Spring @Value使用示例

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@PropertySource(“classpath:config.properties”) ：指定文件的地址

ELConfig .java

package com.netant.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.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.netant.EL")@PropertySource("classpath:config.properties") // public class ELConfig {    @Value("you had a bad day") // 注入普通字符串    private String normal;    @Value("#{systemProperties['os.name']}") // 注入操作系统属性    private String osName;    @Value("#{T(java.lang.Math).random() * 100.0}") // 注入表达式结果    private double randomNumber;    @Value("#{demoService.another}") // 注入其他Bean属性    private String fromAnother;    @Value("classpath:test.txt") // 注入文件资源    private Resource testFile;    @Value("https://www.baidu.com/?tn=57095150_1_oem_dg") // 注入网址资源    private Resource testUrl;    @Value("${jdbc.type}") // 注入配置文件    private String dataBaseType;    @Autowired    private Environment environment; // 注入Properties还可以从Environment中获取    // 若使用@Value注入，则要配置一个 PropertySourcesPlaceholderConfigurer 的Bean    public static PropertySourcesPlaceholderConfigurer propertyConfigure(){        return new PropertySourcesPlaceholderConfigurer();    }    public void outputResource() throws IOException{        System.out.println(normal);        System.out.println(osName);        System.out.println(randomNumber);        System.out.println(fromAnother);        System.out.println(IOUtils.toString(testFile.getInputStream()));        System.out.println(IOUtils.toString(testUrl.getInputStream()));        System.out.println(dataBaseType);        System.out.println(environment.getProperty("jdbc.driver"));    }}

Main.java

package com.netant.EL;import java.io.IOException;import org.springframework.context.annotation.AnnotationConfigApplicationContext;public class Main {    public static void main(String[] args) throws IOException {        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(ELConfig.class);        ELConfig eLConfig = context.getBean(ELConfig.class);        eLConfig.outputResource();        context.close();    }}

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