Captcha:Integrate with the V3 architecture on Android

Returned data

The Captcha server performs behavioral verification on the user's response to determine whether the request is from a human or a machine. It then returns a Captcha code and related parameters to the client. To inspect the returned data, use the Network tab in your browser's developer tools. For details, see Data returned by the V3 client architecture.

1. Import WebView dependency libraries

In Activity.java, import the dependency libraries for the WebView component:

import android.webkit.WebView;
import android.webkit.WebSettings;
import android.webkit.WebViewClient;
import android.webkit.WebChromeClient;
// Or
// import android.webkit.*;

2. Set network permissions

In AndroidManifest.xml, declare the permissions required to load web pages:

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<application
  ...
  android:usesCleartextTraffic="true"
  ...
  >

If your app calls other HTTP resources, add the corresponding configurations.

3. Add the WebView component

In activity_main.xml, add the WebView component to your layout:

<WebView
  android:id="@+id/webview"
  android:layout_height="match_parent"
  android:layout_width="match_parent"
/>

4. Load the HTML5 service page

In MainActivity.java, configure WebView settings and load the service page:

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }
    private void initView() {
        WebView webview = findViewById(R.id.webview);
        WebSettings webSettings = webview.getSettings();

        // Optional: Enable Chrome debugging
        WebView.setWebContentsDebuggingEnabled(true);

        // Required: Make the screen responsive
        webSettings.setUseWideViewPort(true);
        webSettings.setLoadWithOverviewMode(true);

        // Required: Disable caching so the app always loads the latest version of Captcha 2.0
        webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);

        // Required: Enable JavaScript
        webSettings.setJavaScriptEnabled(true);

        // Required: Enable DOM storage
        webSettings.setDomStorageEnabled(true);

        // Load the page within the WebView instead of the default browser
        webview.setWebViewClient(new WebViewClient(){
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                view.loadUrl(url);
                return true;
            }
        });

        // Load the service page
        webview.loadUrl("http://x.x.x.x/demo/");
    }
}

5. Define the Java interface

In MainActivity.java, define the custom Java interface testJsInterface with the getCaptchaVerifyParam method. This method receives the signature verification parameters from the JavaScript layer.

import android.webkit.JavascriptInterface;

public class testJsInterface {
    @JavascriptInterface
    public void getCaptchaVerifyParam(String captchaVerifyParam) {
        // Use captchaVerifyParam to send service and signature verification requests.
        System.out.println(captchaVerifyParam);
    }
}

6. Register the JavaScript bridge

In the initView() method of MainActivity.java, bind the Java interface to the JavaScript layer:

// Build a bridge for JavaScript to call the Java interface
webview.addJavascriptInterface(new testJsInterface(), "testInterface");