-----------------------siwuxie095
表达式 SpEL 方式的属性注入
表达式 SpEL 方式的属性注入是 Spring 3.x 版本后提供的方式
1、编写一个普通类
Book.java:
package com.siwuxie095.property;
public class Book { private String bookName; private int bookPrice; public void setBookName(String bookName) { this.bookName = bookName; } public String getBookName() { return bookName; } public void setBookPrice(int bookPrice) { this.bookPrice = bookPrice; } public int getBookPrice() { return bookPrice; } } |
2、编写另一个普通类
User.java:
package com.siwuxie095.property;
public class User { private String userName; private Book book; public void setUserName(String userName) { this.userName = userName; } public void setBook(Book book) { this.book = book; } public void print() { System.out.println("User:"+userName+ " Book:"+book.getBookName()+ " Cost:"+book.getBookPrice()); } } |
3、在配置文件中注入属性
applicationContext.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" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <!-- 表达式 SpEL 方式的属性注入 --> <bean id="book" class="com.siwuxie095.property.Book"> <property name="bookName" value="#{'十万个为什么'}"></property> <property name="bookPrice" value="#{100}"></property> </bean> <bean id="user" class="com.siwuxie095.property.User"> <property name="userName" value="#{'小明'}"></property> <property name="book" value="#{book}"></property> </bean>
</beans> |
4、编写一个测试类
TestProperty.java:
package com.siwuxie095.property;
import org.junit.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext;
public class TestProperty { /** * 手动加上 @Test 以进行单元测试(将自动导入 JUnit 4 的 jar 包) * * 选中方法名,右键->Run As->JUint Test */ @Test public void testProperty() { // (1) 加载 Spring 的核心配置文件 ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml"); // (2) 得到核心配置文件中创建的对象(获取 Bean 实例) User user=(User) context.getBean("user"); user.print(); } } |
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