Java做的一个学生成绩系统源码

import java.applet.Applet; import java.awt.*; import java.awt.event.*; import java.util.*; import java.lang.*; public class Students extends Applet implements ActionListener { Vector StuInf=new Vector(); StudentInf SI; String xm; String bj; int i,j,xh,cj; static int mid; Label prompt1=new Label("学生成绩管理系统"); Label prompt2=new Label(" 用户:"); Label prompt3=new Label(" 密码:"); Label prompt4=new Label(" 班级:"); Label prompt5=new Label(" 成绩:"); TextField input1=new TextField(8); TextField input2=new TextField(8); TextField input3=new TextField(8); TextField input4=new TextField(8); Button btn1=new Button("登录"); Button btn2=new Button("增加"); Button btn3=new Button("修改"); Button btn4=new Button("删除"); public void init() { setLayout(new GridLayout(6,3)); add(new Label()); add(prompt1); add(new Label()); add(prompt2); add(input1); add(new Label()); add(prompt3); add(input2); add(btn1); add(prompt4); add(input3); add(new Label()); add(prompt5); add(input4); add(new Label()); add(btn2); add(btn3); add(btn4); prompt4.setVisible(false); prompt5.setVisible(false); input3.setVisible(false); input4.setVisible(false); btn2.setVisible(false); btn3.setVisible(false); btn4.setVisible(false); btn1.addActionListener(this); btn2.addActionListener(this); btn3.addActionListener(this); btn4.addActionListener(this); } public void actionPerformed(ActionEvent e) { if(e.getActionCommand()=="登录") { String a,b; a=input1.getText(); b=input2.getText(); input1.setText(""); if((a.equals("12")==true)&&(b.equals("12")==true)) { prompt2.setText(" 姓名:"); prompt3.setText(" 学号:"); prompt4.setVisible(true); prompt5.setVisible(true); input3.setVisible(true); input4.setVisible(true); btn2.setVisible(true); btn3.setVisible(true); btn4.setVisible(true); btn3.setEnabled(false); btn4.setEnabled(false); btn1.setLabel("查询"); input1.setText("登录成功"); input1.selectAll(); } else input2.setText("用户名或密码错"); } if(e.getActionCommand()=="增加") { boolean scucss=true; try { XingMing(); } catch(EmptyException as) { input1.setText("姓名不能为空"); scucss=false; } try { xh=Integer.parseInt(input2.getText()); } catch(NumberFormatException m) { input2.setText("学号为空或格式错"); scucss=false; } bj=input3.getText(); try { ChengJi(); } catch(EmptyException as) { cj=-1; } catch(OverException dd) { input4.setText("应在0-100间"); scucss=false; } catch(NumberFormatException cm) { input4.setText("成绩应为数据"); scucss=false; } if(scucss==true) { SI=new StudentInf(xm,xh,bj,cj); Insert(SI); } } if(e.getActionCommand()=="修改") { xm=input1.getText(); xh=Integer.parseInt(input2.getText()); bj=input3.getText(); cj=Integer.parseInt(input4.getText()); SI=new StudentInf(xm,xh,bj,cj); StuInf.setElementAt(SI, mid); btn3.setEnabled(false); } if(e.getActionCommand()=="删除") { StuInf.removeElementAt(mid); btn4.setEnabled(false); input1.setText("删除成功"); input2.setText(""); input3.setText(""); input4.setText(""); } if(e.getActionCommand()=="查询") { boolean right=true; try { xh=Integer.parseInt(input2.getText()); } catch(NumberFormatException m) { input2.setText("学号为空或格式错"); right=false; } if(right==true) { search(xh); btn3.setEnabled(true); btn4.setEnabled(true); } } } //查找方法 public void search(int k) { boolean exist=false; int low=0; int high=StuInf.size()-1; while(low<=high) { mid=(high+low)/2; StudentInf a1=(StudentInf) StuInf.elementAt(mid); if(a1.getStuNo()==k) { SI=(StudentInf) StuInf.elementAt(mid); String x = String.valueOf(SI.getStuNo()); exist=true; input1.setText(SI.getname()); input1.selectAll(); input2.setText("0"+x); input3.setText(SI.getClassNo()); if(SI.getLevel()==-1) input4.setText("未参加考试"); else { String y = String.valueOf(SI.getLevel()); input4.setText(y); } break; } else if(a1.getStuNo()<k) low=mid+1; else high=mid-1; } if(exist==false) { input1.setText("无此学号学生信息"); input1.selectAll(); } } //添加方法 public void Insert(StudentInf q) { int i=0; if(StuInf.isEmpty()==true) { StuInf.addElement(q); input1.setText(""); input2.setText(""); input3.setText(""); input4.setText(""); } else { StudentInf xh; xh=(StudentInf) StuInf.firstElement(); while(xh.getStuNo()<q.getStuNo()) { i++; if(i<StuInf.size()) xh=(StudentInf) StuInf.elementAt(i); else break; } if(xh.getStuNo()==q.getStuNo()) { input2.setText("此学生信息已存在"); input2.requestFocus(); input2.selectAll(); } else { StuInf.insertElementAt(q,i); input1.setText(""); input2.setText(""); input3.setText(""); input4.setText(""); } } } //异常类 class OverException extends Exception { String over; } class EmptyException extends Exception { String empty; } void XingMing() throws EmptyException { if((input1.getText()).equals("")) throw (new EmptyException()); else xm=input1.getText(); } void ChengJi() throws OverException,EmptyException { if((input4.getText()).equals("")) throw(new EmptyException()); else cj=Integer.parseInt(input4.getText()); if(cj<0||cj>100) throw (new OverException()); } //学生信息类 public class StudentInf { private String name; private int StuNo; private String ClassNo; private int Level; StudentInf(String xingming,int xuehao,String banji,int chengji) { name=xingming; StuNo=xuehao; ClassNo=banji; Level=chengji; } public int getStuNo() { return StuNo; } public String getname() { return name; } public String getClassNo() { return ClassNo; } public int getLevel() { return Level; } } }