java基本例子

文件结构

D:\jp\jarDemo\IAmMainClass.java

import iAmPackage.*;

public class IAmMainClass
{
    public static void main(String[] args) 
    {
        System.out.println("I am MainClass!");
        
//这个是直接调用的方法，必须是静态的。
        iAmPackage.IAmALib.IAmStaticFunction("ha ha");
        
        IAmALib libObj = new IAmALib();
//这个是实例后的对象方法，不需要一定是静态的。				
	libObj.IAmGenaralFunction("gu gu");
    }
    
		
}

D:\jp\jarDemo\iAmPackage\IAmALib.java

package iAmPackage;


public class IAmALib
{
    public static void IAmStaticFunction(String var) 
    {
        System.out.println("I am AmStatic function!" + var);
    }
    
		public void IAmGenaralFunction(String var) 
    {
        System.out.println("I am Genaral function!" + var);
    }
}

D:\jp\jarDemo\MANIFEST.MF

Manifest-Version: 1.0
Created-By: 1.8.0_60 (Oracle Corporation)
Main-Class: IAmMainClass
 //注意最后必须是一行空行

1.编译

D:\jp\jarDemo>javac IAmMainClass.java
D:\jp\jarDemo\iAmPackage>javac IAmALib.java

2.打包

D:\jp\jarDemo>jar cvfm jarDemo.jar ./MANIFEST.MF ./IAmMainClass.class ./iAmPackage/IAmALib.class

3.执行

D:\jp\jarDemo>java -classpath . IAmMainClass

I am MainClass!
I am AmStatic function!ha ha
I am Genaral function!gu gu