Selenium Java RemoteWebDriver文件上传报UnsupportedCommandException求助

问题描述 #

使用Selenium 4.12.1、Chrome 112、ChromeDriver 112及RemoteWebDriver，通过sendKeys方法给//input[@type='file']元素传入文件路径时，触发UnsupportedCommandException，错误信息为unknown command: session/9845d50a442f6c23dc498210a0d253d7/se/file。

环境规格 #

• Selenium版本：4.12.1
• 驱动：RemoteWebDriver
• 操作系统：Linux

代码示例 #

WebElement fileInput = driver.findElement(By.xpath("//input[@type='file']"));  
String filePath = "/path/to/file.txt";  
fileInput.sendKeys(filePath);

错误堆栈 #

org.openqa.selenium.UnsupportedCommandException: unknown command: unknown command: session / 9845 d50a442f6c23dc498210a0d253d7 / se / file
Build info: version: '4.12.1', revision: '8e34639b11' System info: os.name: 'Linux', os.arch: 'amd64', os.version: '5.10.215-181.850.amzn2int.x86_64', java.version: '17.0.11' 
 Driver info: org.openqa.selenium.remote.RemoteWebDriver
Command: [9845 d50a442f6c23dc498210a0d253d7, uploadFile {
            file = UEsDBBQACAgIADtor1gAAAAAAAAAAAAAAAARAAAAYnVsa1NoaXBUZXN0Lnhsc3icuwNwZdHXJZ502LFtq2PbTse2bTvp2LZt27Zt2x07mUr6+9d8M/+aX03Nq1dPdc/aZ6219z2n9rtXRgIIGAkAHBwcgNWkSgXgvz0QAQAA1AWsrRwMrRy0FVxtDO01qV0sLSYSxn730cIJeRPfoDBRw}]
             Capabilities {
                acceptInsecureCerts: true,
                browserName: chrome,
                browserVersion: 112.0 .5615 .49,
                chrome: {
                    chromedriverVersion: 112.0 .5615 .49(bd2a7bcb881c..., userDataDir: /tmp/.org.chromium.Chromium...
                    },
                    goog: chromeOptions: {
                        debuggerAddress: localhost: 46485
                    },
                    networkConnectionEnabled: false,
                    pageLoadStrategy: normal,
                    platformName: linux,
                    proxy: Proxy(),
                    setWindowRect: true,
                    strictFileInteractability: false,
                    timeouts: {
                        implicit: 0,
                        pageLoad: 300000,
                        script: 30000
                    },
                    unhandledPromptBehavior: dismiss and notify,
                    webauthn: extension: credBlob: true,
                    webauthn: extension: largeBlob: true,
                    webauthn: extension: minPinLength: true,
                    webauthn: extension: prf: true,
                    webauthn: virtualAuthenticators: true
                }
                Element: [
                        [RemoteWebDriver: chrome on linux(9845 d50a442f6c23dc498210a0d253d7)] - > xpath: //div[@role='dialog']//input[@accept='.xlsx']]
                         Session ID: 9845 d50a442f6c23dc498210a0d253d
                         at java.base / jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
                         at java.base / jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java: 77)
                         at java.base / jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java: 45)
                         at java.base / java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java: 499)
                        at java.base / java.lang.reflect.Constructor.newInstance(Constructor.java: 480)
                        at org.openqa.selenium.remote.codec.w3c.W3CHttpResponseCodec.createException(Unknown Source)
                        at org.openqa.selenium.remote.codec.w3c.W3CHttpResponseCodec.decode(Unknown Source)
                        at org.openqa.selenium.remote.codec.w3c.W3CHttpResponseCodec.decode(Unknown Source)
                        at org.openqa.selenium.remote.HttpCommandExecutor.execute(Unknown Source)
                        at org.openqa.selenium.remote.RemoteWebDriver.execute(Unknown Source)
                        at org.openqa.selenium.remote.RemoteWebElement.execute(Unknown Source)
                        at org.openqa.selenium.remote.RemoteWebElement.upload(Unknown Source)
                        at java.base / java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java: 197)
                        at java.base / java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java: 1625)
                        at java.base / java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java: 509)
                        at java.base / java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java: 499)
                        at java.base / java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java: 921)
                        at java.base / java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java: 234)
                        at java.base / java.util.stream.ReferencePipeline.collect(ReferencePipeline.java: 682)
                        at org.openqa.selenium.remote.RemoteWebElement.sendKeys(Unknown Source)

已尝试方案 #

• 使用JavaScriptExecutor设置元素可见，无效，问题根源在文件上传请求的端点
• 尝试重写UPLOAD_FILE命令，未解决

原因分析 #

这个错误源于Selenium 4.x版本的RemoteWebDriver使用了W3C协议的新文件上传端点/session/{sessionId}/se/file，但ChromeDriver 112不支持该端点——旧版本ChromeDriver未完全适配Selenium 4的W3C文件上传命令，导致请求被识别为未知命令。

另外，若文件不在Remote节点本地，sendKeys会触发Selenium的跨节点文件上传逻辑，而旧版ChromeDriver无法处理该逻辑，也会引发此错误。

解决方案 #

方案1：JavaScript直接设置元素值（文件在Remote节点本地） #

绕过Selenium的上传命令，直接通过JS设置input元素的value属性：

WebElement fileInput = driver.findElement(By.xpath("//input[@type='file']"));
JavascriptExecutor js = (JavascriptExecutor) driver;
js.executeScript("arguments[0].value = arguments[1];", fileInput, "/path/to/file.txt");

方案2：升级ChromeDriver版本 #

ChromeDriver 112适配性不足，建议升级到与Selenium 4.12.1兼容的版本（Selenium 4.12.1推荐Chrome/ChromeDriver版本114-116），新版本完全支持W3C文件上传命令，可解决端点不识别问题。

方案3：配置FileDetector上传本地文件到Remote节点 #

如果文件在本地机器，需要上传到Remote节点，设置LocalFileDetector让RemoteWebDriver自动处理文件传输：

driver.setFileDetector(new LocalFileDetector());
WebElement fileInput = driver.findElement(By.xpath("//input[@type='file']"));
fileInput.sendKeys(new File("/local/path/to/file.txt").getAbsolutePath());

注：使用Selenium Grid时，需确保Grid节点支持文件上传功能且配置正确。

内容的提问来源于stack exchange，提问作者Automation Coding