Can't run Java example for Selenium / WebDrive

2020-02-26 09:18发布

问题:

Having a problem getting going with Selenium on Java. I'm trying to follow the example on this page: http://code.google.com/p/selenium/wiki/GettingStarted

I'm typing this:

$ javac -cp . -cp ~/Downloads/selenium-2.20.0/selenium-java-2.20.0-srcs.jar -cp ~/Downloads/selenium-2.20.0/selenium-java-2.20.0.jar -g Example.java

And getting this:

alis-mac-pro:selenium ali$ java ExampleException in thread "main" java.lang.NoClassDefFoundError: Example (wrong name: org/openqa/selenium/example/Example)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)

I pasted the code from the example into Example.java.

UPDATE


A kind soul on #java at irc.freenode.net told me to chain my entries in the classpath. So, instead of:

$ javac -cp . -cp ~/Downloads/selenium-2.20.0/selenium-java-2.20.0-srcs.jar -cp ~/Downloads/selenium-2.20.0/selenium-java-2.20.0.jar -g Example.java

I used:

javac -cp .:~/Downloads/selenium-2.20.0/selenium-java-2.20.0-srcs.jar:~/Downloads/selenium-2.20.0/selenium-java-2.20.0.jar -g Example.java

Great! :-) But now new errors:

Example.java:3: cannot find symbol
symbol  : class By
location: package org.openqa.selenium
import org.openqa.selenium.By;
                          ^
Example.java:4: cannot find symbol
symbol  : class WebDriver
location: package org.openqa.selenium
import org.openqa.selenium.WebDriver;
                          ^
Example.java:5: cannot find symbol
symbol  : class WebElement
location: package org.openqa.selenium
import org.openqa.selenium.WebElement;
                          ^
Example.java:6: package org.openqa.selenium.htmlunit does not exist
import org.openqa.selenium.htmlunit.HtmlUnitDriver;
                                   ^
Example.java:13: cannot find symbol
symbol  : class WebDriver
location: class org.openqa.selenium.example.Example
        WebDriver driver = new HtmlUnitDriver();
        ^
Example.java:13: cannot find symbol
symbol  : class HtmlUnitDriver
location: class org.openqa.selenium.example.Example
        WebDriver driver = new HtmlUnitDriver();
                               ^
Example.java:19: cannot find symbol
symbol  : class WebElement
location: class org.openqa.selenium.example.Example
        WebElement element = driver.findElement(By.name("q"));
        ^
Example.java:19: cannot find symbol
symbol  : variable By
location: class org.openqa.selenium.example.Example
        WebElement element = driver.findElement(By.name("q"));
                                                ^
8 errors

UPDATE


I tried:

$ jar tf ~/Downloads/selenium-2.20.0/selenium-java-2.20.0.jar 

But I see the org.openqa.selenium.By class, for example, so it doesn't appear that I'm missing any packages.

UPDATE


Okay! :-) I removed the package specifier. I executed:

$ javac -classpath ~/Downloads/selenium-2.20.0/selenium-java-2.20.0.jar Example.java

Which is what a commenter gave me, except I added the full path to the .jar. Then I executed:

$ java -cp .:~/Downloads/selenium-2.20.0/selenium-java-2.20.0.jar Example

Which gave me:

Exception in thread "main" java.lang.NoClassDefFoundError: org/openqa/selenium/WebDriver
Caused by: java.lang.ClassNotFoundException: org.openqa.selenium.WebDriver
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)

UPDATE


Hurray! Victory, thanks to Mike Kwan. The following is what worked:

alis-mac-pro:selenium ali$ javac -cp ".:/Users/ali/Downloads/selenium-2.20.0/selenium-java-2.20.0.jar:/Users/ali/Downloads/selenium-2.20.0/selenium-java-2.20.0-srcs.jar:/Users/ali/Downloads/selenium-2.20.0/libs/*" Example.java
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
alis-mac-pro:selenium ali$ java -cp ".:/Users/ali/Downloads/selenium-2.20.0/selenium-java-2.20.0.jar:/Users/ali/Downloads/selenium-2.20.0/selenium-java-2.20.0-srcs.jar:/Users/ali/Downloads/selenium-2.20.0/libs/*" Example
Page title is: Cheese! - Google Search

BTW, I added the last part of the "-cp" option (for "libs/*"), because that's where HTMLUnit was when I downloaded the Selenium / WebDriver stuff.

回答1:

Compile like so:

javac -classpath selenium-server-standalone-2.20.0.jar Example.java

Unless you put the Java file in the org.openqa.selenium.example, you will have to remove the package specifier. Run the compiled file like so:

java -cp .:selenium-server-standalone-2.20.0.jar Example

This chains the current directory to the classpath.



回答2:

For those doing a java dynamic web project in eclipse, and receiving the error above, the following link might help:

http://me-ol-blog.blogspot.co.il/2013/07/using-selenium-in-java-dynamic-web.html

Basically, it mentions that the standalone jar is not "standalone" when using dynamic web projects and that a different jar should be used along with its dependent jars.



回答3:

Add html unit driver dependency in your pom file.

<dependency>
    <groupId>org.seleniumhq.selenium</groupId>
    <artifactId>htmlunit-driver</artifactId>
    <version>2.21</version>
</dependency> 

It is working fine for me.