JDBC自定义工具类（完整版）

package util;

/**
 * 连接数据库
 */

import java.sql.CallableStatement;
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 class DBUtil {

    /**
     * 获取连接
     *
     * @return Connection
     * @throws Exception 异常
     */
    public static Connection getCon() throws Exception {
        //数据库驱动名字
        String jdbcName = "com.mysql.jdbc.Driver";
        Class.forName(jdbcName);
        //数据库协议地址
        String dbUrl = "jdbc:mysql://ip:3306/databaseName?useUnicode=true&characterEncoding=UTF-8";
        //数据库用户名
        String dbUser = "username";
        //数据库密码
        String dbPassword = "password";
        Connection conn = DriverManager.getConnection(dbUrl, dbUser, dbPassword);
        return conn;
    }

    /**
     * 关闭连接
     *
     * @param stmt Statement
     * @param conn Connection
     * @throws Exception 异常
     */
    public static void close(Statement stmt, Connection conn) throws Exception {
        if (stmt != null) {
            stmt.close();
            if (conn != null) {
                conn.close();
            }
        }
    }

    /**
     * 关闭连接
     *
     * @param cstmt CallableStatement
     * @param conn  Connection
     * @throws Exception 异常
     */
    public static void close(CallableStatement cstmt, Connection conn) throws Exception {
        if (cstmt != null) {
            cstmt.close();
            if (conn != null) {
                conn.close();
            }
        }
    }


    /**
     * 关闭连接
     *
     * @param pstmt PreparedStatement
     * @param conn  Connection
     * @throws SQLException SQL异常
     */
    public static void close(PreparedStatement pstmt, Connection conn) throws SQLException {
        if (pstmt != null) {
            pstmt.close();
            if (conn != null) {
                conn.close();
            }
        }
    }

    /**
     * 重载关闭方法
     *
     * @param pstmt PreparedStatement
     * @param conn  Connection
     * @throws Exception 异常
     */
    public static void close(ResultSet rs, PreparedStatement pstmt, Connection conn) {
        if (rs != null) {
            try {
                rs.close();
                if (pstmt != null) {
                    pstmt.close();
                    if (conn != null) {
                        conn.close();
                    }
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

}