利用QueryRunner类实现对数据库的增删改查操作,需要先导入jar包:commons-dbutils-1.6。利用QueryRunner类可以实现对数据步骤的简化。
1、添加
运用JDBC工具类实现连接:
package JDBCUtils; import java.io.IOException; import java.io.InputStream; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.Properties; public class JDBCUtils { private static Connection con; private static String driver; private static String url; private static String username; private static String password; static {// 静态代码块只执行一次,获取一次信息即可 try { readConfig(); Class.forName(driver); con = DriverManager.getConnection(url, username, password); } catch (Exception ex) { throw new RuntimeException("数据库连接失败"); } } /* * getClassLoader();返回该类的加载器 * getResourceAsStream();查找具有给定名称的资源 */ private static void readConfig() { InputStream in = JDBCUtils.class.getClassLoader().getResourceAsStream("JDBC.properties"); Properties pro = new Properties(); try { pro.load(in); } catch (IOException e) { e.printStackTrace(); } driver = pro.getProperty("driver"); url = pro.getProperty("url"); username = pro.getProperty("username"); password = pro.getProperty("password"); } public static Connection getConnection() { return con; } public static void close(Connection con) { if (con != null) { try { con.close(); } catch (SQLException e) { e.printStackTrace(); System.out.println("con流关闭异常!"); } } } public static void close(Connection con, Statement stat) { if (stat != null) { try { stat.close(); } catch (SQLException e) { e.printStackTrace(); System.out.println("stat流关闭异常!"); } } if (con != null) { try { con.close(); } catch (SQLException e) { e.printStackTrace(); System.out.println("con流关闭异常!"); } } } public static void close(Connection con, Statement stat, ResultSet rs) { if (rs != null) { try { rs.close(); } catch (SQLException e) { e.printStackTrace(); System.out.println("rs流关闭异常!"); } } if (stat != null) { try { stat.close(); } catch (SQLException e) { e.printStackTrace(); System.out.println("stat流关闭异常!"); } } if (con != null) { try { con.close(); } catch (SQLException e) { e.printStackTrace(); System.out.println("con流关闭异常!"); } } } }
import java.sql.Connection; import java.sql.SQLException; import org.apache.commons.dbutils.QueryRunner; import JDBCUtils.JDBCUtils; public class add { public static void main(String[] args) { Connection con = null; try { con = JDBCUtils.getConnection(); QueryRunner qr = new QueryRunner(); String sql = "INSERT INTO student(studentno,sname,sex,birthday,classno,point,phone,email) VALUES(?,?,?,?,?,?,?,?)"; Object[] params = { "20191811", "Jack", "男", "1988-12-01", "201901", "239", "16623540978", "[email protected]" }; int num = qr.update(con, sql, params); System.out.println("添加了" + num + "行"); } catch (SQLException e) { throw new RuntimeException(e); } JDBCUtils.close(con); } }
2、删除
import java.sql.Connection; import java.sql.SQLException; import org.apache.commons.dbutils.QueryRunner; import JDBCUtils.JDBCUtils; public class DeleteDemo { public static void main(String[] args) { Connection con = null; try { con = JDBCUtils.getConnection(); QueryRunner qr = new QueryRunner(); String sql = "DELETE from Student where sname =?"; Object[] delete = { "Tom" }; qr.update(con, sql, delete); } catch (SQLException e) { throw new RuntimeException(e); } JDBCUtils.close(con); } }
3、修改
import java.sql.Connection; import java.sql.SQLException; import org.apache.commons.dbutils.QueryRunner; import JDBCUtils.JDBCUtils; public class UpdateDemo { public static void main(String[] args) { Connection con = null; try { con = JDBCUtils.getConnection(); QueryRunner qr = new QueryRunner(); String sql = "Update Student set classno=? Where sname=‘韩吟秋‘"; Object[] update = { "201901" }; qr.update(con, sql, update); } catch (SQLException e) { throw new RuntimeException(e); } JDBCUtils.close(con); } }
4、查询
(1)
ArrayHandler: 将结果集的第一行存储到Object[]数组中
ArrayListHandler: 将结果集的每一行存储到Object[]数组中
import java.sql.Connection; import java.sql.SQLException; import java.util.Arrays; import java.util.List; import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.handlers.ArrayListHandler; import JDBCUtils.JDBCUtils; public class SeleteDemo { public static void main(String[] args) { Connection con = null; try { con = JDBCUtils.getConnection(); QueryRunner qr = new QueryRunner(); String sql = "Select * from Student where studentno=?"; Object[] select = { 20191811 }; List<Object[]> list = qr.query(con, sql, new ArrayListHandler(), select); // 将记录封装到一个装有Object[]的List集合中 for (Object[] arr : list) { System.out.println(Arrays.toString(arr)); } } catch (SQLException e) { throw new RuntimeException(e); } JDBCUtils.close(con); } }
(2)
BeanHandler:结果集中第一条记录封装到一个指定的javaBean中。
BeanListHandler:结果集中每一条记录封装到javaBean中,再将javaBean封装到list集合中。
原文地址:https://www.cnblogs.com/zhai1997/p/11382079.html
时间: 2024-10-13 20:37:54