Android内存泄漏

辅助工具leakCananry
辅助工具AndroidProfile

1. Context上下文泄漏.

强引用Activity的Context.

//案例一2020/4/30
public class VersionUtil {
    private Context mContext;
    private static VersionUtil mVersion;

    public VersionUtil(Context context) {
        this.mContext = context;
    }

    public synchronized static VersionUtil getInstance(Context context) {
        if (mVersion == null) {
            mVersion = new VersionUtil(context.getApplicationContext());
        }
        return mVersion;
    }
}

//案例二2020/4/30
public class LoginHelper extends Presenter {
    private Context mContext;
    private static final String TAG = LoginHelper.class.getSimpleName();
    private LogoutView mLogoutView;

    private final String domain = "http://www.ovopark.com:8088/roomservice/weapp/live_room";
    private final MediaType MEDIA_JSON = MediaType.parse("application/json; charset=utf-8");

    private OkHttpClient client;


    public LoginHelper(Context context) {
        mContext = context;

        client = new OkHttpClient.Builder()
                .connectTimeout(5, TimeUnit.SECONDS)
                .readTimeout(5, TimeUnit.SECONDS)
                .writeTimeout(5, TimeUnit.SECONDS)
                .build();

    }

谁用谁泄露

1.1. EventBus使用未回收错误

   @Override
    public void onDestroy() {
        super.onDestroy();
        if (mTimeView != null) {
            mTimeView.recycle();
        }

        if (mProgressView != null) {
            mProgressView.onDestroy();
        }
        if (!EventBus.getDefault().isRegistered(this)) {
            EventBus.getDefault().unregister(this);
        }
    }

1.2. Activity直接回调Fragment的方法（在销毁时候泄漏mContext）

1.3 Callback回调阻止回收

2. Handler 泄漏

在BaseActivity定义的匿名handler

  mHandler = new Handler(getMainLooper()) {
         @Override
         public void handleMessage(Message msg) {
             handlerMessage(msg);
         }
     };
  //子类网络请求后回调了dialog相关操作.
OkHttpRequest.post(DataManager.Urls.MOBILE_LOGIN, params, new StringHttpRequestCallback() {
         @Override
         public void onSuccess(final String result) {
             try {
                 ResponseData<User> responseData = DataProvider.fasetjsonProviderUserData(LoginActivity.this, result);
                 switch (responseData.getStatusCode()) {
                     case ResponseData.STATUS_CODE_SUCCESS:
                         closeDialog();
                         user = responseData.getResponseEntity().getSuccessEntity();
                         if (null != user) {
                             getSeverAddress(user);
                         }
                         saveUserInfo(mEmailStr, mPasswdStr);
                         break;

                     case ResponseData.STATUS_CODE_USER_UNCHECK:
                         closeDialog();
                         Message messageUncheck = Message.obtain();
                         messageUncheck.what = responseData.getStatusCode();
                         messageUncheck.obj = responseData.getResponseEntity().getFailureMsg();
                         mHandler.sendMessage(messageUncheck);
                         break;

                     case ResponseData.STATUS_CODE_USER_UNPASS:
                         closeDialog();
                         Message messageUnpass = Message.obtain();
                         messageUnpass.what = responseData.getStatusCode();
                         messageUnpass.obj = responseData.getResponseEntity().getFailureMsg();
                         userId = responseData.getResponseEntity().getSuccessEntity().getId();
                         mHandler.sendMessage(messageUnpass);
                         break;

                     default:
                         closeDialog();
                         Message message = Message.obtain();
                         message.what = Constants.Prefs.SHOW_TOAST;
                         message.obj = responseData.getResponseEntity().getFailureMsg();
                         // tab_message.arg1 = responseData.getResponseEntity().getFailureMsg();
                         mHandler.sendMessage(message);
                         break;
                 }
             } catch (Exception e) {
                 e.printStackTrace();
                 ReportErrorUtils.postCatchedException(e);
             }
         }

         @Override
         public void onFailure(int failureCode, String msg) {
             closeDialog();
             ToastUtil.showToast(LoginActivity.this, msg);
             if (StringUtils.isBlank(msg)) {
                 ToastUtil.showShortToast(LoginActivity.this, getResources().getString(R.string.connect_unknown_failed));
             }
         }
     });

   - 解决办法使用自定义安全Handler

public class SafeHandler<T extends Context> extends Handler {

    WeakReference<T> mWeakReference ;

    public SafeHandler(T context){
        mWeakReference = new WeakReference<>(context);
    }


    @Override
    public void handleMessage(Message msg) {
        if(mWeakReference.get() == null) return;
    }
}

- invoked 
public void initHandler(){
        mSafeHandler = new SafeHandler<Context>(getContext()){
            @Override
            public void handleMessage(Message msg) {
                super.handleMessage(msg);
                if(msg.what == MSG_REPLAY_TIME_OVER){
                    // 尝试结束，需要比对运行时间如果不足30s补足剩余时间 .
                    tryEndCurrentReplay();
                }
            }
        };
  }

3. MVP中presenter在宿主destroy时候没有销毁http的网络请求.

3.1 销毁网络请求

  /** 取消所有请求请求 */
    public void cancelAll() {
        for (Call call : client.dispatcher().queuedCalls()) {
            call.cancel();
        }
        for (Call call : client.dispatcher().runningCalls()) {
            call.cancel();
        }
    }
  @Override
    public void onDestory() {
        mContext = null;
        mLogoutView = null;
        if(null != client){
            //取消所有网络请求，防止回调.
            cancelAll();
        }
    }
    
    

3.2 在presenter的每个方法中判断view是否已销毁

if (null != mContext && callBack != null) {
    callBack.loginFailed();
 }

4. handler.postDelay(xxx_msg,10*1000);

mHandler.sendEmptyMessageDelayed(MSG_GET_USERSIGN, 10 * 1000);

@Override
protected void onDestroy() {
    if (mHandler != null) {
        mHandler.removeCallbacks(permissionRunnable);
        mHandler.removeCallbacks(noticeLayoutRunnable);
        mHandler.removeMessages(MSG_GET_USERSIGN);
    }
}    