import android.os.Build;
import android.os.Environment;
import android.os.Process;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

public class CrashHandler implements Thread.UncaughtExceptionHandler {
 private static final String TAG = "CrashHandler";
 private static final boolean DEBUG = true;
 // 自定義存儲的目錄
 private static final String PATH = Environment.getExternalStorageDirectory().getPath() + "/myApp/log/";
 private static final String FILE_NAME = "crash";
 private static final String FILE_NAME_SUFFIX = ".txt";
 private String phoneInfo;
 private static CrashHandler instance = new CrashHandler();
 private Thread.UncaughtExceptionHandler mDefaultCrashHandler;

 private CrashHandler() {
 }

 public static CrashHandler getInstance() {
  return instance;
 }

 public void init() {
  mDefaultCrashHandler = Thread.getDefaultUncaughtExceptionHandler();
  Thread.setDefaultUncaughtExceptionHandler(this);
  phoneInfo = getPhoneInformation();
 }

 /**
  * 這個是最關鍵的函數，當程序中有未被捕獲的異常，系統將會自動調用uncaughtException方法
  * thread為出現未捕獲異常的線程，ex為未捕獲的異常，有了這個ex，我們就可以得到異常信息
  */
 @Override
 public void uncaughtException(Thread thread, Throwable ex) {
  try {
   //導出異常信息到SD卡中
   dumpExceptionToSDCard(ex);
   //這里可以上傳異常信息到服務器，便于開發人員分析日志從而解決bug
   uploadExceptionToServer();
  } catch (IOException e) {
   e.printStackTrace();
  }
  ex.printStackTrace();
  //如果系統提供默認的異常處理器，則交給系統去結束程序，否則就由自己結束自己
  if (mDefaultCrashHandler != null) {
   mDefaultCrashHandler.uncaughtException(thread, ex);
  } else {
   try {
    Thread.sleep(2000); // 延遲2秒殺進程
   } catch (InterruptedException e) {
    e.printStackTrace();
   }
   android.os.Process.killProcess(Process.myPid());
  }
 }

 private void dumpExceptionToSDCard(Throwable ex) throws IOException {
  //如果SD卡不存在或無法使用，則無法把異常信息寫入SD卡
  if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
   if (DEBUG) {
    Log.e(TAG, "sdcard unmounted,skip dump exception");
    return;
   }
  }
  File dir = new File(PATH);
  if (!dir.exists()) {
   dir.mkdirs();
  }
  long current = System.currentTimeMillis();
  String time = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.CHINA).format(new Date(current));
  File file = new File(PATH + FILE_NAME + time + FILE_NAME_SUFFIX);
  try {
   PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter(file)));
   pw.println(time);
   pw.println(phoneInfo);
   pw.println();
   ex.printStackTrace(pw);
   pw.close();
   Log.e(TAG, "dump crash info seccess");
  } catch (Exception e) {
   Log.e(TAG, e.getMessage());
   Log.e(TAG, "dump crash info failed");
  }
 }

 private void uploadExceptionToServer() {
  // 將異常信息發送到服務器
 }

 private String getPhoneInformation() {
  StringBuilder sb = new StringBuilder();
  sb.append("App version name:")
    .append(BuildConfig.VERSION_NAME)
    .append(", version code:")
    .append(BuildConfig.VERSION_CODE).append("\n");
  //Android版本號
  sb.append("OS Version: ");
  sb.append(Build.VERSION.RELEASE);
  sb.append("_");
  sb.append(Build.VERSION.SDK_INT).append("\n");
  //手機制造商
  sb.append("Vendor: ");
  sb.append(Build.MANUFACTURER).append("\n");
  //手機型號
  sb.append("Model: ");
  sb.append(Build.MODEL).append("\n");
  //CPU架構
  sb.append("CPU ABI:").append("\n");
  for (String abi : Build.SUPPORTED_ABIS) {
   sb.append(abi).append("\n");
  }
  return sb.toString();
 }
}

@Override
public void onCreate() {
 super.onCreate();
 // init application...
 CrashHandler.getInstance().init();
}