如果大家使用的是maven工程，那么現(xiàn)在pom文件中加入perf4j的依賴。
<dependency>
<groupId>org.perf4j</groupId>
<artifactId>perf4j</artifactId>
<version>0.9.16</version>
<scope>compile</scope>
</dependency>
如果用的是普通工程，那么直接下載jar包放入lib目錄下即可。
例子：
package com.baowu.per4j;
import org.perf4j.LoggingStopWatch;
import org.perf4j.StopWatch;
public class Example1 {
public static void main(String[] args) throws InterruptedException{
method1();
method2();
method3();
}
/**
* 監(jiān)控一處代碼示例
* @throws InterruptedException
*/
private static void method1() throws InterruptedException{
//創(chuàng)建一個監(jiān)控對象，這里使用LoggingStopWatch，它是把結(jié)果直接輸出到控制臺。我們也可以
//使用StopWatch的其他子類，比如：Log4JStopWatch，CommonsLogStopWatch。不過這些子類需
//要工程使用日志框架
StopWatch stopWatch = new LoggingStopWatch("codeBlock1");
//這里就是一些需要監(jiān)控的代碼，我們命名為codeBlock1
//使用線程休眠是為了模擬代碼執(zhí)行時間
Thread.sleep((long)(Math.random() * 1000L));
//停止計算代碼性能
stopWatch.stop();
}
/**
* 一個方法多出代碼監(jiān)控
* @throws InterruptedException
*/
private static void method2() throws InterruptedException{
StopWatch stopWatch = new LoggingStopWatch();
Thread.sleep((long)(Math.random() * 1000L));
stopWatch.lap("codeBlock3");
Thread.sleep((long)(Math.random() * 1000L));
stopWatch.lap("codeBlock4");
Thread.sleep((long)(Math.random() * 1000L));
stopWatch.lap("codeBlock5");
Thread.sleep((long)(Math.random() * 1000L));
stopWatch.stop("codeBlock6");
}
/**
* stop方法可以加入一些說明信息
*/
private static void method3(){
StopWatch stopWatch = new LoggingStopWatch();
try {
// the code block being timed - this is just a dummy example
long sleepTime = (long)(Math.random() * 1000L);
Thread.sleep(sleepTime);
if (sleepTime > 500L) {
throw new Exception("Throwing exception");
}
stopWatch.stop("codeBlock2.success", "Sleep time was < 500 ms");
} catch (Exception e) {
stopWatch.stop("codeBlock2.failure", "Exception was: " + e);
}
}
}
運行結(jié)果：
start[1334457619937] time[355] tag[codeBlock1]
start[1334457620296] time[152] tag[codeBlock3]
start[1334457620453] time[138] tag[codeBlock4]
start[1334457620593] time[598] tag[codeBlock5]
start[1334457621187] time[700] tag[codeBlock6]
start[1334457621890] time[619] tag[codeBlock2.failure] message[Exception was: java.lang.Exception: Throwing exception]