Firefox扩展程序和Java程序通信

实现Firefox扩展程序，和Java RMI Client端进行通信。

在Firefox工具栏注册按钮，点击按钮后弹出Popup.html页面，引用Popup.js脚本，通过脚本向Java RMI client发送消息，Java RMI Client接收消息后转发到Java RMI Server。

Popup.js中的发送代码：

btnSend.addEventListener("click", function(event) {const sending = browser.runtime.sendNativeMessage("native.host", url.value);sending.then(function(resp) {txtResult.textContent = resp.message;}, function(err) {txtResult.textContent = err;});
});

注册的native.json配置文件

{"name": "native.host","description": "Example host for native messaging","path": "native.bat","type": "stdio","allowed_extensions": ["hook@native"]}

执行的native.bat代码

@echo off 
rem  echo off -> close stdout 
call java -cp "C:\Users\cc\OneDrive\src\java\RMIClient\bin" net.RMIClient

Java RMI client程序

public class RMIClient  {public static String read() throws IOException {byte[] _len = new byte[4];System.in.read(_len);ByteBuffer bb = ByteBuffer.wrap(_len);bb.order(ByteOrder.LITTLE_ENDIAN);int length = bb.getInt(0);byte[] message = new byte[length];System.in.read(message);return new String(message, "UTF-8");}public static void write(String s) throws IOException {byte[] utf = s.getBytes("UTF-8");ByteBuffer bb = ByteBuffer.allocate(utf.length + 4);bb.order(ByteOrder.LITTLE_ENDIAN);bb.putInt(0, utf.length);bb.put(4, utf);byte[] bs = bb.array();System.out.write(bs);System.out.flush();}public static void main(String[] args) throws IOException, InterruptedException, NotBoundException {Registry registry = LocateRegistry.getRegistry("127.0.0.1", 1099);IReceive receiver = (IReceive) registry.lookup("Receiver");String data =  read();String result = receiver.receive(data);write(" { \"message\":\"ok\" }" );}}

运行效果，浏览器弹出框，点击"Send"发送浏览器当前地址