第一个简单的依赖注入

基于setter方法注入：
HelloBean.java
public class HelloBean {
    private String helloWord = "Hello!World!";
   
    public void setHelloWord(String helloWord) {
        this.helloWord = helloWord;
    }
    public String getHelloWord() {
        return helloWord;
    }
}

 

applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING/DTD BEAN/EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <bean id="helloBean" class="onlyfun.caterpillar.HelloBean">
        <property name="helloWord"><value>Hello!Justin!</value></property>
    </bean>
</beans>

 

SpringTest.java
import java.io.*;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;

public class SpringTest {
    public static void main(String[] args) throws IOException {
        InputStream is = new FileInputStream("bean.xml");
        BeanFactory factory = new XmlBeanFactory(is);
       
        HelloBean hello = (HelloBean) factory.getBean("helloBean");
        System.out.println(hello.getHelloWord());
    }
}

 

基于构造方法注入:
public class HelloBean {
    private String helloWord = "hello";
  
    public HelloBean(String helloWord) {
        this.helloWord = helloWord;
    }   
 }
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING/DTD BEAN/EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <bean id="helloBean" class="onlyfun.caterpillar.HelloBean">
        <constructor-arg index="0"><value>Greeting</value></constructor-arg>
    </bean>
</beans>
index属性指明通过构造器注入的参数,索引值从0开始.
Test.java
import java.io.*;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
public class Test {
    public static void main(String[] args) throws IOException {
        InputStream is = new FileInputStream("bean.xml");
        BeanFactory factory = new XmlBeanFactory(is);
       
        HelloBean hello = (HelloBean) factory.getBean("helloBean");
        System.out.println(hello.sayHelloToUser());
    }
}
获取XML中bean对象,并调引相应的方法.

 

评论

1 楼 avajworm 2011-03-21  

再次学习。