public class Test {
    public static void main(String[] args) {
        printArray(arr);
        bubbleSort(arr);
        printArray(arr);
    }

    private static final int arr[] = { 3, 8, 7, 2, 1, 5, 6, 9, 0 };

    public static void bubbleSort(int[] arr) {
        int len = arr.length;
        if (len <= 1) {
            return;
        }

        for (int i = 0; i < len - 1; i++) {
            // 之所以 len-1-i, 是因为len-1-i之后的元素已经排序完成
            // （每循环一次，就能将一个最大值沉底）
            for (int j = 0; j < len - 1 - i; j++) {
                if (arr[j] > arr[j + 1]) {
                    swap(arr, j, j + 1);
                }
            }
        }
    }

    public static void swap(int[] arr, int i, int j) {
        if (i < 0 || j < 0) {
            return;
        }

        int len = arr.length;
        if (i == j || i >= len || j >= len) {
            return;
        }

        int tmp = arr[i];
        arr[i] = arr[j];
        arr[j] = tmp;
    }

    public static void printArray(int[] arr) {
        StringBuilder sb = new StringBuilder();
        for (int a : arr) {
            sb.append(a).append(",");
        }
        String result = sb.substring(0, sb.length() - 1).toString();
        System.out.println(result);
    }

} /* Output:
3,8,7,2,1,5,6,9,0
0,1,2,3,5,6,7,8,9
*/// ~

//: .../activity/ActivityMgr.java
public class ActivityMgr {

    public static void start(Activity context, Class clazz){
        Intent intent = new Intent(context, clazz);
        context.startActivity(intent);
    }

    public static class LoginActivity extends SingleFragmentActivity {
        @Override
        public Fragment createFragment() {
            return new LoginFragment();
        }
    }


    public static class ForgetPasswordActivity extends SingleFragmentActivity {
        @Override
        public Fragment createFragment() {
            return new ForgetPasswordFragment();
        }
    }

    public static class RegisterActivity extends SingleFragmentActivity {
        @Override
        public Fragment createFragment() {
            return new RegisterFragment();
        }
    }

    public static class AddDeviceActivity extends SingleFragmentActivity {
        @Override
        public Fragment createFragment() {
            return new AddDeviceFragment();
        }
    }
}

// 启动忘记密码Activity
ActivityMgr.start(mContext, ActivityMgr.ForgetPasswordActivity.class);

// 启动注册Activity
ActivityMgr.start(mContext, ActivityMgr.RegisterActivity.class);

//主界面获取焦点,用来监听返回键
private void getFocus() {
    View view = getView();
    if (view == null) {
        return;
    }

    view.setFocusableInTouchMode(true);
    view.requestFocus();
    view.setOnKeyListener(new View.OnKeyListener() {
        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {
            if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_BACK) {
                // 监听到返回按钮点击事件
                if (mCbControlSelectAll.getVisibility() == View.VISIBLE) {
                    sync(false);
                    return true;
                }
            }
            return false;
        }
    });
}

public interface OnBackPressedListener {
    public void doBack();
}

// create method to set listener in CustomActivity
public void setOnBackPressedListener(OnBackPressedListener onBackPressedListener) {
    this.onBackPressedListener = onBackPressedListener;
}

// in override onBackPressed implement something like that
@Override
public void onBackPressed() {
    if (onBackPressedListener != null)
        onBackPressedListener.doBack();
    else
        super.onBackPressed();
}

// in your fragment in onCreateView you should add our listener
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    activity = getActivity();
    ((CustomActivity)activity).setOnBackPressedListener(new OnBackPressedListener(){
        @override
        public void doBack(){
            // do your logic
        }
    });
    return view;
}

private void setLongClick(final View view) {
    //长按点击事件
    view.setOnLongClickListener(new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View v) {
            //响应长按事件（如果webview继承自安卓原生系统）
            if (view instanceof WebView) {
                WebView.HitTestResult result = ((WebView) view).getHitTestResult();
                if (result != null) {
                    int type = result.getType();
                    //判断点击类型如果是图片
                    if (type == WebView.HitTestResult.IMAGE_TYPE || type == WebView.HitTestResult.SRC_IMAGE_ANCHOR_TYPE) {
                        //弹出对话框
                        showDialog(result.getExtra());
                    }
                }
            } else if (view instanceof X5WebView) {
                //响应长按事件（如果webview继承自腾讯的TBS系统）
                Log.i(TAG, "onLongClick: x5");
                com.tencent.smtt.sdk.WebView.HitTestResult hitTestResult = ((X5WebView) view).getHitTestResult();
                if (hitTestResult != null) {
                    int type = hitTestResult.getType();
                    if (type == X5WebView.HitTestResult.IMAGE_TYPE || type == X5WebView.HitTestResult.SRC_IMAGE_ANCHOR_TYPE) {
                        showDialog(hitTestResult.getExtra());
                    }
                }
            }
            return false;
        }
    });
}

webSettings.setLayoutAlgorithm(WebSettings.LayoutAlgorithm.NARROW_COLUMNS);
webSettings.setUseWideViewPort(true);
webSettings.setJavaScriptEnabled(true);
webSettings.setDomStorageEnabled(true);
webSettings.setLoadWithOverviewMode(true);
webview.setWebViewClient(getWebViewClient());

private WebViewClient getWebViewClient() {
    return new WebViewClient() {
        @Override
        public void onReceivedHttpAuthRequest(WebView view, HttpAuthHandler handler, String host, String realm) {
            // [Android-WebView's onReceivedHttpAuthRequest() not called again - Stack Overflow](https://stackoverflow.com/questions/20399339/android-webviews-onreceivedhttpauthrequest-not-called-again)
            final EditText usernameInput = new EditText(mContext);
            usernameInput.setHint("Username");

            final EditText passwordInput = new EditText(mContext);
            passwordInput.setHint("Password");
            passwordInput.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);

            LinearLayout ll = new LinearLayout(mContext);
            ll.setOrientation(LinearLayout.VERTICAL);
            ll.addView(usernameInput);
            ll.addView(passwordInput);

            AlertDialog.Builder authDialog = new AlertDialog
                    .Builder(mContext)
                    .setTitle("Authentication")
                    .setView(ll)
                    .setCancelable(false)
                    .setPositiveButton("OK", (dialog, whichButton) -> {
                        String username = usernameInput.getText().toString();
                        String password = passwordInput.getText().toString();
                        handler.proceed(username, password);
                        Toast.makeText(mContext, username + ":" + password, Toast.LENGTH_LONG).show();
                        dialog.dismiss();
                    })
                    .setNegativeButton("Cancel", (dialog, whichButton) -> {
                        dialog.dismiss();
                        view.stopLoading();
                    });

            authDialog.show();
        }
    };
}