我构建了一个类来验证向Twitter提交的推文。每当我尝试点击提交按钮时，我都会收到InvalidSelectorException。它似乎有一个完全合理的xpath，采用xpath=(//button[@type='button'])[17]的形式，所以我不确定它在抱怨什么。有一个雄鹅：
public class ValidationTest {
private WebDriver driver;
private String baseUrl;
private StringBuffer verificationErrors = new StringBuffer();
@Before
public void setUp() throws Exception {
// Google Chrome
File file = new File("C:\\Users\\User\\plugins\\Twitter\\src\\chromedriver.exe");
System.setProperty("webdriver.chrome.driver", file.getAbsolutePath());
driver = new ChromeDriver();
// Firefox
// driver = new FirefoxDriver();
baseUrl = "https://www.twitter.com";
driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);
}
@Test
public void testValidation() throws Exception {
// Authentication information
String username = "user123";
String password = "pass123";
// Open site
launchActivity("/");
// Maximize window
maximizeWindow();
// Enter authentication information
sendKeysAndWait("signin-email", username);
sendKeysAndWait("signin-password", password);
// Log in
clickXPathButtonAndWait("//button[@type='submit']");
// Parses a text file to produce an ArrayList from which short (140
// char) messages may be sent
parseStory();
}
/**
*
* @param extension
* The remainder of the URL, after baseUrl
*/
private void launchActivity(String extension) {
driver.get(baseUrl + extension);
}
private void maximizeWindow() throws InterruptedException {
driver.manage().window().maximize();
sleepShort();
}
/**
* s Writes a string to an HTML element and waits a random time
*
* @param elem
* The element to send the keys
* @param keys
* The string to write to the element
* @throws InterruptedException
*/
private void sendKeysAndWait(String elem, String keys) throws InterruptedException {
driver.findElement(By.id(elem)).click();
driver.findElement(By.id(elem)).sendKeys(keys);
sleepShort();
}
/**
*
* @param id
* The id of the button found in HTML
* @throws InterruptedException
*/
private void clickButtonAndWait(String id) throws InterruptedException {
driver.findElement(By.id(id)).click();
sleepShort();
}
@SuppressWarnings("unused")
private void clickCSSButtonAndWait(String id) throws InterruptedException {
driver.findElement(By.cssSelector(id)).click();
sleepShort();
}
private void clickXPathButtonAndWait(String id) throws InterruptedException {
driver.findElement(By.xpath(id)).click();
sleepShort();
}
private void parseStory() throws FileNotFoundException, IOException, InterruptedException {
FileInputStream fstream = new FileInputStream("C:\\Users\\User\\workspace\\Twitter\\src\\text.txt");
BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
String strLine;
List<String> list = new ArrayList<String>();
// Read the text file line by line
while ((strLine = br.readLine()) != null) {
// Create ArrayList to store text in 140 character chunks
while ((strLine = br.readLine()) != null) {
if (!strLine.isEmpty()) {
list.add(strLine);
String[] stringArr = strLine.split("(?<=\\G.{140})");
System.out.println(Arrays.toString(stringArr));
// Send 1.5 messages per minute (40 messages per hour) for a
// total of 960 per day
for (String s : stringArr) {
clickButtonAndWait("tweet-box-home-timeline");
sendKeysAndWait("tweet-box-home-timeline", s);
//TODO The result is not a node set. and therefore cannot be converted to the desired type.
clickXPathButtonAndWait("xpath=(//button[@type='button'])[17]");
sleepLong();
}
System.out.println("All messages have been sent.");
}
}
}
// Close the input stream
br.close();
}
private void sleepLong() throws InterruptedException {
int randomWaitDuration = 75000 + (int) (Math.random() * 105000);
Thread.sleep(randomWaitDuration);
}
private void sleepShort() throws InterruptedException {
int randomWaitDuration = 500 + (int) (Math.random() * 1000);
Thread.sleep(randomWaitDuration);
}
@After
public void tearDown() throws Exception {
driver.quit();
String verificationErrorString = verificationErrors.toString();
if (!"".equals(verificationErrorString)) {
fail(verificationErrorString);
}
}
}
这是我的堆栈跟踪：
org.openqa.selenium.InvalidSelectorException: invalid selector: Unable to locate an element with the xpath expression xpath=(//button[@type='button'])[17] because of the following error:
TypeError: Failed to execute 'evaluate' on 'Document': The result is not a node set, and therefore cannot be converted to the desired type.
(Session info: chrome=51.0.2704.103)
(Driver info: chromedriver=2.21.371459 (36d3d07f660ff2bc1bf28a75d1cdabed0983e7c4),platform=Windows NT 6.1 SP1 x86_64) (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 77 milliseconds
For documentation on this error, please visit: http://seleniumhq.org/exceptions/invalid_selector_exception.html
Build info: version: '2.53.0', revision: '35ae25b', time: '2016-03-15 16:57:40'
System info: host: 'OLCZPR112319', ip: '10.99.133.77', os.name: 'Windows 7', os.arch: 'amd64', os.version: '6.1', java.version: '1.8.0_91'
Driver info: org.openqa.selenium.chrome.ChromeDriver
Capabilities [{applicationCacheEnabled=false, rotatable=false, mobileEmulationEnabled=false, chrome={chromedriverVersion=2.21.371459 (36d3d07f660ff2bc1bf28a75d1cdabed0983e7c4), userDataDir=C:\Users\MNXE\AppData\Local\Temp\scoped_dir1332_417}, takesHeapSnapshot=true, databaseEnabled=false, handlesAlerts=true, hasTouchScreen=false, version=51.0.2704.103, platform=XP, browserConnectionEnabled=false, nativeEvents=true, acceptSslCerts=true, locationContextEnabled=true, webStorageEnabled=true, browserName=chrome, takesScreenshot=true, javascriptEnabled=true, cssSelectorsEnabled=true}]
Session ID: 8d72512617454899692b23a3f15ade99
*** Element info: {Using=xpath, value=xpath=(//button[@type='button'])[17]}
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:206)
at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:158)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:678)
at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:363)
at org.openqa.selenium.remote.RemoteWebDriver.findElementByXPath(RemoteWebDriver.java:500)
at org.openqa.selenium.By$ByXPath.findElement(By.java:361)
at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:355)
at ValidationTest.clickXPathButtonAndWait(ValidationTest.java:124)
at ValidationTest.parseStory(ValidationTest.java:152)
at ValidationTest.testValidation(ValidationTest.java:73)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
答案 0 :(得分：1)
由于xpath表达式无效而发生此异常
"xpath=(//button[@type='button'])[17]"
作为参数传递给clickXPathButtonAndWait()方法。
试试这个
clickXPathButtonAndWait("//button[@type='button']")
用于您第一次登录时使用。