如何使用javac编译java包结构 [英] how to compile java package structures using javac

问题描述

目标

我试图从命令行编译一个java包来导入我自己的另一个包。 p>

以前的工作

我在网上找到了以下教程：http://www.roseindia.net/java/master-java/createsubpackage.shtml

但似乎我得到一个错误，当我尝试编译最终的java文件（CallPackage.java）。

示例的文件结构

这是文件结构：

  + test_directory（包含CallPackage.java）
  - > importpackage 
  - > subpackage（包含HelloWorld.java）
  

代码
$ b

这里是CallPackage.java

  /// CallPackage.java 
 import importpackage .subpackage。*; 
 class CallPackage {
 public static void main（String [] args）{
 HelloWorld h2 = new HelloWorld（）; 
 h2.show（）; 
} 
} 
  

这里是HelloWorld.java

  /// HelloWorld.java 
 
 package importpackage.subpackage; 
 
 public class HelloWorld {
 public void show（）{
 System.out.println（This is the function of the class HelloWorld !!）; 
} 
} 
  

已尝试的步骤 p>

1. 转到子软件包并编译HelloWorld.java

   
   
   

   $ javac HelloWorld。 java




2. 转到test_directory并编译CallPackage.java

   
   
   

   $ javac CallPackage.java

编译器错误

在最后一个cmd上得到错误：

  CallPackage.java:1：package importpackage.subpackage不存在
 import importpackage.subpackage。*; 
 ^ 
 CallPackage.java:4：找不到符号
 symbol：class HelloWorld 
 location：class CallPackage 
 HelloWorld h2 = new HelloWorld（）; 
 ^ 
 CallPackage.java:4：找不到符号
 symbol：class HelloWorld 
 location：class CallPackage 
 HelloWorld h2 = new HelloWorld（）; 
 ^ 
 3错误
  

非常感谢任何帮助！

-Peter

解决方案

您确定importpackage / subpackage在您的类路径中吗？

-cp path或-classpath路径

指定在哪里找到使用者类别文件和（可选）注释处理器和源文件。此类路径覆盖CLASSPATH环境变量中的用户类路径。如果既未指定CLASSPATH，也未指定-cp或-classpath，则用户类路径由当前目录组成。有关更多详细信息，请参阅设置类路径。

如果未指定-sourcepath选项，则还会搜索用户类路径以查找源文件。

如果未指定-processorpath选项，则还将搜索类路径以获取批注处理器。

http://docs.oracle.com/javase/7/docs/technotes/tools/windows /javac.html

goal

I am trying to compile (from the command line) a java package that imports another package of my own.

previous work

I was following a tutorial online located at: http://www.roseindia.net/java/master-java/createsubpackage.shtml

but it seems that I get an error when I try to compile the final java file (CallPackage.java).

File Structure of Example

Here is the file structure:

+test_directory (contains CallPackage.java)
   -> importpackage
       -> subpackage (contains HelloWorld.java)

Code

here is CallPackage.java

/// CallPackage.java
import importpackage.subpackage.*;
class CallPackage{
  public static void main(String[] args){
  HelloWorld h2=new HelloWorld();
  h2.show();
  }
}

and here is HelloWorld.java

///HelloWorld.java

package importpackage.subpackage;

public class HelloWorld {
  public void show(){
  System.out.println("This is the function of the class HelloWorld!!");
  }
}

Attempted Steps

1. go to subpackage and compile HelloWorld.java

   $javac HelloWorld.java

2. go to test_directory and compile CallPackage.java

   $javac CallPackage.java

Compiler Error

but I get an error on the last cmd:

CallPackage.java:1: package importpackage.subpackage does not exist
import importpackage.subpackage.*;
^
CallPackage.java:4: cannot find symbol
symbol  : class HelloWorld
location: class CallPackage
  HelloWorld h2=new HelloWorld();
  ^
CallPackage.java:4: cannot find symbol
symbol  : class HelloWorld
location: class CallPackage
  HelloWorld h2=new HelloWorld();
                    ^
3 errors

Thanks so much for any help!

-Peter

解决方案

Are you sure importpackage/subpackage is in your classpath?

-cp path or -classpath path

Specify where to find user class files, and (optionally) annotation processors and source files. This class path overrides the user class path in the CLASSPATH environment variable. If neither CLASSPATH, -cp nor -classpath is specified, the user class path consists of the current directory. See Setting the Class Path for more details.

If the -sourcepath option is not specified, the user class path is also searched for source files.

If the -processorpath option is not specified, the class path is also searched for annotation processors.

http://docs.oracle.com/javase/7/docs/technotes/tools/windows/javac.html

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