问题描述
对于特定的Java代码段，我想测量：
- 执行时间（很可能线程执行时间）
- 内存使用
- CPU负载（特别是可归因于代码段）
- Execution time (most likely thread execution time)
- Memory usage
- CPU load (specifically attributable to the code segment)
我是相对Java新手而且我是不熟悉如何实现这一目标。我已经被提到，但是我不确定如何使用它，和JMX看起来有点沉重我想要做的事情。
I'm a relative Java novice and am not familiar with how this might be achieved. I've been referred to JMX, however I'm not sure how that might be used, and JMX looks a bit 'heavy' for what I'm looking to do.
理想情况下我想要一些测量类可以告诉我想测量什么，可选择在代码段之前调用 start（）方法，然后调用 stop（）方法。相关指标将记录到我指定的文件中。
Ideally I'd like some measurement class that can be told what I would like to measure, with the option of calling a start() method prior to a code segment and a stop() method after. Relevant metrics would be logged to a file I specify.
例如：
import com.example.metricLogger;
metricLogger logger = new metricLogger();
logger.setLogPath(pathToLogFile);
logger.monitor(executionTime);
logger.monitor(memoryUsage);
logger.monitor(cpuLoad);
logger.start();
/* Code to be measured */
logger.stop();
在Java中是否有任何标准/通用/传统方式实现此目的？
此类测量用于一次性性能比较，因此我不会寻找任何正在进行中的长期监测过程。
Such measurements are for one-off performance comparisons, and so I'm not looking for any in-production long-term monitoring processes.
我很高兴被引用到教程或外部示例，并且不希望在这里得到完整答案。也就是说，如果能够实现上述任何简单的事情，那么真实的例子就会很好。
I'm more than happy to be referred to tutorials or external examples and don't expect a full answer here. That said, if anything as simple as the above can be achieved a realistic example would go down really well.
推荐答案
分析可能是一个更简单的选项，因为您不需要生产中的统计数据。分析也不需要修改代码。 VisualVM（随JDK 1.6.06+发布）是一个简单的工具。如果你想要更深入的东西，我会选择Eclipse TPTP，Netbeans profiler或JProfiler（付费）。
Profiling may be an easier option since you don't require in-production stats. Profiling also doesn't require code modification. VisualVM (which ships w/ the JDK 1.6.06+) is a simple tool. If you want something more in-depth I'd go with Eclipse TPTP, Netbeans profiler, or JProfiler(pay).
如果你想自己写，请考虑以下：
If you want to write you own, consider the following:
执行时间之类的简单测量可以通过计时您感兴趣的部分来完成：
Simple measurments like execution time can be done by "clocking" the section you're interested in:
long start = System.nanoTime(); // requires java 1.5
// Segment to monitor
double elapsedTimeInSec = (System.nanoTime() - start) * 1.0e-9;
您可以使用类似的技术通过Runtime.getRuntime（）监视内存。* memory（）方法。请记住，在垃圾收集环境中跟踪内存使用比简单减法更棘手。
You can use a similar technique to monitor memory via Runtime.getRuntime().*memory() methods. Keep in mind that tracking memory usage in a garbage collected environment is trickier than simple subtraction.
在Java中很难衡量CPU负载，我通常会坚持执行时间和优化较长/重复的部分
CPU load is hard to measure in Java, I typically stick with execution time and optimize the longer / repetitive sections
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