Android Log.isLoggable 妙用

近来发现源码里面好多地方用到了 Log.isLoggable , 一查一看，是个东西，适合系统层以及root 主板设备上使用，能实现动态开关

android.util.Log.isLoggable(TAG, android.util.Log.DEBUG)

如上面代码以及文档说明，setprop log.tag.YOUR_LOG_TAG LEVEL 开启指定级别的日志开关属性，VERBOSE, DEBUG, INFO, WARN, ERROR, ASSERT, or SUPPRESS. SUPPRESS will turn off all logging for your tag. 一目了然了啊，

adb shell setprop log.tag.VxApk D
adb shell setprop log.tag.SUPPRESS

另外还有收获的是，系统重启之后prop 会被还原，所以了解到了重启系统服务这招，ServiceManager/ SystemServer/

adb shell stop
adb shell start

public static boolean restartSystemServer() {
    
    
        try {
    
    
            OutputStream out;
            Process process = createSuProcess();
            String cmd = "stop \n";
            out = process.getOutputStream();
            out.write(cmd.getBytes());
            cmd = "start \n";
            out.write(cmd.getBytes());
            out.flush();
            out.close();
            return true;
        } catch (IOException e) {
    
    
            Log.error(TAG, "restartSystemServer error");
        }
        return false;
 }