conndb.java

BS 架构的指纹识别技术

package com.zkdz.core;

import java.io.*;
import java.util.Properties;
import java.sql.*;

public class ConnDB {
	 public Connection conn = null;
	  public Statement stmt = null;
	  public ResultSet rs = null;
	  private static String propFileName = "/com/zkdz/com/connDB.properties";	//指定资源文件保存的位置
	  private static Properties prop = new Properties();
	  private static String dbClassName =null;
	  private static String dbUrl =null;
	public ConnDB() {

		try {
			InputStream in = getClass().getResourceAsStream(propFileName);
			prop.load(in); // 通过输入流对象加载properties文件
			dbClassName = prop.getProperty("DB_CLASS_NAME");// 获取数据库驱动
			
			dbUrl = prop.getProperty("DB_URL");
		
		} catch (IOException e) {
			e.printStackTrace();
			System.out.println("读资源文件错误!");
		}
	}
   /*
    * 得到数据库实例
    */
	public static Connection getConnection() {
		Connection conn = null;
		try {
			Class.forName(dbClassName).newInstance();
			conn = DriverManager.getConnection(dbUrl);
		} catch (Exception e) {
			System.out.println("创建驱动实例错误");
			
		}
		if (conn == null) {
			System.out.println("创建conn失败" + dbUrl);
		}
		return conn;
	}
  /*
   * 执行查询
   */
	public ResultSet executeQuary(String sql) {

		try {
			conn = getConnection();
			stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
					ResultSet.TYPE_FORWARD_ONLY);
			rs = stmt.executeQuery(sql);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return rs;
	}

	/*
	 * 执行更新、删除、插入操作
	 */ 
	public int executeUpdate(String sql) {
		int result = 0;
		try {
			conn = this.getConnection();
			stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
					ResultSet.TYPE_FORWARD_ONLY);
			result = stmt.executeUpdate(sql);
		} catch (Exception e) {
			e.printStackTrace();
			result = 0;
		}
		return result;
	}

	/*
	 *关闭数据库
	 */
	public void close() {
		try {
			if (rs != null) {
				rs.close();
			}
			if (stmt != null) {
				stmt.close();
			}
			if (conn != null) {
				conn.close();
			}

		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}