声明外部库在Java中 - 编译错误

Question

我不能编译命令行（仅在Eclipse）我Program.java。发生在JUnit类 当我想用

javac Program.java 

编译它“无法找到符号”错误。

Eclipse有JUnit的classes在它的插件，但编译它在我自己，我需要以某种方式编译我的junit.jar与程序。我怎样才能做到这一点？这似乎不符合

javac -cp absolutePathTo\JUnitJar Program.java 

工作或者是这个问题可能造成因为JUnit classes没有在我的（嵌套）新Thread类实现的？

C:\Documents and Settings\xxxx\Desktop\eclipse\xxxx\Program\src\da 
    ta>javac -cp junit-4.10.jar Testworks.java 
    Program.java:81: package org.junit.runner does not exist 
    import org.junit.runner.Description; 
         ^
    Program.java:82: package org.junit.runner does not exist 
    import org.junit.runner.JUnitCore; 
         ^
    Program.java:83: package org.junit.runner does not exist 
    import org.junit.runner.Request; 
         ^
    Program.java:84: package org.junit.runner does not exist 
    import org.junit.runner.Result; 
         ^
    Program.java:85: package org.junit.runner.notification does not exist 
    import org.junit.runner.notification.Failure; 
             ^
    Program.java:86: package org.junit.runner.notification does not exist 
    import org.junit.runner.notification.RunListener; 
             ^
    Program.java:253: cannot find symbol 
    symbol : class JUnitCore 
    location: class data.Program 
      JUnitCore jCore; //-> Core Runner - has no pleaseStop() 
      ^
    Program.java:254: cannot find symbol 
    symbol : class RunListener 
    location: class data.Program 
      RunListener jRl; 
      ^
    Program.java:255: cannot find symbol 
    symbol : class Request 
    location: class data.Program 
      Request jRq; 
      ^
    Program.java:2167: cannot find symbol 
    symbol : class RunListener 
    location: class data.Program 
      class RlOne extends RunListener{ 
           ^
    Program.java:2170: cannot find symbol 
    symbol : class Description 
    location: class data.Program.RlOne 
          public void testRunStarted(Description descRun) 
                ^
    Program.java:2179: cannot find symbol 
    symbol : class Description 
    location: class data.Program.RlOne 
          public void testStarted(Description descStart) 
                ^
    Program.java:2185: cannot find symbol 
    symbol : class Description 
    location: class data.Program.RlOne 
          public void testFinished(Description descFinish) 
                ^
    Program.java:2202: cannot find symbol 
    symbol : class Failure 
    location: class data.Program.RlOne 
          public void testFailure(Failure failure) 
                ^
    Program.java:2211: cannot find symbol 
    symbol : class Description 
    location: class data.Program.RlOne 
          public void testIgnored(Description descIgno) 
                ^
    Program.java:2221: cannot find symbol 
    symbol : class Result 
    location: class data.Program.RlOne 
          public void testRunFinished(Result result) 
                 ^
    Program.java:2422: cannot find symbol 
    symbol : variable Request 
    location: class data.Program.ThirdThread 
            jRq = Request.aClass(cRun); 
             ^
    Program.java:2426: cannot find symbol 
    symbol : variable Request 
    location: class data.Program.ThirdThread 
            jRq = Request.method(cRun, comb_meth.getSelected 
    Item().toString()); 
             ^
    Program.java:2584: cannot find symbol 
    symbol : class JUnitCore 
    location: class data.Program 
          jCore = new JUnitCore(); 
             ^
    19 errors 

当我想用Eclipse来启动它编译Program.class Java命令的输出：

C:\Documents and Settings\xxxx\Desktop\eclipse\xxxx\Program\bin\da 
ta>java Program 
Exception in thread "main" java.lang.NoClassDefFoundError: Program 
Caused by: java.lang.ClassNotFoundException: Program 
     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) 
Could not find the main class: Program. Program will exit. 

Answer 1

现在，我得到它的工作。

我改名junit-4.10.jar到junit.jar，它移动到另一个文件夹，并在某种程度上这解决了这个问题：

javac -classpath "C:\Documents and Settings\x\Desktop\eclipse\x\Program\extres\junit.jar" src\data\Program.java 

BTW：

当我C:\Documents and Settings\x\Desktop\eclipse\x\Program\是它还适用于：

javac -classpath extres\junit.jar src\data\Program.java 

Answer 2

在使用外部罐子javac命令，你应该使用

javac -classpath path-to-external-jar/jarname1.jar;/path-to-external-jar2/jarname2.jar Program.java

同为java命令：

java -classpath path-to-external-jar/jarname1.jar;/path-to-external-jar2/jarname2.jar Program

Answer 3

您确实需要了解更多关于Java CLASSPATH的主题。无论是在编译时还是在运行时，你的错误都是由于你没有提供完整的类路径。