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inspired and modified from this and wechat jsBridge file, with some bugs fix and feature enhancement.

This project make a bridge between Java and JavaScript.

It provides safe and convenient way to call Java code from js and call js code from java.


JsBridge Demo


I strongly recommend

repositories {
    // ...
    maven { url "" }

dependencies {
    compile 'com.github.lzyzsd:jsbridge:1.0.4'

Use it in Java

add com.github.lzyzsd.jsbridge.BridgeWebView to your layout, it is inherited from WebView.

Register a Java handler function so that js can call

    webView.registerHandler("submitFromWeb", new BridgeHandler() {
        public void handler(String data, CallBackFunction function) {
            Log.i(TAG, "handler = submitFromWeb, data from web = " + data);
            function.onCallBack("submitFromWeb exe, response data from Java");

js can call this Java handler method "submitFromWeb" through:

        , {'param': str1}
        , function(responseData) {
            document.getElementById("show").innerHTML = "send get responseData from java, data = " + responseData

You can set a default handler in Java, so that js can send message to Java without assigned handlerName

    webView.setDefaultHandler(new DefaultHandler());
        , function(responseData) {
            document.getElementById("show").innerHTML = "repsonseData from java, data = " + responseData

Register a JavaScript handler function so that Java can call

    WebViewJavascriptBridge.registerHandler("functionInJs", function(data, responseCallback) {
        document.getElementById("show").innerHTML = ("data from Java: = " + data);
        var responseData = "Javascript Says Right back aka!";

Java can call this js handler function "functionInJs" through:

    webView.callHandler("functionInJs", new Gson().toJson(user), new CallBackFunction() {
        public void onCallBack(String data) {


You can also define a default handler use init method, so that Java can send message to js without assigned handlerName

for example:

    window.WebViewJavascriptBridge.init(function(message, responseCallback) {
        console.log('JS got a message', message);
        var data = {
            'Javascript Responds': 'Wee!'
        console.log('JS responding with', data);

will print 'JS got a message hello' and 'JS responding with' in webview console.


This lib will inject a WebViewJavascriptBridge Object to window object. You can listen to WebViewJavascriptBridgeReady event to ensure window.WebViewJavascriptBridge is exist, as the blow code shows:

    if (window.WebViewJavascriptBridge) {
        //do your work here
    } else {
            , function() {
                //do your work here

Or put all JsBridge function call into window.WVJBCallbacks array if window.WebViewJavascriptBridge is undefined, this task queue will be flushed when WebViewJavascriptBridgeReady event triggered.

Copy and paste setupWebViewJavascriptBridge into your JS:

function setupWebViewJavascriptBridge(callback) {
	if (window.WebViewJavascriptBridge) {
        return callback(WebViewJavascriptBridge);
	if (window.WVJBCallbacks) {
        return window.WVJBCallbacks.push(callback);
	window.WVJBCallbacks = [callback];

Call setupWebViewJavascriptBridge and then use the bridge to register handlers or call Java handlers:

setupWebViewJavascriptBridge(function(bridge) {
	bridge.registerHandler('JS Echo', function(data, responseCallback) {
		console.log("JS Echo called with:", data);
	bridge.callHandler('ObjC Echo', {'key':'value'}, function(responseData) {
		console.log("JS received response:", responseData);

It same with, that would be easier for you to define same behavior in different platform between Android and iOS. Meanwhile, writing concise code.


This project is licensed under the terms of the MIT license.