使用jtds连接数据库，采用泛型

[java]代码库
package com.dtl.rmgr.util;
 
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
 
public class DB {
    private static String url;
    private static String username;
    private static String password;
    private static String classDriver;
 
    static {
        try {
            InputStream in = DB.class.getResourceAsStream("/jdbc.properties");
            Properties prop = new Properties();
            prop.load(in);
            in.close();
            url = prop.getProperty("url");
            username = prop.getProperty("username");
            password = prop.getProperty("password");
            classDriver = prop.getProperty("classDriver");
            Class.forName(classDriver);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
 
    }
 
    // static {
    // try {
    // url = "jdbc:oracle:thin:@localhost:1521:oratlq";
    // username = "rmgr";
    // password = "rmgr";
    // classDriver = "oracle.jdbc.OracleDriver";
    // Class.forName(classDriver);
    // } catch (Exception e) {
    // // TODO Auto-generated catch block
    // e.printStackTrace();
    // }
    //
    // }
 
    // 获取一个连接
    public static Connection getConn() {
        Connection conn = null;
        try {
            conn = DriverManager.getConnection(url, username, password);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return conn;
    }
 
    // 关闭一个连接
    public static void closeConn(Connection conn) {
        if (null != conn) {
            try {
                conn.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
 
    // 执行增，删，改
    public static int update(Connection conn, String sql, Object... parames) {
        int count = 0;
        try {
            PreparedStatement pstmt = conn.prepareStatement(sql);
            for (int i = 0; i < parames.length; i++) {
                pstmt.setObject(i + 1, parames[i]);
            }
            count = pstmt.executeUpdate();
            pstmt.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return count;
    }
 
    public static int update(String sql, Object... parames) {
        Connection conn = null;
        try {
            conn = getConn();
            return update(conn, sql, parames);
        } finally {
            closeConn(conn);
        }
    }
 
    // 执行查询 找到则放回lists 否则为空
    public static <T> List<T> query(Connection conn, String sql,
            IResultSet<T> irs, Object... parames) {
        List<T> lists = null;
        try {
            lists = new ArrayList<T>();
            PreparedStatement pstmt = conn.prepareStatement(sql);
            for (int i = 0; i < parames.length; i++) {
                pstmt.setObject(i + 1, parames[i]);
            }
            ResultSet rs = pstmt.executeQuery();
            while (rs.next()) {
                // 读取一行放到lists 集合中
                T t = irs.readRow(rs);
                lists.add(t);
            }
            rs.close();
            pstmt.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
 
        return lists;
    }
 
    public static <T> List<T> query(String sql, IResultSet<T> irs,
            Object... parames) {
        Connection conn = null;
        List<T> lists = null;
        try {
            conn = getConn();
            lists = query(conn, sql, irs, parames);
        } finally {
            DB.closeConn(conn);
        }
        return lists;
    }
     
     
    public static int getMaxId(String sql) {// 获取数据库中department表的最大id
        int id = 1;
        Connection conn = DB.getConn();
        try {
            PreparedStatement pstmt = conn.prepareStatement(sql);
            ResultSet rs = pstmt.executeQuery();
            if (rs.next()) {
                id += rs.getInt(1);
            }
            rs.close();
            pstmt.close();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
        return id;
    }
 
}
用户注册

用户登录

发表随想

该用户最新代码

编程随想

[java]代码库

网友评论 (发表评论)

发表评论：

评论须知：

扫码下载

输入口令后可复制整站源码
