spring El

 package com.wisely.heighlight_spring4.ch2.el;

 import java.io.IOException;

 import org.apache.commons.io.IOUtils;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.PropertySource;
 import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
 import org.springframework.core.env.Environment;
 import org.springframework.core.io.Resource;

 @Configuration
 @ComponentScan("com.wisely.heighlight_spring4.ch2.el")
 @PropertySource("classpath:com/wisely/heighlight_spring4/ch2/el/test.properties")    //加载属性资源文件
 public class ElConfig {
     @Value("I love you!")    //普通的字符串
     private String normal;

     @Value("#{systemProperties['os.name']}")    //系统属性
     private String osName;

     @Value("#{ T(java.lang.Math).random() * 100.0 }")        //表达式结果
     private double randomNumber;

     @Value("#{demoService.another}")    //其他Bean属性
     private String fromAnother;

     @Value("classpath:com/wisely/heighlight_spring4/ch2/el/test.txt")    //文件资源
     private Resource testFile;

     @Value("http://www.baidu.com")    //网址资源
     private Resource testUrl;

     @Value("${book.name}")        //配置文件
     private String bookName;

     @Autowired
     private Environment environment;

     @Bean
     public static PropertySourcesPlaceholderConfigurer propertyConfigure() {
         return new PropertySourcesPlaceholderConfigurer();
     }

     public void outputResource() {
         try {
             System.out.println("normal:"+normal);
             System.out.println("osName:"+osName);
             System.out.println("randomNumber:"+randomNumber);
             System.out.println("fromAnother:"+fromAnother);

             System.out.println("testFile:"+IOUtils.toString(testFile.getInputStream()));
             System.out.println("testUrl:"+IOUtils.toString(testUrl.getInputStream()));
             System.out.println("bookName:"+bookName);
             System.out.println("environment:"+environment.getProperty("book.author"));
         } catch (IOException e) {
             e.printStackTrace();
         }
     }
 }

 package com.wisely.heighlight_spring4.ch2.el;

 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;

 @Service
 public class DemoService {
     @Value("其它类的属性")
     private String another;            //注入普通的字符串

     public String getAnother() {
         return another;
     }

     public void setAnother(String another) {
         this.another = another;
     }

 }