java运用JDBC技术实现对表数据的增删改查操作

第一步：导包

第二步：写一个工具类    JDBCUtils.java

代码如下：

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

/**
 * 该工具类:
 * 作用1: 注册驱动
 *
 * 作用2: 提供获取Connection连接对象的静态方法
 *
 * 作用3: 提供一个关闭 close资源的方法  可能会关闭3个资源.
 */
public class JDBCUtils {
    private static final String URL = "jdbc:mysql://localhost:3306/day05";
    private static final String USERNAME = "root";
    private static final String PASSWORD = "root";

    static {
        /*try {
            DriverManager.registerDriver(new Driver());
        } catch (SQLException e) {
            e.printStackTrace();
        }*/

        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

    public static Connection getConnection() throws SQLException {
        Connection connection = DriverManager.getConnection(URL, USERNAME, PASSWORD);
        return connection;
    }

    public static void closeResource(Connection connection, Statement statement, ResultSet resultSet){
        if(connection != null){
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if(statement != null){
            try {
                statement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if(resultSet != null){
            try {
                resultSet.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

    }
}

第三步：写一个测试类   JDBCUtilsTest.java

代码如下：

import org.junit.Test;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;


public class JDBCUtilsTest {
    @Test
    public void testQuery() throws SQLException {
        Connection connection = JDBCUtils.getConnection();
        Statement statement = connection.createStatement();
        ResultSet resultSet = statement.executeQuery("select * from user");
        while (resultSet.next()){
            int id = resultSet.getInt("id");
            String name = resultSet.getString("name");
            System.out.println("id = " + id + ", name = "+name);
        }
        JDBCUtils.closeResource(connection,statement,resultSet);
    }
}

第四步：数据库中表数据提前添加进入  

运行结果如下: