JavaFXWebEngine:在后台工作程序中到底发生了什么?UI挂起在loadContent(大HTML文档)上
从文档中: 加载总是在后台线程上进行。启动的方法 在安排后台作业后立即加载并返回。追踪 如果要进行和/或取消作业,请使用可从中获得的Worker实例 getLoadWorker()方法 我通过JavaFXWebEngine:在后台工作程序中到底发生了什么?UI挂起在loadContent(大HTML文档)上,java,javafx,javafx-webengine,Java,Javafx,Javafx Webengine,从文档中: 加载总是在后台线程上进行。启动的方法 在安排后台作业后立即加载并返回。追踪 如果要进行和/或取消作业,请使用可从中获得的Worker实例 getLoadWorker()方法 我通过WebEngine.loadContent(String)在WebView上加载了一个。那根绳子大约有五百万个字符长。在Platform.runLater()中运行时(我必须在JavaFX线程中运行它,否则会出错),我的UI会挂起大约一分钟 如果我没有在Platform.runLater()中运行它,我会得
WebEngine.loadContent(String)
在WebView上加载了一个。那根绳子大约有五百万个字符长。在Platform.runLater()
中运行时(我必须在JavaFX线程中运行它,否则会出错),我的UI会挂起大约一分钟
如果我没有在Platform.runLater()中运行它,我会得到:
java.lang.IllegalStateException: Not on FX application thread; currentThread = populator
at com.sun.javafx.tk.Toolkit.checkFxUserThread(Toolkit.java:236)
at com.sun.javafx.tk.quantum.QuantumToolkit.checkFxUserThread(QuantumToolkit.java:423)
at javafx.scene.web.WebEngine.checkThread(WebEngine.java:1216)
at javafx.scene.web.WebEngine.loadContent(WebEngine.java:931)
at javafx.scene.web.WebEngine.loadContent(WebEngine.java:919)
...
我不能通过webEngine.getLoadWorker().getProgress()
查询webEngine,也不能通过webEngine.getLoadWorker().cancel()
取消webEngine,因为我必须再次在挂起的JavaFX线程上运行它
因此,我必须等待页面加载,然后任何以前提交的Platform.runLater(()->webEngine.getLoadWorker().getProgress())
都会运行(在网页加载过程中),每次都会给我1.0
我用于查询工作者的代码:
// WebView
wvIn.getEngine().getLoadWorker().stateProperty().addListener(new ChangeListener<Worker.State>() {
class ProgressThread extends Thread {
private Worker.State loadWorkerState;
synchronized Worker.State getLoadWorkerState() {
return loadWorkerState;
}
synchronized void setLoadWorkerState(Worker.State loadWorkerState) {
this.loadWorkerState = loadWorkerState;
}
{
setDaemon(true);
setName("LoadingWebpageProgressThread");
}
public void run() {
while (true) {
try {
if (getLoadWorkerState() == Worker.State.RUNNING)
// piWv ProgressIndicator (WebView loading)
Platform.runLater(() -> piWv.setVisible(true));
while (getLoadWorkerState() == Worker.State.RUNNING) {
Platform.runLater(() -> {
piWv.setProgress(wvIn.getEngine().getLoadWorker().getProgress());
// TODO delete
System.out.println(wvIn.getEngine().getLoadWorker().getProgress());
});
Thread.sleep(100);
}
if (getLoadWorkerState() == Worker.State.SUCCEEDED) {
Platform.runLater(() -> piWv.setProgress(1d));
Thread.sleep(100);
Platform.runLater(() -> {
piWv.setVisible(false);
piWv.setProgress(0d);
});
}
synchronized (this) {
wait();
}
} catch (InterruptedException e) {
}
}
}
};
final ProgressThread progressThread = new ProgressThread();
{
progressThread.start();
}
// executed on JavaFX Thread
@Override
public void changed(ObservableValue<? extends State> observable, State oldValue, State newValue) {
if (newValue == State.SUCCEEDED) {
JSObject window = (JSObject) wvIn.getEngine().executeScript("window");
window.setMember("controller", mainController);
progressThread.setLoadWorkerState(newValue);
progressThread.interrupt();
} else if (newValue == State.RUNNING) {
progressThread.setLoadWorkerState(newValue);
progressThread.interrupt();
}
// TODO delete
System.out.println(oldValue + "->" + newValue);
}
});
//WebView
wvIn.getEngine().getLoadWorker().stateProperty().addListener(新的ChangeListener()){
类ProgressThread扩展线程{
私人工人。国家装卸工人州;
已同步的工作程序。状态getLoadWorkerState(){
返回装载机状态;
}
同步的void setLoadWorkerState(Worker.State loadWorkerState){
this.loadWorkerState=loadWorkerState;
}
{
setDaemon(true);
setName(“加载网页进度线程”);
}
公开募捐{
while(true){
试一试{
if(getLoadWorkerState()==Worker.State.RUNNING)
//piWv ProgressIndicator(网络视图加载)
Platform.runLater(()->piWv.setVisible(true));
while(getLoadWorkerState()==Worker.State.RUNNING){
Platform.runLater(()->{
piWv.setProgress(wvIn.getEngine().getLoadWorker().getProgress());
//待办事项删除
System.out.println(wvIn.getEngine().getLoadWorker().getProgress());
});
睡眠(100);
}
if(getLoadWorkerState()==Worker.State.successed){
Platform.runLater(()->piWv.setProgress(1d));
睡眠(100);
Platform.runLater(()->{
piWv.setVisible(假);
设定进度(0d);
});
}
已同步(此){
等待();
}
}捕捉(中断异常e){
}
}
}
};
最终ProgressThread ProgressThread=新ProgressThread();
{
progressThread.start();
}
//在JavaFX线程上执行
@凌驾
public void changed(observevalue您在问题中显示的HTML文件几乎立即加载到我的机器上
在我看来,问题在于你的代码。嗯,它相当麻烦。请允许我指出,它看起来不是很好,因为它很容易出错,并且使用异常来实现一种形式的
看起来你还没有完全理解这个概念。
除非为了简洁起见以某种方式切断了问题中的代码段,ProgressThread
实例是完全无用的。
您已经有了一个根据需要调度事件的方法,在JavaFX应用程序线程上执行回调;只需使用它
indicator.setVisible(false); // Start hidden
engine.getLoadWorker().progressProperty().addListener((observable, oldValue, newValue) -> {
indicator.setProgress(newValue.doubleValue());
indicator.setVisible(indicator.getProgress() != 1D);
});
或者,您可以使用以下功能:
请注意,在我的机器上,加载过程中的进度始终为零。我认为问题出在您的HTML代码中:如果您尝试加载其他资源,例如您现在正在阅读的网页,则进度指示器将提供一种更愉快的体验,在页面打开之前被更新数次帐篷已经装好了。所以
我最终构建了自己的Http服务器来测试load
,而不是loadContent
(注意:这是一个坏服务器):
我做了一些基准测试——测量loadWorker从开始运行到成功运行的时间:
via BadHttpServer:
javascript and style after body: 13,5 s
javascript and style before body: 8,6 s
so I continued to test with javascript and style before body.
without javascript injection: 8,5 s
I continued to test with javascript injection.
Next I did with loadContent: 170 s - no UI resposivness during loading
Yep - almost 3 minutes...
So I returned back with BadHttpServer.
Next I tried "throttling the bandwidth" by changing the sleep time.
no sleep: 8,2 s
5 ms sleep: 6,8 s
10 ms sleep: 6,7 s
20 ms sleep: 11,6 s
In these cases the UI was responsive, although it was lagging a bit.
The progressIndicator showed nicely, pausing a bit at 90%.
By increasing the sleep time, the UI was more responsive.
通过BadHttpServer:
正文后的javascript和样式:13,5秒
正文前的javascript和样式:8,6 s
所以我继续在body之前使用javascript和样式进行测试。
没有javascript注入:8,5秒
我继续使用javascript注入进行测试。
接下来,我对loadContent进行了测试:170 s-加载期间没有UI响应
是的-差不多3分钟。。。
所以我带着BadHttpServer回来了。
接下来,我尝试通过改变睡眠时间来“调节带宽”。
无睡眠:8,2秒
5毫秒睡眠:6,8秒
10毫秒睡眠:6,7秒
20毫秒睡眠:11,6秒
在这些情况下,UI是响应性的,尽管有点滞后。
progressIndicator表现不错,在90%时稍作停顿。
通过增加睡眠时间,UI的响应性更强。
因此,我想loadContent
方法可能会更好一些,除非我在实现它时做了一些错误…loadContent
的文档说“与load(String)一样,这个方法是异步的”,所以我猜你不应该用平台调用它。runLater
。直接调用它时会出现什么错误?我编辑了这个问题,以包括如果我不从JavaFX线程运行它会发生什么。这可能与此相关--可能只是WebEngine的一个bug/性能问题…@SlumpA关于这一点有一个未解决的问题:.还有一个解释是为什么它必须b
engine.documentProperty().addListener((observable, oldValue, newValue) -> {
if (newValue == null) {
return;
}
JSObject window = (JSObject)engine.executeScript("window");
window.setMember("controller", mainController);
});
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Calendar;
import java.util.Locale;
import java.util.TimeZone;
import java.util.zip.GZIPOutputStream;
public class BadHttpServer {
private static int request = 0, connection = 0;
private static final BadHttpServer SINGLETON = new BadHttpServer();
private ServerSocket serverSocket;
private String htmlString, formattedDate;
private byte[] compressedHTML;
public String getURL() {
return "http://localhost:60000";
}
synchronized byte[] getCompressedHTML() {
return compressedHTML;
}
synchronized void setCompressedHTML(String string) {
try (ByteArrayOutputStream baos = new ByteArrayOutputStream(string.length() / 2);
GZIPOutputStream gos = new GZIPOutputStream(baos);) {
gos.write(string.getBytes("utf-8"));
gos.close();
this.compressedHTML = baos.toByteArray();
formattedDate = String.format(Locale.US, "%1$ta, %1$td %1$tb %1$tY %1$tH:%1$tM:%1$tS %1$tZ",
Calendar.getInstance(TimeZone.getTimeZone("GMT")));
} catch (IOException e) {
e.printStackTrace();
}
}
private synchronized String getFormattedDate() {
return formattedDate;
}
private BadHttpServer() {
try {
serverSocket = new ServerSocket(60000);
} catch (IOException e) {
e.printStackTrace();
}
new Thread() {
{
setDaemon(true);
setName("serverSocketThread");
}
public void run() {
while (true) {
try {
new Thread(acceptAndSendHTML(serverSocket.accept())) {
{
setDaemon(true);
setName("acceptThread" + connection++);
}
}.start();
} catch (IOException e) {
e.printStackTrace();
}
}
};
}.start();
}
protected Runnable acceptAndSendHTML(final Socket socket) {
return new Runnable() {
@Override
public void run() {
try (BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream(), "ASCII"));
BufferedWriter asciiWriter = new BufferedWriter(
new OutputStreamWriter(socket.getOutputStream(), "ASCII"));
BufferedOutputStream bos = new BufferedOutputStream(socket.getOutputStream(), 1000)) {
while (!socket.isClosed()) {
int request = BadHttpServer.request++;
// READING
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append(br.readLine() + "\r\n");
for (String line = ""; !(line = br.readLine()).isEmpty(); stringBuilder.append(line + "\r\n"))
;
// TODO delete
System.out.print("Connection " + request + " request: " + stringBuilder);
// WRITING
byte[] compressedHTML = getCompressedHTML();
asciiWriter.write("HTTP/1.1 100 Continue\r\n");
asciiWriter.write("\r\n");
asciiWriter.write("HTTP/1.1 200 OK\r\n");
asciiWriter.write("Date: " + getFormattedDate() + "\r\n");
asciiWriter.write("Content-Type: text/html; charset=utf-8\r\n");
asciiWriter.write("Content-Encoding: gzip\r\n");
asciiWriter.write("Content-Charset: utf-8\r\n");
asciiWriter.write("Content-Length: " + compressedHTML.length + "\r\n");
// TODO delete
System.out.println("Content-Length: " + compressedHTML.length + "\r\n");
asciiWriter.write("\r\n");
asciiWriter.flush();
for (int writtenOverall = 0, writtenThisIteration = 0; writtenOverall < compressedHTML.length; writtenOverall += writtenThisIteration) {
bos.write(compressedHTML, writtenOverall,
writtenThisIteration = Math.min(compressedHTML.length - writtenOverall, 1000));
Thread.sleep(10); // Bandwidth throttling
}
bos.flush();
}
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
}
public static BadHttpServer getIntance() {
return SINGLETON;
}
public synchronized void setHtmlString(String htmlString) {
this.htmlString = htmlString;
setCompressedHTML(htmlString);
}
synchronized String getHtmlString() {
return htmlString;
}
}
BadHttpServer.getIntance().setHtmlString(htmlString);
Platform.runLater(() -> wvIn.getEngine().load(BadHttpServer.getIntance().getURL()));
via BadHttpServer:
javascript and style after body: 13,5 s
javascript and style before body: 8,6 s
so I continued to test with javascript and style before body.
without javascript injection: 8,5 s
I continued to test with javascript injection.
Next I did with loadContent: 170 s - no UI resposivness during loading
Yep - almost 3 minutes...
So I returned back with BadHttpServer.
Next I tried "throttling the bandwidth" by changing the sleep time.
no sleep: 8,2 s
5 ms sleep: 6,8 s
10 ms sleep: 6,7 s
20 ms sleep: 11,6 s
In these cases the UI was responsive, although it was lagging a bit.
The progressIndicator showed nicely, pausing a bit at 90%.
By increasing the sleep time, the UI was more responsive.