jcef浏览器实现链接过滤与链接监听

1月18日，北京，聊聊2025如何加入技术开发？

本文代码是基于jcef（Java Chromium嵌入式框架），jdk的Nashorn引擎(jdk8-jdk14)支持的js脚本，实现链接过滤与链接监听功能。
jcef的接口提供CefResourceRequestHandlerAdapter类来处理链接，在onBeforeResourceLoad和onResourceLoadComplete方法中可以完成链接过滤和监听功能
CefResourceRequestHandlerAdapter源码如下：

public abstract class CefResourceRequestHandlerAdapter implements CefResourceRequestHandler {
    public CefResourceRequestHandlerAdapter() {
    }

    public CefCookieAccessFilter getCookieAccessFilter(CefBrowser var1, CefFrame var2, CefRequest var3) {
        return null;
    }

    public boolean onBeforeResourceLoad(CefBrowser var1, CefFrame var2, CefRequest var3) {
        return false;
    }

    public CefResourceHandler getResourceHandler(CefBrowser var1, CefFrame var2, CefRequest var3) {
        return null;
    }

    public void onResourceRedirect(CefBrowser var1, CefFrame var2, CefRequest var3, CefResponse var4, StringRef var5) {
    }

    public boolean onResourceResponse(CefBrowser var1, CefFrame var2, CefRequest var3, CefResponse var4) {
        return false;
    }

    public void onResourceLoadComplete(CefBrowser var1, CefFrame var2, CefRequest var3, CefResponse var4, Status var5, long var6) {
    }

    public void onProtocolExecution(CefBrowser var1, CefFrame var2, CefRequest var3, BoolRef var4) {
    }
}

1、链接过滤实现
链接过滤实现很简单，onBeforeResourceLoad返回boolean值，false会继续请求链接，true停止请求。
2、链接监听
jcef自身没有直接提供链接内容的获取，但是可以在onResourceLoadComplete监听到所有成功请求，通过内置方法再次请求获取内容。

本文以https://my.oschina.net/penngo网址为例，屏蔽当前页面的个人头像链接和监控技能雷达接口内容

主要实现代码：

public class RequestHandler extends CefResourceRequestHandlerAdapter implements CefRequestHandler {
	......省略代码
    public void onResourceLoadComplete(CefBrowser browser, CefFrame frame, CefRequest request, CefResponse response, CefURLRequest.Status status, long var6) {
        // 此处实现链接内容监听
        String url = request.getURL();
        String code = readTxt("monitor.js");
        runcode(request, code);

    }


    @Override
    public boolean onBeforeResourceLoad(CefBrowser browser, CefFrame frame, CefRequest request) {
    	// 此处实现链接过滤、广告屏蔽
        String code = readTxt("filter.js");
        if(code != null){
            return runFilter(request, code);
        }
        else{
            return false;
        }
    }

    public void runcode(CefRequest request, String code){
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("JavaScript");
        try{
            engine.put("request", request);
            engine.put("CefURLRequestClientAdapter", com.jingji21.writing.webview.cef.CefURLRequestClientAdapter.class);
            engine.put("CefURLRequest", org.cef.network.CefURLRequest.class);
            engine.eval(code);
        }
        catch(Exception ex){
            ex.printStackTrace();
        }
    }

    public boolean runFilter(CefRequest request, String code){
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("JavaScript");
        try{
            engine.put("request", request);
            // 执行这个脚本
            engine.eval(code);
            Invocable invocable = (Invocable) engine;

            Object result = invocable.invokeFunction("filter", request);
            return (boolean)result;
        }
        catch(Exception ex){
            ex.printStackTrace();
        }
        return false;
    }

    public String readTxt(String txtPath) {
        File file = new File(txtPath);
        if(file.isFile() && file.exists()){
            try {
                FileInputStream fileInputStream = new FileInputStream(file);
                InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream);
                BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

                StringBuffer sb = new StringBuffer();
                String text = null;
                while((text = bufferedReader.readLine()) != null){
                    sb.append(text);
                }
                return sb.toString();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return null;
    }
    ......省略代码
}

屏蔽链接脚本filter.js

var System = Java.type('java.lang.System');
function filter(request){
    if(request.getURL().equals("https://static.oschina.net/uploads/user/58/117179_200.gif?t=1380194723000") == true){
        System.out.println("屏蔽链接=====" + request.getURL());
        return true;
    }
    return false;
}

链接监控脚本monitor.js

var System = Java.type('java.lang.System');
/* System.out.println("onResourceLoadComplete=====" + request.getURL()); */
if(request.getURL().equals("https://my.oschina.net/penngo/radar/getUserPortraitRadarMap") == true){
    System.out.println("监控链接=====" + request.getURL());
    var CefURLRequest = CefURLRequest.static;
    var cefURLRequestClientAdapter = CefURLRequestClientAdapter.static;
    var Adapter = Java.extend(cefURLRequestClientAdapter);
    var cefURLRequestClientAdapter = new Adapter(){
        onRequestComplete : function(cefURLRequest) {
            try {
                var result = cefURLRequestClientAdapter.byteStream.toString("UTF-8");
                System.out.println("监控内容=====:" + result);
            } catch (e) {
                e.printStackTrace();
            }
        }
    };
    CefURLRequest.create(request, cefURLRequestClientAdapter);
}

最后把RequestHandler添加到浏览器中

CefApp cefApp_ = CefApp.getInstance();
CefClient client_ = cefApp_.createClient();
client_.addRequestHandler(new RequestHandler());

运行效果

控制台输出