全局異常捕獲

若是某個應用安裝的Thread.UncaughtExceptionHandler未移交給默認的Thread.UncaughtExceptionHandler，則當出現未捕獲的異常時，系統不會終止應用，即不會出現系統默認的「抱歉，xxx應用已中止運行」.所以，咱們就能夠對應用的異常進行全局捕獲，從而將異常保存下來，方便之後分析問題.

所以咱們能夠自定一個類去實現該接口，該類主要用於收集錯誤信息和保存錯誤信息.

詳細代碼

package com.example.yicangbuhuo;

import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Environment;
import android.os.Looper;
import android.text.TextUtils;
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.lang.reflect.Field;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

/**
 * Created by asus on 2017/11/21.
 */
public class CrashHandler implements Thread.UncaughtExceptionHandler {

    private static CrashHandler sInstance = null;
    private Thread.UncaughtExceptionHandler mDefaultHandler;
    private Context mContext;
    // 保存手機信息和異常信息
    private Map<String, String> mMessage = new HashMap<>();

    public static CrashHandler getInstance() {
        if (sInstance == null) {
            synchronized (CrashHandler.class) {
                if (sInstance == null) {
                    synchronized (CrashHandler.class) {
                        sInstance = new CrashHandler();
                    }
                }
            }
        }
        return sInstance;
    }

    private CrashHandler() {
    }

    /**
     * 初始化默認異常捕獲
     *
     * @param context context
     */
    public void init(Context context) {
        mContext = context;
        // 獲取默認異常處理器
        mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();
        // 將此類設爲默認異常處理器
        Thread.setDefaultUncaughtExceptionHandler(this);
    }

    @Override
    public void uncaughtException(Thread t, Throwable e) {
        if (!handleException(e)) {
            // 未通過人爲處理,則調用系統默認處理異常,彈出系統強制關閉的對話框
            if (mDefaultHandler != null) {
                mDefaultHandler.uncaughtException(t, e);
            }
        } else {
            // 已經人爲處理,系統本身退出
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e1) {
                e1.printStackTrace();
            }

            android.os.Process.killProcess(android.os.Process.myPid());

            System.exit(1);
        }
    }

    /**
     * 是否人爲捕獲異常
     *
     * @param e Throwable
     * @return true:已處理 false:未處理
     */
    private boolean handleException(Throwable e) {
        if (e == null) {// 異常是否爲空
            return false;
        }
        new Thread() {// 在主線程中彈出提示
            @Override
            public void run() {
                Looper.prepare();
                Toast.makeText(mContext, "捕獲到異常", Toast.LENGTH_SHORT).show();
                Looper.loop();
            }
        }.start();
        collectErrorMessages();
        saveErrorMessages(e);
        return false;
    }

    /**
     * 1.收集錯誤信息
     */
    private void collectErrorMessages() {
        PackageManager pm = mContext.getPackageManager();
        try {
            PackageInfo pi = pm.getPackageInfo(mContext.getPackageName(), PackageManager.GET_ACTIVITIES);
            if (pi != null) {
                String versionName = TextUtils.isEmpty(pi.versionName) ? "null" : pi.versionName;
                String versionCode = "" + pi.versionCode;
                mMessage.put("versionName", versionName);
                mMessage.put("versionCode", versionCode);
            }
            // 經過反射拿到錯誤信息
            Field[] fields = Build.class.getFields();
            if (fields != null && fields.length > 0) {
                for (Field field : fields) {
                    field.setAccessible(true);
                    try {
                        mMessage.put(field.getName(), field.get(null).toString());
                    } catch (IllegalAccessException e) {
                        e.printStackTrace();
                    }
                }
            }
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
    }

    /**
     * 2.保存錯誤信息
     *
     * @param e Throwable
     */
    private void saveErrorMessages(Throwable e) {
        StringBuilder sb = new StringBuilder();
        for (Map.Entry<String, String> entry : mMessage.entrySet()) {
            String key = entry.getKey();
            String value = entry.getValue();
            sb.append(key).append("=").append(value).append("\n");
        }
        Writer writer = new StringWriter();
        PrintWriter pw = new PrintWriter(writer);
        e.printStackTrace(pw);
        Throwable cause = e.getCause();
        // 循環取出Cause
        while (cause != null) {
            cause.printStackTrace(pw);
            cause = e.getCause();
        }
        pw.close();
        String result = writer.toString();
        sb.append(result);
        String time = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.CHINA).format(new Date());
        String fileName = "crash-" + time + "-" + System.currentTimeMillis() + ".log";
        // 有無SD卡
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            String path = Environment.getExternalStorageDirectory().getPath() + "crash/";
            File dir = new File(path);
            if (!dir.exists()) dir.mkdirs();
            FileOutputStream fos = null;
            try {
                fos = new FileOutputStream(path + fileName);
                fos.write(sb.toString().getBytes());
            } catch (Exception e1) {
                e1.printStackTrace();
            } finally {
                if (fos != null) {
                    try {
                        fos.close();
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                }
            }
        }
    }
}

 

使用

public class App extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        CrashHandler.getInstance().init(this);
    }
}