不多說 先來原始碼

package com.lx.core.util;


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


import org.apache.log4j.Logger;


public class PropertiesUtil {


private static Properties prop;


private static Logger log = Logger.getLogger(PropertiesUtil.class);

private static Long lastModified = 0l;  


private static void init() {


prop = new Properties();
String filepath = PropertiesUtil.class.getClassLoader().getResource("/properties/config.properties").getPath();
log.info(filepath);
FileInputStream fis = null;
try {
fis = new FileInputStream(filepath);
prop.load(fis);
} catch (IOException e) {
log.error("載入系統路徑資原始檔錯誤!");
e.printStackTrace();
}
}


public static String getProperty(String key) {


if (prop == null || isPropertiesModified()) {
init();
}
String value = prop.get(key).toString();
return value;
}

//判斷是否被修改過  
public static boolean isPropertiesModified() {  
        boolean returnValue = false;  
        File file = new File(PropertiesUtil.class.getClassLoader().getResource("/properties/config.properties").getPath());  
        if (file.lastModified() > lastModified) {  
        lastModified=file.lastModified();
            returnValue = true;  
        }  
        return returnValue;  
    } 
}

isPropertiesModified方法來判斷配置檔案的最後修改時間和lastModified 中儲存的最後修改時間戳是否一致,一致,不進行重新載入.不一致  重新讀取檔案內容到記憶體

以下是測試類

package com.lx.core.util;


import org.springframework.stereotype.Service;


@Service  
public class TaskJob {  

    public void AutoLaunchSend() throws Exception{
   
    String zxq=PropertiesUtil.getProperty("zxq");
   
    System.out.println(zxq);
   
    }
}