servlet
package demo;
import java.sql.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class JDBC {
public Connection connect() throws ClassNotFoundException, SQLException{
Connection conn=null;
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://47.122.1.22/pzj_users?"
+ "user=root_user&password=pzj2020@&useUnicode=true&characterEncoding=UTF8";
conn=DriverManager.getConnection(url);
return conn;
}
public void close(Statement stat,Connection conn) throws SQLException{
if(stat!=null){
stat.close();
}
if(conn!=null){
conn.close();
}
}
public int insert(HttpServletRequest request, HttpServletResponse response) throws ClassNotFoundException, SQLException{
Connection conn=null;
Statement stat=null;
String name=request.getParameter("name");
String password=request.getParameter("password");
conn=connect();
stat=conn.createStatement();
int i=stat.executeUpdate("insert into shule_user values('"+name+"','"+password+"')");
close(stat,conn);
return i;
}
public int delete(HttpServletRequest request, HttpServletResponse response) throws ClassNotFoundException, SQLException{
Connection conn=null;
Statement stat=null;
String name=request.getParameter("name");
conn=connect();
stat=conn.createStatement();
int i=stat.executeUpdate("delete from shule_user where name ='"+name+"'");
close(stat,conn);
return i;
}
public int change(HttpServletRequest request, HttpServletResponse response) throws ClassNotFoundException, SQLException{
Connection conn=null;
Statement stat=null;
String name=request.getParameter("name");
String password=request.getParameter("password");
conn=connect();
stat=conn.createStatement();
int i=stat.executeUpdate("update shule_user set password='"+password+"' where name ='"+name+"'");
close(stat,conn);
return i;
}
public String view(HttpServletRequest request, HttpServletResponse response) throws ClassNotFoundException, SQLException{
Connection conn=null;
Statement stat=null;
ResultSet rs=null;
conn=connect();
stat=conn.createStatement();
String Data="";
rs=stat.executeQuery("select * from shule_user");
while(rs.next())
{
Data+=rs.getString("name")+" "+rs.getString("password")+" "+"\n";
}
if(rs!=null){
rs.close();
}
close(stat,conn);
return Data;
}
}
