五十三、bean的管理-bean的获取、bean的作用域、第三方bean

bean的管理-bean的获取

bean的管理-bean的作用域

bean的管理-第三方bean

总结

代码

DeptController

java 复制代码

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 {

    @Autowired
    private DeptService deptService;

    public DeptController(){
        System.out.println("DeptController constructor ....");
    }

    @GetMapping
    public 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();
    }

    @PostMapping
    public Result save(@RequestBody Dept dept){
        deptService.save(dept);
        return Result.success();
    }
}

DeptService（接口）

java 复制代码

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）

java 复制代码

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 {
    @Autowired
    private DeptMapper deptMapper;

    @Override
    public List<Dept> list() {
        List<Dept> deptList = deptMapper.list();
        return deptList;
    }

    @Override
    public void delete(Integer id) {
        deptMapper.delete(id);
    }

    @Override
    public void save(Dept dept) {
        dept.setCreateTime(LocalDateTime.now());
        dept.setUpdateTime(LocalDateTime.now());
        deptMapper.save(dept);
    }
}

CommonConfig（配置类）

java 复制代码

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 复制代码

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

SpringbootWebConfig2ApplicationTests

java 复制代码

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 {

    @Autowired
    private ApplicationContext applicationContext; //IOC容器对象

    //获取bean对象
    @Test
    public 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
    @Test
    public void testScope(){
        for (int i = 0; i < 10; i++) {
            DeptController deptController = applicationContext.getBean(DeptController.class);
            System.out.println(deptController);
        }
    }

    @Autowired
    private SAXReader saxReader;

    //第三方bean的管理
    @Test
    public 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);
    }


    @Test
    public void testGetBean2(){
        Object saxReader = applicationContext.getBean("reader");
        System.out.println(saxReader);
    }
}