简单介绍sql server 累计求和实现代码

导读	这篇文章主要为大家详细介绍了Java实现简易学籍管理系统，文中示例代码介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们可以参考一下

本文实例为大家分享了Java实现简易学籍管理系统的具体代码，供大家参考，具体内容如下

1、我们先来讲讲什么是泛型化编程

package 学生管理系统;
  
import java.util.ArrayList;
import java.util.List;
  
/*
 * 进行泛型化编程
 * @autor：pcb
 * */
public class TestGeneric {
    //进行泛型化编程，规定类型。
    public List  courses;
    public TestGeneric() {
        this.courses = new ArrayList();
    }
    public void testAdd() {
        CourseClass cr1 = new CourseClass("1","大学语文");
        courses.add(cr1);
        //泛型集合中不能添加规定意外的对象
        //courses.add("能否添加一些奇怪的东西");
        CourseClass cr2 = new CourseClass("2","Java基础");
        courses.add(cr2);
    }
    public void testForEach() {
        //进行泛型之后，可直接利用它规定的类型及其子类型直接进行访问
        for(CourseClass cr:courses) {
            System.out.println(cr.id+":"+cr.name);
        }
    }
    //泛型集合可以添加泛型的子类型的对象实例
    public void testChild() {
        ChildCourse ccr = new ChildCourse();
        ccr.id = "3";
        ccr.name = "我是子类的课程实例对象";
        courses.add(ccr);
    }
    //泛型必须使用包装类型进行创建,例如：int和integer
    public void testBaic() {
        List list = new ArrayList();
        list.add(1);
        System.out.println("基本类型必须使用包装类作为泛型！"+list.get(0));
    }
    public static void main(String[] args) {
        TestGeneric tg = new TestGeneric();
        tg.testAdd();
        tg.testForEach();
        tg.testChild();
        tg.testForEach();
        tg.testBaic();
        //tg.testForEach();
    }
}

2、我们开始进行管理系统的创建，创建一个学生类和一个课程类

package 学生管理系统;
  
import java.util.HashSet;
import java.util.Set;
public class StudentsClass implements Comparable  {
    public String id;
    public String name;
     
    public Set courses;
     
    public StudentsClass(String id,String name){
        this.id=id;
        this.name=name;
        this.courses=new HashSet();
    }
  
    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }
  
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (!(obj instanceof StudentsClass))
            return false;
        StudentsClass other = (StudentsClass) obj;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }
    public int compareTo(StudentsClass o) {
        return this.id.compareTo(o.id);
    }
}
package 学生管理系统;
  
public class CourseClass {
    public String id;
    public String name;
    public CourseClass(String id,String name){
        this.id=id;
        this.name=name;
    }
    public CourseClass() {
         
    }
     
    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (!(obj instanceof CourseClass))
            return false;
        CourseClass other = (CourseClass) obj;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }
}

3、利用List进行增加课程，删除课程，修改课程等的操作

package 学生管理系统;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
  
public class ListTest {
    //创建
public List coursesToSelect;
    //构造器
    public ListTest(){
         this.coursesToSelect = new ArrayList(); 
    }
     
    public void testAdd(){
        //加课
          CourseClass cr1 = new CourseClass("1","数据结构");
          coursesToSelect.add(cr1); 
          CourseClass temp = (CourseClass)coursesToSelect.get(0);
          System.out.println("添加了课程:"+temp.id+":"+temp.name);
          CourseClass cr2 = new CourseClass("2","c语言");
          coursesToSelect.add(0, cr2);
          CourseClass temp2 = (CourseClass)coursesToSelect.get(0);
          System.out.println("添加了课程:"+temp2.id+":"+temp2.name);
          CourseClass[] Course={new CourseClass("3","离散数学"),new CourseClass("4","汇编语言")};
          coursesToSelect.addAll(Arrays.asList(Course));
          CourseClass temp3 = (CourseClass)coursesToSelect.get(2);
          CourseClass temp4 = (CourseClass)coursesToSelect.get(3);
          System.out.println("添加了两门课程："+temp3.id+":"+temp3.name+";"+temp4.id+":"+temp4.name);
          CourseClass[] Course1= {new CourseClass("5","高等数学"),new CourseClass("6","大学英语")};
          coursesToSelect.addAll(2, Arrays.asList(Course1));
          CourseClass temp5 = (CourseClass)coursesToSelect.get(2);
          CourseClass temp6 = (CourseClass)coursesToSelect.get(3);
          System.out.println("添加了两门课程："+temp5.id+":"+temp5.name+";"+temp6.id+":"+temp6.name);
  
    }
        //迭代器输入方法
        public void testIterator() {
            Iterator it = coursesToSelect.iterator();
            System.out.println("可选择的课程（通过迭代器访问）：");
            while(it.hasNext()) {
                CourseClass cr  = (CourseClass) it.next();
                System.out.println("课程"+":"+cr.id+":"+cr.name);
            }
                 
        }
        //利用foreach语句进行遍历
        public void testForEach() {
            System.out.println("可选择的课程（通过FOREACH访问）：");
            for(Object obj:coursesToSelect) {
                CourseClass cr  = (CourseClass) obj;
                System.out.println("课程"+":"+cr.id+":"+cr.name);
            }
        }
        //进行修改操作
        public void testModify() {
            coursesToSelect.set(4, new CourseClass("7","毛概"));
        }
        //利用对象进行删除操作
        public void testRmove1() {
            System.out.println("通过对象进行删除");
            CourseClass cr = (CourseClass) coursesToSelect.get(4);
            System.out.println("我是课程："+cr.id+":"+cr.name);
            coursesToSelect.remove(cr);
            System.out.println("成功删除课程！！");
            testForEach();
        }
        //利用索引值进行删除操作
        public void testRmove2() {
//            CourseClass cr = (CourseClass) coursesToSelect.get(4);
//            System.out.println("我是课程："+cr.id+":"+cr.name);
            System.out.println("通过索引值进行删除");
            coursesToSelect.remove(4);
            System.out.println("成功删除课程！！");
            testForEach();
        }
        //进行删除，删除多位置的方法操作
        public void testRmove3() {
            System.out.println("删除4位置和5位置的课程");
            CourseClass [] Course={(CourseClass) coursesToSelect.get(4),(CourseClass) coursesToSelect.get(5)};
            //将Course数组转化成一个集合传递进去
            coursesToSelect.removeAll(Arrays.asList(Course));
            System.out.println("成功删除课程！！");
            testForEach();
            }
    public static void main(String[] args) {
        ListTest it = new ListTest();
        it.testAdd();
        it.test();
        //it.testIterator();
        //it.testForEach();
        //it.testModify();
        //it.testForEach();
        //it.testRmove2();
        it.testRmove3();
    }
}

4、利用set集合进行删除，添加，查询操作

package 学生管理系统;
  
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
  
public class SetTest {
    //创建
    public List  coursesToSelect;
    //向屏幕读取
    private Scanner console;
     
    public StudentsClass student;
    //进行构造
    public SetTest() {
        coursesToSelect = new ArrayList();
        console = new Scanner(System.in);
    }
     
    public void testAdd(){
        //加课
          CourseClass cr1 = new CourseClass("1","数据结构");
          coursesToSelect.add(cr1); 
          CourseClass temp = (CourseClass)coursesToSelect.get(0);
          //System.out.println("添加了课程:"+temp.id+":"+temp.name);
          CourseClass cr2 = new CourseClass("2","c语言");
          coursesToSelect.add(0, cr2);
          CourseClass temp2 = (CourseClass)coursesToSelect.get(0);
          //System.out.println("添加了课程:"+temp2.id+":"+temp2.name);
          CourseClass[] Course={new CourseClass("3","离散数学"),new CourseClass("4","汇编语言")};
          coursesToSelect.addAll(Arrays.asList(Course));
          CourseClass temp3 = (CourseClass)coursesToSelect.get(2);
          CourseClass temp4 = (CourseClass)coursesToSelect.get(3);
          //System.out.println("添加了两门课程："+temp3.id+":"+temp3.name+";"+temp4.id+":"+temp4.name);
          CourseClass[] Course1= {new CourseClass("5","高等数学"),new CourseClass("6","大学英语")};
          coursesToSelect.addAll(2, Arrays.asList(Course1));
          CourseClass temp5 = (CourseClass)coursesToSelect.get(2);
          CourseClass temp6 = (CourseClass)coursesToSelect.get(3);
          //System.out.println("添加了两门课程："+temp5.id+":"+temp5.name+";"+temp6.id+":"+temp6.name);
  
    }
    public void testForEach() {
        System.out.println("可选择的课程（通过FOREACH访问）：");
        for(Object obj:coursesToSelect) {
            CourseClass cr  = (CourseClass) obj;
            System.out.println("课程"+":"+cr.id+":"+cr.name);
        }
    }
    //查询是否包含此课程
    public void testListContains() {
        CourseClass course = coursesToSelect.get(0);
        System.out.println("取得课程："+course.name);
         
        System.out.println("备选课程是否包含课程："+course.name+","
                +coursesToSelect.contains(course));
        System.out.println("请输入课程名称：");
        String name = console.next();
        CourseClass course2 = new CourseClass();
        course2.name = name;
        System.out.println("新创建课程："+course2.name);
        System.out.println("备选课程是否包含课程："+course2.name+","
                +coursesToSelect.contains(course2));
        //indexof来求出索引
                if(coursesToSelect.contains(course2)) {
                    System.out.println("课程："+course2.name+"的索引位置为："+
                coursesToSelect.indexOf(course2));
                }
    }
    public void creatStudentAndSelect() {
        //创建一个学生对象
                 student = new StudentsClass("1","小明");
                System.out.println("欢迎学生："+student.name+"选课！");
                //从键盘输入课程
                Scanner console = new Scanner(System.in);
                for(int i = 0;i<3;i++) {
                    System.out.println("请输入课程ID");
                    String courseId = console.next();
                    for(CourseClass cr :coursesToSelect) {
                        if(cr.id.equals(courseId)) {
                            student.courses.add(cr);
                        student.courses.add(null);
                        student.courses.add(cr);
                        }
                    }
                }
    }
    //测试Set的contains方法
    public void testSetContains() {
        System.out.println("请输入学生已选的课程名：");
        String name =  console.next();
        CourseClass course2 = new CourseClass();
        course2.name = name;
        System.out.println("新创建课程："+course2.name);
        System.out.println("备选课程是否包含课程："+course2.name+","
                +student.courses.contains(course2));        
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        SetTest st = new SetTest();
        st.testAdd();
         st.testForEach();
        st.testListContains();
//        st.creatStudentAndSelect();
//        st.testSetContains();
    }
}

5、利用Map进行增加，删除，查询，修改操作

package 学生管理系统;
  
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Scanner;
import java.util.Set;
  
public class MapTest {
     
public Mapstudents;
    //利用哈希键值对进行创建
    public MapTest() {
    this.students = new HashMap();
}
    //进行学生的插入操作
     public void testPut() {
         Scanner console = new Scanner (System.in);
         int i = 0;
         while(i<3) {
             System.out.println("请输入学生ID：");
             String ID = console.next();
             StudentsClass st = students.get(ID);
             if(st == null) {
                 System.out.println("请输入学生姓名：");
                 String name = console.next();
                 StudentsClass newStudent = new StudentsClass(ID,name);
                 students.put(ID,newStudent);
                 System.out.println("成功添加学生："+students.get(ID).name);
                 i++;
             }else {
                 System.out.println("该学生ID已经被占用！");
                 continue;
             }
         }
     }
     //利用keyset方法将key值放在一个集合中，然后利用key值进行遍历
     public void testKeySet() {
         SetkeySet = students.keySet();
         //进行遍历
         for(String stuID:keySet) {
             StudentsClass st = students.get(stuID);
             if(st != null) {
                 System.out.println("学生："+st.name);
             }
         }
     }
     //进行删除操作
     public void testRmove() {
         Scanner console = new Scanner(System.in);
         while(true) {
         System.out.println("请输入要删除的学生ID！");
         String ID = console.next();
         StudentsClass st = students.get(ID);
          if(st == null) {
              System.out.println("该ID不存在！");
              continue;
          }
          students.remove(ID);
          System.out.println("成功删除学生："+st.name);
          break;
     }
}
     //通过entryset来遍历Map
     public void testEntrySet() {
         Set>entrySet = students.entrySet();
        for(Entry entry:entrySet) {
                System.out.println("取得键："+entry.getKey());
                System.out.println("对应的值为："+entry.getValue().name);
        } 
     }
     //进行修改操作
     public void testModify() {
         System.out.println("请输入要修改的学生ID：");
         Scanner console = new Scanner(System.in);
         while(true) {
             String stuID = console.next();
             StudentsClass student = students.get(stuID);
             if(student == null) {
                 System.out.println("该ID不存在！请重新输入！");
                 continue;
             }
             System.out.println("当前学生ID，所对应的学生为："+student.name);
             System.out.println("请输入新的学生姓名:");
             String name =  console.next();
             StudentsClass newStudent = new StudentsClass(stuID,name);
             students.put(stuID,newStudent);
             System.out.println("修改成功");
         }
     }
     //通过键值或值进行查询操作
     public void testContainsKeyOrValue() {
         System.out.println("请输入要查询的学生ID：");
         Scanner console = new Scanner(System.in);
         String id = console.next();
         System.out.println("您输入的学生ID为："+id+"在学生映射表中是否存在："+
         students.containsKey(id)
                 );
         if(students.containsKey(id)) {
             System.out.println("对应的学生为："+students.get(id).name);
         }
         System.out.println("请输入要查询的学生姓名：");
         String name = console.next();
         if(students.containsValue(new StudentsClass(null,name)))
             System.out.println("在学生映射表中确实包含学生："+name);
         else
             System.out.println("在学生映射表中不存在该学生");
     }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        MapTest mt = new MapTest();
        mt.testPut();
        mt.testKeySet();
//        mt.testRmove();
//        mt.testEntrySet();
//        mt.testModify();
//        mt.testEntrySet();
        mt.testContainsKeyOrValue();
    }
}

6、进行重载比较

package 学生管理系统;
  
import java.util.Comparator;
  
public class StudentComparator implements Comparator {
  
    @Override
    public int compare(StudentsClass o1, StudentsClass o2) {
        // TODO Auto-generated method stub
         
         
        return o1.name.compareTo(o2.name);
    }
  
}

7、进行排序操作

package 学生管理系统;
  
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Random;
  
public class CollectionTest {
     
    //利用Collection内部方法进行排序操作
    public void testSort1() {
        //进行整形排序
        ListintergerList = new ArrayList();
        Random random = new Random();
        Integer k;
        for(int i = 0;i < 10; i++) {
             do {
            k = random.nextInt(100);
             }while(intergerList.contains(k));
             intergerList.add(k);
             System.out.println("成功添加整数："+k);
             System.out.println("--------排序前-------");
             for(Integer integer:intergerList) {
                 System.out.println("元素："+integer);
             }
             Collections.sort(intergerList);
             System.out.println("--------排序后-------");
             for(Integer integer:intergerList) 
                 System.out.println("元素："+integer);
        }
    }
    //进行String排序
    public void testSort2() {
        ListstringList = new ArrayList();
        stringList.add("microsoft");
        stringList.add("google");
        stringList.add("lenovo");
        System.out.println("--------排序前-------");
        for(String string : stringList) {
            System.out.println("元素："+string);
        }
        Collections.sort(stringList);
        System.out.println("--------排序后-------");
        for(String string : stringList) {
            System.out.println("元素："+string);
        }
    }
    //对StudentsClass类进行排序，这里就需要进行equal和hashcode的重载
    public void testSort3() {
        ListStudentList = new ArrayList();
        Random random = new Random();
        StudentList.add(new StudentsClass(random.nextInt(1000)+"","mike"));
        StudentList.add(new StudentsClass(random.nextInt(1000)+"","lucy"));
        StudentList.add(new StudentsClass(random.nextInt(1000)+"","angel"));
        System.out.println("--------排序前-------");
        for(StudentsClass student:StudentList) {
            System.out.println("学生："+student.id+student.name);
        }
        Collections.sort(StudentList);
        System.out.println("--------排序后-------");
        for(StudentsClass student:StudentList) {
            System.out.println("学生："+student.id+student.name);
        }
        Collections.sort(StudentList,new StudentComparator());
        System.out.println("----------按照姓名排序----------");
        for(StudentsClass student:StudentList) {
            System.out.println("学生："+student.id+student.name);
        }
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        CollectionTest ct = new CollectionTest();
        //ct.testSort1();
        //ct.testSort2();
        ct.testSort3();
    }
  
}

8、辅助类。

package 学生管理系统;
  
public class ChildCourse extends CourseClass {  
     
}

以上就是本文的全部内容，希望对大家的学习有所帮助。

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简单介绍sql server 累计求和实现代码

简单介绍sql server 累计求和实现代码

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