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spring 引用Bean的属性值
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引用Bean的属性值
从Spring3.0开始，可以通过#{beanName.beanProp}的方式方便地引用另一个bean的属性值
1、不需要使用PropertyPlaceholderConfigurer。
2、这里是井号
demo
1、xml配置实现
package test;
import org.springframework.beans.factory.annotation.Value;
public class User {
private String name;
@Value("#{initUser.age}")
private int age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
User.java
package test;
class InitUser {
private int age;
private String name;
public void initAgeName() throws InterruptedException {
Thread.sleep(9000);
this.age = 47;
this.name = "zs";
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
InitUser.java
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<!--开启包扫描，因为User类使用到了@Value注解；包扫描不支持裸体类上的注解 -->
<context:component-scan base-package="test"/>
<!-- 使用外部属性文件值赋值 -->
<bean id="user" class="test.User" p:name="#{initUser.name}"/>
<!-- 实例化InitUser -->
<bean id="initUser" class="test.InitUser" init-method="initAgeName"/>
</beans>
my.xml
package test; import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext; public class Driver {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("my.xml");
User user = context.getBean("user", User.class);
System.out.println(user.getName());
System.out.println(user.getAge());
}
}
Driver.java
2、Java配置实现
package test;
import org.springframework.beans.factory.annotation.Value;
public class User {
@Value("#{initUser.name}")
private String name;
@Value("#{initUser.age}")
private int age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
User.java
package test;
class InitUser {
private int age;
private String name;
public void initAgeName() throws InterruptedException {
Thread.sleep(9000);
this.age = 47;
this.name = "zs";
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
InitUser.java
package test; import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration; @Configuration
@ComponentScan// 因为使用了@Value注解，所以要开启包扫描
public class MyConfig {
@Bean
public InitUser initUser() throws InterruptedException {
InitUser initUser = new InitUser();
initUser.initAgeName();
return initUser;
}
@Bean
public User user() {
return new User();
}
}
MyConfig
package test; import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext; public class Driver {
public static void main(String[] args) {
ApplicationContext context = new AnnotationConfigApplicationContext(MyConfig.class);
User user = context.getBean("user", User.class);
System.out.println(user.getName());
System.out.println(user.getAge());
}
}
Driver.java
