如何让 Eclipse 包含第三方库

Question

classpath

<?xml version="1.0" encoding="UTF-8"?>
<classpath>
    <classpathentry exported="true" kind="lib" path="lib/jsoup-1.7.2.jar"/>
    <classpathentry kind="src" path="src"/>
    <classpathentry exported="true" kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.7"/>
    <classpathentry kind="output" path="bin"/>
</classpath>

I get the following error:

Exception in thread "main" java.lang.NoClassDefFoundError: gSportsParser (wrong
name: gSportsParser/gSportsParser)
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(Unknown Source)
        at java.security.SecureClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.access$100(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)

which is due to java not being able to find the Jsoup jar. I have looked up this problem and I've tried editing the build path, putting the jsoup in the same directory as the .class and in a subdirectory of the directory of class (/lib) to no avail. How do I make Java realize jsoup is there?

Answer 1

In Eclipse (the same as using javac to compile and java or javaw to run), the build classpath is separate from the runtime classpath. Adding JARs to your build classpath does not necessarily add them to the runtime classpath of your program/app.

You didn't mention how you're running your app, but in Eclipse there is the concept of Launch Configurations that are used to configure the runtime for a program. A Launch Configuration is created when you do something like right-click on a project or class and choose Run As... You can also view and edit the launch configurations from the toolbar buttons for Run and Debug. The bottom line is that Launch Configurations have a classpath and it must included all the projects and libraries (JARs) that your code uses.

Answer 2

You need to include the jar file in your classpath. If you use eclipse, after adding the jar file , you should have something like the attached illustration