blocks|key|261865|text|假设您使用了cd+C:/projects，而HelloWorld.class使用的是C:/projects/com，那么只需键入：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|261866|java+com.HelloWorld|code-block|syntax|javascript|261867|entityMap^0|6|E|M|G|16|F|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|U|8|@]|D|@]|E|$]]]|L|$]]

Suppose you did <code>cd C:/projects</code> and <code>HelloWorld.class</code> is in <code>C:/projects/com</code>, then just type:

<pre><code>java com.HelloWorld
</code></pre>

blocks|key|261892|text|尝试使用绝对目录或将HelloWorld.class放入..\last_directory\com|type|unstyled|depth|inlineStyleRanges|entityRanges|data|261893|1.+java+-cp+.......\last_directory+com.HelloWorld
2.+java+-cp+.......\last_directory+HelloWorld(with+created+com)|code-block|syntax|javascript|261894|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Try to use absolute directory or put your HelloWorld.class into ..\last_directory\com

<pre><code>1. java -cp .......\last_directory com.HelloWorld
2. java -cp .......\last_directory HelloWorld(with created com)
</code></pre>

blocks|key|261913|text|在Java文件夹下创建一个名为com的文件夹，并将HelloWorld.java放入com文件夹。然后再次运行javac和java。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|261914|entityMap^0|F|3|P|F|16|3|1J|5|1P|4|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|G|$]]

Create a folder named <code>com</code> under Java folder and put the <code>HelloWorld.java</code> into <code>com</code> folder. Then run again <code>javac</code> and <code>java</code>.

blocks|key|261932|text|您应该首先通过在CMD中键入以下命令来编译它，例如，您的文件位于c:\+directory中：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|261933|C:\com>javac+HelloWorld.java|code-block|syntax|javascript|261934|之后，您可以通过键入以下命令来运行结果：|261935|c:\com>java+HelloWorld|261936|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

You should compile it first by typing this command in CMD, for exemple your file is in c:\ directory :

<pre><code>C:\com&gt;javac HelloWorld.java
</code></pre>

After that you can run the result by typing:

<pre><code>c:\com&gt;java HelloWorld
</code></pre>

blocks|key|45388|text|在运行java类时不需要-cp标志，在从二进制(jar)文件运行类或主程序时需要-cp。从命令行运行主程序时，需要确保类与java文件中的包名位于相同的文件夹结构中，例如。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|45389|home/user/foo+java+com.test.className+++

here+classNmae+class+file+and+exist+under+home/user/foo/com/test|code-block|syntax|javascript|45390|希望能有所帮助。|45391|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

You do not need a -cp flag while running a java class , -cp needed while running a class or a main program from a binary (jar) file.
While running a main program from a command line you need to make sure you have the class in the same folder structure as package name in the java file, ex.

<pre><code>home/user/foo java com.test.className 

here classNmae class file and exist under home/user/foo/com/test
</code></pre>

hope it helps.

blocks|key|261995|text|当你直接从你的'*.class‘文件的文件夹中执行'java’命令时，可能会出现这样的问题。此命令应从项目的“父”目录执行。下面的文章很好地解释了这一切：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|261996|http://javarevisited.blogspot.de/2015/04/error-could-not-find-or-load-main-class-helloworld-java.html|offset|length|261997|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|2T|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@$D|O|E|P|1|Q]]|A|$]]|$1|F|3|-4|5|6|7|R|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|C]]]]

There could be such a problem, when you are executing 'java' command directly from folder of your '*.class' files. This command should be executed from project 'parent' directory. All is well explained in the following article:

<a href="http://javarevisited.blogspot.de/2015/04/error-could-not-find-or-load-main-class-helloworld-java.html" rel="nofollow noreferrer">http://javarevisited.blogspot.de/2015/04/error-could-not-find-or-load-main-class-helloworld-java.html</a>

blocks|key|262033|text|当您编译java代码时，使用-d，在您的例子中，它将是|type|unstyled|depth|inlineStyleRanges|entityRanges|data|262034|javac+-d+.+com.HelloWorld.java|code-block|syntax|javascript|262035|在上面的命令之后，java编译器生成一个名为"com“的文件夹，在"com”文件夹下，你会看到你的HelloWorld.class|262036|然后在运行javac的同一文件夹下，运行以下命令|262037|java+com.HelloWorld|262038|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|D|7|S|8|@]|9|@]|A|$E|F]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

When you compile the java code, use -d, in your case, it would be

<pre><code>javac -d . com.HelloWorld.java
</code></pre>

After the above command, java compiler generate a folder named "com", under the "com" folder, you will see your HelloWorld.class

Then under the same folder as you run javac, run the following command

<pre><code>java com.HelloWorld
</code></pre>

blocks|key|45459|text|假设该文件位于C:/projects/com/HelloWorld，您可以尝试以下方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|45460|1.java+-cp+c:/projects+com.HelloWorld|offset|length|style|CODE|45461|2.cd+c:/projects|45462|java+com.HelloWorld|45463|(示例2在很多情况下都不起作用，比如java进程。)|45464|如果没有包声明，会有一些小的变化。|45465|1.java+-cp+c:/projects/com+HelloWorld|45466|2.cd+c:/projects/com|45467|java+HelloWorld|45468|(出于同样的原因，它并不好。)|45469|或者，相对路径是可以的，但有一些风险。最后，记住将类文件放在cmd的末尾。|45470|entityMap^0|0|2|Z|0|2|E|0|0|J|0|0|0|2|Z|0|2|I|0|0|F|0|0|0^^$0|@$1|2|3|4|5|6|7|11|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|12|8|@$D|13|E|14|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|15|8|@$D|16|E|17|F|G]]|9|@]|A|$]]|$1|J|3|K|5|6|7|18|8|@$D|19|E|1A|F|G]]|9|@]|A|$]]|$1|L|3|M|5|6|7|1B|8|@]|9|@]|A|$]]|$1|N|3|O|5|6|7|1C|8|@]|9|@]|A|$]]|$1|P|3|Q|5|6|7|1D|8|@$D|1E|E|1F|F|G]]|9|@]|A|$]]|$1|R|3|S|5|6|7|1G|8|@$D|1H|E|1I|F|G]]|9|@]|A|$]]|$1|T|3|U|5|6|7|1J|8|@$D|1K|E|1L|F|G]]|9|@]|A|$]]|$1|V|3|W|5|6|7|1M|8|@]|9|@]|A|$]]|$1|X|3|Y|5|6|7|1N|8|@]|9|@]|A|$]]|$1|Z|3|-4|5|6|7|1O|8|@]|9|@]|A|$]]]|10|$]]

Suppose the file locates at C:/projects/com/HelloWorld 
and you can try the following ways. 

1.<code>java -cp c:/projects com.HelloWorld</code> 

2.<code>cd c:/projects</code> 
 &nbsp;<code>java com.HelloWorld</code> 
(The example 2 is not working in many situation,such as java process.)

if there is no package declaration and there will be a little change.

1.<code>java -cp c:/projects/com HelloWorld</code> 

2.<code>cd c:/projects/com</code> 
 &nbsp;<code>java HelloWorld</code> 
(It's not good with the same reason.)

alternatively,relative path will be ok but has some risk.
Last remember put the class file in end of cmd.

I keep getting errors when I make my <code>.class</code> part of a <code>package</code> and try to run it from cmd.

Here's the code that works after using <code>javac</code> and then java:

<pre><code>class HelloWorld {
 public static void main(String[] args) {
 System.out.println("Hello World!");
 }
}
</code></pre>

and then the code that does not work:

<pre><code>package com;

class HelloWorld {
 public static void main(String[] args) {
 System.out.println("Hello World!");
 }
}
</code></pre>

giving me this error after trying to run the program via the command: <code>java HelloWorld</code>:

<pre><code>Exception in thread "main" java.lang.NoClassDefFoundError: HelloWorld (wrong nam
e: com/HelloWorld)
 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)
</code></pre>

Here's what I've tried doing so far:

<pre><code>java -cp . HelloWorld
java -cp . com.HelloWorld
java -cp . com/HelloWorld
java HelloWorld
java com.HelloWorld
java com/HelloWorld
</code></pre>

Keep in mind that <code>javac</code> returns with no errors and that simply removing <code>package com;</code> solves the problem. Sometimes in other scenarios I get an error that says the main class file cannot be found or something along those lines.

What am I doing wrong?

How to run a .class file that is part of a package from cmd?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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当我使我的.class成为package的一部分并试图从命令运行它时，我一直收到错误。下面是在使用javac和java之后的工作代码：class HelloWorld {    public static void main(String[] args) {        System.out.println("Hel...

问如何运行cmd包中的.class文件？
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问如何运行cmd包中的.class文件？
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