Android之TimingLogger类

概述

摘自官方文档：

A utility class to help log timings splits throughout a method call. Typical usage is:
TimingLogger timings = new TimingLogger(TAG, "methodA"); 
// ... do some work A ... timings.addSplit("work A");
// ... do some work B ... timings.addSplit("work B");
// ... do some work C ... timings.addSplit("work C"); 

timings.dumpToLog(); 

The dumpToLog call would add the following to the log:
D/TAG ( 3459): methodA: begin
D/TAG ( 3459): methodA: 9 ms, work A 
D/TAG ( 3459): methodA: 1 ms, work B 
D/TAG ( 3459): methodA: 6 ms, work C 
D/TAG ( 3459): methodA: end, 16 ms 

以下是针对TimingLogger的封装：

public class MethodTimeTraceLogger {
    private String tag;
    private TimingLogger logger;

    public MethodTimeTraceLogger(String tag) {
        this.tag = tag;
    }

    public MethodTimeTraceLogger setLoggerLabel(String label) {
        if (logger != null) {
            logger.reset(tag, label);
        } else {
            logger = new TimingLogger(tag, label);
        }
        return this;
    }

    public MethodTimeTraceLogger addSplit(String msg) {
        logger.addSplit(msg);
        return this;
    }

    public void dumpToLog() {
        logger.dumpToLog();
    }
}

调用方式如下，

常见错误

1.无法输出日志
原因分析：在TimingLogger的构造方法中会依次调用reset(tag, label)->reset(tag, label)->reset()方法，其中有这样一条语句：mDisabled = !Log.isLoggable(mTag, Log.VERBOSE);这个mDisable的值表示mTag为VERBOSE级别时是否不能打印，如果用Log打印一下，会发现它的值为true，就是说不能打印级别为VERBOSE的mTag的日志。因为默认情况下只打印INFO以上的日志，所以可通过以下命令，使其在日志级别为VERBOSE以上时都可以打印:
adb shell setprop log.tag.[TimingLogger实例化时的TAG值] VERBOSE

改进版：自定义MethodDebugLogger测试类

/**
 * Created by Administrator on 2016/6/3.
 * 方法调试日志类
 */
public class MethodDebugLogger {
    private static final UtilsLog lg = UtilsLogFactory.getLogger(MethodDebugLogger.class);
    private long startTime;
    private long wholeTime = 0;//花费总时间
    private String methodName;
    private StringBuilder stringBuilder;

    public MethodDebugLogger(String methodName) {
        this.startTime = getStandedTime();
        this.methodName = methodName;
        this.wholeTime = 0;
        this.stringBuilder = new StringBuilder(this.methodName).append(":start");
    }

    public MethodDebugLogger addSplit(String msg) {
        long curTime = getStandedTime();
        this.stringBuilder.append("\n")
                .append(methodName)
                .append(":")
                .append(curTime - startTime)
                .append("ms,")
                .append(msg);
        this.wholeTime += (curTime - startTime);
        this.startTime = curTime;
        return this;
    }

    public void dumpToLog() {
        this.stringBuilder.append("\n").append(methodName).append(":").append(wholeTime).append(",end with whole time");
        lg.e(this.stringBuilder.toString());
    }

    /**
     * 获得标准时间
     *
     * @return
     */
    public long getStandedTime() {
        return System.currentTimeMillis();
    }
}

来自为知笔记(Wiz)