捕获android异常，并打印出日志到本地库
import java.io.File;
import java.io.FileOutputStream;
import java.io.FilenameFilter;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.Thread.UncaughtExceptionHandler;
import java.sql.Date;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.TreeSet;
import java.lang.reflect.Field;
import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Build;
import android.os.Environment;
import android.os.Looper;
import android.util.Log;
import android.widget.Toast;
public class CrashHandler implements UncaughtExceptionHandler {
public static final String TAG ="CrashHandler";
//系统默认的UncaughtException处理类
private Thread.UncaughtExceptionHandler mDefaultHandler;
private static CrashHandler instance=new CrashHandler();
private Context mcontext;
/*使用Properties 来保存设备的信息和错误堆栈信息*/
private Properties mDeviceCrashInfo =new Properties();
//存储设备信息
private Map
private SimpleDateFormat formatdate=new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");
private CrashHandler(){
}
//保证只有一个实例
public static CrashHandler getInstance()
{
if(instance==null)
instance =new CrashHandler();
return instance;
}
public void init(Context context)
{
mcontext=context;
//获得默认的handle
mDefaultHandler=Thread.getDefaultUncaughtExceptionHandler();
//重新设置handle 设置该CrashHandler为程序的默认处理器
Thread.setDefaultUncaughtExceptionHandler(this);
}
/**
* 当UncaughtException发生时会转入该函数来处理
*/
public void uncaughtException(Thread thread, Throwable ex) {
// TODO Auto-generated method stub
//如果用户没有处理则让系统默认的异常处理器来处理
if(!handleException(ex)&&mDefaultHandler!=null)
{
mDefaultHandler.uncaughtException(thread, ex);
}
else{
try{
Thread.sleep(3000);
}catch(InterruptedException e)
{
Log.e(TAG, "error");
}
//结束程序
android.os.Process.killProcess(android.os.Process.myPid());
System.exit(1);
}
}
//Throwable 包含了其线程创建时线程执行堆栈的快照
private boolean handleException(Throwable ex) {
// TODO Auto-generated method stub
if(ex==null)
{
return false;
}
final String msg = ex.getLocalizedMessage();
new Thread()
{
public void run()
{
Looper.prepare();
Toast.makeText(mcontext, "msg"+msg, Toast.LENGTH_LONG).show();
Looper.loop();
}
}.start();
//收集设备信息
collectDeviceInfo(mcontext);
//保存信息
saveCrashInfo2File(ex);
//发送错误报告
sendCrashReportsToServer(mcontext);
return true;
}
public void sendPreviousReportsToServer(){
sendCrashReportsToServer(mcontext);
}
private void sendCrashReportsToServer(Context mcontext) {
String[] crFiles = getCrashReportFiles(mcontext);
if(crFiles!=null&&crFiles.length>0){
TreeSet
sortedFiles.addAll(Arrays.asList(crFiles));
for(String fileName :sortedFiles){
File cr =new File(mcontext.getFilesDir(),fileName);
postReport(cr);
//cr.delete();
}
}
}
private void postReport(File cr) {
// TODO 使用HTTP Post 发送错误报告到服务器
}
private static final String CRASH_REPORTER_EXTENSION=".cr";
private String[] getCrashReportFiles(Context mcontext) {
File filesDir =mcontext.getFilesDir();
FilenameFilter filter =new FilenameFilter(){
public boolean accept(File dir, String filename) {
return filename.endsWith(CRASH_REPORTER_EXTENSION);
}
};
return filesDir.list(filter);
}
private String saveCrashInfo2File(Throwable ex)
{
// TODO Auto-generated method stub
StringBuffer buffer=new StringBuffer();
for(Map.Entry
{
String key=entry.getKey();
String value=entry.getValue();
buffer.append(key+"="+value+'\n');
}
//可以用其回收在字符串缓冲区中的输出来构造字符串
Writer writer=new StringWriter();
//向文本输出流打印对象的格式化表示形式
PrintWriter printWriter = new PrintWriter(writer);
//将此 throwable 及其追踪输出至标准错误流
ex.printStackTrace(printWriter);
Throwable cause = ex.getCause();
while(cause!=null)
{
//异常链
cause.printStackTrace();
cause = cause.getCause();
}
printWriter.close();
String result = writer.toString();
buffer.append(result);
try{
long timestamp=System.currentTimeMillis();
String time=formatdate.format(new Date(timestamp));
String fileName = "crash-" + time + "-" + timestamp + ".log";
// 判断SD卡是否存在，并且是否具有读写权限
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
{
String path = Environment.getExternalStorageDirectory().getAbsolutePath()+"/crash_xy/";// /sdcard/crash/crash-time-timestamp.log
File file=new File(path);
if(!file.exists())
{
file.mkdirs();
}
FileOutputStream trace=mcontext.openFileOutput(path+fileName, Context.MODE_PRIVATE);
mDeviceCrashInfo.store(trace, "");
trace.flush();
trace.close();
//output 针对内存来说的 output到file中
FileOutputStream fos = new FileOutputStream(path + fileName);
fos.write(buffer.toString().getBytes());
fos.flush();
fos.close();
}
return fileName;
}catch(Exception e)
{
Log.e(TAG, "an error occured while writing file...", e);
}
return null;
}
private void collectDeviceInfo(Context ctx) {
try{
PackageManager pm=ctx.getPackageManager();
PackageInfo pi = pm.getPackageInfo(ctx.getPackageName(), PackageManager.GET_ACTIVITIES);
if(pi!=null)
{
String versionName = pi.versionName == null ? "null" : pi.versionName;
String versionCode = pi.versionCode + "";
mDevInfos.put("versionName", versionName);
mDevInfos.put("versionCode", versionCode);
}
}catch(NameNotFoundException e)
{
Log.v(TAG, "NameNotFoundException");
}
//使用反射 获得Build类的所有类里的变量
// Class 代表类在运行时的一个映射
//在Build类中包含各种设备信息,
// 例如: 系统版本号,设备生产商 等帮助调试程序的有用信息
// 具体信息请参考后面的截图
Field[] fields = Build.class.getDeclaredFields();
for(Field field :fields)
{
try{
field.setAccessible(true);
//get方法返回指定对象上此 Field 表示的字段的值
mDevInfos.put(field.getName(), field.get(null).toString());
Log.v(TAG, field.getName()+":"+field.get(null).toString());
}catch(Exception e)
{
Log.e(TAG, "an error occured when collect crash info", e);
}
}
}
//使用HTTP服务之前，需要确定网络畅通，我们可以使用下面的方式判断网络是否可用
public static boolean isNetworkAvailable(Context context)
{
ConnectivityManager mgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo[] info = mgr.getAllNetworkInfo();
if (info != null)
{
for (int i = 0; i < info.length; i++)
{
if (info[i].getState() == NetworkInfo.State.CONNECTED){
return true;
}
}
}
return false;
}
}
记得加上写入本地文件的权限
一般都是放在Application中初始化处理程序，自定义一个Application,并在AndroidManifest.xml配置 初始化在onCreate（）中
在MainActivity中 throw new NullPointerException（）；测试 能够在本地生成文件 表明成功。