通过自己写的JDBC工具类实现增删改查

package day28_02;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ResourceBundle;

public class JdbcUtil {
    static final String CLASSDRIVER;
    static final String URL;
    static final String NAME;
    static final String PASSWORD;

    static {
        ResourceBundle rb = ResourceBundle.getBundle("Config");

        CLASSDRIVER = rb.getString("classDriver");
        URL = rb.getString("url");
        NAME = rb.getString("name");
        PASSWORD = rb.getString("password");
        try {
            Class.forName(CLASSDRIVER);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    public static Connection getConnection() throws SQLException {

        
        return DriverManager.getConnection(URL, NAME, PASSWORD);

        
    }

    public static void closeResource(Connection conn, Statement stmt, ResultSet rs) {
        closeResult(rs);
        closeStatement(stmt);
        closeConnection(conn);
    }

    private static void closeConnection(Connection conn) {
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        conn = null;
    }

    private static void closeStatement(Statement stmt) {
        if (stmt != null) {
            try {
                stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        stmt = null;

    }

    private static void closeResult(ResultSet rs) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        rs = null;
    }
}



以上是JDBC工具类

---

 

  以下代码执行增删改查操作

 

package day28_02;

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

import org.junit.Test;

public class JdbcUtilTest {
    /**
     * 查询全部信息
     */
    @Test
    public void test() {
        // 驱动，连接
        Connection conn = null;
        ResultSet rs = null;
        PreparedStatement pst = null;
        try {
            conn = JdbcUtil.getConnection();

            // 编写sql
            String sql = "SELECT * FROM a_students";

            // 语句执行者
            pst = conn.prepareStatement(sql);

            // 设置参数

            // 执行，获取结果
            rs = pst.executeQuery();

            // 处理结果
            while (rs.next()) {
                System.out.println(
                        rs.getString(1) + "---" + rs.getString(2) + "---" + rs.getString(3) + "---" + rs.getString(4));
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        // 释放资源
        JdbcUtil.closeResource(conn, pst, rs);
    }

    /**
     * 修改信息
     */
    @Test
    public void update() {
        Connection conn = null;
        PreparedStatement pst = null;

        try {
            // 获得连接
            conn = JdbcUtil.getConnection();
            // 编写sql
            String sql = "UPDATE a_students SET s_id = ? WHERE s_id = ?";
            // 获得语句执行者
            pst = conn.prepareStatement(sql);
            // 设置变量
            pst.setString(1, "owen17082413");
            pst.setString(2, "owen17082414");

            int i = pst.executeUpdate();
            // System.out.println(1);
            // System.out.println(i);
            if (i == 1) {
                System.out.println("success");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JdbcUtil.closeResource(conn, pst, null);
        }
    }

    /**
     * 添加数据
     */
    @Test
    public void insert() {
        Connection conn = null;
        PreparedStatement pst = null;
        try {
            // 获取连接
            conn = JdbcUtil.getConnection();
            // 编写sql
            String sql = "INSERT INTO a_students VALUES(?,?,?,?)";

            // 创建语句执行者
            pst = conn.prepareStatement(sql);

            // 设置参数
            pst.setString(1, "owen17082415");
            pst.setString(2, "吴奇隆");
            pst.setString(3, "黄淑宁");
            pst.setString(4, "15636316713");

            // 执行sql，获取结果
            int i = pst.executeUpdate();

            // 处理结果
            if (i == 1) {
                System.out.println("success");
            } else {
                System.out.println("fail");
            }

        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JdbcUtil.closeResource(conn, pst, null);
        }
    }

    /**
     * 删除数据
     */
    @Test
    public void delete() {
        Connection conn = null;
        PreparedStatement pst = null;

        try {
            // 获取连接
            conn = JdbcUtil.getConnection();

            // 编写sql
            String sql = "DELETE FROM a_students WHERE s_id = ?";

            // 创建语句执行者
            pst = conn.prepareStatement(sql);

            // 设置参数
            pst.setString(1, "owen17082415");

            // 执行sql，获得结果
            int i = pst.executeUpdate();

            // 处理结果
            if (i == 1) {
                System.out.println("success");
            } else {
                System.out.println("fail");
            }

        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JdbcUtil.closeResource(conn, pst, null);
        }
    }
}