servlet 웹 입/출력

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

import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

public class Nana extends HttpServlet
{
	public void service(HttpServletRequest request
			, HttpServletResponse response)
			throws IOException, ServletException
	{
		//OutputStream os = response.getOutputStream();
		//PrintStream out = new PrintStream(os,true);
        PrintWriter out = response.getWriter();
		out.println("Hello Servlet!");
	}
}

 

한글 출력

한글을 출력으로 내보낼때 setContentType으로 contenttype을 지정해서 보내준다.(인코딩 방식의 차이 때문에)

package com.newlec.web;

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

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

@WebServlet("/hello")
public class Nana extends HttpServlet{
	@Override
	protected void service(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
		PrintWriter out = res.getWriter();
		res.setCharacterEncoding("UTF-8");
		res.setContentType("text/html; charset=UTF-8");
		for (int i =0; i<100; i++) {
			out.println((i+1)+": 한글 servlet <br >");
		}
	}
}

 

get요청과 쿼리스트링

query로 요청할때 http://localhost:8080/hello?cnt=3

위처럼 cnt 값을 파라미터로 넣어주면 된다.

package com.newlec.web;

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

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

@WebServlet("/hello")
public class Nana extends HttpServlet{
	@Override
	protected void service(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
		PrintWriter out = res.getWriter();
		res.setCharacterEncoding("UTF-8");
		res.setContentType("text/html; charset=UTF-8");
		int cnt = Integer.parseInt(req.getParameter("cnt"));
		for (int i =0;i<cnt; i++) {
			out.println("안녕 servlet<br/>");
		}
	}
}