Spring入门之setter DI注入

1、新建Java项目导入依赖jar包，参考前一章

2、以不同文件格式输出为例

3、定义接口IOutputGenerator.java

package com.spring.output;

public interface IOutputGenerator {
		public void generateOutput();
}

4、CsvOutputGenerator和JsonOutputGenerator类，分别实现接口

CsvOutputGenerator.java

package com.spring.output;

public class CsvOutputGenerator implements IOutputGenerator{

	@Override
	public void generateOutput() {
		// TODO Auto-generated method stub
		System.out.println("CSV output Generator");
	}

}

JsonOutputGenerator.java

package com.spring.output;

public class JsonOutputGenerator implements IOutputGenerator{

	@Override
	public void generateOutput() {
		// TODO Auto-generated method stub
		System.out.println("Json output Generator");
	}

}

5、编写辅助类，通过setter注入

OutputHelper.java

package com.spring.output;

public class OutputHelper {

	IOutputGenerator outputGenerator;
	public void generateOutput(){
		outputGenerator.generateOutput();
	}
	public void setOutputGenerator(IOutputGenerator outputGenerator) {
		this.outputGenerator = outputGenerator;
	}
}

6、编辑beans.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"
	xmlns:p="http://www.springframework.org/schema/p"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
	<bean id="OutputHelper" class="com.spring.output.OutputHelper">
		<property name="outputGenerator" ref="JsonOutputGenerator"></property>
	</bean>
	<bean id="CsvOutputGenerator" class="com.spring.output.CsvOutputGenerator"></bean>
	<bean id="JsonOutputGenerator" class="com.spring.output.JsonOutputGenerator"></bean>
</beans>

7、测试：

package com.spring.output;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		ApplicationContext content = new ClassPathXmlApplicationContext("beans.xml");
		OutputHelper outputHelper = (OutputHelper) content.getBean("OutputHelper");
		outputHelper.generateOutput();
	}

}

8、可修改beans.xml中的ref的值

<property name="outputGenerator" ref=""></property>

9、运行结果

Json output Generator