java版本DbhelperMysql

package com.hebut.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public final class DBHelper {

// 此方法为获取数据库连接

public static Connection getConnection() {
        Connection conn = null;
        try {

String driver = "com.mysql.jdbc.Driver"; // 数据库驱动
            String url = "jdbc:MySQL://127.0.0.1:3306/school";// 数据库
            String user = "root"; // 用户名
            String password = "hadoop"; // 密码
            Class.forName(driver); // 加载数据库驱动
            if (null == conn) {
                conn = DriverManager.getConnection(url, user, password);
            }

} catch (ClassNotFoundException e) {
            System.out.println("Sorry,can't find the Driver!");
            e.printStackTrace();
        } catch (SQLException e) {

e.printStackTrace();

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

}

return conn;

}

/**

* 增删改【Add、Del、Update】

*

* @param sql

* @return int

*/

public static int executeNonQuery(String sql) {
        int result = 0;
        Connection conn = null;
        Statement stmt = null;
        try {
            conn = getConnection();
            stmt = conn.createStatement();
            result = stmt.executeUpdate(sql);
        } catch (SQLException err) {
            err.printStackTrace();
            free(null, stmt, conn);

} finally {
            free(null, stmt, conn);
        }
        return result;
    }

/**

* 增删改【Add、Delete、Update】

*

* @param sql

* @param obj

* @return int

*/

public static int executeNonQuery(String sql, Object... obj) {

int result = 0;
        Connection conn = null;
        PreparedStatement pstmt = null;
        try {
            conn = getConnection();
            pstmt = conn.prepareStatement(sql);
            for (int i = 0; i < obj.length; i++) {
                pstmt.setObject(i + 1, obj[i]);

}
            result = pstmt.executeUpdate();
        } catch (SQLException err) {

err.printStackTrace();
            free(null, pstmt, conn);
        } finally {
            free(null, pstmt, conn);
        }

return result;

}

/**

* 查【Query】

*

* @param sql

* @return ResultSet

*/

public static ResultSet executeQuery(String sql) {
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;
        try {

conn = getConnection();
            stmt = conn.createStatement();
            rs = stmt.executeQuery(sql);
        } catch (SQLException err) {
            err.printStackTrace();
            free(rs, stmt, conn);
        }

return rs;

}

/**

* 查【Query】

*

* @param sql

* @param obj

* @return ResultSet

*/

public static ResultSet executeQuery(String sql, Object... obj) {
        Connection conn = null;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        try {

conn = getConnection();

pstmt = conn.prepareStatement(sql);
            for (int i = 0; i < obj.length; i++) {

pstmt.setObject(i + 1, obj[i]);
            }
            rs = pstmt.executeQuery();
        } catch (SQLException err) {

err.printStackTrace();
            free(rs, pstmt, conn);

}

return rs;
    }

/**

* 判断记录是否存在

*

* @param sql

* @return Boolean

*/

public static Boolean isExist(String sql) {

ResultSet rs = null;

try {

rs = executeQuery(sql);

rs.last();

int count = rs.getRow();

if (count > 0) {

return true;

} else {

return false;

}

} catch (SQLException err) {

err.printStackTrace();

free(rs);

return false;

} finally {

free(rs);

}

}

/**

* 判断记录是否存在

*

* @param sql

* @return Boolean

*/

public static Boolean isExist(String sql, Object... obj) {

ResultSet rs = null;

try {

rs = executeQuery(sql, obj);

rs.last();

int count = rs.getRow();

if (count > 0) {

return true;

} else {

return false;

}

} catch (SQLException err) {

err.printStackTrace();

free(rs);

return false;

} finally {

free(rs);

}

}

/**

* 获取查询记录的总行数

*

* @param sql

* @return int

*/

public static int getCount(String sql) {

int result = 0;

ResultSet rs = null;

try {

rs = executeQuery(sql);

rs.last();

result = rs.getRow();

} catch (SQLException err) {

free(rs);

err.printStackTrace();

} finally {

free(rs);

}

return result;

}

/**

* 获取查询记录的总行数

*

* @param sql

* @param obj

* @return int

*/

public static int getCount(String sql, Object... obj) {

int result = 0;

ResultSet rs = null;

try {

rs = executeQuery(sql, obj);

rs.last();

result = rs.getRow();

} catch (SQLException err) {

err.printStackTrace();

} finally {

free(rs);

}

return result;

}

/**

* 释放【ResultSet】资源

*

* @param rs

*/

public static void free(ResultSet rs) {

try {

if (rs != null) {

rs.close();

}

} catch (SQLException err) {

err.printStackTrace();

}

}

/**

* 释放【Statement】资源

*

* @param st

*/

public static void free(Statement st) {

try {

if (st != null) {

st.close();

}

} catch (SQLException err) {

err.printStackTrace();

}

}

/**

* 释放【Connection】资源

*

* @param conn

*/

public static void free(Connection conn) {

try {

if (conn != null) {

conn.close();

}

} catch (SQLException err) {

err.printStackTrace();

}

}

/**

* 释放所有数据资源

*

* @param rs

* @param st

* @param conn

*/

public static void free(ResultSet rs, Statement st, Connection conn) {

free(rs);

free(st);

free(conn);

}

}