重载 员工的属性和方法

Employee.java

package com.google.eshop.javase;

public class Employee {
	//不要把main方法写入一个类，main方法不是类必须
	//TestEyployee 单元测试   压力测试
	//类中的两部分1.属性  2.方法（1.构造方法      2.普通方法）
		//Integer eid;
	    private Integer eid;
		private String ename;
		//String gender;
		private String genter;
		//Boolean married;
		private Boolean married;
		//方法重载只能通过参数列表的不同来区分，不能通过是否有返回值来区分
		//只要参数列表不同就可以了   可以交换参数之间的次序  尽量不要通过参数的次序来区别不同的方法
		//这样的做法会让编译器的压力比较大
		public Employee(){
			
		}
		public Employee(int id,String name) {
			eid=id;
			ename=name;
		}
		public Employee(int id,String name,Boolean isMarried) {
			eid=id;
			ename=name;
			married=isMarried;
		}
		/*public void setEid(Integer eid) {
			this.eid = eid;
		}
		public void setEname(String ename) {
			this.ename = ename;
		}
		public void setGenter(String genter) {
			this.genter = genter;
		}
		public void setMarried(Boolean married) {
			this.married = married;
		}*/
		public Integer getEid() {
			return eid;
		}
		public String getEname() {
			return ename;
		}
		public String getGenter() {
			return genter;
		}
		public Boolean getMarried() {
			return married;
		}
		public void working(int eid,String name) {
			System.out.println("工号："+eid+"名字："+name+"在工作");
		}
		/*public void working(String ename,int eid) {
			System.out.println("NO："+eid+"isMarried："+ename+"在工作");
		}*/
		public String eat(int eid,String name,Boolean married) {
			return "工号"+eid+"姓名："+name+"婚否"+married;
		}

	}

TestEmployee.java

package com.google.eshop.javase;

import java.util.Stack;

public class TestEmployee {
	//Employee emp是引用  在堆栈中（Stack）   new后面的是对象（地址空间）（heap）堆
	public static void main(String[] args) {
		//System.out.println(i);   没有赋值
		//局部变量必须赋值
		Employee emp=new Employee();
		emp=new Employee();
		emp.working(22,"");
		emp.working(45, "");
		/*if(null!=emp) {
			   emp.eid=12;
			   emp.ename="john";
			   emp.working(emp.eid, emp.ename);
			}*/
		//泛型 generic type 1.5新特性
		//限制在一个对象内，只能放置一种类型
		Stack
 
   stack=new Stack
  
   (); //stack.push("abc"); //报错，只能是int型 stack.push(12); //进栈 stack.push(34); stack.push(56); stack.push(67); int top=stack.peek(); //顶元素 System.out.println(top); int element=stack.pop(); System.out.println(element); element=stack.pop(); //出栈 System.out.println(element); String str="def"; str.indexOf("a"); int result=Integer.parseInt("126358"); System.out.println(result); } }
  
 

TestInterface.java

package com.google.eshop.javase;
//堆栈，堆，常量存储，非RAM存储

public class TestInterface {

	public static void main(String[] args) {
		//如果对象只使用一次可以使用匿名对象，如果要多次使用，需要用引用指向他
		//new Employee().eid=34;
		new Employee().getEid();
		new Employee().working(12, "abc");
		new Employee().working(23, "gates");
		Employee emp=new Employee();
		emp=new Employee();
		emp.working(34, "def");
		emp.working(56, "ios");
		//emp.eid=456;
		//字符串少做拼接操作
		String str="abc";
		String a="abc";
		System.out.println(a+str);
		str=new String("def");
		System.out.println(a+str);
	}
}

TestOverLoading.java

package com.google.eshop.javase;

public class TestOverLoading {
	public static void main(String[] args) {
		Employee employee=new Employee();//无变量
		System.out.println(employee.getEname());
		employee=new Employee(23,"bush");//两个变量
		System.out.println(employee.getEname());
		employee=new Employee(45,"gates",false);//三个变量
		System.out.println(employee.getEname());
	}

}

WrapClass.java

package com.google.eshop.javase;

import java.math.BigDecimal;
import java.math.BigInteger;
//import java.lang.*;  默认已导入，不需再导
//默认导入的是java.lang.*
//import javax.xml.crypto.Data;
//javax  扩展包
public class WrapClass {
   @SuppressWarnings("deprecation")
public static void main(String[] args) {
	   Employee emp=new Employee();
	   System.out.println(emp);
	   Integer a=45+56;
	    a=new Integer(56);//autoBoxing
	    a=new Integer(5555);//autoBoxing
	    System.out.println(a.intValue());
	    System.out.println(a);//unBoxing
	    String str=new String("andiod");
	    //String str=new String();
	    System.out.println(str);
	//int Integer
    //double  Double
	//char  Character
	//有两个数据类型是没有对应基本数据类型的  没有自动拆装箱的功能
	 BigInteger bi=new BigInteger("555555");
	 BigInteger ab=bi.add(new BigInteger("7777777"));
	 //bi.subtract(ab);
	 //bi.multiply(ab);
	 //bi.divide(ab);
	 System.out.println(ab);
	 BigDecimal bd=new BigDecimal("678.9999999");
	            bd=BigDecimal.valueOf(56.789);
	 System.out.println(bd.divide(new BigDecimal("0.1")));
	 //Data data;
	 //int c=5;
	 Integer c=new Integer(555);
	         c=555;//将一个基本类型赋值给一个引用类型   autoBoxing
	  System.out.println(c.intValue());
	  System.out.println(c);//将一个引用类型的值直接取出来 不用方法 unBoxing
	  Employee emp1=new Employee();
	  System.out.println(emp1);
}
}