jsbridge

JsBridge is a bridge library for bidirectional communication between Android WebView and JavaScript, inspired by WeChat's WebView JsBridge implementation. It provides a secure and reliable message passing mechanism, supporting both Java-to-JavaScript and JavaScript-to-Java calls. ## Key Features - **Bidirectional Communication**: Supports calls in both directions between Java and JavaScript, with a callback mechanism. - **Multiple Communication Channels**: Supports four channels: URL Scheme interception, @JavascriptInterface, evaluateJavascript(), and loadUrl("javascript:"), compatible with different Android versions. - **Persistent Callbacks**: Supports callbacks with multiple responses, suitable for real-time updates, event streams, and other scenarios. - **Domain Whitelist**: Can restrict which domains can call native methods, enhancing security. - **Message Queue**: Messages sent before JS injection completes are automatically queued and dispatched uniformly after injection, preventing message loss. - **Custom WebView Integration**: Can be easily integrated into custom WebViews via BridgeHelper. ## Installation Add the dependency via the JitPack repository: ```groovy repositories { maven { url "https://jitpack.io" } } dependencies { implementation 'com.github.happydog-intj:JsBridge:v2.1.0' } ``` ## Quick Start ### Using BridgeWebView Add BridgeWebView to your layout and initialize it in the Activity: ```java BridgeWebView webView = findViewById(R.id.webView); webView.setGson(new Gson()); webView.addJavascriptInterface( new MainJavascriptInterface( webView.getCallbacks(), webView.getPersistentCallbacks(), webView), "WebViewJavascriptBridge"); webView.loadUrl("file:///android_asset/demo.html"); ``` ### Java Calling JavaScript Register a handler on the JS side, then call it from Java: ```javascript WebViewJavascriptBridge.registerHandler("functionInJs", function(data, responseCallback) { document.getElementById("show").innerHTML = "data from Java: = " + data; responseCallback("Javascript Says Right back aka!"); }); ``` ```java webView.callHandler("functionInJs", new Gson().toJson(user), new OnBridgeCallback() { @Override public void onCallBack(String data) { Log.d(TAG, "response from JS: " + data); } }); ``` ### JavaScript Calling Java Create a @JavascriptInterface class, and the JS side can call it: ```java public class MainJavascriptInterface extends BridgeWebView.BaseJavascriptInterface { @JavascriptInterface public void submitFromWeb(String data, String callbackId) { Log.d("JSInterface", "data from web: " + data); mWebView.responseFromWeb("response from Java", callbackId); } } ``` ```javascript WebViewJavascriptBridge.callHandler( 'submitFromWeb', {'param': 'value'}, function(responseData) { document.getElementById("show").innerHTML = "response: " + responseData; } ); ``` ### Persistent Callbacks By default, callbacks are automatically deleted after the first call. Use `callHandlerPersistent()` for multiple responses: ```java webView.callHandlerPersistent("functionInJs", data, new OnBridgeCallback() { @Override public void onCallBack(String data) { Log.d(TAG, "called again: " + data); } }); ``` ### Domain Whitelist Restrict which domains can call native methods: ```java webView.addAllowedHost("example.com"); webView.addAllowedHost("*.example.com"); ``` When the whitelist is empty (default), all domains are allowed. ## Custom WebView Integration Integrate into a custom WebView via BridgeHelper: ```java public class CustomWebView extends WebView implements WebViewJavascriptBridge, IWebView { private BridgeHelper bridgeHelper; private void init() { getSettings().setJavaScriptEnabled(true); bridgeHelper = new BridgeHelper(this); setWebViewClient(new WebViewClient() { @Override public void onPageStarted(WebView view, String url, Bitmap favicon) { bridgeHelper.onPageStarted(); } @Override public void onPageFinished(WebView view, String url) { bridgeHelper.onPageFinished(); } @Override public boolean shouldOverrideUrlLoading(WebView view, String url) { return bridgeHelper.shouldOverrideUrlLoading(url); } }); } } ``` ## Compatibility - **Android 11+ (API 30+)**: Adapted, file access permissions are disabled by default, and cache strategy is determined by the host app. - **HarmonyOS**: Community provides a ported version `@alvin917/jsbridge`. - **Embedded Devices**: If WebView creation crashes, check the device's WebView provider. ## License MIT License.