4.1 Resource
- spring用来调用外部资源数据的方式
- 支持调用文件或者是网址
- 在系统中调用properties文件可参考<<02点睛Spring4.1-Java Config>>中结合@PropertySource和Environment来使用
- 也可以使用@Value来注入资源,@Value的使用将在<<13点睛Spring4.1-Spring EL>>章节中有更详细的使用
4.2 示例
4.2.1 新增commons-io到maven依赖
需使用commons-io的IOUtils工具类将InputStream转换成String 在pom.xml的中添加如下
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.3</version>
</dependency>
4.2.2 新建测试用info.txt
sadfasdfasdfasdfasdfsad
sadfasdfasdfasdfasdfsad
sadfasdfasdfasdfasdfsad
4.2.3 测试
package com.wisely.resource;
import java.io.IOException;
import org.apache.commons.io.IOUtils;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.core.io.Resource;
import org.springframework.core.io.UrlResource;
import org.springframework.stereotype.Component;
@Component
public class Main {
@Value("classpath:com/wisely/resource/info.txt")
private Resource info;
public static void main(String[] args) throws IOException {
AnnotationConfigApplicationContext context =
new AnnotationConfigApplicationContext("com.wisely.resource");
Main main = context.getBean(Main.class);
System.out.println(main.injectInfo());
System.out.println("----------------------------");
//classpath: spring的一个模拟协议,类似于http：
Resource file = context.getResource("classpath:com/wisely/resource/info.txt");
System.out.println(IOUtils.toString(file.getInputStream()));
System.out.println("----------------------------");
Resource url = (UrlResource) context.getResource("http://www.baidu.com");
System.out.println(IOUtils.toString(url.getInputStream()));
context.close();
}
public String injectInfo() throws IOException{
return IOUtils.toString(info.getInputStream());
}
}
输出结果
sadfasdfasdfasdfasdfsad
sadfasdfasdfasdfasdfsad
sadfasdfasdfasdfasdfsad
----------------------------
sadfasdfasdfasdfasdfsad
sadfasdfasdfasdfasdfsad
sadfasdfasdfasdfasdfsad
----------------------------
<!DOCTYPE html><!--STATUS OK--><html><head>
.......