[3]Selenium学习系列---- 一个简单的Selenium Java 工程

在前面的一个章节，笔者介绍了[1]Selenium学习系列---- Selenium IDE工具的安装，顺便告诉大家一个小秘密，其实Selenium IDE还可以录制网页的操作过程，并导出成C#，Java，Python，Ruby等各种各样形式的代码。笔者就以Selenium IDE录制并导出Java代码为例子，给大家演示一个Selenium Hello World项目。

1. 打开Selenium IDE,并输入一个目标网站地址并开启录制功能。本文以Tomcat的官方网站为例子，http://tomcat.apache.org/

2. 上面红线框内的准备就绪后，点击Selenium IDE右边录制按钮，开始录制。

3. 这个时候在http://tomcat.apache.org/网站上的任意操作都会被Selenium IDE记录下来。

4. 选择导出代码，并取名为ApacheWebSiteTest.java

5. 打开Eclipse，新建一个Maven的工程，下面是Maven的pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.sample.selenium</groupId><artifactId>selenium-learn</artifactId><version>0.0.1-SNAPSHOT</version><name>selenium-learn</name><description>selenium-learn1</description><repositories><repository><id>central</id><name>Maven Repository Switchboard</name><layout>default</layout><url>http://repo1.maven.org/maven2</url><snapshots><enabled>false</enabled></snapshots></repository></repositories><dependencies><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version></dependency><dependency><groupId>org.seleniumhq.selenium</groupId><artifactId>selenium-java</artifactId><version>3.0.1</version></dependency></dependencies></project>

6. 把上面的ApacheWebSiteTest.java复制到这个maven项目中。

package com.example.tests;import java.util.regex.Pattern;import java.util.concurrent.TimeUnit;import org.junit.*;import static org.junit.Assert.*;import static org.hamcrest.CoreMatchers.*;import org.openqa.selenium.*;import org.openqa.selenium.firefox.FirefoxDriver;import org.openqa.selenium.support.ui.Select;public class ApacheWebSiteTest {  private WebDriver driver;  private String baseUrl;  private boolean acceptNextAlert = true;  private StringBuffer verificationErrors = new StringBuffer();  @Before  public void setUp() throws Exception {    driver = new FirefoxDriver();    baseUrl = "http://tomcat.apache.org/";    driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);  }  @Test  public void testApacheWebSite() throws Exception {    driver.get(baseUrl + "/");    driver.findElement(By.linkText("Home")).click();    driver.findElement(By.linkText("PoweredBy")).click();    driver.findElement(By.linkText("Tomcat Connectors")).click();    driver.findElement(By.linkText("Tomcat 8.5")).click();    driver.findElement(By.xpath("(//a[contains(text(),'Tomcat Native')])[2]")).click();    driver.findElement(By.linkText("archive download site")).click();    driver.findElement(By.linkText("Tomcat Native")).click();  }  @After  public void tearDown() throws Exception {    driver.quit();    String verificationErrorString = verificationErrors.toString();    if (!"".equals(verificationErrorString)) {      fail(verificationErrorString);    }  }  private boolean isElementPresent(By by) {    try {      driver.findElement(by);      return true;    } catch (NoSuchElementException e) {      return false;    }  }  private boolean isAlertPresent() {    try {      driver.switchTo().alert();      return true;    } catch (NoAlertPresentException e) {      return false;    }  }  private String closeAlertAndGetItsText() {    try {      Alert alert = driver.switchTo().alert();      String alertText = alert.getText();      if (acceptNextAlert) {        alert.accept();      } else {        alert.dismiss();      }      return alertText;    } finally {      acceptNextAlert = true;    }  }}

7. 注意上面的代码跑起来是会抛出下面的异常的

java.lang.IllegalStateException: The path to the driver executable must be set by the webdriver.gecko.driver system property; for more information, see https://github.com/mozilla/geckodriver. The latest version can be downloaded from https://github.com/mozilla/geckodriver/releasesat com.google.common.base.Preconditions.checkState(Preconditions.java:199)at org.openqa.selenium.remote.service.DriverService.findExecutable(DriverService.java:109)at org.openqa.selenium.firefox.GeckoDriverService.access$000(GeckoDriverService.java:37)at org.openqa.selenium.firefox.GeckoDriverService$Builder.findDefaultExecutable(GeckoDriverService.java:95)at org.openqa.selenium.remote.service.DriverService$Builder.build(DriverService.java:296)at org.openqa.selenium.firefox.FirefoxDriver.createCommandExecutor(FirefoxDriver.java:277)at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:247)at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:242)at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:238)at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:127)at com.example.tests.ApacheWebSiteTest.setUp(ApacheWebSiteTest.java:20)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.RunBefores.evaluate(RunBefores.java:24)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:678)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)java.lang.NullPointerExceptionat com.example.tests.ApacheWebSiteTest.tearDown(ApacheWebSiteTest.java:39)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.RunAfters.evaluate(RunAfters.java:33)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:678)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

8. 解决方法是，针对Firefox浏览器，需要下载geckodriver.exe web驱动（webDriver，网上可以搜索geckodriver.exe 的下载）并在setup（）方法中设置下面的类似代码：

 @Before  public void setUp() throws Exception {    System.setProperty("webdriver.gecko.driver","D:/drivers/geckodriver.exe");    driver = new FirefoxDriver();    baseUrl = "http://tomcat.apache.org/";    driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);  }

恭喜你，第一个Selenium Hello World的例子就这样写成了，是不是很简单啊！！！！

对了，对于上面7中遇到的问题，还有另外一种更智能和方便的解决方案（前提是读者的网络足够强大能访问这些网站，具体原因，你懂的！）

在Pom.xml文件的依赖中加入

<dependency>    <groupId>io.github.bonigarcia</groupId>    <artifactId>webdrivermanager</artifactId>    <version>1.4.10</version></dependency>

然后在每次新建WebDriver对象之前，调用下面的方法。比如在setup（）方法中。

MarionetteDriverManager.getInstance().setup();

如果读者对于后面的一种方式感兴趣的话，可以自己测试验证。