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五十三、bean的管理-bean的获取、bean的作用域、第三方bean

news 2025/9/24 8:02:19

bean的管理-bean的获取

bean的获取

bean的管理-bean的作用域

bean的作用域

bean的管理-第三方bean

第三方bean

总结

代码

DeptController

package com.itheima.controller;import com.itheima.pojo.Dept;
import com.itheima.pojo.Result;
import com.itheima.service.DeptService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Lazy;
import org.springframework.context.annotation.Scope;
import org.springframework.web.bind.annotation.*;
import java.util.List;//@Lazy//延迟初始化bean对象，因为默认初始化ben对象是在容器启动时候就初始化
@Scope("prototype")
@RestController
@RequestMapping("/depts")
public class DeptController {@Autowiredprivate DeptService deptService;public DeptController(){System.out.println("DeptController constructor ....");}@GetMappingpublic Result list(){List<Dept> deptList = deptService.list();return Result.success(deptList);}@DeleteMapping("/{id}")public Result delete(@PathVariable Integer id)  {deptService.delete(id);return Result.success();}@PostMappingpublic Result save(@RequestBody Dept dept){deptService.save(dept);return Result.success();}
}

DeptService（接口）

package com.itheima.service;import com.itheima.pojo.Dept;import java.util.List;public interface DeptService {/*** 查询所有的部门数据* @return*/List<Dept> list();/*** 删除部门* @param id*/void delete(Integer id);/*** 新增部门* @param dept*/void save(Dept dept);
}

DeptService（实现DeptService接口）

package com.itheima.service.impl;import com.itheima.mapper.DeptMapper;
import com.itheima.pojo.Dept;
import com.itheima.service.DeptService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Service;import java.time.LocalDateTime;
import java.util.List;@Slf4j
@Service
public class DeptServiceImpl implements DeptService {@Autowiredprivate DeptMapper deptMapper;@Overridepublic List<Dept> list() {List<Dept> deptList = deptMapper.list();return deptList;}@Overridepublic void delete(Integer id) {deptMapper.delete(id);}@Overridepublic void save(Dept dept) {dept.setCreateTime(LocalDateTime.now());dept.setUpdateTime(LocalDateTime.now());deptMapper.save(dept);}
}

CommonConfig（配置类）

配置类

package com.itheima.config;import com.itheima.service.DeptService;
import org.dom4j.io.SAXReader;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;@Configuration //配置类
public class CommonConfig {//声明第三方bean@Bean //将当前方法的返回值对象交给IOC容器管理, 成为IOC容器bean//通过@Bean注解的name/value属性指定bean名称, 如果未指定, 默认是方法名public SAXReader reader(DeptService deptService){System.out.println(deptService);return new SAXReader();}}

1.xml

<?xml version="1.0" encoding="UTF-8"?>
<emp><name>Tom</name><age>18</age>
</emp>

SpringbootWebConfig2ApplicationTests

package com.itheima;import com.itheima.controller.DeptController;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.ApplicationContext;@SpringBootTest
class SpringbootWebConfig2ApplicationTests {@Autowiredprivate ApplicationContext applicationContext; //IOC容器对象//获取bean对象@Testpublic void testGetBean(){//根据bean的名称获取DeptController bean1 = (DeptController) applicationContext.getBean("deptController");System.out.println(bean1);//根据bean的类型获取DeptController bean2 = applicationContext.getBean(DeptController.class);System.out.println(bean2);//根据bean的名称 及 类型获取DeptController bean3 = applicationContext.getBean("deptController", DeptController.class);System.out.println(bean3);}//bean的作用域@Testpublic void testScope(){for (int i = 0; i < 10; i++) {DeptController deptController = applicationContext.getBean(DeptController.class);System.out.println(deptController);}}@Autowiredprivate SAXReader saxReader;//第三方bean的管理@Testpublic void testThirdBean() throws Exception {//SAXReader saxReader = new SAXReader();Document document = saxReader.read(this.getClass().getClassLoader().getResource("1.xml"));Element rootElement = document.getRootElement();String name = rootElement.element("name").getText();String age = rootElement.element("age").getText();System.out.println(name + " : " + age);}@Testpublic void testGetBean2(){Object saxReader = applicationContext.getBean("reader");System.out.println(saxReader);}
}