JDBC的简单封装

1、dataSource.properties

driver=oracle.jdbc.driver.OracleDriver
url=jdbc:oracle:thin:@localhost:1521:orcl
username=username
password=password

2、代码示例

package com.example;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

public class JdbcUtil {
    /** 数据库驱动 */
    private static String driver;
    /** 数据库连接url */
    private static String url;
    /** 用户名 */
    private static String username;
    /** 密码 */
    private static String password;

    static {
        // 创建properties对象获取属性文件的内容
        Properties properties = new Properties();
        // 获取属性文件的读取流对象
        InputStream is = JdbcUtil.class.getResourceAsStream("/dataSource.properties");
        try {
            // 加载属性配置文件
            properties.load(is);
            // 获取jdbc参数
            driver = properties.getProperty("driver");
            url = properties.getProperty("url");
            username = properties.getProperty("username");
            password = properties.getProperty("password");
            // 加载驱动
            Class.forName(driver);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

    /**
     * DML操作
     *
     * @param sql  sql语句
     * @param objs 占位参数
     * @return 影响的结果行数
     */
    public static int executeDML(String sql, Object... objs) {
        // 创建连接对象
        Connection conn = getConnection();
        // 创建sql命令对象
        PreparedStatement ps = getPreparedStatement(sql, conn);
        try {
            // 手动提交事务
            conn.setAutoCommit(false);
            // 给占位符赋值
            for (int i = 0; i < objs.length; i++) {
                ps.setObject(i + 1, objs[i]);
            }
            int i = ps.executeUpdate();
            conn.commit();
            return i;
        } catch (Exception e) {
            try {
                conn.rollback();
            } catch (SQLException e1) {
                e1.printStackTrace();
            }
        } finally {
            // 关闭资源
            close(ps);
            close(conn);
        }
        // 返回结果
        return -1;
    }

    /**
     * 获取Connection对象
     *
     * @return Connection对象
     */
    public static Connection getConnection() {
        Connection conn = null;
        try {
            conn = DriverManager.getConnection(url, username, password);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;

    }
    
    /**
     * 获取PreparedStatement对象
     *
     * @param sql  sql语句
     * @param conn Connection连接对象
     * @return PreparedStatement实例
     */
    public static PreparedStatement getPreparedStatement(String sql, Connection conn) {

        PreparedStatement ps = null;
        try {
            ps = conn.prepareStatement(sql);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return ps;

    }

    /**
     * 获取Statement对象
     *
     * @param conn Connection连接对象
     * @return Statement实例
     */
    public static Statement getStatement(Connection conn) {
        Statement stmt = null;
        try {
            stmt = conn.createStatement();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return stmt;

    }

    /**
     * 关闭资源
     *
     * @param autoCloseable AutoCloseable接口实现类
     */
    public static void close(AutoCloseable autoCloseable) {
        if (autoCloseable != null) {
            try {
                autoCloseable.close();
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    }
}