국비 45일차 서블릿 파라미터 처리(values, names, map)

2021. 3. 12. 20:19

2021.03.12 국비교육 45일차

[TOC]

요청 파라미터 처리 메서드

  • doPost 방식으로 보내면 한글이 깨짐 --> 한글처리 해줘야함

getParameter

package com.controller;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;


    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //post 한글처리
        request.setCharacterEncoding("utf-8");
        //요청작업 처리

        System.out.println("LoginServlet.doGet() 실행 ==");
        String userid = request.getParameter("userid");//html name = "userid"의 value를 String 리턴
        String passwd = request.getParameter("passwd");

        System.out.println(userid);
        System.out.println(passwd);

        //응답처리
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        out.print("<html><body>");
        out.print("이름은" + userid);
        out.print("암호는" + passwd);
        out.print("</body></html>");
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("doPost 호출 ===");
        doGet(request, response);
    }

}

getParameterValues

  • name이 같은것들 value찾아옴
package com.controller;

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/TestServlet")
public class TestServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8"); // 한글인코딩
        String [] fruits = request.getParameterValues("fruit");//스트링 배열 리턴
        for(String s : fruits) {
            System.out.println(s);
        }


        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
    }
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

}

getParameterNames

  • enumerate 활용하여 출력하기
package com.controller;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;


    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //post 한글처리
        request.setCharacterEncoding("utf-8");

        Enumeration<String> keys=request.getParameterNames(); //key값만 Enumeration으로 리턴


        response.setContentType("text/html;charset=utf-8");
        PrintWriter out = response.getWriter();
        //응답처리
        out.print("<html><body>");
        while(keys.hasMoreElements()) { //다음키 여부 확인
            String key = keys.nextElement();//키값 하나 받기
            String value = request.getParameter(key);//키에 해당하는 값 파싱
            System.out.println(key + "\t" + value);
            out.print(key+ " : " +value + "<br>");
        }
        out.print("</body></html>");

    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

}

getParameterMap

package com.controller;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Map;
import java.util.Set;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;


    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //post 한글처리
        request.setCharacterEncoding("utf-8");

        Map<String, String[]> map = request.getParameterMap();//String key, String[] value


        response.setContentType("text/html;charset=utf-8");
        PrintWriter out = response.getWriter();
        //응답처리
        out.print("<html><body>");
        Set<String> keys = map.keySet(); // Keyset 얻기
        for(String key : keys) {
            String[] values =map.get(key);
            String mesg = "";
            for(String s: values) {
                mesg += s;
            }
            out.print(key + "========" + mesg + "<br>");
        }

        out.print("</body></html>");
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

}

IntiParam

  • Web.xml에서 value값 지정해서 넘겨줄수 있음

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