1.计算天数 /*给定一个年月日,计算是一年的第几天 (如输入:2 15 结果:第46天) */ public class Demo1 { public static void main(String[] args){ int year = 2012; int month = 12; int day = 31; int total = 0; //累计天数 /* switch(month - 1) {//0 - 11 case 0: total = day;break; case 1: total…

1.bank类 package com.yfs.javase; //类封装 public class BankCard { //属性 int balance;//默认0 实例变量 分配给每个对象一个 //String name; // 方法 存钱 public void saveMoney(int money) { if(money < 0) { System.out.println("非法操作..."); return; } System.out.println("向…

1.USB package com.yfs.javase; public interface USB { //定义规范 public void read(); public void write(); } 2.UDisk读写 package com.yfs.javase; public class UDisk implements USB { @Override public void read() { System.out.println("从U盘读取数据..."); } @Over…

1.Person package com.yfs.javase; public class Person { private String name; private int age; private char sex; private void privateMehtod() { System.out.println("call privateMehtod()..."); } public Person() { //System.out.println("创建Perosn对…

Intent对象和Bundle对象 功能主要是在 MainActivity中定义了2个EditText,当用户输入内容,把他传入到第二个活动, 自己新创的活动中,MyActivity中 放在MainActivity.java文件上 public class MainActivity extends ActionBarActivity { EditText et1; //activity_main.xml文件拖入两个EditText EditText et2; Button button; //拖…

1.JdbcUtil package com.yfs.javase.jdbc; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class JdbcUtil { private static final String driver = "sun.j…

1.Mouse package com.yfs.javase; public class Mouse { private int index = 1; private boolean isLive = false; //跳出方法 同步锁 public synchronized void jump() { while(true) { if(!isLive ) { System.out.println("跳出第 " + index + " 田鼠"); //修改田鼠状态…

1.for package com.yfs.javase; import java.awt.Color; import java.util.Calendar; import java.util.HashSet; import java.util.Set; @SuppressWarnings("all") public class ForDemo { /** * @param args */ public static void main(String[] args) { //useAr…

Person类: package com.yfs.javase; import java.util.Date; public class Person implements Comparable { private String name; private int age; private char sex; public static Date date = new Date(); @Override public int hashCode() { final int prime = 31;…

1.set/list package com.yfs.javase; import java.util.ArrayList; import java.util.Collection; import java.util.HashSet; import java.util.LinkedHashSet; import java.util.LinkedList; import java.util.List; import java.util.Set; import java.util.SortedSet…