建用户（JSON）
curl -X POST "http://localhost:8080/api/sample/users" \-H "Content-Type: application/json" \-d '{"name":"Alice","age":20,"tags":["java","spring"]}'

{"id":1700000000000,"name":"Alice","age":20,"tags":["java","spring"]}
  1. POST /api/sample/users/batch — 批量创建（JSON）
curl -X POST "http://localhost:8080/api/sample/users/batch" \-H "Content-Type: application/json" \-d '{"users":[{"name":"A","age":18},{"name":"B","age":19}]}'

{"created":2}
  1. POST /api/sample/login — 登录（JSON）
curl -X POST "http://localhost:8080/api/sample/login" \-H "Content-Type: application/json" \-d '{"username":"u","password":"p"}'

{"ok":true,"token":"demo-token"}
  1. POST /api/sample/orders — 创建订单（JSON）
curl -X POST "http://localhost:8080/api/sample/orders" \-H "Content-Type: application/json" \-d '{"userId":"U1","items":[{"sku":"S1","quantity":2,"price":10.5},{"sku":"S2","quantity":1,"price":20}]}'

{"orderId":"ORD-1700000000000","userId":"U1","total":41.0}
  1. POST /api/sample/orders/{id}/pay — 支付订单（JSON）
curl -X POST "http://localhost:8080/api/sample/orders/ORD-1/pay" \-H "Content-Type: application/json" \-d '{"method":"alipay","channel":"app"}'

{"orderId":"ORD-1","paid":true,"method":"alipay","channel":"app"}
  1. POST /api/sample/upload — 单文件上传（multipart）
curl -X POST "http://localhost:8080/api/sample/upload" \-F "file=@/path/to/a.png" -F "desc=头像"

{"name":"a.png","size":12345,"desc":"头像"}
  1. POST /api/sample/uploads — 多文件上传（multipart）
curl -X POST "http://localhost:8080/api/sample/uploads" \-F "files=@/path/to/a.png" \-F "files=@/path/to/b.jpg"

{"count":2,"names":["a.png","b.jpg"],"sizes":[12345,23456]}
  1. POST /api/sample/feedback — 文本反馈（text/plain）
curl -X POST "http://localhost:8080/api/sample/feedback" \-H "Content-Type: text/plain" --data-binary "很好用！"

{"received":12}
  1. POST /api/sample/submit — 表单提交（x-www-form-urlencoded）
curl -X POST "http://localhost:8080/api/sample/submit" \-H "Content-Type: application/x-www-form-urlencoded" \-d "title=建议&content=内容很多&tags=java&tags=spring"

{"title":"建议","contentLen":12,"tags":["java","spring"]}
  1. POST /api/sample/compute — 数值计算（JSON）
  • 功能：avg=true 返回平均值，否则返回总和
curl -X POST "http://localhost:8080/api/sample/compute" \-H "Content-Type: application/json" \-d '{"numbers":[1,2,3.5],"avg":true}'

{"avg":2.1666666667,"count":3}

package com.example.demo.controller;import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.util.List;
import java.util.Map;@RestController
@RequestMapping("/api/sample")
public class SampleApiController {private static final Logger log = LoggerFactory.getLogger(SampleApiController.class);// ---------- GET ----------@GetMapping("/ping")public Map<String, Object> ping() {return Map.of("ok", true, "ts", System.currentTimeMillis());}@GetMapping("/version")public Map<String, Object> version() {return Map.of("app", "demo", "version", "1.0.0", "build", "local");}@GetMapping("/users")public Map<String, Object> listUsers(@RequestParam(defaultValue = "1") int page,@RequestParam(defaultValue = "10") int size,@RequestParam(required = false) String keyword) {return Map.of("page", page,"size", size,"keyword", keyword,"items", List.of(Map.of("id", 1, "name", "Alice", "age", 20),Map.of("id", 2, "name", "Bob", "age", 22)));}@GetMapping("/users/{id}")public Map<String, Object> userDetail(@PathVariable long id) {return Map.of("id", id, "name", "User-" + id, "age", 18 + (id % 10));}@GetMapping("/search")public Map<String, Object> search(@RequestParam(name = "q") String keyword,@RequestParam(required = false) List<String> tags) {return Map.of("q", keyword, "tags", tags, "results", List.of("r1", "r2"));}@GetMapping("/headers")public Map<String, Object> headers(@RequestHeader(value = "X-Trace-Id", required = false) String traceId,@RequestHeader(value = "User-Agent", required = false) String userAgent) {return Map.of("traceId", traceId, "userAgent", userAgent);}@GetMapping("/ip")public Map<String, Object> ip(HttpServletRequest request,@RequestHeader(value = "User-Agent", required = false) String userAgent) {String xff = request.getHeader("X-Forwarded-For");String ip = xff != null && !xff.isBlank() ? xff.split(",")[0].trim() : request.getRemoteAddr();return Map.of("ip", ip, "userAgent", userAgent);}@GetMapping("/rate-limit")public Map<String, Object> rateLimit(HttpServletResponse response) {int limit = 100, remaining = 42; // 演示值response.setHeader("X-RateLimit-Limit", String.valueOf(limit));response.setHeader("X-RateLimit-Remaining", String.valueOf(remaining));response.setHeader("X-RateLimit-Window", "1m");return Map.of("window", "1m", "limit", limit, "remaining", remaining);}@GetMapping("/echo")public Map<String, Object> echo(@RequestParam String message) {return Map.of("message", message, "ts", System.currentTimeMillis());}@GetMapping("/time")public Map<String, Object> time(@RequestParam(required = false) String tz) {ZoneId zone;try {zone = tz != null && !tz.isBlank() ? ZoneId.of(tz) : ZoneId.systemDefault();} catch (Exception e) {zone = ZoneId.systemDefault();}ZonedDateTime now = ZonedDateTime.now(zone);return Map.of("now", now.toString(), "zone", zone.getId(), "epochMs", System.currentTimeMillis());}// ---------- POST ----------public static class CreateUserReq {private String name;private Integer age;private List<String> tags;public String getName() { return name; }public void setName(String name) { this.name = name; }public Integer getAge() { return age; }public void setAge(Integer age) { this.age = age; }public List<String> getTags() { return tags; }public void setTags(List<String> tags) { this.tags = tags; }}public static class BatchCreateUserReq {private List<CreateUserReq> users;public List<CreateUserReq> getUsers() { return users; }public void setUsers(List<CreateUserReq> users) { this.users = users; }}@PostMapping(value = "/users", consumes = "application/json")public Map<String, Object> createUser(@RequestBody CreateUserReq req) {long id = System.currentTimeMillis();log.info("create user: {} {} {}", req.getName(), req.getAge(), req.getTags());return Map.of("id", id, "name", req.getName(), "age", req.getAge(), "tags", req.getTags());}@PostMapping(value = "/users/batch", consumes = "application/json")public Map<String, Object> batchCreate(@RequestBody BatchCreateUserReq req) {int count = req.getUsers() != null ? req.getUsers().size() : 0;return Map.of("created", count);}public static class LoginReq {private String username;private String password;public String getUsername() { return username; }public void setUsername(String username) { this.username = username; }public String getPassword() { return password; }public void setPassword(String password) { this.password = password; }}@PostMapping(value = "/login", consumes = "application/json")public Map<String, Object> login(@RequestBody LoginReq req) {boolean ok = req.getUsername() != null && !req.getUsername().isBlank();return Map.of("ok", ok, "token", ok ? "demo-token" : null);}public static class OrderItem {private String sku;private Integer quantity;private Double price;public String getSku() { return sku; }public void setSku(String sku) { this.sku = sku; }public Integer getQuantity() { return quantity; }public void setQuantity(Integer quantity) { this.quantity = quantity; }public Double getPrice() { return price; }public void setPrice(Double price) { this.price = price; }}public static class CreateOrderReq {private String userId;private List<OrderItem> items;public String getUserId() { return userId; }public void setUserId(String userId) { this.userId = userId; }public List<OrderItem> getItems() { return items; }public void setItems(List<OrderItem> items) { this.items = items; }}@PostMapping(value = "/orders", consumes = "application/json")public Map<String, Object> createOrder(@RequestBody CreateOrderReq req) {double total = 0.0;if (req.getItems() != null) {for (OrderItem it : req.getItems()) {if (it.getPrice() != null && it.getQuantity() != null) {total += it.getPrice() * it.getQuantity();}}}String orderId = "ORD-" + System.currentTimeMillis();return Map.of("orderId", orderId, "userId", req.getUserId(), "total", total);}public static class PayReq {private String method; // e.g., wechat, alipay, cardprivate String channel; // e.g., app, webpublic String getMethod() { return method; }public void setMethod(String method) { this.method = method; }public String getChannel() { return channel; }public void setChannel(String channel) { this.channel = channel; }}@PostMapping(value = "/orders/{id}/pay", consumes = "application/json")public Map<String, Object> pay(@PathVariable String id, @RequestBody PayReq req) {return Map.of("orderId", id, "paid", true, "method", req.getMethod(), "channel", req.getChannel());}@PostMapping(value = "/upload", consumes = "multipart/form-data")public Map<String, Object> upload(@RequestParam("file") MultipartFile file,@RequestParam(required = false) String desc) {return Map.of("name", file.getOriginalFilename(), "size", file.getSize(), "desc", desc);}@PostMapping(value = "/uploads", consumes = "multipart/form-data")public Map<String, Object> uploads(@RequestParam("files") List<MultipartFile> files) {var names = files.stream().map(MultipartFile::getOriginalFilename).toList();var sizes = files.stream().map(MultipartFile::getSize).toList();return Map.of("count", files.size(), "names", names, "sizes", sizes);}@PostMapping(value = "/feedback", consumes = "text/plain")public Map<String, Object> feedback(@RequestBody String body) {return Map.of("received", body != null ? body.length() : 0);}@PostMapping(value = "/submit", consumes = "application/x-www-form-urlencoded")public Map<String, Object> submit(@RequestParam String title,@RequestParam String content,@RequestParam(required = false) List<String> tags) {return Map.of("title", title, "contentLen", content.length(), "tags", tags);}public static class ComputeReq {private List<Double> numbers;private Boolean avg; // true: 返回平均值；false/null：返回总和public List<Double> getNumbers() { return numbers; }public void setNumbers(List<Double> numbers) { this.numbers = numbers; }public Boolean getAvg() { return avg; }public void setAvg(Boolean avg) { this.avg = avg; }}@PostMapping(value = "/compute", consumes = "application/json")public Map<String, Object> compute(@RequestBody ComputeReq req) {double sum = 0.0;int n = 0;if (req.getNumbers() != null) {for (Double d : req.getNumbers()) {if (d != null) { sum += d; n++; }}}boolean avg = Boolean.TRUE.equals(req.getAvg());return avg ? Map.of("avg", n > 0 ? sum / n : 0.0, "count", n): Map.of("sum", sum, "count", n);}
}

提示：如启用了拦截器或安全配置，上述接口同样需要按规则携带必要的认证信息（如 X-Auth-Token）才能访问。

作者：xuan
个人博客：https://blog.ybyq.wang
欢迎访问我的博客，获取更多技术文章和教程。


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