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

问题描述

我正在尝试编译(从命令行)一个导入我自己的另一个包的 java 包.我正在关注在线教程，但似乎在我尝试编译最终的 java 文件 (CallPackage.java).

I am trying to compile (from the command line) a java package that imports another package of my own. I was following a tutorial online but it seems that I get an error when I try to compile the final java file (CallPackage.java).

这里是文件结构:

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

这是 CallPackage.java:

Here is 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:

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!!");
  }
}

尝试的步骤

1. 转到子包并使用 $javac HelloWorld.java 编译 HelloWorld.java.
2. 转到 test_directory 并使用 $javac CallPackage.java 编译 CallPackage.java.

1. Go to the subpackage and compile HelloWorld.java with $javac HelloWorld.java.
2. Go to test_directory and compile CallPackage.java with $javac CallPackage.java.

这给了我最后一条命令的错误:

This gives me an error on the last command:

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

如何编译这两个包?非常感谢您的帮助！

How can I compile both packages? Thanks so much for any help!

推荐答案

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

Are you sure importpackage/subpackage is in your classpath?

-cp 路径或 -classpath 路径

-cp path or -classpath path

指定在哪里可以找到用户类文件，以及(可选)注释处理器和源文件.该类路径覆盖 CLASSPATH 环境变量中的用户类路径.如果 CLASSPATH、-cp 和 -classpath 均未指定，则用户类路径由当前目录组成.有关详细信息，请参阅设置类路径.

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.

如果未指定 -sourcepath 选项，还会在用户类路径中搜索源文件.

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

如果未指定 -processorpath 选项，还会在类路径中搜索注解处理器.

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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