springboot使用jdbc连接mysql(不用配置文件)
1、连接mysql的工具类:
package com.jzproject.common.mysql; import com.alibaba.fastjson.JSON; import com.alibaba.fastjson.JSONArray; import org.springframework.jdbc.core.JdbcTemplate; import java.sql.*; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class JDBCconnet { private static String driver = "com.mysql.cj.jdbc.Driver"; private static String url = "jdbc:mysql://localhost:3306/test?userSSL=false&serverTimezone=UTC"; private static String user = "root"; private static String pass = "123456"; public static List<Map<String, Object>> selectList(){ List<Map<String, Object>> list = new ArrayList<Map<String, Object>>(); try { Class.forName(driver); Connection conn = DriverManager.getConnection(url ,user, pass); String sql = " SELECT * FROM pmw_infolist\n" + "WHERE classid = '17' "; Statement statement = conn.createStatement(); ResultSet r = statement.executeQuery(sql); ResultSetMetaData md = r.getMetaData(); //获取结果集 int columnCount = md.getColumnCount(); //总列数 while(r.next()){ Map rowData = new HashMap(); for (int i = 1; i <= columnCount; i++) { rowData.put(md.getColumnName(i), r.getObject(i)); } list.add(rowData); } } catch (Exception e) { e.printStackTrace(); } return list; } public static void main(String[] args){ List<Map<String, Object>> list = selectList(); System.out.println(JSONArray.toJSONString(list)); } }
如果运行报错:java.lang.ClassNotFoundException: com.mysql.cj.jdbc.Driver
解决办法:配置idea导入连接mysql的jar包
找到本地maven仓库里的jar包,直接加进来就ok了
。