Spring课程 Spring入门篇 2-2 Spring注入方式

本节主要讲了以下两块内容：

1　　　　xml两种注入方式

2　　　　注入方式代码实现

3　　　　特别注意

1　　　　xml两种注入方式

构造注入和set注入

2　　　　注入方式代码实现

2.1　　set注入方式的实现

实现类

package com.imooc.ioc.injection.service;

import com.imooc.bean.ioc.interfaces.InjectionDao;
import com.imooc.bean.ioc.interfaces.InjectionService;

public class InjectionServiceImpl implements InjectionService {

    private InjectionDao injectionDao;

    //set注入
    public void setInjectionDao(InjectionDao injectionDao) {
        this.injectionDao = injectionDao;
    }

    @Override
    public void save(String sArgs) {
        injectionDao.save(sArgs);
        // TODO Auto-generated method stub
        System.out.println("开始保存！！！"+sArgs);
    }

}

注入类

package com.imooc.ioc.injection.service;

import com.imooc.bean.ioc.interfaces.InjectionDao;

public class InjectionDaoImpl implements InjectionDao{

    @Override
    public void save(String args) {
        // TODO Auto-generated method stub
        System.out.println("导层保存参数"+args);
    }

}

spring-injection.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd"
default-init-method="init" default-destroy-method="destroy">

<bean id="injectionService" class="com.imooc.ioc.injection.service.InjectionServiceImpl">
<property name="injectionDao" ref="injectionDao"/>
</bean> 

<bean id="injectionDao" class="com.imooc.ioc.injection.service.InjectionDaoImpl"></bean> 

</beans>

测试类：

package com.imooc.test.ioc.interfaces;

import org.junit.Test;

import com.imooc.bean.ioc.interfaces.InjectionService;
import com.imooc.test.base.UnitTestBase;

public class TestInjectionService extends UnitTestBase{

    public TestInjectionService() {
        super("classpath*:spring-injection.xml");
        // TODO Auto-generated constructor stub
    }

    @Test
    public void testInjectionService(){
        //得到当前对象
        InjectionService iService = super.getbean("injectionService");
        iService.save("12345");
    }

}

2.2　　构造注入方式的实现

实现类

package com.imooc.ioc.injection.service;

import com.imooc.bean.ioc.interfaces.InjectionDao;
import com.imooc.bean.ioc.interfaces.InjectionService;

public class InjectionServiceImpl implements InjectionService {

    private InjectionDao injectionDao;

    /*//set注入
    public void setInjectionDao(InjectionDao injectionDao) {
        this.injectionDao = injectionDao;
    }*/

    //构造器注入
    //注意：这里要有 this.injectionDao = injectionDao;
    public InjectionServiceImpl(InjectionDao injectionDao) {
        // TODO Auto-generated constructor stub
        this.injectionDao = injectionDao;
    }

    @Override
    public void save(String sArgs) {
        injectionDao.save(sArgs);
        // TODO Auto-generated method stub
        System.out.println("开始保存！！！"+sArgs);
    }

}

注入类：（同上）

spring-injection.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd"
default-init-method="init" default-destroy-method="destroy">

<!-- <bean id="injectionService" class="com.imooc.ioc.injection.service.InjectionServiceImpl">
<property name="injectionDao" ref="injectionDao"/>
</bean>  -->

<!-- 注意：这里是ref -->
<bean id = "injectionService" class="com.imooc.ioc.injection.service.InjectionServiceImpl">
<constructor-arg name="injectionDao" ref="injectionDao"></constructor-arg>
</bean>

<bean id="injectionDao" class="com.imooc.ioc.injection.service.InjectionDaoImpl"></bean> 

</beans>

测试类：

package com.imooc.test.ioc.interfaces;

import org.junit.Test;

import com.imooc.bean.ioc.interfaces.InjectionService;
import com.imooc.test.base.UnitTestBase;

public class TestInjectionService extends UnitTestBase{

    public TestInjectionService() {
        super("classpath*:spring-injection.xml");
        // TODO Auto-generated constructor stub
    }

    @Test
    public void testInjectionService(){
        //得到当前对象
        InjectionService iService = super.getbean("injectionService");
        iService.save("12345");
    }

    @Test
    public void testInjectionServiceConstruct(){
        //得到当前对象
        try {
            InjectionService iService = super.getbean("injectionService");
            iService.save("12346");
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }

    }

}

3　　　　特别注意

xml配置的name，实现类中的变量，必须保证完全一致，否则，系统报错，找不到指定的方法。

原文地址：https://www.cnblogs.com/1446358788-qq/p/10421538.html