如何只将应用程序日志写入android中的外部文件

public String writeLogToFile()
{
    try 
        {
            Process process = Runtime.getRuntime().exec("logcat -d");
            BufferedReader bufferedReader = new BufferedReader( new InputStreamReader(process.geTinputStream()));
            StringBuilder log=new StringBuilder();
            String line;
            while ((line = bufferedReader.readLine()) != null) 
                {
                    log.append(linE);
                }
            bufferedReader.close();
            return log.toString();
        } 
    catch (IOException E) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return null;
        }
}

以下是如何读取当前应用程序的日志.要过滤日志,我获取进程ID(pid)并将其与logcat@L_616_5@的每一行进行比较.

在logcat的参数中,我指定读取最后200行并随时间显示日志.

public String writeLogToFile() {
    StringBuilder logs = new StringBuilder();
    int pid = android.os.process.myPid();
    String pidPattern = String.format("%d):",pid);
    try {
        Process process = new ProcessBuilder()
                .command("logcat","-t","200","-v","time")
                .redirectErrorStream(true)
                .start();

        InputStream in = null;

        try {
            in = process.geTinputStream();

            BufferedReader reader = new BufferedReader(new InputStreamReader(in));

            String line;
            while ((line = reader.readLine()) != null) {
                if (line.contains(pidPattern)) {
                    logs.append(linE).append("\n");
                }
            }
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException E) {
                    Log.e(tag,"CAnnot close input stream",E);
                }
            }
        }
    } catch (IOException E) {
        Log.e(tag,"CAnnot read logs",E);
    }

    return log.toString();
}