1. 场景
打印日志的时候，需要获取是在哪个地方被调用了，把调用点的信息一并打印出来。
2. 获取自身被调用点的方法
可以通过获取线程的调用栈，遍历后找到调用点。
3. 代码实现
import java.text.SimpleDateFormat;
import java.util.Date;public class Log {private static final String INFO = "INFO";private static final String WARN = "WARN";private static final String ERROR = "ERROR";private static final String DEBUG = "DEBUG";private static final String THREAD_CLASS_NAME = Thread.class.getName();private static final String SELF_CLASS_NAME = Log.class.getName();private static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");private static StackTraceElement findCallPoint() {Thread currentThread = Thread.currentThread();StackTraceElement[] stackTraces = currentThread.getStackTrace();for (StackTraceElement stackTrace : stackTraces) {if (THREAD_CLASS_NAME.equals(stackTrace.getClassName()) || SELF_CLASS_NAME.equals(stackTrace.getClassName())) {continue;}return stackTrace;}return null;}private static String getMsgPrefix(String msgType) {StackTraceElement callPoint = findCallPoint();if (callPoint == null) {return "-";}return String.format("%s %s --- %s(%d) \t%s()\t", DATE_FORMAT.format(new Date()), msgType,callPoint.getClassName(), callPoint.getLineNumber(), callPoint.getMethodName());}public static void info(String msg) {System.out.println(getMsgPrefix(INFO) + msg);}public static void warn(String msg) {System.out.println(getMsgPrefix(WARN) + msg);}public static void error(String msg) {System.out.println(getMsgPrefix(ERROR) + msg);}public static void debug(String msg) {System.out.println(getMsgPrefix(DEBUG) + msg);}
}
4. 测试
测试代码：
package com.example.study.controller;public class Test {public static void main(String[] args) {Log.info("=====testLog main=====");testLog();}private static void testLog() {Log.info("=====testLog info=====");Log.warn("=====testLog warn=====");Log.error("=====testLog error=====");Log.debug("=====testLog debug=====");}
}
控制台输出：
2024-12-26 23:18:35.313 INFO --- com.example.study.controller.Test(7) main() =====testLog main=====
2024-12-26 23:18:35.315 INFO --- com.example.study.controller.Test(12) testLog() =====testLog info=====
2024-12-26 23:18:35.315 WARN --- com.example.study.controller.Test(13) testLog() =====testLog warn=====
2024-12-26 23:18:35.315 ERROR --- com.example.study.controller.Test(14) testLog() =====testLog error=====
2024-12-26 23:18:35.315 DEBUG --- com.example.study.controller.Test(15) testLog() =====testLog debug=====
