使用Java面向对象程序操作Oralce数据库实现界面增,删,改,查

创建Oracle脚本



系统界面及代码

一、StuManage.java 主界面，默认显示并查询出学生

package StuManage;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class StuManager extends JFrame implements ActionListener{
JPanel jpanel1,jpanel2;
JLabel jlabel1;
JTextField jtextfield1;
JButton jbutton1,jbutton2,jbutton3,jbutton4;
JTable jtable1;
JScrollPane jsp = null;
StuModel sm = null;

StuManager(){
this.setLayout(new GridLayout(3,1));
//布局一行
jpanel1 = new JPanel();
jlabel1 = new JLabel("用户名");
jtextfield1 = new JTextField(10);
jbutton1 = new JButton("查询");
jbutton1.addActionListener(this);
jpanel1.add(jlabel1);
jpanel1.add(jtextfield1);
jpanel1.add(jbutton1);

//布局二行
sm = new StuModel();
String[] paras = {"1"};
sm.queryStu("select * from student where 1=? ", paras);
jtable1 = new JTable(sm);
jsp = new JScrollPane(jtable1);

//布局三行
jpanel2  = new JPanel();
jbutton2 = new JButton("添加");
jbutton2.addActionListener(this);
jbutton3 = new JButton("修改");
jbutton3.addActionListener(this);
jbutton4 = new JButton("删除");
jbutton4.addActionListener(this);
jpanel2.add(jbutton2);
jpanel2.add(jbutton3);
jpanel2.add(jbutton4);

this.add(jpanel1,BorderLayout.NORTH);
this.add(jsp);
this.add(jpanel2,BorderLayout.SOUTH);
}
//主函数
public static void main(String[] args){
StuManager stu = new StuManager();
stu.setTitle("学生信息管理系统（李雁冬）");
stu.setSize(350,300);
stu.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
stu.setVisible(true);
}

@Override
public void actionPerformed(ActionEvent e) {
//查询
if(e.getSource()==jbutton1){
//把对表的数据封装到stuModel中,完成查询
String sql = "";
String name = this.jtextfield1.getText().trim();
if( name !=null && !name.trim().equals("")){
sql = "select * from student where stuname= ?";
}
else{
JOptionPane.showMessageDialog(jbutton1, "输入条件","提示：",1);
return ;
}
//构建新的数据模型，并更新
sm = new StuModel();
String[] paras = {name};
sm.queryStu(sql, paras);
this.jtable1.setModel(sm);
}
//添加学生
else if(e.getSource()==jbutton2){
StuAdd add = new StuAdd(this,"添加学生",true);

//*添加完成重新再获得模型，同理其他操作
sm = new StuModel();
String[] paras = {"1"};
sm.queryStu("select * from student where 1 =?", paras);
this.jtable1.setModel(sm);

}
//修改学生
else if(e.getSource()==jbutton3){
int rowNum = this.jtable1.getSelectedRow();
System.out.println("修改第"+(rowNum+1)+"行");
if(rowNum == -1){
JOptionPane.showMessageDialog(this, "请选择修改的行");
return ;
}
new StuUpdate(this,"修改学生",true, sm, rowNum);
sm = new StuModel();

String[] paras = {"1"};
sm.queryStu("select * from student where 1 =?", paras);

this.jtable1.setModel(sm);
}
//删除学生
else if(e.getSource()==jbutton4){
//1.得到学生的ID,getSelectedRow会返回用户点中的行，如果一行未选，则返回-1
int rowNum = this.jtable1.getSelectedRow();
if(rowNum == -1){
JOptionPane.showMessageDialog(this, "请选择所要删除的学生");
return ;
}

//得到学生的ID
String stuId = (String) sm.getValueAt(rowNum, 0);
String sql = "delete from student where stuid=?";
String[] paras ={stuId};
sm = new StuModel();
String[] paras1 ={"1"};
sm.updateStu(sql, paras);
sm.queryStu("select * from student where 1=?", paras1);
this.jtable1.setModel(sm);
JOptionPane.showMessageDialog(this, "删除成功");
}
}
}

二、StuModel.java *数据操作模型界面（修改、删除学生）

package StuManage;

import java.sql.ResultSet;
import java.util.Vector;
import javax.swing.table.AbstractTableModel;

public class StuModel extends AbstractTableModel{
Vector rowData,columnNames;

public boolean updateStu(String sql,String[] paras){
StuDAO ss = new StuDAO();
return ss.update(sql, paras);
}
public void queryStu(String sql,String[] paras){
StuDAO he = null;
//表中间
columnNames = new Vector();
columnNames.add("学号");
columnNames.add("姓名");
columnNames.add("性别");
columnNames.add("年龄");
columnNames.add("籍贯");
columnNames.add("所在系");
rowData = new Vector();  //rowData可存放多行

try{
he = new StuDAO();
ResultSet rs = he.query(sql, paras);

while(rs.next()){
Vector hang = new Vector();
hang.add(rs.getString(1));
hang.add(rs.getString(2));
hang.add(rs.getString(3));
hang.add(rs.getInt(4));
hang.add(rs.getString(5));
hang.add(rs.getString(6));
//加入到rowData
rowData.add(hang);
}

}catch(Exception e){
e.printStackTrace();
}finally{
he.close();
}
}
@Override
public int getRowCount() {
// 得到列数
return this.rowData.size();
}
@Override
public int getColumnCount() {
// 得到行数
return this.columnNames.size();
}
@Override
public Object getValueAt(int row, int column) {
// 得到指定行、列的数据
return ((Vector)this.rowData.get(row)).get(column);
}
@Override
public String getColumnName(int column) {
return (String) this.columnNames.get(column);
}
}

三、StuAdd.java 添加/修改学生界面

修改时学号为置灰状态

package StuManage;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class StuAdd extends JDialog implements ActionListener {
JLabel jl1,jl2,jl3,jl4,jl5,jl6;
JTextField jtf1,jtf2,jtf3,jtf4,jtf5,jtf6;
JButton jbutton1,jbutton2;
JPanel jpanel1,jpanel2,jpanel3;
//父窗口、窗口名、*是否模态
public StuAdd(Frame owner,String title,boolean modal){
super(owner,title,modal);
jpanel1 = new JPanel(new GridLayout(6,1,1,1));
jl1 = new JLabel("学号");
jl2 = new JLabel("姓名");
jl3 = new JLabel("性别");
jl4 = new JLabel("年龄");
jl5 = new JLabel("籍贯");
jl6 = new JLabel("所在系");
jpanel1.add(jl1);
jpanel1.add(jl2);
jpanel1.add(jl3);
jpanel1.add(jl4);
jpanel1.add(jl5);
jpanel1.add(jl6);

jpanel2 = new JPanel(new GridLayout(6,1,1,1));
jtf1 = new JTextField(10);
jtf2 = new JTextField(10);
jtf3 = new JTextField(10);
jtf4 = new JTextField(10);
jtf5 = new JTextField(10);
jtf6 = new JTextField(10);
jpanel2.add(jtf1);
jpanel2.add(jtf2);
jpanel2.add(jtf3);
jpanel2.add(jtf4);
jpanel2.add(jtf5);
jpanel2.add(jtf6);

jpanel3 = new JPanel();
jbutton1 = new JButton("保存");
jbutton1.addActionListener(this);
jbutton2 = new JButton("取消");
jpanel3.add(jbutton1);
jpanel3.add(jbutton2);

this.add(jpanel1,BorderLayout.WEST);
this.add(jpanel2,BorderLayout.EAST);
this.add(jpanel3,BorderLayout.SOUTH);
this.setTitle("添加学生信息");
this.setSize(200, 200);
this.setVisible(true);
}
@Override
public void actionPerformed(ActionEvent e) {
if(e.getSource()==jbutton1){
StuModel temp = new StuModel();
String sql = "insert into student values(?,?,?,?,?,?)";
String[] paras = {jtf1.getText(),jtf2.getText(),jtf3.getText(),jtf4.getText(),jtf5.getText(),jtf6.getText()};

if(!temp.updateStu(sql, paras)){
JOptionPane.showMessageDialog(this, "添加失败");
}
else{
this.setVisible(false);
JOptionPane.showMessageDialog(this, "添加成功");
}

//关闭对话框
this.dispose();

}
}
}

四、StuDao.java //操作Oracle数据库实体类，进行增、删、改操作合并

package StuManage;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class StuDAO {
Connection con =null;
PreparedStatement pstm = null;
ResultSet rs = null;
String driver = "oracle.jdbc.driver.OracleDriver";
String url = "jdbc:oracle:thin:@localhost:1521:study";
String userName = "admin";
String passWord = "admin";

public ResultSet query(String sql){
try{
Class.forName(driver);
con = DriverManager.getConnection(url,userName,passWord);
pstm = con.prepareStatement(sql);
rs = pstm.executeQuery();
}
catch(Exception e){
e.printStackTrace();
}finally{
//暂时不能关闭
}
return rs;
}
public ResultSet query(String sql,String[] paras){
try{
Class.forName(driver);
con = DriverManager.getConnection(url,userName,passWord);
pstm = con.prepareStatement(sql);

for(int i=0;i<paras.length;i++){
pstm.setString(i+1 , paras[i]);
}
rs = pstm.executeQuery();
}
catch(Exception e){
e.printStackTrace();
}finally{
//暂时不能关闭
}
return rs;
}
//增、删、改合并
public boolean update(String sql,String[] paras){
boolean b = true;
try{
Class.forName(driver);
con = DriverManager.getConnection(url,userName,passWord);
pstm = con.prepareStatement(sql);

for(int i=0;i<paras.length;i++){
pstm.setString(i+1 , paras[i]);
}

//执行语句操作
if(pstm.executeUpdate()!=1){
b=false;
}
}
catch(Exception e1){
b=false;
e1.printStackTrace();
}finally{
this.close();
}
return b;
}

public void close(){
try{
if(rs!=null)rs.close();
if(pstm!=null)pstm.close();
if(con!=null)con.close();
}
catch(Exception e2){
e2.printStackTrace();
}
}
}

完

其他

开始学习用SQLServer2008数据库，引入sqljdbc4.jar

交作业中间练习了Oracle，引入classes12.jar，stuDAO模块进行数据库的连接修改

创建SQLServer数据库表student

--sqlserver
--手动创建数据库study（略）
drop table dbo.student;
create table dbo.student(
stuID  char(10)  Primary key  not null,
stuName varchar(20),
stuSex CHAR(2) DEFAULT '男' CHECK(StuSex='男' OR stuSex='女'),
stuAge varchar(3),
stuDate  DateTime,
stuDept varchar(10)
);
ALTER TABLE student ALTER column stuDate Date; --修改表列属性
insert into student values(4,'李四','男',27,'2016-03-28','计算机系');
select * from study.dbo.student where stuName like '%王小兵%'

【问题】

错误: 提示找不到或无法加载主类 study.student.test2.stuManage

[解决]

右击-调试方式-java应用程序

或右击stuManage界面–Run As–Java Application

【问题】

java.lang.NullPointerException

at study.student.test3.Model.(Model.java:32)

at study.student.test3.Model.main(Model.java:70)

[原因]

缺少语句 rs = pstm.executeQuery();

【问题】

SQLServer加载驱动、创建数据库连接。执行SQL语句

//1.加载驱动

Class.forName(“com.microsoft.sqlserver.jdbc.SQLServerDriver”);

//2.创建数据库的连接

ct=DriverManager.getConnection(“jdbc:sqlserver://127.0.0.1:1433;DatabaseName=study”,”sa”,”123456”);

//3.执行SQL语句

pstm = ct.prepareStatement(“select * from [study].[dbo].[student]”);

//更新

rs = pstm.executeQuery();