├── .gitignore
├── README.md
├── SafeLooper.java
├── SafeLooper.png
├── Sample
    ├── AndroidManifest.xml
    ├── proguard-project.txt
    ├── project.properties
    ├── res
    │   ├── layout
    │   │   └── activity_main.xml
    │   └── values
    │   │   └── strings.xml
    └── src
    │   └── com
    │       └── github
    │           └── mmin18
    │               └── safelooper
    │                   ├── MainActivity.java
    │                   └── SafeLooper.java
└── safelooper.apk


/.gitignore:
--------------------------------------------------------------------------------
 1 | # built application files
 2 | *.apk
 3 | *.ap_
 4 | 
 5 | # files for the dex VM
 6 | *.dex
 7 | 
 8 | # Java class files
 9 | *.class
10 | 
11 | # generated files
12 | bin/
13 | gen/
14 | 
15 | # Local configuration file (sdk path, etc)
16 | local.properties
17 | 
18 | # Eclipse project files
19 | .classpath
20 | .project
21 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | SafeLooper
 2 | ==========
 3 | 
 4 | SafeLooper catches unexpected exceptions in Android applications to avoid showing force close dialog.
 5 | 
 6 | A normal Android application (except games) is driven by event loop, known as android.os.Looper. When you throw a uncaught exception in the main thread, the main thread's looper will stop and Android will show a force close dialog. You won't have a chance to recover the main thread's looper since it has already stopped.
 7 | 
 8 | If you can create a sub looper, pull message from event queue and process it with a try-catch block, you can catch the unexpected exceptions and avoid the application from crash.
 9 | 
10 | Here is how a SafeLooper works:
11 | 
12 | ![SafeLooper](https://raw.github.com/mmin18/SafeLooper/master/SafeLooper.png)
13 | 
14 | All you need to do is import SafeLooper.java into your project and call SafeLooper.install() when your application start.
15 | 
16 | 
17 | 	// install SafeLooper in main thread
18 | 	SafeLooper.install();
19 | 	
20 | 	// receive the uncaught exception if you don't want to ignore it
21 | 	SafeLooper.setUncaughtExceptionHandler(...);
22 | 
23 | You can also test the <https://raw.github.com/mmin18/SafeLooper/master/safelooper.apk> on your device.
24 | 


--------------------------------------------------------------------------------
/SafeLooper.java:
--------------------------------------------------------------------------------
  1 | // The MIT License Header
  2 | // 
  3 | // Copyright (c) 2013 Tu Yimin
  4 | // 
  5 | // http://github.com/mmin18
  6 | // 
  7 | // Permission is hereby granted, free of charge, to any person obtaining a copy
  8 | // of this software and associated documentation files (the "Software"), to deal
  9 | // in the Software without restriction, including without limitation the rights
 10 | // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 11 | // copies of the Software, and to permit persons to whom the Software is
 12 | // furnished to do so, subject to the following conditions:
 13 | // 
 14 | // The above copyright notice and this permission notice shall be included in
 15 | // all copies or substantial portions of the Software.
 16 | // 
 17 | // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 18 | // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 19 | // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 20 | // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 21 | // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 22 | // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 23 | // THE SOFTWARE.
 24 | 
 25 | import java.lang.reflect.Field;
 26 | import java.lang.reflect.InvocationTargetException;
 27 | import java.lang.reflect.Method;
 28 | 
 29 | import android.os.Binder;
 30 | import android.os.Handler;
 31 | import android.os.Looper;
 32 | import android.os.Message;
 33 | import android.os.MessageQueue;
 34 | 
 35 | /**
 36 |  * SafeLooper catches unexpected exceptions in Looper to avoid showing force
 37 |  * close dialog.
 38 |  * <p>
 39 |  * After call SafeLooper.install(), the main looper will be take over. Uncaught
 40 |  * exceptions will be send to uncaughtExceptionHandler and the looper will
 41 |  * continues.<br>
 42 |  * 
 43 |  * @author yimin.tu
 44 |  * 
 45 |  */
 46 | public class SafeLooper implements Runnable {
 47 | 	private static final Object EXIT = new Object();
 48 | 	private static final ThreadLocal<SafeLooper> RUNNINGS = new ThreadLocal<SafeLooper>();
 49 | 	private static Thread.UncaughtExceptionHandler uncaughtExceptionHandler;
 50 | 	private static Handler handler = new Handler(Looper.getMainLooper());
 51 | 
 52 | 	/**
 53 | 	 * Install SafeLooper in the main thread
 54 | 	 * <p>
 55 | 	 * Notice the action will take effect in the next event loop
 56 | 	 */
 57 | 	public static void install() {
 58 | 		handler.removeMessages(0, EXIT);
 59 | 		handler.post(new SafeLooper());
 60 | 	}
 61 | 
 62 | 	/**
 63 | 	 * Exit SafeLooper after millis in the main thread
 64 | 	 * <p>
 65 | 	 * Notice the action will take effect in the next event loop
 66 | 	 */
 67 | 	public static void uninstallDelay(long millis) {
 68 | 		handler.removeMessages(0, EXIT);
 69 | 		handler.sendMessageDelayed(handler.obtainMessage(0, EXIT), millis);
 70 | 	}
 71 | 
 72 | 	/**
 73 | 	 * Exit SafeLooper in the main thread
 74 | 	 * <p>
 75 | 	 * Notice the action will take effect in the next event loop
 76 | 	 */
 77 | 	public static void uninstall() {
 78 | 		uninstallDelay(0);
 79 | 	}
 80 | 
 81 | 	/**
 82 | 	 * Tell if the SafeLooper is running in the current thread
 83 | 	 */
 84 | 	public static boolean isSafe() {
 85 | 		return RUNNINGS.get() != null;
 86 | 	}
 87 | 
 88 | 	/**
 89 | 	 * The same as Thread.setDefaultUncaughtExceptionHandler
 90 | 	 */
 91 | 	public static void setUncaughtExceptionHandler(
 92 | 			Thread.UncaughtExceptionHandler h) {
 93 | 		uncaughtExceptionHandler = h;
 94 | 	}
 95 | 
 96 | 	@Override
 97 | 	public void run() {
 98 | 		if (RUNNINGS.get() != null)
 99 | 			return;
100 | 
101 | 		Method next;
102 | 		Field target;
103 | 		try {
104 | 			Method m = MessageQueue.class.getDeclaredMethod("next");
105 | 			m.setAccessible(true);
106 | 			next = m;
107 | 			Field f = Message.class.getDeclaredField("target");
108 | 			f.setAccessible(true);
109 | 			target = f;
110 | 		} catch (Exception e) {
111 | 			return;
112 | 		}
113 | 
114 | 		RUNNINGS.set(this);
115 | 		MessageQueue queue = Looper.myQueue();
116 | 		Binder.clearCallingIdentity();
117 | 		final long ident = Binder.clearCallingIdentity();
118 | 
119 | 		while (true) {
120 | 			try {
121 | 				Message msg = (Message) next.invoke(queue);
122 | 				if (msg == null || msg.obj == EXIT)
123 | 					break;
124 | 
125 | 				Handler h = (Handler) target.get(msg);
126 | 				h.dispatchMessage(msg);
127 | 				final long newIdent = Binder.clearCallingIdentity();
128 | 				if (newIdent != ident) {
129 | 				}
130 | 				msg.recycle();
131 | 			} catch (Exception e) {
132 | 				Thread.UncaughtExceptionHandler h = uncaughtExceptionHandler;
133 | 				Throwable ex = e;
134 | 				if (e instanceof InvocationTargetException) {
135 | 					ex = ((InvocationTargetException) e).getCause();
136 | 					if (ex == null) {
137 | 						ex = e;
138 | 					}
139 | 				}
140 | 				// e.printStackTrace(System.err);
141 | 				if (h != null) {
142 | 					h.uncaughtException(Thread.currentThread(), ex);
143 | 				}
144 | 				new Handler().post(this);
145 | 				break;
146 | 			}
147 | 		}
148 | 
149 | 		RUNNINGS.set(null);
150 | 	}
151 | }
152 | 


--------------------------------------------------------------------------------
/SafeLooper.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/mmin18/SafeLooper/44f1b77f2b9aa1c8348b5ee6724acaf960ebd394/SafeLooper.png


--------------------------------------------------------------------------------
/Sample/AndroidManifest.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <manifest xmlns:android="http://schemas.android.com/apk/res/android"
 3 |     package="com.github.mmin18.safelooper"
 4 |     android:versionCode="1"
 5 |     android:versionName="1.0" >
 6 | 
 7 |     <uses-sdk
 8 |         android:minSdkVersion="8"
 9 |         android:targetSdkVersion="16" />
10 | 
11 |     <application
12 |         android:label="@string/app_name" >
13 |         <activity
14 |             android:name=".MainActivity"
15 |             android:label="@string/app_name" >
16 |             <intent-filter>
17 |                 <action android:name="android.intent.action.MAIN" />
18 | 
19 |                 <category android:name="android.intent.category.LAUNCHER" />
20 |             </intent-filter>
21 |         </activity>
22 |     </application>
23 | 
24 | </manifest>


--------------------------------------------------------------------------------
/Sample/proguard-project.txt:
--------------------------------------------------------------------------------
 1 | # To enable ProGuard in your project, edit project.properties
 2 | # to define the proguard.config property as described in that file.
 3 | #
 4 | # Add project specific ProGuard rules here.
 5 | # By default, the flags in this file are appended to flags specified
 6 | # in ${sdk.dir}/tools/proguard/proguard-android.txt
 7 | # You can edit the include path and order by changing the ProGuard
 8 | # include property in project.properties.
 9 | #
10 | # For more details, see
11 | #   http://developer.android.com/guide/developing/tools/proguard.html
12 | 
13 | # Add any project specific keep options here:
14 | 
15 | # If your project uses WebView with JS, uncomment the following
16 | # and specify the fully qualified class name to the JavaScript interface
17 | # class:
18 | #-keepclassmembers class fqcn.of.javascript.interface.for.webview {
19 | #   public *;
20 | #}
21 | 


--------------------------------------------------------------------------------
/Sample/project.properties:
--------------------------------------------------------------------------------
 1 | # This file is automatically generated by Android Tools.
 2 | # Do not modify this file -- YOUR CHANGES WILL BE ERASED!
 3 | #
 4 | # This file must be checked in Version Control Systems.
 5 | #
 6 | # To customize properties used by the Ant build system edit
 7 | # "ant.properties", and override values to adapt the script to your
 8 | # project structure.
 9 | #
10 | # To enable ProGuard to shrink and obfuscate your code, uncomment this (available properties: sdk.dir, user.home):
11 | #proguard.config=${sdk.dir}/tools/proguard/proguard-android.txt:proguard-project.txt
12 | 
13 | # Project target.
14 | target=android-8
15 | 


--------------------------------------------------------------------------------
/Sample/res/layout/activity_main.xml:
--------------------------------------------------------------------------------
 1 | <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2 |     xmlns:tools="http://schemas.android.com/tools"
 3 |     android:layout_width="match_parent"
 4 |     android:layout_height="match_parent"
 5 |     android:padding="6dip"
 6 |     android:orientation="vertical"
 7 |     tools:context=".MainActivity" >
 8 | 
 9 |     <TextView
10 |         android:id="@+id/status"
11 |         android:layout_width="wrap_content"
12 |         android:layout_height="wrap_content"
13 |         android:background="#A00"
14 |         android:text="SafeLooper is OFF" />
15 | 
16 |     <Button
17 |         android:id="@+id/install"
18 |         style="?android:attr/buttonStyleSmall"
19 |         android:layout_width="wrap_content"
20 |         android:layout_height="wrap_content"
21 |         android:text="Install SafeLooper" />
22 | 
23 |     <Button
24 |         android:id="@+id/crash"
25 |         style="?android:attr/buttonStyleSmall"
26 |         android:layout_width="wrap_content"
27 |         android:layout_height="wrap_content"
28 |         android:text="Let me crash !" />
29 | 
30 |     <Button
31 |         android:id="@+id/crash_in_background"
32 |         style="?android:attr/buttonStyleSmall"
33 |         android:layout_width="wrap_content"
34 |         android:layout_height="wrap_content"
35 |         android:text="Crash in background thread !" />
36 | 
37 |     <ScrollView
38 |         android:layout_width="match_parent"
39 |         android:layout_height="0px"
40 |         android:layout_weight="1">
41 |     <TextView
42 |         android:id="@+id/text"
43 |         android:layout_width="match_parent"
44 |         android:layout_height="wrap_content"
45 |         android:text="There is no crash" />
46 |     </ScrollView>
47 | 
48 | </LinearLayout>


--------------------------------------------------------------------------------
/Sample/res/values/strings.xml:
--------------------------------------------------------------------------------
1 | <?xml version="1.0" encoding="utf-8"?>
2 | <resources>
3 | 
4 |     <string name="app_name">SafeLooper</string>
5 | 
6 | </resources>


--------------------------------------------------------------------------------
/Sample/src/com/github/mmin18/safelooper/MainActivity.java:
--------------------------------------------------------------------------------
 1 | package com.github.mmin18.safelooper;
 2 | 
 3 | 
 4 | import java.io.PrintWriter;
 5 | import java.io.StringWriter;
 6 | 
 7 | import android.app.Activity;
 8 | import android.os.Bundle;
 9 | import android.view.View;
10 | import android.widget.TextView;
11 | 
12 | public class MainActivity extends Activity implements View.OnClickListener,
13 | 		Thread.UncaughtExceptionHandler {
14 | 	Thread.UncaughtExceptionHandler androidExceptionHandler;
15 | 
16 | 	@Override
17 | 	protected void onCreate(Bundle savedInstanceState) {
18 | 		super.onCreate(savedInstanceState);
19 | 
20 | 		// save android default handler, it will show you the force close dialog
21 | 		androidExceptionHandler = Thread.getDefaultUncaughtExceptionHandler();
22 | 
23 | 		setContentView(R.layout.activity_main);
24 | 		findViewById(R.id.install).setOnClickListener(this);
25 | 		findViewById(R.id.crash).setOnClickListener(this);
26 | 		findViewById(R.id.crash_in_background).setOnClickListener(this);
27 | 	}
28 | 
29 | 	@Override
30 | 	public void onClick(View v) {
31 | 		switch (v.getId()) {
32 | 
33 | 		case R.id.crash:
34 | 			// crash directly in main thread
35 | 			throw new RuntimeException("Opps!!");
36 | 
37 | 		case R.id.crash_in_background:
38 | 			// create a background thread to crash
39 | 			new Thread("crash-in-background") {
40 | 				@Override
41 | 				public void run() {
42 | 					throw new RuntimeException("Opps in background!!");
43 | 				}
44 | 			}.start();
45 | 			break;
46 | 
47 | 		case R.id.install:
48 | 			if (!SafeLooper.isSafe()) {
49 | 
50 | 				// install SafeLooper in main thread
51 | 				SafeLooper.install();
52 | 				SafeLooper.setUncaughtExceptionHandler(this);
53 | 				// process any uncaught exception in other threads
54 | 				Thread.setDefaultUncaughtExceptionHandler(this);
55 | 
56 | 				// update UI
57 | 				((TextView) v).setText("Uninstall SafeLooper");
58 | 				TextView t = (TextView) findViewById(R.id.status);
59 | 				t.setText("SafeLooper is ON");
60 | 				t.setBackgroundColor(0xFF00A000);
61 | 
62 | 			} else {
63 | 
64 | 				SafeLooper.uninstall();
65 | 				Thread.setDefaultUncaughtExceptionHandler(androidExceptionHandler);
66 | 
67 | 				// update UI
68 | 				((TextView) v).setText("Install SafeLooper");
69 | 				TextView t = (TextView) findViewById(R.id.status);
70 | 				t.setText("SafeLooper is OFF");
71 | 				t.setBackgroundColor(0xFFA00000);
72 | 
73 | 			}
74 | 			break;
75 | 		}
76 | 	}
77 | 
78 | 	@Override
79 | 	public void uncaughtException(Thread thread, Throwable ex) {
80 | 		// print the crash info on the screen
81 | 		StringWriter buf = new StringWriter();
82 | 		buf.append("Crashed in " + thread + "\n\n");
83 | 		PrintWriter w = new PrintWriter(buf);
84 | 		ex.printStackTrace(w);
85 | 		final String txt = buf.toString();
86 | 		runOnUiThread(new Runnable() {
87 | 			@Override
88 | 			public void run() {
89 | 				((TextView) findViewById(R.id.text)).setText(txt);
90 | 			}
91 | 		});
92 | 	}
93 | 
94 | }
95 | 


--------------------------------------------------------------------------------
/Sample/src/com/github/mmin18/safelooper/SafeLooper.java:
--------------------------------------------------------------------------------
  1 | // The MIT License Header
  2 | // 
  3 | // Copyright (c) 2013 Tu Yimin
  4 | // 
  5 | // http://github.com/mmin18
  6 | // 
  7 | // Permission is hereby granted, free of charge, to any person obtaining a copy
  8 | // of this software and associated documentation files (the "Software"), to deal
  9 | // in the Software without restriction, including without limitation the rights
 10 | // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 11 | // copies of the Software, and to permit persons to whom the Software is
 12 | // furnished to do so, subject to the following conditions:
 13 | // 
 14 | // The above copyright notice and this permission notice shall be included in
 15 | // all copies or substantial portions of the Software.
 16 | // 
 17 | // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 18 | // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 19 | // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 20 | // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 21 | // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 22 | // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 23 | // THE SOFTWARE.
 24 | 
 25 | package com.github.mmin18.safelooper;
 26 | 
 27 | import java.lang.reflect.Field;
 28 | import java.lang.reflect.InvocationTargetException;
 29 | import java.lang.reflect.Method;
 30 | 
 31 | import android.os.Binder;
 32 | import android.os.Handler;
 33 | import android.os.Looper;
 34 | import android.os.Message;
 35 | import android.os.MessageQueue;
 36 | 
 37 | /**
 38 |  * SafeLooper catches unexpected exceptions in Looper to avoid showing force
 39 |  * close dialog.
 40 |  * <p>
 41 |  * After call SafeLooper.install(), the main looper will be take over. Uncaught
 42 |  * exceptions will be send to uncaughtExceptionHandler and the looper will
 43 |  * continues.<br>
 44 |  * 
 45 |  * @author yimin.tu
 46 |  * 
 47 |  */
 48 | public class SafeLooper implements Runnable {
 49 | 	private static final Object EXIT = new Object();
 50 | 	private static final ThreadLocal<SafeLooper> RUNNINGS = new ThreadLocal<SafeLooper>();
 51 | 	private static Thread.UncaughtExceptionHandler uncaughtExceptionHandler;
 52 | 	private static Handler handler = new Handler(Looper.getMainLooper());
 53 | 
 54 | 	/**
 55 | 	 * Install SafeLooper in the main thread
 56 | 	 * <p>
 57 | 	 * Notice the action will take effect in the next event loop
 58 | 	 */
 59 | 	public static void install() {
 60 | 		handler.removeMessages(0, EXIT);
 61 | 		handler.post(new SafeLooper());
 62 | 	}
 63 | 
 64 | 	/**
 65 | 	 * Exit SafeLooper after millis in the main thread
 66 | 	 * <p>
 67 | 	 * Notice the action will take effect in the next event loop
 68 | 	 */
 69 | 	public static void uninstallDelay(long millis) {
 70 | 		handler.removeMessages(0, EXIT);
 71 | 		handler.sendMessageDelayed(handler.obtainMessage(0, EXIT), millis);
 72 | 	}
 73 | 
 74 | 	/**
 75 | 	 * Exit SafeLooper in the main thread
 76 | 	 * <p>
 77 | 	 * Notice the action will take effect in the next event loop
 78 | 	 */
 79 | 	public static void uninstall() {
 80 | 		uninstallDelay(0);
 81 | 	}
 82 | 
 83 | 	/**
 84 | 	 * Tell if the SafeLooper is running in the current thread
 85 | 	 */
 86 | 	public static boolean isSafe() {
 87 | 		return RUNNINGS.get() != null;
 88 | 	}
 89 | 
 90 | 	/**
 91 | 	 * The same as Thread.setDefaultUncaughtExceptionHandler
 92 | 	 */
 93 | 	public static void setUncaughtExceptionHandler(
 94 | 			Thread.UncaughtExceptionHandler h) {
 95 | 		uncaughtExceptionHandler = h;
 96 | 	}
 97 | 
 98 | 	@Override
 99 | 	public void run() {
100 | 		if (RUNNINGS.get() != null)
101 | 			return;
102 | 
103 | 		Method next;
104 | 		Field target;
105 | 		try {
106 | 			Method m = MessageQueue.class.getDeclaredMethod("next");
107 | 			m.setAccessible(true);
108 | 			next = m;
109 | 			Field f = Message.class.getDeclaredField("target");
110 | 			f.setAccessible(true);
111 | 			target = f;
112 | 		} catch (Exception e) {
113 | 			return;
114 | 		}
115 | 
116 | 		RUNNINGS.set(this);
117 | 		MessageQueue queue = Looper.myQueue();
118 | 		Binder.clearCallingIdentity();
119 | 		final long ident = Binder.clearCallingIdentity();
120 | 
121 | 		while (true) {
122 | 			try {
123 | 				Message msg = (Message) next.invoke(queue);
124 | 				if (msg == null || msg.obj == EXIT)
125 | 					break;
126 | 
127 | 				Handler h = (Handler) target.get(msg);
128 | 				h.dispatchMessage(msg);
129 | 				final long newIdent = Binder.clearCallingIdentity();
130 | 				if (newIdent != ident) {
131 | 				}
132 | 				msg.recycle();
133 | 			} catch (Exception e) {
134 | 				Thread.UncaughtExceptionHandler h = uncaughtExceptionHandler;
135 | 				Throwable ex = e;
136 | 				if (e instanceof InvocationTargetException) {
137 | 					ex = ((InvocationTargetException) e).getCause();
138 | 					if (ex == null) {
139 | 						ex = e;
140 | 					}
141 | 				}
142 | 				// e.printStackTrace(System.err);
143 | 				if (h != null) {
144 | 					h.uncaughtException(Thread.currentThread(), ex);
145 | 				}
146 | 				new Handler().post(this);
147 | 				break;
148 | 			}
149 | 		}
150 | 
151 | 		RUNNINGS.set(null);
152 | 	}
153 | }
154 | 


--------------------------------------------------------------------------------
/safelooper.apk:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/mmin18/SafeLooper/44f1b77f2b9aa1c8348b5ee6724acaf960ebd394/safelooper.apk


--------------------------------------------------------------------------------