应该在lib / ext中放置一个jar文件而不是在Windows XP上使用CLASSPATH吗？(Should putting a jar file in lib/ext work instead of using a CLASSPATH on Windows XP?)

 我有两个jar文件，A.jar和B.jar。 A包含我的main函数，它依赖于B中定义的类。 
 
 我将A和B放在同一个文件夹中，该文件夹位于Windows PATH中，并尝试在A中运行我的主... 
 
java -jar A.jar -dosomething
 
 这给了我一个B方法的java.lang.NoClassDefFound错误，我在-dosomething下面的代码中调用它。 有趣的是，它找到了A.jar并调用了main方法，但它找不到B.jar，即使它与A.jar位于同一个文件夹中。 
 
 所以我（再次）阅读了关于CLASSPATHs和JAVA_HOME变量的内容，并确保我的JAVA_HOME指向正确的位置。 这个文档描述了我应该如何将我的扩展jar文件（在我的案例B中）放入/ lib / ext文件夹中，所以我尝试了，但是我得到了相同的java.lang.NoClassDefFound错误。 
 
 我使用的是Java jdk1.5.0_10，所以为了更好的衡量，我还将B.jar放在了jre / lib / ext文件夹下面。 
 
 所以现在我有三个地方，PATH上的本地文件夹，JAVA_HOME / lib / ext和JAVA_HOME / jre / lib / ext，我仍然得到同样的错误。 
 
 应该使用lib / ext工作吗？ 我到底在哪里放置我的B.jar文件才能正常工作？ 

I have two jar files, A.jar and B.jar. A contains my main function and it relies on classes defined in B.
 
I put A and B in the same folder, which is in the Windows PATH, and try and run my main in A...
 
java -jar A.jar -dosomething
 
This gives me a java.lang.NoClassDefFound error on a method of B that I call in the code underneath -dosomething. Interestingly it has found A.jar and called the main method, but it can't find B.jar, even though it is in the same folder as A.jar.
 
So I read around (again) about CLASSPATHs and the JAVA_HOME variable and I made sure that my JAVA_HOME is pointing to the right place. This document describes how I should be able to put my extension jar file(s), in my case B, into the /lib/ext folder, so I tred that, but I get the same java.lang.NoClassDefFound error.
 
I am using Java jdk1.5.0_10, so for good measure I also placed B.jar in the jre/lib/ext folder underneath there.
 
So now I have it in three places, the local folder on the PATH, JAVA_HOME/lib/ext and JAVA_HOME/jre/lib/ext and I still get the same error.
 
Should using lib/ext work? Where on earth have I got to put my B.jar file for this to work properly?

原文：https://stackoverflow.com/questions/8773081