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;
    }

}