SpringBoot在工具類中讀取配置文件（ClassPathResource）

1、創建配置文件（application.properties）

spring.activemq.broker-url=tcp://localhost:61616
spring.activemq.user=admin
spring.activemq.password=admin
spring.activemq.in-memory=true
spring.activemq.pool.enabled=false

2、創建工具類（PropertiesUtil.java）

package com.jeff.utils;

import java.io.IOException;
import java.util.Properties;

import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.support.PropertiesLoaderUtils;

public class PropertiesUtil {

    private static String user;

    static {
        System.out.println("application.properties屬性文件讀取開始");
        ClassPathResource resource = new ClassPathResource("application.properties");
        try {
            Properties properties = PropertiesLoaderUtils.loadProperties(resource);
            user = properties.getProperty("spring.activemq.user");
            System.out.println("user的值：" + user);
        } catch (IOException e) {
            System.out.println("application.properties屬性文件讀取異常" + e);
        }
        System.out.println("application.properties屬性文件讀取完成");
    }

    public static String getUser() {
        System.out.println("獲取user的值：" + user);
        return user;
    }

}

3、創建測試類（MyController.java）

package com.jeff.controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.jeff.utils.PropertiesUtil;

@RestController
public class MyController {

    @RequestMapping("myTest")
    public String myTest() {
        PropertiesUtil.getUser();
        return "success";
    }

}

4、打開瀏覽器訪問 http://localhost:8080/myTest,控制台輸出結果