初学java，自己写的学员管理系统

import java.util.Scanner;

/**

 * 操作界面类

 */

public class  JieMian{

 StudentList yi=new StudentList();

 Scanner input = new Scanner(System.in);

 /**

  * 学员管理主界面

  */

 public void caiDan(){

     yi.chuShi();

        boolean lin=true;

     do{

      System.out.println("\n-----------ACCP学员管理系统-------------\n");

      System.out.println("\t\t1.教员登录");

      System.out.println("\t\t2.班主任登录 ");

      System.out.println("\t\t0.退出");

         System.out.println("\n----------------------------------------");

         System.out.print("请选择：");

         if(input.hasNextInt()==true){

            int choice = input.nextInt();

            switch(choice){

            case 1:

                caiDan1();

                break;

            case 2:

                caiDan2();

                break;

            case 0:

             System.out.println("程序退出，谢谢使用！");

                 return;

            default:

                 System.out.print("输入有误！请重新输入：");

            }

         }else{

          System.out.print("输入不合法!");

          lin=false;

         }

      }while(lin);

 }

 /**

  * 教员管理界面

  */

 public void caiDan1(){

  do{

            System.out.println("\n----------欢迎进行教员管理模块--------------\n");

            System.out.println("\t\t1.登记分数");

            System.out.println("\t\t2.扣作业表现分");

            System.out.println("\t\t3.显示学员信息");

            System.out.println("\t\t4.显示不及格的学员信息");

            System.out.println("\t\t0.返回上级菜单");

            System.out.println("\n-------------------------------------------");

            System.out.print("请选择以上功能：");

              int choice = input.nextInt();

              switch(choice){

              case 1:

                  System.out.print("请选择登记的项目 1.java  2.html  3.sql ：");

                  int lin=input.nextInt();

                  if(lin==1){

                   Student xin=new Student();

                 System.out.print("请输入登记的姓名：");

                 xin.name=input.next();

                 yi.java(xin);

                  }else if(lin==2){

                   Student xin=new Student();

                 System.out.print("请输入登记的姓名：");

                 xin.name=input.next();

                 yi.html(xin);

                  }else if(lin==3){

                   Student xin=new Student();

                 System.out.print("请输入登记的姓名：");

                 xin.name=input.next();

                 yi.sql(xin);

                  }else{

                   System.out.println("输入有误！");

                  }

                  return;

              case 2:

             System.out.print("请输入查找的姓名：");

             String name=input.next();

             yi.zuoY(name);

             break;

              case 3:

                yi.showAllStudent();

                break;

              case 4:

                yi.showUnPassStudent();

                break;

              case 0:

               return;

              default:

                   System.out.print("输入有误！请重新输入：");

              }

      }while(true);

 }

 /**

  * 班主任管理界面

  */

 public void caiDan2(){

   do{

         System.out.println("\n----------欢迎进行班主任管理模块--------------\n");

         System.out.println("\t\t1.考勤扣分");

         System.out.println("\t\t2.显示学员信息");

         System.out.println("\t\t3.按成绩高低显示学员信息");

         System.out.println("\t\t4.按姓名查找学员");

         System.out.println("\t\t5.添加学员");

         System.out.println("\t\t0.返回上级菜单");

         System.out.println("\n---------------------------------------------");

         System.out.print("请选择以上功能：");

         if(input.hasNextInt()==true){

             int choice = input.nextInt();

             switch(choice){

             case 1:

            System.out.print("请输入查找的姓名：");

            String name=input.next();

                  yi.kaoQ(name);

                  break;

             case 2:

               yi.showAllStudent();

               break;

             case 3:

               yi.chengJ();

                  break;

             case 4:

            System.out.print("请输入查找的姓名：");

            String name1=input.next();

            yi.seekStudent(name1);

            break;

             case 5:

              do{

               Student xin=new Student();

               System.out.print("请输入添加的姓名：");

               xin.name=input.next();

          if(yi.addStudent(xin)==true){

           System.out.println("录入成功！");

          }else if(yi.addStudent(xin)==false){

           System.out.println("姓名重复！");

          }

          System.out.println("y继续/其他退出\n是否继续？:");

          String lin=input.next();

          if(!"y".equals(lin)){

           break;

          }

              }while(true);

              break;

             case 0:

             return;

             default:

                  System.out.print("输入有误！请重新输入：");

             }

          }else{

           System.out.print("输入不合法！程序结束！");

          }

       }while(true);

 }

 

}

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import java.util.Scanner;

/**

 * 综合管理类

 */

public class StudentList { 

    Student[] students=new Student[20];

    public void chuShi(){

     students[0]= new Student();

     students[0].name="小龙女";

     students[0].zuoWei=1;

     students[0].java=87;

     students[0].html=65;

     students[0].sql=97;

     students[1]= new Student();

     students[1].name="嫦娥";

     students[1].zuoWei=2;

     students[1].java=77;

     students[1].html=49;

     students[1].sql=83;

     students[2]= new Student();

     students[2].name="西施";

     students[2].zuoWei=3;

     students[2].java=31;

     students[2].html=93;

     students[2].sql=77;

     students[3]= new Student();

     students[3].name="杨贵妃";

     students[3].zuoWei=4;

     students[3].java=19;

     students[3].html=88;

     students[3].sql=59;

     students[4]= new Student();

     students[4].name="小蛮腰";

     students[4].zuoWei=5;

     students[4].java=97;

     students[4].html=100;

     students[4].sql=82;

     students[5]= new Student();

     students[5].name="貂蝉";

     students[5].zuoWei=6;

     students[5].java=34;

     students[5].html=84;

     students[5].sql=76;

    }

     //显示所有学员信息

    public void showAllStudent(){

  System.out.println("座位\t"+"姓名\t"+"java成绩\t\t"+"html成绩\t\t"+"sql成绩\t"+"出勤\t"+"作业表现");

  for(int i=0;i<students.length;i++){

   if(students[i]!=null){

    System.out.print(students[i]+"\n");

   }

  }

    }

    //添加学员信息,要求不能同名，要有空位才能添加，添加成功返回true

    public boolean addStudent(Student a){

     boolean jia=false;

     for(int lin=0;lin<students.length;lin++){

      if(students[lin]!=null){

       if(students[lin].name.equals(a.name)){

        jia=false;

        return jia;

       }

      }

     }

     for(int j=0;j<students.length;j++){

   if(students[j]==null){

    students[j]=new Student();

    students[j].zuoWei=j+1;

    students[j]=a;

    jia=true;

    return jia;

   }

     }

     System.out.println("班级学员已满！");

  return jia;

    }

    //根据姓名查找学员姓名，找到返回该学员，没找到返回null

    public Student seekStudent(String a){

     

  for(int i=0;i<students.length;i++){

   if(students[i]!=null){

    if(students[i].name.equals(a)){

     System.out.println("座位\t"+"姓名\t"+"java成绩\t\t"+"html成绩\t\t"+"sql成绩\t"+"出勤\t"+"作业表现");

     System.out.println(students[i]+"\n");

     return students[i];

    }

   }

  }

  System.out.println("没有找到该同学！");

  return null;

    }

   

    //登记java分数

    public Student java(Student a){

     Scanner input=new Scanner(System.in);

     

  for(int i=0;i<students.length;i++){

   if(students[i]!=null){

    if(students[i].name.equals(a.name)){

     System.out.print("请输入"+a.name+"的java成绩：");

     students[i].java=input.nextInt();

     System.out.println("登记成功！");

     return students[i];

    }

   }

  }

  System.out.println("没有找到该同学！");

  return null;

    }

   

    //登记html分数

    public Student html(Student a){

     Scanner input=new Scanner(System.in);

     

  for(int i=0;i<students.length;i++){

   if(students[i]!=null){

    if(students[i].name.equals(a.name)){

     System.out.print("请输入"+a.name+"的html成绩：");

     students[i].html=input.nextInt();

     System.out.println("登记成功！");

     return students[i];

    }

   }

  }

  System.out.println("没有找到该同学！");

  return null;

    }

   

    //登记sql分数

    public Student sql(Student a){

     Scanner input=new Scanner(System.in);

     

  for(int i=0;i<students.length;i++){

   if(students[i]!=null){

    if(students[i].name.equals(a.name)){

     System.out.print("请输入"+a.name+"的sql成绩：");

     students[i].sql=input.nextInt();

     System.out.println("登记成功！");

     return students[i];

    }

   }

  }

  System.out.println("没有找到该同学！");

  return null;

    }

   

   

    //将不及格的学员找出，自成一个全新的数组返回

    public void showUnPassStudent(){

     Student[] xin=new Student[20];

     int j=0;

     for(int i=0;i<students.length;i++){

      if(students[i]!=null){

       if(students[i].java<60||students[i].html<60||students[i].sql<60){

        xin[j]=students[i];

        j++;

       }

      }

     }

     System.out.println("座位\t"+"姓名\t"+"java成绩\t\t"+"html成绩\t\t"+"sql成绩\t"+"出勤\t"+"作业表现");

     for(int a=0;a<xin.length;a++){

      if(xin[a]!=null){

       System.out.println(xin[a]+"\n");

      }

     }

    }

   

    //按成绩排序，返回一个全新的已排好序的数组，不影响原数组

    public Student[] sortByScore(){

     Student[] pai=new Student[20];

     for(int a=0;a<students.length;a++){

      

      pai[a]=students[a];

     }

     for(int i=0;i<pai.length-1;i++){  //外层循环决定趟数，数组长度-1

      for(int j=pai.length-1;j>i;j--){ //每次得到一个最小或最大的值，放在最上的做位置

       if(pai[j]!=null){

        if(pai[j].java>pai[j-1].java){ //内层循环从最后元素开始，前后两两比较，进行交换

         Student lin = pai[j];

         pai[j] = pai[j-1];

         pai[j-1] = lin;

        }

       }

      }

     }

     return pai;

    }

    /**

     * 成绩按高低输出

     */

    public void chengJ(){

     Student[] xin=new Student[20];

     xin=sortByScore();

     System.out.println("座位\t"+"姓名\t"+"java成绩\t\t"+"html成绩\t\t"+"sql成绩\t"+"出勤\t"+"作业表现");

     for(int i=0;i<students.length;i++){

      if(xin[i]!=null){

       System.out.println(xin[i]+"\n");

      }

     }

    }

   

    /**

     * 扣作业表现分

     */

    public void zuoY(String a){

     Scanner input=new Scanner(System.in);

     

  for(int i=0;i<students.length;i++){

   if(students[i]!=null){

    if(students[i].name.equals(a)){

     System.out.print("请输入"+a+"要扣的作业表现分：");

     int lin=input.nextInt();

     students[i].zuoYe=students[i].zuoYe-lin;

     System.out.println("修改成功！");

     return;

    }

   }

  }

  System.out.println("没有找到该同学！");

    }

   

   

    /**

     * 扣考勤分

     */

    public void kaoQ(String a){

     Scanner input=new Scanner(System.in);

     

  for(int i=0;i<students.length;i++){

   if(students[i]!=null){

    if(students[i].name.equals(a)){

     System.out.print("请输入"+a+"要扣的考勤分：");

     int lin=input.nextInt();

     students[i].chuQin=students[i].chuQin-lin;

     System.out.println("修改成功！");

     return;

    }

   }

  }

  System.out.println("没有找到该同学！");

    }

}

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/**

 * 学生信息类

 */

public class Student{ 

 int zuoWei,chuQin=100,zuoYe=100;

 String name;

 double java=0,html=0,sql=0;

 public String toString(){

  return zuoWei+"\t"+name+"\t"+java+"\t\t"+html+"\t\t"+sql+"\t"+chuQin+"\t"+zuoYe;

 }

}

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public class XueY {

 public static void main(String[] args){

  JieMian yi=new JieMian();

  yi.caiDan();

 }

}