datapagedisplayframe.java

JAVA数据库编程实例随书源码

package datapagedisplay;
import com.borland.jbcl.layout.*;
import java.awt.*;
import java.awt.event.*;
import java.lang.*;
import java.lang.Object.*;
import java.sql.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;

/**
   * Title:				数据分页显示程序
   * Description:			教学示范
   * Copyright:				Copyright (c) 2003
   * Company:				北京师范大学计算机系
   * @author				孙一林
   * @version				1.0
   */

public class DataPageDisplayFrame extends JFrame {
  private JPanel contentPane;
  private XYLayout xYLayout1 = new XYLayout();          // 构造XYLayout布局管理器
  // 创建显示信息的组件
  private Button firstpageButton = new Button();
  private Button nextpageButton = new Button();
  private Label label1 = new Label();
  private TextField recordnumField = new TextField();
  private Button confirmButton = new Button();
  private Button prepageButton = new Button();
  private Button lastpageButton = new Button();
  private Label label2 = new Label();
  private Label label3 = new Label();
  private TextField pagedisplayField = new TextField();

  Vector vector;                                        // 声明一个向量对象
  String[] title = {"学号","姓名","年龄","性别","系名"};   // 二维表列名
  Connection connection = null;                         // 声明Connection接口对象connection
  ResultSet rs = null;                                  // 定义数据库查询的结果集
  Statement statement = null;                           // 定义查询数据库的Statement对象
  AbstractTableModel tm;                                // 声明一个AbstractTableModel类对象tm
  String sql;
  int everypagenumber;                                  // 定义变量存储每页显示记录个数
  int t;
  int lastpagenum;                                      // 定义变量存储最后一页码数
  int pagenum=0;                                        // 初始化变量用来表示当前页的的页码数

  public DataPageDisplayFrame() {
    enableEvents(AWTEvent.WINDOW_EVENT_MASK);
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }

  private void jbInit() throws Exception  {
    contentPane = (JPanel) this.getContentPane();
    // 初始化组件
    firstpageButton.setLabel("首页");
    firstpageButton.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        firstpageButton_actionPerformed(e);
      }
    });
    contentPane.setLayout(xYLayout1);
    this.setSize(new Dimension(455, 417));
    this.setTitle("数据分页显示");
    nextpageButton.setLabel("下一页");
    nextpageButton.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        nextpageButton_actionPerformed(e);
      }
    });
    label1.setText("请输入每页显示的记录数：");
    confirmButton.setLabel("确认");
    confirmButton.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        confirmButton_actionPerformed(e);
      }
    });
    prepageButton.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        prepageButton_actionPerformed(e);
      }
    });
    prepageButton.setLabel("上一页");
    lastpageButton.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        lastpageButton_actionPerformed(e);
      }
    });
    lastpageButton.setLabel("尾页");
    label2.setText("第");
    label3.setText("页");
    contentPane.add(label1, new XYConstraints(44, 241, 148, 28));
    contentPane.add(recordnumField,new XYConstraints(212, 236, 68, 32));
    contentPane.add(confirmButton,new XYConstraints(315, 236, 68, 32));
    contentPane.add(nextpageButton,new XYConstraints(240, 297, 77, 39));
    contentPane.add(prepageButton,new XYConstraints(135, 297, 77, 39));
    contentPane.add(firstpageButton,new XYConstraints(30, 297, 77, 39));
    contentPane.add(lastpageButton,new XYConstraints(345, 297, 77, 39));
    contentPane.add(pagedisplayField, new XYConstraints(392, 352, 30, 19));
    contentPane.add(label2, new XYConstraints(373, 349, 22, 24));
    contentPane.add(label3, new XYConstraints(428, 349, 22, 24));
    createtable();                             // 在初始化函数中调用createtable()函数显示表格
  }

  void createtable() {                         // 定义createtable()函数
    JTable table;                              // 声明一个JTable类对象table
    JScrollPane scroll;                        // 声明一个滚动杠对象scroll
    vector = new Vector();                     // 创建向量对象
    tm = new AbstractTableModel() {            // 创建AbstractTableModel类对象tm
      public int getColumnCount() {            // 取得表格列数
        return title.length;
      }
      public int getRowCount() {               // 取得表格行数
        return vector.size();
      }
      public Object getValueAt(int row, int column) { // 取得单元格中的属性值
        if(!vector.isEmpty()) {
          return ((Vector)vector.elementAt(row)).elementAt(column);
        }
        else {
          return null;
        }
      }
      public void setValueAt(Object value, int row, int column) {// 数据模型不可编辑，该方法设置为空

      }
      public String getColumnName(int column) {   // 取得表格列名
        return title[column];
      }
      public Class getColumnClass(int c) {        // 取得列所属对象类
        return getValueAt(0,c).getClass();
      }
      public boolean isCellEditable(int row, int column) {// 设置单元格不可编辑，为缺省实现
        return false;
      }
    };
    table = new JTable(tm);                             // 生成自己的数据模型
    table.setToolTipText("Display Query Result");       // 设置帮助提示
    table.setAutoResizeMode(table.AUTO_RESIZE_OFF);     // 设置表格调整尺寸模式
    table.setCellSelectionEnabled(false);               // 设置单元格选择方式
    table.setShowHorizontalLines(true);                 // 设置是否显示单元格之间的分割线
    table.setShowVerticalLines(true);
    scroll = new JScrollPane(table);                    // 给表格加上滚动杠
    scroll.setBounds(6,20,540,250);
    contentPane.add(scroll,new XYConstraints(16, 20, 395, 200));
  }

  protected void processWindowEvent(WindowEvent e) {
    super.processWindowEvent(e);
    if (e.getID() == WindowEvent.WINDOW_CLOSING) {
      System.exit(0);
    }
  }

  void firstpageButton_actionPerformed(ActionEvent e) {    // 处理“首页”按钮情况
    try {
      pagenum=1;                                           // 首页所以pagenum设为1
      int recordnum=0;                                     // 初始化数据表中的记录数
      Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");       // 实例化JDBC-ODBC桥的驱动
      String url = "jdbc:odbc:TestDbStu";                  // 设置连接字符串
      connection = DriverManager.getConnection(url);       // 连接数据库
      // 创建Statement接口对象
      statement = connection.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
      sql = "select * from studentbase ";
      // 执行statement对象的executeQuery方法，查询studentbase表，将查询结果放入rs中
      rs = statement.executeQuery(sql);
      while(rs.next()) {
        recordnum++;                                       // 统计数据表中的记录个数
      }
      // 求得分页显示的页码总数
      int t=recordnum%everypagenumber;
      if (t!=0)
        lastpagenum=(recordnum/everypagenumber+1);
      else
        lastpagenum=recordnum/everypagenumber;
      rs.beforeFirst() ;
      String displaypage=pagenum+"/"+lastpagenum;
      pagedisplayField.setText(displaypage) ;              // 显示当前页码情况
      vector.removeAllElements();                          // 初始化向量对象
      tm.fireTableStructureChanged();                      // 更新表格内容
      for(int i=1;i<=everypagenumber;i++) {
        rs.next();
        Vector rec_vector = new Vector();
        // 从结果集中取数据放入向量rec_vector中
        rec_vector.addElement(String.valueOf(rs.getInt(1)));
        rec_vector.addElement(rs.getString(2));
        rec_vector.addElement(String.valueOf(rs.getInt(3)));
        rec_vector.addElement(rs.getString(4));
        rec_vector.addElement(rs.getString(5));
        vector.addElement(rec_vector);                     // 向量rec_vector加入向量vector中
      }
      tm.fireTableStructureChanged();                      // 更新表格，显示向量vector的内容
    }
    catch(SQLException ex){                                // 捕捉异常
      System.out.println("\nERROR:----- SQLException -----\n");
      while (ex != null) {
        System.out.println("Message:   " + ex.getMessage());
        System.out.println("SQLState:  " + ex.getSQLState());
        System.out.println("ErrorCode: " + ex.getErrorCode());
        ex = ex.getNextException();
      }
    }
    catch(Exception ex ) {
      ex.printStackTrace();
    }
    finally {
      try {
        if(statement != null) {
          statement.close();                                // 关闭Statement接口实例
        }
        if(connection != null) {
          connection.close();                               // 关闭Connection接口实例
        }
      }
      catch (SQLException ex)  {