硒木偶驱动程序无法访问浏览器第二次启动时异常

Question

我目前正在玩硒木偶WebDriver。在我的应用程序中，我想按顺序打开多个木偶驱动程序。基本上是这样的：

MarionetteDriver driver = new MarionetteDriver();
// do some stuff
driver.quit();
// a while later
driver = new MarionetteDriver();
// do some stuff
driver.quit();

现在我面临的问题是，只有第一个木偶实例可以成功启动，并且对于以后的每次尝试，我都会收到以下异常。问题每次都会发生，并且使用的端口总是会更改，因此显然没有端口冲突。

Exception in thread "main" org.openqa.selenium.remote.UnreachableBrowserException: Could not start a new session. Possible causes are invalid address of the remote server or browser start-up failure.
Build info: version: '2.48.2', revision: '41bccdd10cf2c0560f637404c2d96164b67d9d67', time: '2015-10-09 13:08:06'
System info: host: 'qqilihq.local', ip: '192.168.1.2', os.name: 'Mac OS X', os.arch: 'x86_64', os.version: '10.11.2', java.version: '1.7.0_71'
Driver info: driver.version: MarionetteDriver
    at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:641)
    at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:247)
    at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:232)
    at org.openqa.selenium.firefox.MarionetteDriver.run(MarionetteDriver.java:84)
    at org.openqa.selenium.firefox.MarionetteDriver.<init>(MarionetteDriver.java:73)
    at org.openqa.selenium.firefox.MarionetteDriver.<init>(MarionetteDriver.java:45)
    at MyMainClass.main(MyMainClass.java:131)
Caused by: org.openqa.selenium.WebDriverException: org.apache.http.conn.HttpHostConnectException: Connect to localhost:41886 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused
Build info: version: '2.48.2', revision: '41bccdd10cf2c0560f637404c2d96164b67d9d67', time: '2015-10-09 13:08:06'
System info: host: 'qqilihq.local', ip: '192.168.1.2', os.name: 'Mac OS X', os.arch: 'x86_64', os.version: '10.11.2', java.version: '1.7.0_71'
Driver info: driver.version: MarionetteDriver
    at org.openqa.selenium.remote.service.DriverCommandExecutor.execute(DriverCommandExecutor.java:91)
    at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:620)
    ... 6 more
Caused by: org.apache.http.conn.HttpHostConnectException: Connect to localhost:41886 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused
    at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.java:151)
    at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.connect(PoolingHttpClientConnectionManager.java:353)
    at org.apache.http.impl.execchain.MainClientExec.establishRoute(MainClientExec.java:380)
    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:236)
    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184)
    at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88)
    at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:71)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:55)
    at org.openqa.selenium.remote.internal.ApacheHttpClient.fallBackExecute(ApacheHttpClient.java:143)
    at org.openqa.selenium.remote.internal.ApacheHttpClient.execute(ApacheHttpClient.java:89)
    at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:142)
    at org.openqa.selenium.remote.service.DriverCommandExecutor.execute(DriverCommandExecutor.java:82)
    ... 7 more
Caused by: java.net.ConnectException: Connection refused
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:579)
    at org.apache.http.conn.socket.PlainConnectionSocketFactory.connectSocket(PlainConnectionSocketFactory.java:74)
    at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.    java:134)
    ... 20 more

任何指示赞赏！

Answer 1

经过深入挖掘，我得出了以下发现，最终解决了我的问题：

1. 木偶或 wires使用两个端口(请参阅wires --help(;marionette-port和webdriver-port：

   Usage:
       ./wires [OPTIONS]
   WebDriver to marionette proxy.
   optional arguments:
     -h,--help             show this help message and exit
     -b,--binary BINARY    Path to the Firefox binary
     --webdriver-host WEBDRIVER_HOST
                           Host to run webdriver server on
     --webdriver-port WEBDRIVER_PORT
                           Port to run webdriver on
     --marionette-port MARIONETTE_PORT
                           Port to run marionette on
     --connect-existing    Connect to an existing firefox process
   

   当同时运行多个MarionetteDrivers时，两个端口显然必须与已经运行的实例不同。但是，当使用默认构造函数new MarionetteDriver()时，marionette-port保持不变(并且不是基于某些自由端口确定的(。我们对GeckoDriverService.Builder使用了一些解决方法(见下文(，以始终选择两个随机选择的可用端口。

2. 当前(版本 2.48.2(GeckoDriverService有一个空的 waitUntilAvailable() 实现(如果WebDriver准备就绪，应该检查(。偶尔，这会导致上面发布UnreachableBrowserException。

为了规避这些问题，我们在最后做了这样的事情：

// determine free ports for Marionette and WebDriver
final int marionettePort = PortProber.findFreePort();
final int webDriverPort = PortProber.findFreePort();
// override, as GeckoDriverService provides no direct way to set the Marionette port
GeckoDriverService.Builder builder = new GeckoDriverService.Builder() {
    @Override
    protected ImmutableList<String> createArgs() {
        Builder<String> argsBuilder = ImmutableList.builder();
        argsBuilder.addAll(super.createArgs());
        argsBuilder.add(String.format("--marionette-port=%d", marionettePort));
        return argsBuilder.build();
    }
};
builder.usingPort(webDriverPort);
builder.usingDriverExecutable(pathToDriver);
GeckoDriverService driverService = builder.build();
try {
    driverService.start();
} catch (IOException e) {
    throw new IllegalStateException("Could not start the GeckoDriverService", e);
}
try {
    // keep checking the WebDriver port via Socket until it's available;
    // as far as I could tell, there is nothing more "high level", e.g. REST API
    waitUntilReady(webDriverPort, TimeUnit.SECONDS.toMillis(30));
} catch (InterruptedException e) {
    // ignore
}
return new MarionetteDriver(driverService, capabilities);

Answer 2

您需要处理木偶所需的二进制文件。您可以手动执行此操作(自行下载二进制文件并导出适当的变量(，也可以使用WebDriverManager自动执行此操作。只需添加以下依赖项：

<dependency>
   <groupId>io.github.bonigarcia</groupId>
   <artifactId>webdrivermanager</artifactId>
    <version>1.6.0</version>
</dependency>

然后，在代码中调用：

FirefoxDriverManager.getInstance().setup();

Answer 3

大多数情况下，当Selenium找不到驱动程序所需的exe时，会发生UnreachableBrowserException。由于您尚未设置驱动程序功能，因此我假设以下步骤将解决您的问题。

根据Mozilla MDN链接，木偶被设置为所需的功能

DesiredCapabilities capabilities = DesiredCapabilities.firefox();
// Set Marionette on so the Grid will use this instead of normal FirefoxDriver
capabilities.setCapability("marionette", true);
WebDriver driver = new RemoteWebDriver(capabilities); 

此外，木偶可执行文件被添加到路径(在Windows中(：

将可执行文件添加到路径

Selenium将尝试在路径中使用可执行文件。您需要使用以下方法将其添加到路径中。

最后，另一个SO问题，其中处理了无法访问的浏览器异常问题。

Answer 4

我有类似的问题，通过使用覆盖的构建器实现创建覆盖的 MarionetteDriver 实例来解决。不过，接受的答案是更优雅的解决方案。确实有很多时间深入了解根本原因

public static class CustomBuilder extends org.openqa.selenium.firefox.GeckoDriverService.Builder {
    @Override
    protected GeckoDriverService createDriverService(File exe, int port, ImmutableList<String> args, ImmutableMap<String, String> environment) {
        try {
            return new GeckoDriverService(exe, port, args, environment) {
                @Override
                protected void waitUntilAvailable() throws MalformedURLException {
                    logger.info("Waiting until avaliable");
                    try {
                        Thread.sleep(10000);
                    } catch (InterruptedException e) {
                    }
                    super.waitUntilAvailable();
                    logger.info("Finished waiting until avaliable");
                }
            };
        } catch (IOException e) {
            throw new WebDriverException(e);
        }
    }
}