Spring学习三----------注入方式

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Spring注入方式

　　本篇博客只讲最常用的两种注入方式：设值注入和构造器注入。代码为完整代码，复制即可使用。

1.目录结构

2.pom.xml

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>org.spring</groupId>
	<artifactId>Spring</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>Spring</name>
	<url>http://maven.apache.org</url>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<spring.version>4.3.7.RELEASE</spring.version>
	</properties>

	<dependencies>
		<!-- junit依赖 -->
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.12</version>
			<scope>test</scope>
		</dependency>
		<!-- spring依赖 -->
		<dependency>
		    <groupId>org.springframework</groupId>
		    <artifactId>spring-core</artifactId>
		    <version>${spring.version}</version>
		</dependency>
		<dependency>
		    <groupId>org.springframework</groupId>
		    <artifactId>spring-beans</artifactId>
		    <version>${spring.version}</version>
		</dependency>
		<dependency>
		    <groupId>org.springframework</groupId>
		    <artifactId>spring-context</artifactId>
		    <version>${spring.version}</version>
		</dependency>
	</dependencies>
</project>

2.spring-ioc.xml(两种注入方式，任选一种)

　　2.1 设值注入

<?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">
        
	<bean id="injectService" class="org.spring.ioc.injection.service.impl.InjectionServiceImpl">
		<!-- 设值注入 -->
		<property name="injectDao" ref="injectDao"/>
	</bean>
	
	<bean id="injectDao" class="org.spring.ioc.injection.dao.impl.InjectionDaoImpl"></bean>        
        
</beans>

　　2.2 构造器注入

<?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">
        
	<bean id="injectService" class="org.spring.ioc.injection.service.impl.InjectionServiceImpl">
		<!-- 构造器注入 -->
		<constructor-arg name="injectDao" ref="injectDao"/>
	</bean>
	
	<bean id="injectDao" class="org.spring.ioc.injection.dao.impl.InjectionDaoImpl"></bean>        
        
</beans>

3.InjectionDao

package org.spring.ioc.injection.dao;

public interface InjectionDao {

	String save(String word);

}

4.InjectionDaoImpl

package org.spring.ioc.injection.dao.impl;

import org.spring.ioc.injection.dao.InjectionDao;

public class InjectionDaoImpl implements InjectionDao {

	public String save(String word) {
		
		return "数据保存成功！保存的数据是：" + word.hashCode();
		
	}

}

5.InjectionService

package org.spring.ioc.injection.service;

public interface InjectionService {
	
	String save(String word);

}

6.InjectionServiceImpl(两种注入方式，任选一种)

　　6.1 设值注入

package org.spring.ioc.injection.service.impl;

import org.spring.ioc.injection.dao.InjectionDao;
import org.spring.ioc.injection.service.InjectionService;

public class InjectionServiceImpl implements InjectionService {

	private InjectionDao injectDao;
	
	//设值注入
	public void setInjectDao(InjectionDao injectDao) {
		this.injectDao = injectDao;
	}
	
	public String save(String word) {
		
		System.out.println("传递过来的参数是：" + word);
		return injectDao.save(word);
		
	}

}

　　6.2 构造器注入

package org.spring.ioc.injection.service.impl;

import org.spring.ioc.injection.dao.InjectionDao;
import org.spring.ioc.injection.service.InjectionService;

public class InjectionServiceImpl implements InjectionService {

	private InjectionDao injectDao;
	
	//构造器注入
	public InjectionServiceImpl(InjectionDao injectDao) {
		this.injectDao = injectDao;
	}
	
	public String save(String word) {
		
		System.out.println("传递过来的参数是：" + word);
		return injectDao.save(word);
		
	}

}

7.UnitTestBase.java

package org.spring.ioc.test;

import org.junit.After;
import org.junit.Before;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.util.StringUtils;

/**
 * 单元测试初始化类
 *
 */
public class UnitTestBase {
	
	private ClassPathXmlApplicationContext context;
	private String springXmlPath;
	
	/**
	 * 无参构造器
	 */
	public UnitTestBase() {
		
	}

	/**
	 * 含参构造器
	 * 
	 * @param springXmlPath
	 * 						spring配置文件路径
	 */
	public UnitTestBase(String springXmlPath) {
		
		this.springXmlPath = springXmlPath;
		
	}
	
	/**
	 * 初始化spring配置文件
	 */
	@Before//在@Test注解的方法执行前执行
	public void before() {
		
		if(StringUtils.isEmpty(springXmlPath)) {//默认spring配置文件路径
			springXmlPath = "classpath*:spring-*.xml";
		}
		//加载配置文件
		context = new ClassPathXmlApplicationContext(springXmlPath.split("[,\s]+"));
		//启动组件
		context.start();
		
	}
	
	/**
	 * 销毁spring组件
	 */
	@After//在@Test注解的方法执行后执行
	public void after() {
		
		context.destroy();//销毁组件
		
	}
	
	/**
	 * 获取spring中定义的bean实例
	 * 
	 * @param beanId
	 * 					
	 * @return
	 */
	@SuppressWarnings("unchecked")
	protected <T extends Object> T getBean(String beanId) {
		
		return (T) context.getBean(beanId);
		
	}
	
	/**
	 * 获取spring中定义的bean实例
	 * 
	 * @param clazz
	 * 				
	 * @return
	 */
	protected <T extends Object> T getBean(Class<T> clazz) {
		
		return (T) context.getBean(clazz);
		
	}

}

8.TestInject.java

package org.spring.ioc.test;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.BlockJUnit4ClassRunner;
import org.spring.ioc.injection.service.InjectionService;

@RunWith(BlockJUnit4ClassRunner.class)//指定JUnit默认执行类
public class TestInject extends UnitTestBase {
	
	public TestInject() {//通过构造方法传入spring配置文件路径
		
		super("classpath*:spring-ioc.xml");
		
	}
	
	@Test
	public void testInj() {
		
		InjectionService injectService = super.getBean("injectService");//从spring容器中获取依赖对象
		System.out.println(injectService.save("Word."));
		
	}
	
}

9.效果预览

 参考：http://www.imooc.com/video/3668