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