正确写法：
public class StaticLeakActivity extends AppCompatActivity {
private static NonStaticClass mResource = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_static_leak);
if (mResource == null) {
mResource = new NonStaticClass();
}
}
private static class NonStaticClass {
}
}
只需要把内部类改为static就行了，这样它就不会持有外部类StaticLeakActivity的引用，这样StaticLeakActivity的内存就可以被顺利回收。
3、Handler造成的内存泄漏
================
Handler造成的内存泄漏是非常常见的，因为使用的多。
错误写法：
public class HandlerLeakActivity extends AppCompatActivity {
private final Handler mLeakHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_handler_leak);
mLeakHandler.postDelayed(new Runnable() {
@Override
public void run() {
}
},10006010);
finish();
}
}
分析：Handler是一个TLS变量，意思就是说它的生命周期和HandlerLeakActivity 的生命周期是不一样的，这样就可能导致内存泄漏。以上代码中，我们使用mLeakHandler发送了一个延时任务，同时finish掉HandlerLeakActivity，由于执行延时任务的message还存在于主线程中，它就会持有HandlerLeakActivity中的mLeakHandler的引用（message持有mLeakHandler的引用，mLeakHandler又持有HandlerLeakActivity的引用），这种情况下finish，HandlerLeakActivity是不会被回收的。
那么，解决办法是什么呢？
1、将Handler的声明变为静态的
2、通过弱引用的方式引入Activity
3、在activity的onDestory方法中调用handler.removeCallback()
参考文章：使用Handler容易产生的内存泄露以及介绍下Java的4种引用
正确写法：
public class HandlerLeakActivity extends AppCompatActivity {
private static class MyHandler extends Handler {
private final WeakReference mActivity;
public MyHandler(HandlerLeakActivity activity) {
mActivity = new WeakReference(activity);
}
@Override
public void handleMessage(Message msg) {
HandlerLeakActivity activity = mActivity.get();
if (activity != null) {
//…
}
}
}
private final MyHandler myHandler = new MyHandler(this);
private static final Runnable mRunnable = new Runnable() {
@Override
public void run() {
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_handler_leak);
myHandler.postDelayed(mRunnable, 1000 * 60 * 10);
finish();
}
@Override
protected void onDestroy() {
super.onDestroy();
myHandler.removeCallbacks(mRunnable);
}
}
4、线程造成的内存泄漏
===========
public class ThreadLeakActivity extends AppCompatActivity {
@Override
protected v
oid onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_thread_leak);
testThreadLeak();
}
private void testThreadLeak() {
new AsyncTask<Void, Void, Void>() {
@Override
protected Void doInBackground(Void… params) {
SystemClock.sleep(10000);
return null;
}
}.execute();
new Thread(new Runnable() {
@Override
public void run() {
SystemClock.sleep(10000);
}
}).start();
}
static class MyAsyncTask extends AsyncTask<Void, Void, Void> {
private WeakReference weakReference;
public MyAsyncTask(Context context) {
weakReference = new WeakReference<>(context);
}
@Override
protected Void doInBackground(Void… voids) {
SystemClock.sleep(10000);
return null;
}
@Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
ThreadLeakActivity activity = (ThreadLeakActivity) weakReference.get();
if (activity != null) {
}
}
}
static class MyRunnable implements Runnable{
@Override
public void run() {
SystemClock.sleep(10000);
}
}
}
方法testThreadLeak()里面的写法会造成内存泄漏，解决办法就是创建静态内部类。
5、WebView造成的内存泄漏
================
public class WebviewLeakActivity extends AppCompatActivity {
dLeakActivity) weakReference.get();
if (activity != null) {
}
}
}
static class MyRunnable implements Runnable{
@Override
public void run() {
SystemClock.sleep(10000);
}
}
}
方法testThreadLeak()里面的写法会造成内存泄漏，解决办法就是创建静态内部类。
5、WebView造成的内存泄漏
================
public class WebviewLeakActivity extends AppCompatActivity {
