JDBC简单封装类

封装类

package JDBChelp;
import java.sql.*;
//jdbc封装类
public class JDBChelp {
    private JDBChelp(){}
  static {
      try {
          Class.forName("com.mysql.cj.jdbc.Driver");
      } catch (ClassNotFoundException e) {
          e.printStackTrace();
      }
  }
  public static Connection getConnection() throws Exception{
      String url="jdbc:mysql://localhost:3306/mydate";
      String user="root";
      String password ="123456";
      return   DriverManager.getConnection(url,user,password);
  }
  public  static void close(Connection con , Statement sta, ResultSet rs){
        if(rs!=null){
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        } if(sta!=null){
          try {
              sta.close();
          } catch (SQLException e) {
              e.printStackTrace();
          }
      } if(con!=null){
          try {
              con.close();
          } catch (SQLException e) {
              e.printStackTrace();
          }
      }
  }
}

测试

package JDBCpackage;
import JDBChelp.JDBChelp;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
//测试JDBChelp封装类
//测试模糊查询
public class JDBCtest05 {
    public static void main(String[] args) {
        Connection con=null;
        PreparedStatement ps=null;
        ResultSet set=null;
        try {
            con= JDBChelp.getConnection();//链接
            String sql ="select name from student where name like ?";
            ps=con.prepareStatement(sql);
            ps.setString(1,"张三");
            set=ps.executeQuery();
            while(set.next()){
                System.out.println(set.getString("name"));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            JDBChelp.close(con,ps,set);
        }
    }
}

这也是链接数据库的一种方法，把代码封装可以简短后面的代码！但不是必要的！