println()循环50次…

恩，这个我以前做过，并且实现了。我晚上给你发我咋做的。

可以，请搜索我的控制台版贪吃蛇，用到清屏幕

回到寝室了 http://wenwen.sogou.com/z/q329717071.htm，http://down.51cto.com/data/80661

/**
系统登陆。要求使用初始化参数的方式输入用户名和密码。在程序运行之前先判断输入的参数个数是否合法。如果不合法，
则提醒用户的程序执行不，并退出程序。如果用户已经正确输入了参数，则就可以进行用户名和密码的验证。
如果信息正确则显示“欢迎雷柔光临！”，否则显示“错误的用户名及密码”
*/
import java.util.Scanner;
public class denglu
{
public static void main(String [] args)
{
Scanner input = new Scanner(System.in);
Chushihua yonghu = new Chushihua();
String c;
String c1;
String y = "y";
String n = "n";
System.out.println("------------------------------欢迎使用雷大班长用户登录系统--------------------");
System.out.println("\n");
System.out.println(" -------------请初始化用户名及密码----------");
System.out.println("\n");
System.out.print(" --------------请初始化用户名：");
String name = input.next();
System.out.println("\n");
String mima1;
String mima2;
while(true)
{
System.out.print(" ---------------请初始化密码：");
mima1 = input.next();
System.out.println("\n");
System.out.print(" ---------------请确认初始化密码：");
mima2 = input.next();
if (mima1.equals(mima2))
{
CLS.CLS();
System.out.println("\n");
System.out.println("\n");
System.out.println("--------------------------恭喜您，注册用户成功！------------------------------");
System.out.println("是否继续（y/n）?");
c = input.next();
//用户密码输入验证
if (c.equals(y))
{
CLS.CLS();
System.out.println("------------------------------欢迎使用雷大班长用户登录系统--------------------");
YanZheng lei = new YanZheng();
lei.y = yonghu;
System.out.println("\n");
System.out.println("-----------用户登录界面：");
System.out.println("\n");
System.out.print(" -------------------------请输入用户名：");
String me = input.next();
System.out.println("\n");
System.out.print( " ------------------------请输入密码：");
String pc = input.next();
lei.me1 = name;
lei.pc1 = mima1;
lei.setMe(me);
lei.setPc(pc);
lei.sure();
}
break;
} else
{
CLS.CLS();
System.out.println("\n");
System.out.println("\n");
System.out.println("------------------------您两次密码输入有误，请查正后再次输入------------------");
System.out.println("是否继续（y/n）?");
c1 = input.next();
if (c1.equals(n))
{
break;
}
}
}
//yonghu.sure();
yonghu.setName(name);
yonghu.setMima1(mima1);
yonghu.setMima2(mima2);
//Runtime.getRuntime().exec("cmd /c start cls ");
}
}
class Chushihua
{
private String name;
private String mima1;
private String mima2;
public void setName(String name)
{
this.name = name;
}
public String gerName()
{
return name;
}
public void setMima1(String mima1)
{
this.mima1 = mima1;
}
public String gerMima1()
{
return mima1;
}
public void setMima2(String mima2)
{
this.mima2 = mima2;
}
public String getMima2()
{
return mima2;
}
}
class YanZheng
{
private String me;
private String pc;
String me1;
String pc1;
Chushihua y;
public void setMe(String me)
{
this.me = me;
}
public void setPc(String pc)
{
this.pc = pc;
}
public String getMe()
{
return me;
}
public String getpc()
{
return pc;
}
public void sure()
{
if (me.equals(me1))
{
if (pc.equals(pc1))
{
CLS.CLS();
System.out.println("\n");
System.out.println("\n");
System.out.println("\n");
System.out.println("*****************************欢迎雷大人光临！！！******************************");
}else
{
CLS.CLS();
System.out.println("\n");
System.out.println("\n");
System.out.println("\n");
System.out.println("$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$傻x。。。密码错误！$$$$$$$$$$$$$$$$$$$$$$$$$$$ ");
}
}else
{
CLS.CLS();
System.out.println("\n");
System.out.println("\n");
System.out.println("\n");
System.out.println("$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$傻x。。。用户名错误！$$$$$$$$$$$$$$$$$$$$$$$$$$$ ");
}
}
}

怎能实现输入的密码不显示密码，而显示***呢？

雷大班长。。。好逗，。

syso

用java实现在命令方式清屏
java实现清屏功能
1. 编写一个类ClearScreen.java
public class ClearScreen{
Static
{
loadLibrary("Clear");
}
public native static void clearScreen();
public static void main(String[] args){
clearScreen();
}
}
2. javac ClearScreen.java -> ClearScreen.class
3. javah ClearScreen -> ClearScreen.h
4. 编写ClearScreen.cpp实现native方法clearScreen();
#include <jni.h>
#include "ClearScreen.h"
#include <stdlib.h>
JNIEXPORT VOID JNICALL Java_ClearScreen_clearScreen(JNIEnv *, jclass)
{
system("cls");
}
5.安装一个microsoft compiler 编译ClearScreen.cpp，得到Clear.dll
注意：将Jdk安装环境include目录下的jawt_md.h jni_md.h jni.h三个头文件copy到 Microsoft Visual Studio的include目录下
cl -LD ClearScreen.cpp -FeClear.dll
其中 -LD create .dll -Fe name executable file

直接cls不就行了

直接调系统命令行清屏吧。