安卓应用程序的java文件记录器

Question

我希望最简单的记录器就是简单地将错误（主要是异常）记录到安卓文件系统中的日志文件中。例如，我过去在PC java上登录文件的最简单、最方便（至少在我看来）的方式是，简单地将所有异常打印到控制台，并将系统重定向到控制台和我的文件，就我所知，这在安卓上并不足够，我猜这是因为安卓操作系统的设计，那么在安卓系统中最简单的方法是什么呢

请注意，这个项目中已经有很多代码，我真的不想再看一遍，在catch块上添加日志调用或其他任何东西来记录我的异常，因为我只需要做一点点来记录这些异常，这对我的用例来说是最好的

谢谢你

Answer 1

它还没有完成，但运行非常稳定。它保存了人类可读的json数组，包括异常名称、时间、堆栈跟踪和其他数据。还可以保存logcat的日志

使用：

ExceptionWriter ew = new ExceptionWriter(new File(Environment.getExternalStorageDirectory(), "debug.txt"));
ew.w(new IllegalArgumentException("some msg"), "additional message");

来源：

import java.io.*;
import java.text.SimpleDateFormat;
import java.util.concurrent.ConcurrentLinkedQueue;

/**
 * User: elevenetc
 * Date: 10/9/13
 * Time: 12:52 PM
 */
public class ExceptionWriter {

    private final StringBuilder sb;
    private final ExceptionWriter.WriteExceptionTask writeExceptionTask;
    private final SimpleDateFormat dataFormat;
    private int totalExceptions;
    private StringBuilder stackBuilder = new StringBuilder();

    public int getTotalExceptions(){return totalExceptions;}

    public ExceptionWriter(File file) throws IOException {
        if(file != null){
            writeExceptionTask = new WriteExceptionTask(file);
            sb = new StringBuilder();
            dataFormat = new SimpleDateFormat("yyyy.MM.dd HH:mm:ss");
            new Thread(writeExceptionTask).start();
        }else{
            sb = null;
            writeExceptionTask = null;
            dataFormat = null;
        }

    }

    public synchronized int wLogcat(){
        try {
            writeExceptionTask.addStreamToRead(Runtime.getRuntime().exec("logcat -d -v time").getInputStream());
        } catch (IOException e) {
            e.printStackTrace();
        }

        return 0;
    }

    public int w(Exception debugException, String caughtMessage){
        return w(debugException, caughtMessage, null);
    }

    public synchronized int w(Exception debugException, String caughtMessage, String additionalData){

        if(writeExceptionTask == null) return -1;

        sb.setLength(0);

        StackTraceElement[] stackTrace = debugException == null ? null : debugException.getStackTrace();

        sb.append("{\"date\":\"");sb.append(getTime());
        sb.append("\",\"exceptionClassName\":\"");sb.append(debugException == null ? null : debugException.getClass());
        sb.append("\",\"exceptionMessage:\":\"");sb.append(debugException == null ? null : debugException.getMessage());
        sb.append("\",\"caughtMessage:\":\"");sb.append(caughtMessage);
        if(additionalData != null) {sb.append("\",\"data:\":\"");sb.append(additionalData);}
        sb.append("\",\"stack\":");sb.append(stackToString(stackTrace));
        sb.append("},");

        writeExceptionTask.stringQueue.add(sb.toString());

        totalExceptions++;

        return 0;
    }

    public void destroy() {
        if(writeExceptionTask != null) {
            writeExceptionTask.stop();
        }
    }

    private String getTime(){
        return dataFormat.format(System.currentTimeMillis());
    }

    private String stackToString(StackTraceElement[] stackTrace){

        if(stackTrace == null) return null;

        stackBuilder.setLength(0);

        stackBuilder.append("[");
        for (int i = 0; i < stackTrace.length; i++) {
            StackTraceElement e = stackTrace[i];

            stackBuilder.append("{\"");
            stackBuilder.append(e.getLineNumber());
            stackBuilder.append("\":\"");
            stackBuilder.append(e.getClassName());
            stackBuilder.append(".");
            stackBuilder.append(e.getMethodName());
            stackBuilder.append("\"}");

            if(i != stackTrace.length -1) stackBuilder.append(",");
        }
        stackBuilder.append("]");
        return stackBuilder.toString();
    }

    ///////////////////////////////////////////////
    /// Static classes
    ///////////////////////////////////////////////

    private class WriteExceptionTask implements Runnable {

        private final File file;
        private boolean running;
        private final ConcurrentLinkedQueue<String> stringQueue;
        private final ConcurrentLinkedQueue<InputStream> isQueue;
        private final FileWriter writer;

        private WriteExceptionTask(File file) throws IOException {
            this.file = file;
            writer = new FileWriter(this.file, true);
            stringQueue = new ConcurrentLinkedQueue<String>();
            isQueue = new ConcurrentLinkedQueue<InputStream>();
            running = true;
        }

        public void addStreamToRead(InputStream is){
            if(is != null){
                isQueue.add(is);
            }
        }

        @Override
        public void run() {
            while(running){
                if(!stringQueue.isEmpty()){

                    //TODO check file existence

                    try {
                        writer.append(stringQueue.poll());
                        writer.flush();
                    } catch (IOException e) {
                        e.printStackTrace();
                        running = false;
                    }
                }

                if(!isQueue.isEmpty()){
                    InputStream is = isQueue.poll();
                    BufferedReader reader = new BufferedReader(new InputStreamReader(is));

                    StringBuilder builder = new StringBuilder("{\"catLog\":\"");

                    String aux;

                    try {

                        while ((aux = reader.readLine()) != null) {
                            //TODO view like array or \n
                            builder.append(aux);
                        }

                    } catch (IOException e) {
                        e.printStackTrace();
                    }

                    builder.append("\"},");

                    stringQueue.add(builder.toString());
                }
            }

            try {
                writer.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        public void stop() {
            running = false;
        }
    }

}