mysql.java

一个注册系统,Java的Mod1格式的

package com.jdon.simpleregister;

import java.sql.*;
import java.io.*;

/**
 *
 * <p>Title: </p>
 * <p>Description:
 * JDBC通用操作类
 *
 * 关于数据库的主要操作有：获取数据库连接；数据库查询、插入、修改、删除；
 * 断开数据库连接。这些数据库操作对于操作不同的数据表应该说都是统一的，
 * 因此，数据库的JDBC操作是可以做成一个通用类，这样就能达到重用目的。
 *
 * </p>
 * <p>Copyright: Jdon.com Copyright (c) 2003</p>
 * <p>Company: 上海解道计算机技术有限公司</p>
 * @author banq
 * @version 1.0
 */

public class Mysql {

  private Connection conn = null;
  private Statement stmt = null;
  private PreparedStatement prepstmt = null;

  /**
   * 以创建Statement 初始化Mysql
   */
  public Mysql() {
    try {
      Class.forName(Constants.dbdriver);
      conn = DriverManager.getConnection(Constants.dburl);
      stmt = conn.createStatement();
    } catch (Exception e) {
      System.err.println("Mysql init error: " + e);
    }
  }

  /**
   * 以创建PreparedStatement 初始化Mysql
   */
  public Mysql(String sql) {
    try {
      Class.forName(Constants.dbdriver);
      conn = DriverManager.getConnection(Constants.dburl);
      prepareStatement(sql);
    } catch (Exception e) {
      System.err.println("Mysql init error: " + e);
    }

  }

  public Connection getConnection() {
    return conn;
  }

  public void prepareStatement(String sql) throws SQLException {
    prepstmt = conn.prepareStatement(sql);
  }

  public void setString(int index, String value) throws SQLException {
    prepstmt.setString(index, value);
  }

  public void setInt(int index, int value) throws SQLException {
    prepstmt.setInt(index, value);
  }

  public void setBoolean(int index, boolean value) throws SQLException {
    prepstmt.setBoolean(index, value);
  }

  public void setDate(int index, Date value) throws SQLException {
    prepstmt.setDate(index, value);
  }

  public void setLong(int index, long value) throws SQLException {
    prepstmt.setLong(index, value);
  }

  public void setFloat(int index, float value) throws SQLException {
    prepstmt.setFloat(index, value);
  }

  public void setBinaryStream(int index, InputStream in, int length) throws
      SQLException {
    prepstmt.setBinaryStream(index, in, length);
  }

  public void clearParameters() throws SQLException {
    prepstmt.clearParameters();
  }

  public PreparedStatement getPreparedStatement() {
    return prepstmt;
  }

  public Statement getStatement() {
    return stmt;
  }

  /**
   * 执行Statement查询语句
   * @param sql
   * @return
   * @throws SQLException
   */
  public ResultSet executeQuery(String sql) throws SQLException {
    if (stmt != null) {
      return stmt.executeQuery(sql);
    } else
      return null;
  }

  /**
   * 执行PreparedStatement查询语句
   * @return
   * @throws SQLException
   */
  public ResultSet executeQuery() throws SQLException {
    if (prepstmt != null) {
      return prepstmt.executeQuery();
    } else
      return null;
  }

  /**
   * 执行Statement更改语句
   * @param sql
   * @throws SQLException
   */
  public void executeUpdate(String sql) throws SQLException {
    if (stmt != null)
      stmt.executeUpdate(sql);
  }

  /**
   * 执行PreparedStatement更改语句
   * @throws SQLException
   */
  public void executeUpdate() throws SQLException {
    if (prepstmt != null)
      prepstmt.executeUpdate();
  }

  /**
   * 关闭连接
   */
  public void close() {
    try {
      if (stmt != null) {
        stmt.close();
        stmt = null;
      }
      if (prepstmt != null) {
        prepstmt.close();
        prepstmt = null;
      }
      conn.close();
      conn = null;
    } catch (Exception e) {
      System.err.println("Mysql close error: " + e);
    }

  }
}