1、

import java.util.Scanner;
public class Email {
	public static void main(String[] args){
		Scanner in=new Scanner(System.in);
		System.out.println("请输入一个email地址：");
		String e=in.next();
		if((!e.startsWith("@"))&&((e.endsWith("com"))||(e.endsWith("cn"))||(e.endsWith("net"))||(e.endsWith("gov"))||(e.endsWith("edu"))||(e.endsWith("org")))&&(e.indexOf("@")!=-1)&&(e.indexOf(".")!=-1)&&((e.indexOf("@"))<(e.indexOf(".")))){
			System.out.println("该地址有效！");
		}
		else
			System.out.println("地址非法！");
	}
}







2、import java.util.Scanner;
public class Test {
	public static void main(String[] args){
		Scanner in=new Scanner(System.in);
		System.out.println("请输入一个字符串：");
		String x=in.next();
		System.out.println("请输入要查找的子串：");
		String y=in.next();
		System.out.println("字串的个数为："+times(x,y));
	}
	public static int times(String m,String n){
		int count=0,x=0,y;
		x=m.indexOf(n);
		y=n.length();
		while(x!=-1){
			count++;
			x=m.indexOf(n,x+y);
		}
		return count;
	}
}







3、import java.util.Scanner;

public class Wenjian {
	public static void main(String args[]) {
		String flag;
		Scanner wenjian = new Scanner(System.in);
		System.out.print("请输入文件:\n");
		//System.out.println();
		String str1 = wenjian.nextLine();
		String sz1[] = str1.split("\\,");
		for (int i = 0; i < sz1.length; i++) {
			System.out.print(sz1[i]+" ");
		}
		System.out.println("\n将文件名首字母变成大写：");
		for (int j = 0; j < sz1.length; j++) {
			char b = sz1[j].charAt(0);
			b = (char) (b - 32);
			flag = sz1[j].substring(1);
			System.out.print(b + flag+" ");
		}
		String hz[] = new String[sz1.length];
		for (int z = 0; z < sz1.length; z++) {
			int y = sz1[z].lastIndexOf(".");
			hz[z] = sz1[z].substring(y + 1);
		}
		System.out.println("\n最终统计：");
		System.out.println("文件名称 \t 数量");
		int sz[] = new int[sz1.length];
		for (int i = 0; i < hz.length; i++) {
			if (hz[i].equals("niu") == false) {
				sz[i]++;
			}
			for (int j = i + 1; j < hz.length; j++) {
				if (hz[i].equals(hz[j])) {
					hz[j] = "niu";
					sz[i]++;
				}
			}
			if (hz[i].equals("niu") == false) {
				System.out.println(hz[i] + "  \t " + sz[i]);
			}
		}
	}
}




4、import NYJ.*;

public class TestDemo {

public static void main(String args[]) {

Worker[] workers = new Worker[5];
Worker[] workers1 = new Worker[5];
for (int i = 0; i < 5; i++) {

workers[i] = new Worker("0000" + (i + 1), "worker" + (i + 1), "女", "宣传部",
new MyDate("2017", "10", (i + 1) + ""), new MyDate("2017", "11", "" + (i + 1)));
workers1[i] = new Worker("0000" + (6 + i), "worker" + (6 + i), "男", "办公部",
new MyDate("2017", "10", (i + 6) + ""), new MyDate("2017", "11", "" + (i + 6)));
}

display(workers);
display(workers1);

}

public static void display(Worker[] workers) {

for (int i = 0; i < workers.length; i++) {
System.out.println(workers[i]);
}
}
}
import NYJ.MyDate;

public class Worker {

String workerId;	
String workerName;	
String workerSex;	
String workerPartment;	
MyDate workerBirthday;	
MyDate workerBeginDate;	

public Worker() {

}

public Worker(String id,String name,String sex,String partment,MyDate birthday,MyDate beginDate) {

this.workerId = id;
this.workerName = name;
this.workerSex = sex;
this.workerPartment = partment;
this.workerBirthday = birthday;
this.workerBeginDate = beginDate;
}


public String getWorkerId() {
return workerId;
}

public void setWorkerId(String workerId) {
this.workerId = workerId;
}

public String getWorkerName() {
return workerName;
}

public void setWorkerName(String workerName) {
this.workerName = workerName;
}

public String getWorkerSex() {
return workerSex;
}

public void setWorkerSex(String workerSex) {
this.workerSex = workerSex;
}

public String getWorkerPartment() {
return workerPartment;
}

public void setWorkerPartment(String workerPartment) {
this.workerPartment = workerPartment;
}

public MyDate getWorkerBirthday() {
return workerBirthday;
}

public void setWorkerBirthday(MyDate workerBirthday) {
this.workerBirthday = workerBirthday;
}

public MyDate getWorkerBeginDate() {
return workerBeginDate;
}

public void setWorkerBeginDate(MyDate workerBeginDate) {
this.workerBeginDate = workerBeginDate;
}

public String toString() {
return "\n职工号：" + workerId + "\n姓名：" + workerName
+ "\n性别：" + workerSex + "\n职工部门："
+ workerPartment + "\n生日：" + workerBirthday
+ "\n工作时间：" + workerBeginDate;
}

}
public class MyDate {

private String year;
private String month;
private String day;

public MyDate() {

}

public MyDate(String year, String month, String day) {

this.year = year;
this.month = month;
this.day = day;
}

public String getYear() {
return year;
}

public void setYear(String year) {
this.year = year;
}

public String getMonth() {
return month;
}

public void setMonth(String month) {
this.month = month;
}

public String getDay() {
return day;
}

public void setDay(String day) {
this.day = day;
}

public String toString() {
return this.year + "-" + this.month + "-" + this.day ;
}

}