【黑马程序员】后端Web基础--Maven基础和基础知识
文章目录
- 1. Maven
- 1.1 IDEA集成Maven
- 1.2 依赖管理
- 1.2.1 依赖配置
- 1.2.2 排除依赖
- 1.2.3 生命周期
- 1.3 单元测试
- 1.3.1 概述
- 1.3.2 test
- 1.3.3 断言
- 1.3.4 常见注解
- 1.3.5 Maven依赖范围
- 1.3.6 maven常见问题
- 2. Web基础
- 2.1 SpringBoot Web入门
- 2.1.1 入门程序
- 2.1.2 HTTP协议
- 2.1.2.1 请求协议
- 2.1.2.2 响应协议
- 2.2 SpringBoot Web案例
- 2.3 分层解耦
- 2.3.1 三层架构
- 2.3.2 IOC与DI
1. Maven
1.1 IDEA集成Maven
1.2 依赖管理
1.2.1 依赖配置
可以去这个网站搜索我们需要配置的依赖的坐标
1.2.2 排除依赖
<!--配置依赖--><dependencies><!-- https://mvnrepository.com/artifact/org.springframework/spring-context --><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>6.1.4</version><!--排除依赖--><exclusions><exclusion><groupId>io.micrometer</groupId><artifactId>micrometer-observation</artifactId></exclusion></exclusions></dependency></dependencies>
1.2.3 生命周期
主要关注以下五个生命周期的阶段
同一套生命周期中,后面的阶段运行,前面的阶段都会运行
1.3 单元测试
1.3.1 概述
测试方法:白盒测试,黑盒测试,灰盒测试
1.3.2 test
- pom.xml文件中引入Junit依赖
- 在目录下创建test类,编写对应的测试方法,在方法上声明@test注解
- 运行
package com.itheima;import org.junit.jupiter.api.Test;public class UserServiceTest {@Testpublic void testGetAge(){UserService userservice = new UserService();Integer age = userservice.getAge("100000200001021234");System.out.println(age);}
}
package com.itheima;import java.time.LocalDate;
import java.time.Period;
import java.time.format.DateTimeFormatter;public class UserService {/*** 给定一个身份证号, 计算出该用户的年龄* @param idCard 身份证号*/public Integer getAge(String idCard){if (idCard == null || idCard.length() != 18) {throw new IllegalArgumentException("无效的身份证号码");}String birthday = idCard.substring(6, 14);LocalDate parse = LocalDate.parse(birthday, DateTimeFormatter.ofPattern("yyyyMMdd"));return Period.between(parse, LocalDate.now()).getYears();}/*** 给定一个身份证号, 计算出该用户的性别* @param idCard 身份证号*/public String getGender(String idCard){if (idCard == null || idCard.length() != 18) {throw new IllegalArgumentException("无效的身份证号码");}return Integer.parseInt(idCard.substring(16,17)) % 2 == 1 ? "男" : "女";}}
1.3.3 断言
测试运行结果是绿色并不能说明代码没问题
使用断言判断期望得到的值是否和结果相同
package com.itheima;import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;public class UserServiceTest {@Testpublic void testGetAge(){UserService userservice = new UserService();Integer age = userservice.getAge("100000200001021234");System.out.println(age);}// @Test
// public void testGetGender(){
// UserService userservice = new UserService();
// String gender = userservice.getGender("100000200001021234");
// System.out.println(gender);
// }// 断言@Test
// public void testGenderWithAssert(){
// UserService userservice = new UserService();
// String gender = userservice.getGender("100000200001021234");
//// System.out.println(gender);
// //断言;
// Assertions.assertEquals("男",gender,"性别获取错误");
//}public void testGenderWithAssert(){UserService userservice = new UserService();String gender = userservice.getGender("100000200001021234");
// System.out.println(gender);//断言;
// Assertions.assertEquals("男",gender,"性别获取错误");Assertions.assertThrows(IllegalArgumentException.class,()->{userservice.getGender(null);});}
}
1.3.4 常见注解
package com.itheima;
import org.junit.jupiter.api.*;public class UserServiceTest {/*** @BeforeAll //在所有的单元测试方法运行之前,运行一次*/@BeforeAllpublic static void beforeAll(){System.out.println("before All");}/*** @AfterAll //在所有的单元测试方法运行之后,运行一次*/@AfterAllpublic static void afterAll(){System.out.println("after All");}/*** @BeforeEach //在每一个单元测试方法运行之前,都会运行一次*/@BeforeEachpublic void beforeEach(){System.out.println("before Each");}/*** @AfterEach //在每一个单元测试方法运行之后,都会运行一次*/@AfterEachpublic void afterEach(){System.out.println("after Each");}// 断言@Testpublic void testGetAge(){UserService userservice = new UserService();Integer age = userservice.getAge("100000200001021234");System.out.println(age);}@Test //这里要是不写Test的话,测试的时候会忽视这个方法public void testGenderWithAssert(){UserService userservice = new UserService();String gender = userservice.getGender("100000200001021234");System.out.println(gender);//断言;
// Assertions.assertEquals("男",gender,"性别获取错误");Assertions.assertThrows(IllegalArgumentException.class,()->{userservice.getGender(null);});}/*** 参数化测试*/@DisplayName("测试用户性别")@ParameterizedTest@ValueSource(strings = {"100000200010011011", "100000200010011031", "100000200010011051"})public void testGetGender2(String idCard) {UserService userService = new UserService();String gender = userService.getGender(idCard);// 断言Assertions.assertEquals("男", gender);}
}
1.3.5 Maven依赖范围
<!--Junit依赖--><dependency><groupId>org.junit.jupiter</groupId><artifactId>junit-jupiter</artifactId><version>5.9.1</version><scope>test</scope></dependency>
1.3.6 maven常见问题
2. Web基础
2.1 SpringBoot Web入门
2.1.1 入门程序
package com.itheima;import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;@RestController//说明是一个请求处理类
public class HelloController {@RequestMapping("/hello")public String hello(String name){System.out.println("name:"+name);return "hello"+ name+"~";}
}
连不上spring.io的话换阿里云
2.1.2 HTTP协议
2.1.2.1 请求协议
请求数据格式
请求数据获取
package com.itheima;import jakarta.servlet.http.HttpServletRequest;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;@RestController
public class RequestController {@RequestMapping("/request")public String request(HttpServletRequest request) {//1. 获取请求方式String method = request.getMethod();System.out.println("请求方式:"+ method);//2.获取请求url地址String url = request.getRequestURL().toString();System.out.println("请求URL:"+ url);
// 获取uriString uri = request.getRequestURI();System.out.println("请求URI:"+ uri);//3. 获取请求协议String protocol = request.getProtocol();System.out.println("请求协议:"+ protocol);//4. 获取请求参数String name = request.getParameter("name");System.out.println("name:"+ name);String age = request.getParameter("age");System.out.println("age:"+ age);//5. 获取请求头String header = request.getHeader("Accept");System.out.println("Accept:"+ header);return "OK";}
}
2.1.2.2 响应协议
重定向:浏览器向A发出请求,但是实际在B服务器,A会返回状态码和资源位置,浏览器会自动再次发出请求
200:处理成功
404:请求资源不存在
500:服务器发生不可预测的错误
响应数据设置:
package com.itheima;import jakarta.servlet.http.HttpServletResponse;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import java.io.IOException;
@RestController
public class ResponseController {
// 1. 设置HttpServletResponse响应数据@RequestMapping("/response")public void response(HttpServletResponse response) throws IOException{// 1.设置响应状态码response.setStatus(401);// 2.设置响应头response.setHeader("name","itheima");// 3.设置响应体response.getWriter().write("<h1>Hello Response</h1>");}// 2. 使用ResponseEntity对象封装响应数据@RequestMapping("/response2")public ResponseEntity<String> response2(){return ResponseEntity.status(401).header("name","itheima").body("<h1>Hello Response</h1>");}
}
2.2 SpringBoot Web案例
如果创建模块有问题可能是Lombok没加版本号的原因,也有可能是注解的原因,目前不知道为什么,别使用Lombok的注解,自己写getter setter方法
我的项目文件不能右键添加模块:文件->项目结构->选择左边模块->把目录xml文件添加进去
出现了创建不成功的情况,最后01改成02创建成功了
package com.itheima.pojo;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;import java.time.LocalDateTime;
@Data // 提供get set方法
@NoArgsConstructor // 无参构造
@AllArgsConstructor // 全参构造
public class user {// idprivate Integer id;private String username;private String password;private String name;private Integer age;private LocalDateTime updateTime;;}
package com.itheima.controller;import cn.hutool.core.io.IoUtil;
import com.itheima.pojo.user;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.List;//import static jdk.internal.org.jline.utils.InfoCmp.Capability.lines;@RestController
public class UserController {@RequestMapping("/list")public List<user> list() throws Exception {//1. 加载读取user.txt文件,获取用户数据
// InputStream in = new FileInputStream("D:\\SoftWare\\JAVA\\project\\WebAI_Project\\web-ai-project-01\\springboot-web-0417\\src\\main\\resources\\user.txt");InputStream in = this.getClass().getClassLoader().getResourceAsStream("user.txt");ArrayList<String> lines = IoUtil.readLines(in, StandardCharsets.UTF_8, new ArrayList<>());
//2. 解析用户信息,封装成user对象,封装为一个list集合List<user> userList =lines.stream().map(line -> {String[] parts = line.split(",");Integer id = Integer.parseInt(parts[0]);String username = parts[1];String password = parts[2];String name = parts[3];Integer age = Integer.parseInt(parts[4]);LocalDateTime updateTime = LocalDateTime.parse(parts[5], DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));return new user(id, username, password, name, age, updateTime);}).toList();//3. 返回数据(json)return userList;}
}
2.3 分层解耦
2.3.1 三层架构
单一职责原则
2.3.2 IOC与DI
IOC详细解释:
DI详解:
存在多个相同类型的bean,代码会报错
package com.itheima.controller;import cn.hutool.core.io.IoUtil;
import com.itheima.pojo.User;
import com.itheima.service.UserService;
import com.itheima.service.impl.UserServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.List;//import static jdk.internal.org.jline.utils.InfoCmp.Capability.lines;@RestController
public class UserController {
// @RequestMapping("/list")
// public List<User> list() throws Exception {
// //1. 加载读取user.txt文件,获取用户数据
//// InputStream in = new FileInputStream("D:\\SoftWare\\JAVA\\project\\WebAI_Project\\web-ai-project-01\\springboot-web-0417\\src\\main\\resources\\user.txt");
// InputStream in = this.getClass().getClassLoader().getResourceAsStream("user.txt");
// ArrayList<String> lines = IoUtil.readLines(in, StandardCharsets.UTF_8, new ArrayList<>());
////2. 解析用户信息,封装成user对象,封装为一个list集合
// List<User> userList =lines.stream().map(line -> {
// String[] parts = line.split(",");
// Integer id = Integer.parseInt(parts[0]);
// String username = parts[1];
// String password = parts[2];
// String name = parts[3];
// Integer age = Integer.parseInt(parts[4]);
// LocalDateTime updateTime = LocalDateTime.parse(parts[5], DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
// return new User(id, username, password, name, age, updateTime);
// }).toList();
//
// //3. 返回数据(json)
// return userList;
// }
// private UserService userService = new UserServiceImpl();
//方式一. 属性注入
// @Autowired
// private UserService userService;//使用IOC和DI实现
////方式二. 构造方法注入
// private final UserService userService;
// @Autowired // 如果当前类中只有一个构造函数,@Autowired可以省略
// public UserController(UserService userService) {
// this.userService = userService;
// }//方式三. setter方法注入private UserService userService;@Qualifier("userServiceImpl")@Autowiredpublic void setUserService(UserService userService) {this.userService = userService;}@RequestMapping("/list")public List<User> list() {
// 1. 调用service,获取数据List<User> userList = userService.findAll();return userList;
// return userService.findAll();}}
package com.itheima.dao.impl;import cn.hutool.core.io.IoUtil;
import com.itheima.dao.UserDao;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Repository;import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
//@Component //将当前类交给IOC容器处理
@Repository("userDao")
public class UserDaoImpl implements UserDao {//1. 加载读取user.txt文件,获取用户数据@Overridepublic List<String> findAll() {InputStream in = this.getClass().getClassLoader().getResourceAsStream("user.txt");ArrayList<String> lines = IoUtil.readLines(in, StandardCharsets.UTF_8, new ArrayList<>());return lines;}
}
package com.itheima.service.impl;import com.itheima.dao.UserDao;
import com.itheima.dao.impl.UserDaoImpl;
import com.itheima.pojo.User;
import com.itheima.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.List;
//@Component
@Service
public class UserServiceImpl implements UserService {@Autowired //应用程序运行时会自动查找该类型的bean对象,并赋值给该成员变量private UserDao UserDao;@Overridepublic List<User> findAll(){//1. 调用dao获取数据List<String> lines = UserDao.findAll();//2. 解析用户信息,封装成user对象,封装为一个list集合List<User> userList =lines.stream().map(line -> {String[] parts = line.split(",");Integer id = Integer.parseInt(parts[0]);String username = parts[1];String password = parts[2];String name = parts[3];Integer age = Integer.parseInt(parts[4]);LocalDateTime updateTime = LocalDateTime.parse(parts[5], DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));return new User(id, username, password, name, age, updateTime);}).toList();return userList;}}