step2_frame.java

《JAVA网络编程实例》源代码

import java.sql.*;
import java.awt.*;
import java.awt.event.*;

/**
 * File:        step2_Frame.java
 * 按照转乘方式查寻，交互操作的第二步的界面和处理代码
 */

public class step2_Frame extends Frame {

////////////////////////////////
//这个界面提供一次转乘方式的乘车路线查寻。
//
//请按照按钮上序号所提示的步骤顺序操作：
//1，查找中间转乘车站：   给出可能的转乘站。
//2，到换乘站路线：       查寻如何乘车可以从  “始  站”  到达  “转乘站”。
//3，到目标站路线：       查寻如何乘车可以从  “转乘站”  到达  “目标站”。
//
//这个版本的查询系统仅仅提供最多一次转乘的功能。
//更多次转乘可以通过手工反复寻找中间转乘车站拉达到目的。
////////////////////////////////

  public String mystat1=new String("");
  public String mystat2=new String("");

  Button button1 = new Button();
  Button button2 = new Button();
  TextField user_mystat1 = new TextField();
  TextField user_mystat2 = new TextField();
  Choice stat_choice = new Choice();
  Button button3 = new Button();
  Button button4 = new Button();
  Choice line_list1 = new Choice();
  Choice line_list2 = new Choice();
  Label label1 = new Label();
  Label label2 = new Label();
  Label label3 = new Label();
  Label label4 = new Label();
  Label label5 = new Label();
  Label label6 = new Label();
  Label label7 = new Label();
  Label label8 = new Label();
  Label label9 = new Label();

  public step2_Frame() {
    this.setSize(550,300);
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  private void jbInit() throws Exception {
    this.setLayout(null);
    button2.setLabel("取消");
    button2.setBounds(new Rectangle(380, 179, 85, 26));
    button2.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        button2_actionPerformed(e);
      }
    });
    user_mystat1.setText("出发站");
    user_mystat1.setBounds(new Rectangle(6, 120, 76, 42));
    user_mystat2.setText("到达站");
    user_mystat2.setBounds(new Rectangle(421, 119, 83, 40));
    this.setVisible(true);
    button1.setLabel("1，查找中间转乘车站");
    button1.setBounds(new Rectangle(143, 180, 215, 26));
    button1.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        button1_actionPerformed(e);
      }
    });
    button3.setLabel("2，到换乘站路线");
    button3.setBounds(new Rectangle(86, 121, 126, 23));
    button3.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        button3_actionPerformed(e);
      }
    });
    button4.setLabel("3，到目标站路线");
    button4.setBounds(new Rectangle(284, 119, 133, 22));
    button4.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        button4_actionPerformed(e);
      }
    });
    label1.setText("始站：");
    label1.setBounds(new Rectangle(8, 94, 86, 28));
    label2.setText("目标站：");
    label2.setBounds(new Rectangle(425, 92, 86, 28));
    label3.setText("换乘站：");
    label3.setBounds(new Rectangle(214, 91, 86, 28));

    label5.setText("请按照按钮上序号所提示的步骤顺序操作：");
    label5.setBounds(new Rectangle(18, 6, 359, 26));
    label6.setText("1，查找中间转乘车站：   给出可能的转乘站。");
    label6.setBounds(new Rectangle(20, 31, 276, 16));
    label7.setText("2，到换乘站路线：       查寻如何乘车可以从  “始  站”  到达  “转乘站”。");
    label7.setBounds(new Rectangle(19, 50, 438, 16));
    label8.setText("3，到目标站路线：       查寻如何乘车可以从  “转乘站”  到达  “目标站”。");
    label8.setBounds(new Rectangle(20, 70, 446, 16));
    label9.setText("----------------------------------------------------------------------------------------------------");
    label9.setBounds(new Rectangle(7, 84, 468, 14));
    line_list2.setBounds(new Rectangle(286, 142, 131, 18));
    line_list1.setBounds(new Rectangle(87, 142, 125, 19));
    stat_choice.setBounds(new Rectangle(216, 119, 66, 24));
    label4.setBounds(new Rectangle(87, 85, 86, 28));
    this.add(label4, null);
    this.add(label6, null);
    this.add(label5, null);
    this.add(button1, null);
    this.add(label1, null);
    this.add(user_mystat1, null);
    this.add(line_list1, null);
    this.add(button3, null);
    this.add(label3, null);
    this.add(stat_choice, null);
    this.add(button4, null);
    this.add(line_list2, null);
    this.add(label2, null);
    this.add(user_mystat2, null);
    this.add(button2, null);
    this.add(label9, null);
    this.add(label8, null);
    this.add(label7, null);
  }

  void button1_actionPerformed(ActionEvent e) {
  /////////////////////
  //1，查找中间转乘车站：   给出可能的转乘站。
  /////////////////////
    String driverName = "sun.jdbc.odbc.JdbcOdbcDriver";
    String databaseURL = "jdbc:odbc:bjtdb";
    String user = "bjtdb";
    String password = "bjtdb";

    String sqlStr="SELECT distinct stat FROM stat_line WHERE line in (select line from stat_line where stat='"+user_mystat1.getText() +"') and stat in (SELECT stat FROM stat_line WHERE line in (select line from stat_line where stat='"+user_mystat2.getText() +"'))";
    System.out.print(sqlStr);
    try {
        Class.forName (driverName);
        System.out.println ("成功加载JDBC-ODBC驱动程序！");
    }
    catch (java.lang.ClassNotFoundException ex) {
        System.out.println ("加载JDBC-ODBC驱动程序失败！");
        System.out.println (ex.getMessage ());
        return;
    }
     try {
          Connection con = DriverManager.getConnection (databaseURL, user, password);
          System.out.println ("连接bjtdb数据库成功！");
          Statement stmt = con.createStatement();
          try{
            ResultSet result = stmt.executeQuery(sqlStr);
            line_list1.removeAll();

            if (!result.next()) {
               msgFrame f=new msgFrame("没有中间转乘车站。由于计算过于复杂，请手工查找。");
               f.show();
            } else {
               msgFrame f=new msgFrame("列表显示了可行中间转乘车站。请选择。");
               f.show();
            };

            stat_choice.removeAll();

            //读出当前的记录
            stat_choice.add(result.getString(1) );

            //循环读出剩下的所有记录
            while (result.next()) {
              String returnInfo = result.getString(1);
              System.out.println(returnInfo);
              stat_choice.add(returnInfo);
            }       // end while
          }
          catch(SQLException ex){
            System.out.println ("查询数据库数据失败！");
            System.err.println("SQLException: " + ex.getMessage());
          }
          con.close();
 }
        catch(SQLException ex) {
            System.out.println ("连接bjtdb数据库失败！");
            System.err.println("SQLException: " + ex.getMessage());
            return;
  }

  }// end void

  void button2_actionPerformed(ActionEvent e) {
    this.hide();
  }

  void button3_actionPerformed(ActionEvent e) {
  /////////////////////////
  //2，到换乘站路线：       查寻如何乘车可以从  “始  站”  到达  “转乘站”。
  /////////////////////////

    String driverName = "sun.jdbc.odbc.JdbcOdbcDriver";
    String databaseURL = "jdbc:odbc:bjtdb";
    String user = "bjtdb";
    String password = "bjtdb";
    String sqlStr="SELECT DISTINCT line FROM stat_line WHERE stat='"+user_mystat1.getText()+"' and line in (SELECT line FROM stat_line where stat='"+stat_choice.getSelectedItem()+"')";
    System.out.println(sqlStr);
    try {
        Class.forName (driverName);
        System.out.println ("成功加载JDBC-ODBC驱动程序！");
    }
    catch (java.lang.ClassNotFoundException ex) {
        System.out.println ("加载JDBC-ODBC驱动程序失败！");
        System.out.println (ex.getMessage ());
        return;
    }
    try {
          Connection con = DriverManager.getConnection (databaseURL, user, password);
          System.out.println ("连接bjtdb数据库成功！");
          Statement stmt = con.createStatement();
          try{
            ResultSet result = stmt.executeQuery(sqlStr);
            line_list1.removeAll();
            while (result.next()) {
              String returnInfo = result.getString(1);
              line_list1.add(returnInfo);
            }       // end while
          }
          catch(SQLException ex){
            System.out.println ("查询数据库数据失败！");
            System.err.println("SQLException: " + ex.getMessage());
          }
          con.close();
 }
        catch(SQLException ex) {
          System.out.println ("连接bjtdb数据库失败！");
          System.err.println("SQLException: " + ex.getMessage());
          return;
 }

 }

  void button4_actionPerformed(ActionEvent e) {

  /////////////////////////
  //3，到目标站路线：       查寻如何乘车可以从  “转乘站”  到达  “目标站”。
  /////////////////////////

    String driverName = "sun.jdbc.odbc.JdbcOdbcDriver";
    String databaseURL = "jdbc:odbc:bjtdb";
    String user = "bjtdb";
    String password = "bjtdb";
    String sqlStr="SELECT DISTINCT line FROM stat_line WHERE stat='"+stat_choice.getSelectedItem()+"' and line in (SELECT line FROM stat_line where stat='"+user_mystat2.getText() +"')";
    System.out.println(sqlStr);
    try {
        Class.forName (driverName);
        System.out.println ("成功加载JDBC-ODBC驱动程序！");
    }
    catch (java.lang.ClassNotFoundException ex) {
        System.out.println ("加载JDBC-ODBC驱动程序失败！");
        System.out.println (ex.getMessage ());
        return;
    }
    try {
          Connection con = DriverManager.getConnection (databaseURL, user, password);
          System.out.println ("连接bjtdb数据库成功！");
          Statement stmt = con.createStatement();
          try{
            ResultSet result = stmt.executeQuery(sqlStr);
            line_list2.removeAll();
            while (result.next()) {
              String returnInfo = result.getString(1);
              line_list2.add(returnInfo);
            }       // end while
          }
          catch(SQLException ex){
            System.out.println ("查询数据库数据失败！");
            System.err.println("SQLException: " + ex.getMessage());
          }
          con.close();
 }
        catch(SQLException ex) {
          System.out.println ("连接bjtdb数据库失败！");
          System.err.println("SQLException: " + ex.getMessage());
          return;
 }

 }
}