Android Studio MainActivity.java ::错误：＆＃39;}＆＃39;预期

Question

我是Android开发的新手，当Android Studio进入＆＃34;主要活动＆＃34;编译类我得到错误错误＆＃39;}＆＃39;预期 android

public class ShowWebView extends Activity {

    //private Button button;
    private WebView webView;

    final Activity activity = this;

    public Uri imageUri;

    private static final int FILECHOOSER_RESULTCODE   = 2888;
    private ValueCallback<Uri> mUploadMessage;
    private Uri mCapturedImageURI = null;

    private View adview;

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        //////////////////////////SETUP Web Link//////////////////////////////////
        String webViewUrl = "http://doblist.com/";

        //Get webview
        webView = (WebView) findViewById(R.id.webView1);
        //startWebView("http://50.73.3.244/Mobile/");

        // Javascript inabled on webview
        webView.getSettings().setJavaScriptEnabled(true);

        // Other webview options
        webView.getSettings().setLoadWithOverviewMode(true);

        //webView.getSettings().setUseWideViewPort(true);

        //Other webview settings
        webView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
        webView.setScrollbarFadingEnabled(false);
        webView.getSettings().setBuiltInZoomControls(true);
        webView.getSettings().setPluginState(WebSettings.PluginState.ON);
        webView.getSettings().setAllowFileAccess(true);
        webView.getSettings().setSupportZoom(true);

        //Load url in webview
        webView.loadUrl(webViewUrl);

        // Define Webview manage classes
        startWebView();
    }

    private void startWebView() {

        //Create new webview Client to show progress dialog
        //Called When opening a url or click on link

        webView.setWebViewClient(new WebViewClient() {
            ProgressDialog progressDialog;

            //If you will not use this method url links are open in new brower not in webview
            public boolean shouldOverrideUrlLoading(WebView view, String url) {

                // Check if Url contains ExternalLinks string in url
                // then open url in new browser
                // else all webview links will open in webview browser
                if(url.contains("3j3j3j2i3j2i3ji2"))
                {

                    // Could be cleverer and use a regex
                    //Open links in new browser
                    view.getContext().startActivity(
                            new Intent(Intent.ACTION_VIEW, Uri.parse(url)));

                    // Here we can open new activity

                    return true;

                } else {

                    // Stay within this webview and load url
                    view.loadUrl(url);
                    return true;
                }
            }

            //Show loader on url load
            public void onLoadResource (WebView view, String url) {

                // if url contains string androidexample
                // Then show progress  Dialog
                if (progressDialog == null && url.contains("lol")
                        ) {
                    // in standard case YourActivity.this
                    progressDialog = new ProgressDialog(ShowWebView.this);
                    progressDialog.setMessage("Loading...");
                    progressDialog.show();
                }
            }

            // Called when all page resources loaded
            public void onPageFinished(WebView view, String url) {
                try{
                    // Close progressDialog
                    if (progressDialog.isShowing()) {
                        progressDialog.dismiss();
                        progressDialog = null;
                    }
                }catch(Exception exception){
                    exception.printStackTrace();
                }
            }
        });

        // implement WebChromeClient inner class
        // we will define openFileChooser for select file from camera
        webView.setWebChromeClient(new WebChromeClient() {

            // openFileChooser for Android 3.0+
            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType){
                /**updated, out of the IF **/
                mUploadMessage = uploadMsg;
                /**updated, out of the IF **/

                try{
                    File imageStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "AndroidExampleFolder");
                    if (!imageStorageDir.exists()) {
                        imageStorageDir.mkdirs();
                    }
                    File file = new File(imageStorageDir + File.separator + "IMG_" + String.valueOf(System.currentTimeMillis()) + ".jpg");
                    mCapturedImageURI = Uri.fromFile(file); // save to the private variable

                    final Intent captureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
                    captureIntent.putExtra(MediaStore.EXTRA_OUTPUT, mCapturedImageURI);
                    // captureIntent.putExtra(MediaStore.EXTRA_SCREEN_ORIENTATION, ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

                    Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                    i.addCategory(Intent.CATEGORY_OPENABLE);
                    i.setType("image/*");

                    Intent chooserIntent = Intent.createChooser(i, "Image Chooser");
                    chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Parcelable[] { captureIntent });

                    startActivityForResult(chooserIntent, FILECHOOSER_RESULTCODE);
                }
                catch(Exception e){
                    Toast.makeText(getBaseContext(), "Camera Exception:"+e, Toast.LENGTH_LONG).show();
                }
                //}
            }

            // openFileChooser for Android < 3.0
            public void openFileChooser(ValueCallback<Uri> uploadMsg){
                openFileChooser(uploadMsg, "");
            }

            //openFileChooser for other Android versions
            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
                openFileChooser(uploadMsg, acceptType);
            }

            /** Added code to clarify chooser. **/

            //The webPage has 2 filechoosers and will send a console message informing what action to perform, taking a photo or updating the file
            public boolean onConsoleMessage(ConsoleMessage cm) {
                onConsoleMessage(cm.message(), cm.lineNumber(), cm.sourceId());
                //Toast.makeText(getBaseContext(), cm.message()+" :message", Toast.LENGTH_LONG).show();
                return true;
            }
            public void onConsoleMessage(String message, int lineNumber, String sourceID) {
                //Log.d("androidruntime", "Per c�nsola: " + message);
                //Toast.makeText(getBaseContext(), message+":message", Toast.LENGTH_LONG).show();
                //if(message.endsWith("foto")){ boolFileChooser= true; }
                //else if(message.endsWith("pujada")){ boolFileChooser= false; }
            }
            /** Added code to clarify chooser. **/
        });
    }
    // Return here when file selected from camera or from SDcard

    @Override
    protected void onActivityResult(int requestCode, int resultCode,
                                    Intent intent) {

        if(requestCode==FILECHOOSER_RESULTCODE)
        {

            if (null == this.mUploadMessage) {
                return;
            }

            Uri result=null;

            try{
                if (resultCode != RESULT_OK) {

                    result = null;

                } else {

                    // retrieve from the private variable if the intent is null
                    result = intent == null ? mCapturedImageURI : intent.getData();
                }
            }
            catch(Exception e)
            {
                Toast.makeText(getApplicationContext(), "activity :"+e, Toast.LENGTH_LONG).show();
            }
            mUploadMessage.onReceiveValue(result);
            mUploadMessage = null;
        }
    }

    // Open previous opened link from history on webview when back button pressed

    @Override
    // Detect when the back button is pressed
    public void onBackPressed() {
        if(webView.canGoBack()) {
            webView.goBack();
        } else {
            // Let the system handle the back button
            super.onBackPressed();
        }
    }
    public class MainActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);
    }

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();

        if (id == R.id.nav_camera) {
            // Handle the camera action
        } else if (id == R.id.nav_gallery) {

        } else if (id == R.id.nav_slideshow) {

        } else if (id == R.id.nav_manage) {

        } else if (id == R.id.nav_share) {

        } else if (id == R.id.nav_send) {

        }

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }
}

这是我的MainActivity类已编译，但我收到错误错误＆＃39;}＆＃39;预期 android

Answer 1

在课程结束时你错过了}。

基本上你忘记关闭ShowWebView课了。您需要做的就是最后添加}。其余的代码对我来说很好。

令我惊讶的是，您的IDE（Android Studio）应该检测到此错误，应该看起来像这样。