首先在 pom.xml中引入commons-io 用于将流转换成字符串
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.5</version>
</dependency>
- 新建一个属性类
package com.xiaohan.el;
import org.springframework.stereotype.Service;
// 演示的属性类
@Service
public class DemoService {
private String another = "类的属性";
public String getAnother() {
return another;
}
}
- 在resouce目录下创建一个test.txt文件 内容随意
- 在resouce目录下创建一个test.properties文件
p.name=zhangsan
p.age=23
- 新建一个使用资源的类
package com.xiaohan.el;
import org.apache.commons.io.IOUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.env.Environment;
import org.springframework.core.io.Resource;
import org.springframework.stereotype.Service;
@Service
public class UseResourceService {
//普通字符串
@Value("Hello")
private String normal;
// 操作系统属性
@Value("#{systemProperties['os.name']}")
private String osName;
// 表达式结果
@Value("#{T(java.lang.Math).random() * 100}")
private double randomNumber;
// 其它Bean的属性
@Value("#{demoService.another}")
private String fromAnother;
// 文件资源
@Value("classpath:test.txt")
private Resource testFile;
// 网络资源
@Value("http://www.baidu.com")
private Resource baiduHtml;
// 配置文件
@Value("${p.name}")
private String author;
// 配置文件
@Autowired
private Environment environment;
public void outputResource() {
try {
System.err.println(normal);
System.err.println(osName);
System.err.println(randomNumber);
System.err.println(fromAnother);
System.err.println(IOUtils.toString(testFile.getInputStream()));
System.err.println(IOUtils.toString(baiduHtml.getInputStream()));
System.err.println(author);
System.err.println(environment.getProperty("p.age"));
} catch (Exception e) {
e.printStackTrace();
}
}
}
- 配置类
package com.xiaohan.el;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
@Configuration
@ComponentScan("com.xiaohan.el")
// 加载资源文件
@PropertySource("classpath:test.properties")
public class ElConfig {
}
- Main测试类
package com.xiaohan.el;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
// EL&资源调用
public class Main {
public static void main(String[] args) {
ApplicationContext ac = new AnnotationConfigApplicationContext(ElConfig.class);
UseResourceService useResourceService = ac.getBean(UseResourceService.class);
useResourceService.outputResource();
}
}
输出
Hello
Windows 10
5.099909206748354
类的属性
test.txt内容
<!DOCTYPE html>
<!--STATUS OK--><html> <head><meta http-equiv=content-type content=text/html;charset=utf-8><meta http-equiv=X-UA-Compatible content=IE=Edge><meta content=always name=referrer><link rel=stylesheet type=text/css href=http://s1.bdstatic.com/r/www/cache/bdorz/baidu.min.css>
......<title>百度一下，你就知道</title>......
zhangsan
23
