应用发布之后，总有人反馈说发生crash，，但是由于拿不到log，我无法定位问题。后来发现，我们应该收集crash日志，并上传到服务器。
国内有很多的三方机构提供了崩溃收集的sdk，我们可以直接拿来使用，比如，我之前做的app使用的是bugHD()提供的服务。
但是崩溃收集的原理是什么呢？搜索了一下，发现使用的是java中的uncaughtExceptionHandler,我们可以通过Thread.setDefautUncaughtExceptionHandler()设置我们自己的UncaughtExceptionHandler。它其实是一个接口，实现方法即可。
我写的一个demo：
import android.os.Looper;import android.widget.Toast;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.PrintWriter;import java.io.StringWriter;import java.io.Writer;import java.text.SimpleDateFormat;import java.util.Date;import java.util.Locale;import java.util.Map;/** * Created by Rowandjj on 2015/5/19. * * 崩溃日志收集 */public class CrashHandler implements Thread.UncaughtExceptionHandler{private static CrashHandler sInstance = null;private static Object lock = new Object();private Thread.UncaughtExceptionHandler mDefaultExceptionHandler;private CrashHandler(){}public static CrashHandler getInstance(){if (sInstance == null){synchronized (lock){if (sInstance == null)sInstance = new CrashHandler();}}return sInstance;}public void register(){mDefaultExceptionHandler = Thread.getDefaultUncaughtExceptionHandler();Thread.setDefaultUncaughtExceptionHandler(this);}@Overridepublic void uncaughtException(Thread thread, Throwable ex){//生成日志final String filename = cacheLog(ex);new Thread(new Runnable(){@Overridepublic void run(){Looper.prepare();if(filename != null)Toast.makeText(AppEnv.getAppContext(),"程序崩溃了:( \n崩溃日志已保存到"+filename+"",Toast.LENGTH_SHORT).show();Looper.loop();}}).start();try{Thread.sleep(2000);} catch (InterruptedException e){e.printStackTrace();}mDefaultExceptionHandler.uncaughtException(thread,ex);}private String cacheLog(Throwable ex){if(ex == null)return null;Map<String, String> hardwareInfo = HardwareUtils.getHardwareInfo();StringBuilder buffer = new StringBuilder();for (Map.Entry<String, String> me : hardwareInfo.entrySet()){buffer.append(me.getKey() + ":" + me.getValue() + "\n");}buffer.append("packname:" + AppEnv.getPackageName() + "\n");buffer.append("versionname:" + AppEnv.getVersionName() + "\n");buffer.append("versioncode:" + AppEnv.getVersionCode() + "\n");Writer writer = new StringWriter();PrintWriter printWriter = new PrintWriter(writer);ex.printStackTrace(printWriter);Throwable cause = ex.getCause();while (cause != null){cause.printStackTrace(printWriter);cause = cause.getCause();}printWriter.close();String result = writer.toString();buffer.append(result);long timestamp = System.currentTimeMillis();SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss", Locale.CHINA);String time = formatter.format(new Date());String filename = "crash-" + time + "-" + timestamp + ".log";File file = new File(BasicUtils.getStoreDir(), filename);try{if (!file.exists())file.createNewFile();FileOutputStream out = new FileOutputStream(file);out.write(buffer.toString().getBytes());out.close();Logger.d(this,file.getAbsolutePath());return file.getAbsolutePath();} catch (IOException e){e.printStackTrace();}return null;}}然后在你应用的Application中调用
CrashHandler.getInstance().register();即可。
应用出现crash时，会把log保存到本地。如果希望上传到服务器，加上一个http上传模块即可。
部分代码没有贴出，大家自己脑补。
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