count.java

JAVA程序设计导论那本书上的一些源代码. 在学那本书的下来的

package chapter27;

import java.sql.*;

public class Count {
  private int count = 0;
  private Statement statement = null;

  public Count() {
    initializeJdbc();
  }

  /** Return count property */
  public int getCount() {
    try {
      ResultSet rset = statement.executeQuery
        ("select countValue from Count");
      rset.next();
      count = rset.getInt(1);
    }
    catch (Exception ex) {
      ex.printStackTrace();
    }

    return count;
  }

  /** Increase count */
  public void increaseCount() {
    count++;
    try {
      statement.executeUpdate(
        "update Count set countValue = " + count);
    }
    catch (Exception ex) {
      ex.printStackTrace();
    }
  }

  /** Initialize database connection */
  public void initializeJdbc() {
    try {
      Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");

      // Connect to the sample database
      Connection connection = DriverManager.getConnection(
        "jdbc:odbc:exampleMDBDataSource");

      statement = connection.createStatement();
    }
    catch (Exception ex) {
      ex.printStackTrace();
    }
  }
}