public class Test{ public static void main(String [] args) { int i=95; switch(i>=90?1:i>=80?2:i>=70?3:i>=60?4:5) {case 1: System.out.println("你的成绩为优秀!"); break; case 2: System.out.println("你的成绩为良好!"); break; case 3: System.out.println("你的成绩为中等!"); break; case 4: System.out.println("你的成绩为及格!"); break; default: System.out.println("你的成绩为不及格!"); break; } } }
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.event.*;
import javax.swing.table.*;
public class student extends JFrame{
Container ctp=getContentPane();
JPanel jp1=new JPanel();
JLabel lb1=new JLabel("学号");
JTextField stuNum=new JTextField(8);
JButton numQuery=new JButton("按学号查询");
JButton allQuery=new JButton("显示所有记录");
Vector vector;
String title[]={"学号","姓名","班级","课程名称","成绩"
};
Connection cnt=null;
Statement st=null;
ResultSet rs=null;
AbstractTableModel tm;
student(){
super("学生信息查询");
setSize(550,300);
ctp.setLayout(new FlowLayout());
jp1.add(lb1);
jp1.add(stuNum);
jp1.add(numQuery);
jp1.add(allQuery);
ctp.add(jp1);
createable();
this.setVisible(true);
numQuery.addActionListener(
new java.awt.event.ActionListener(){
public void actionPerformed(ActionEvent e){
numQuery_actionPerformed(e);
}
});
allQuery.addActionListener(
new java.awt.event.ActionListener(){
public void actionPerformed(ActionEvent e){
allQuery_actionPerformed(e);
}
});
}
void createable(){
JTable table;
JScrollPane scroll;
vector=new Vector();
tm=new AbstractTableModel(){
public int getColumnCount(){
return title.length;
}
public int getRowCount(){
return vector.size();
}
public Object getValueAt(int row,int column){
if(!vector.isEmpty()){
return((Vector)vector.elementAt(row)).elementAt(column);
}
else{
return null;
}
}
public String getColumnName(int column){
return title[column];
}
};
table=new JTable(tm);
table.setAutoResizeMode(table.AUTO_RESIZE_OFF);
table.setCellSelectionEnabled(false);
scroll=new JScrollPane(table);
ctp.add(scroll);
}
void numQuery_actionPerformed(ActionEvent e){
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection cnt=DriverManager.getConnection("jdbc:odbc:jiayuan","sa","6325554");
st=cnt.createStatement();
String sql="select * from 学生成绩表 where 学号 ="+stuNum.getText();
rs=st.executeQuery(sql);
stuNum.setText("");
vector.removeAllElements();
tm.fireTableStructureChanged();
while(rs.next()){
Vector rec_vector=new Vector();
rec_vector.addElement(rs.getString(1));
rec_vector.addElement(rs.getString(2));
rec_vector.addElement(rs.getString(3));
rec_vector.addElement(rs.getString(4));
rec_vector.addElement(String.valueOf(rs.getInt(5)));
vector.addElement(rec_vector);
}
tm.fireTableStructureChanged();
rs.close();
st.close();
cnt.commit();
}catch(Exception ex){
System.out.println("Exception");
}
}
void allQuery_actionPerformed(ActionEvent e){
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection cnt=DriverManager.getConnection("jdbc:odbc:jiayuan","sa","6325554");
st=cnt.createStatement();
String sql="select * from 学生成绩表";
rs=st.executeQuery(sql);
vector.removeAllElements();
tm.fireTableStructureChanged();
while(rs.next()){
Vector rec_vector=new Vector();
rec_vector.addElement(rs.getString(1));
rec_vector.addElement(rs.getString(2));
rec_vector.addElement(rs.getString(3));
rec_vector.addElement(rs.getString(4));
rec_vector.addElement(String.valueOf(rs.getInt(5)));
vector.addElement(rec_vector);
}
tm.fireTableStructureChanged();
rs.close();
st.close();
cnt.commit();
}catch(Exception ex){
System.out.println("Exception");
}
}
public static void main(String args[]){
student st=new student();
st.setDefaultCloseOperation(EXIT_ON_CLOSE);
}
}
你建一个数据库就可以实现了
public static void main(String [] args)
{
int i=95;
switch(i>=90?1:i>=80?2:i>=70?3:i>=60?4:5)
{case 1:
System.out.println("你的成绩为优秀!");
break;
case 2:
System.out.println("你的成绩为良好!");
break;
case 3:
System.out.println("你的成绩为中等!");
break;
case 4:
System.out.println("你的成绩为及格!");
break;
default:
System.out.println("你的成绩为不及格!");
break;
}
}
}
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.event.*;
import javax.swing.table.*;
public class student extends JFrame{
Container ctp=getContentPane();
JPanel jp1=new JPanel();
JLabel lb1=new JLabel("学号");
JTextField stuNum=new JTextField(8);
JButton numQuery=new JButton("按学号查询");
JButton allQuery=new JButton("显示所有记录");
Vector vector;
String title[]={"学号","姓名","班级","课程名称","成绩"
};
Connection cnt=null;
Statement st=null;
ResultSet rs=null;
AbstractTableModel tm;
student(){
super("学生信息查询");
setSize(550,300);
ctp.setLayout(new FlowLayout());
jp1.add(lb1);
jp1.add(stuNum);
jp1.add(numQuery);
jp1.add(allQuery);
ctp.add(jp1);
createable();
this.setVisible(true);
numQuery.addActionListener(
new java.awt.event.ActionListener(){
public void actionPerformed(ActionEvent e){
numQuery_actionPerformed(e);
}
});
allQuery.addActionListener(
new java.awt.event.ActionListener(){
public void actionPerformed(ActionEvent e){
allQuery_actionPerformed(e);
}
});
}
void createable(){
JTable table;
JScrollPane scroll;
vector=new Vector();
tm=new AbstractTableModel(){
public int getColumnCount(){
return title.length;
}
public int getRowCount(){
return vector.size();
}
public Object getValueAt(int row,int column){
if(!vector.isEmpty()){
return((Vector)vector.elementAt(row)).elementAt(column);
}
else{
return null;
}
}
public String getColumnName(int column){
return title[column];
}
};
table=new JTable(tm);
table.setAutoResizeMode(table.AUTO_RESIZE_OFF);
table.setCellSelectionEnabled(false);
scroll=new JScrollPane(table);
ctp.add(scroll);
}
void numQuery_actionPerformed(ActionEvent e){
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection cnt=DriverManager.getConnection("jdbc:odbc:jiayuan","sa","6325554");
st=cnt.createStatement();
String sql="select * from 学生成绩表 where 学号 ="+stuNum.getText();
rs=st.executeQuery(sql);
stuNum.setText("");
vector.removeAllElements();
tm.fireTableStructureChanged();
while(rs.next()){
Vector rec_vector=new Vector();
rec_vector.addElement(rs.getString(1));
rec_vector.addElement(rs.getString(2));
rec_vector.addElement(rs.getString(3));
rec_vector.addElement(rs.getString(4));
rec_vector.addElement(String.valueOf(rs.getInt(5)));
vector.addElement(rec_vector);
}
tm.fireTableStructureChanged();
rs.close();
st.close();
cnt.commit();
}catch(Exception ex){
System.out.println("Exception");
}
}
void allQuery_actionPerformed(ActionEvent e){
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection cnt=DriverManager.getConnection("jdbc:odbc:jiayuan","sa","6325554");
st=cnt.createStatement();
String sql="select * from 学生成绩表";
rs=st.executeQuery(sql);
vector.removeAllElements();
tm.fireTableStructureChanged();
while(rs.next()){
Vector rec_vector=new Vector();
rec_vector.addElement(rs.getString(1));
rec_vector.addElement(rs.getString(2));
rec_vector.addElement(rs.getString(3));
rec_vector.addElement(rs.getString(4));
rec_vector.addElement(String.valueOf(rs.getInt(5)));
vector.addElement(rec_vector);
}
tm.fireTableStructureChanged();
rs.close();
st.close();
cnt.commit();
}catch(Exception ex){
System.out.println("Exception");
}
}
public static void main(String args[]){
student st=new student();
st.setDefaultCloseOperation(EXIT_ON_CLOSE);
}
}