定义一个复数类.（1）构造函数重载默认构造函数 、带参数构造函数（2）定义友元函数,完成输出复数对象的功能.（3）定义成

package com。test;public class ComplexNum {\x09// Z = a + bi\x09private int Rez;\x09// 实部\x09private int Imz;\x09// 虚部\x09\x09\x09public int getRez() {\x09\x09return Rez;\x09}\x09public void setRez(int rez) {\x09\x09Rez = rez;\x09}\x09public int getImz() {\x09\x09return Imz;\x09}\x09public void setImz(int imz) {\x09\x09Imz = imz;\x09}\x09public ComplexNum(){}\x09\x09// 构造函数\x09public ComplexNum(int rez,int imz) {\x09\x09super();\x09\x09Rez = rez;\x09\x09Imz = imz;\x09}\x09\x09// 加\x09public static void plus(ComplexNum a,ComplexNum b){\x09\x09ComplexNum temp = new ComplexNum();\x09\x09temp。setRez(a。getRez()+b。getRez());\x09\x09temp。setImz(a。getImz()+b。getImz());\x09\x09display(temp);\x09}\x09\x09// 减\x09public static void minus(ComplexNum a,ComplexNum b){\x09\x09ComplexNum temp = new ComplexNum();\x09\x09temp。setRez(a。getRez()-b。getRez());\x09\x09temp。setImz(a。getImz()-b。getImz());\x09\x09display(temp);\x09}\x09\x09// 显示\x09public static void display(ComplexNum a){\x09\x09StringBuffer sb = new StringBuffer();\x09\x09sb。append(a。getRez());\x09\x09if(a。getImz()>0){\x09\x09\x09sb。append("+"+a。getImz()+"i");\x09\x09}else if(a。getImz()