创建jar文件

运行环境：jdk1.8.0_162 + window10 + Ecipse Java Photon(4.8.0).

　　本文将会演示两种创建并使用java的jar的常用方法。1、使用“Eclipse Java Photon”创建并使用jar。2、使用cmd窗口doc命令创建并使用jar。演示实例：复数类。其代码如下：

package Complex;

public class complex {
    // 1. 私有属性：real（实部）、imag（虚部）。
    private double real, imag;
    // 2. 无参构造与带参构造
    public complex(){
        real=0.0;
        imag=0.0;
    }
    public complex(double r, double i) {
        real=r;
        imag=i;
    }
    // 3. 编写获取属性值和设置属性值的方法
    public double Real() {
        return real;
    }
    public double Imag() {
        return imag;
    }
    public void set(double r, double i) {
        real=r;
        imag=i;
    }
    // 4. 定义一个实现输出复数信息的方法
    public void print(complex case1) {
        if (case1.imag==0) {
            System.out.println(case1.real);
        } else {
            if(case1.imag>0) {
                System.out.println(case1.real+ " " +"+"+ " " +case1.imag+"i");
            }else {
                System.out.println(case1.real+ " " +case1.imag+"i");
            }
        }
        
        if(case1.real==0) {
            System.out.println(case1.imag+"i");
        }
    }
    // 5.定义复数的四则运算
    public complex add(complex a, complex b) {
        complex c = new complex();
        c.real=a.real+b.real;
        c.imag=a.imag+b.imag;
        return c;
    }
    public complex sup(complex a, complex b) {
        complex c = new complex();
        c.real=a.real-b.real;
        c.imag=a.imag-b.imag;
        return c;
    }
    public complex mul(complex a, complex b) {
        complex c = new complex();
        double x1,y1,x2,y2;
        x1=a.real; y1=a.imag;
        x2=b.real; y2=b.imag;
        c.real=x1*x2-y1*y2;
        c.imag=x1*y2+x2*y1;
        return c;
    }
    public complex div(complex x1, complex x2) {
        complex x3 = new complex();
        double a,b,c,d,k;
        a=x1.real; b=x1.imag;
        c=x2.real; d=x2.imag;
        k=1/(c*c+d*d);
        x3.real=k*(a*c+b*d);
        x3.imag=k*(b*c-a*d);
        return x3;
    }
}

Complex