HttpServletResponse响应

一、HttpServletResponse详解

   定义，response对象值想客户端作出的响应。

          我们以例子来说明：

字符流输出UTF-8中文数据响应到客户端

package com.dp.java.response;

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

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ResponseDom1 extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
//		test1(response);
//		test2(response);
//		test3(response);
//		test4(response);
		test5(response);
	}
	
	/**
	 *输出整数
	 */
	private void test5(HttpServletResponse response) throws IOException {
		int i=80;
		response.getOutputStream().write((i+"").getBytes());
		//字符集将此 String 编码为 byte 序列，并将结果存储到一个新的 byte 数组中。
	}
	/**
	 *字符流输出UTF-8中文数据(第四种方式)到客户端
	 */
	private void test4(HttpServletResponse response) throws IOException {
		String s="Mr_Li13的servlet数据传输到网页上;第四种方式";
		ServletOutputStream out=response.getOutputStream();
		response.setContentType("text/html;charest=UTF-8");//设置页面显示编码格式和设置输出流编码格式
		out.write(s.getBytes("UTF-8"));//输出到web客户端
	}
	
	/**
	 *字符流输出UTF-8中文数据(第三种方式)到客户端
	 */
	private void test3(HttpServletResponse response) throws IOException {
		String s="Mr_Li13的servlet数据传输到网页上;第三种方式";
		response.setContentType("text/html;charest=UTF-8");//设置页面显示编码格式和设置输出流编码格式
		PrintWriter out = response.getWriter();//拿到输出流对象
		out.write(s);//输出到web客户端
	}
	
	/**
	 *字符流输出UTF-8中文数据(第二种方式)到客户端
	 */
	private void test2(HttpServletResponse response) throws IOException {
		String s="Mr_Li13的servlet数据传输到网页上;第二种方式";
		response.setCharacterEncoding("UTF-8");//设置输出流编码格式
		response.setContentType("text/html;charest=UTF-8");//设置页面显示编码格式和设置输出流编码格式
		PrintWriter out = response.getWriter();//拿到输出流对象
		out.write(s);//输出到web客户端
	}
	
	/**
	 *字符流输出UTF-8中文数据(第一种方式)到客户端
	 */
	private void test1(HttpServletResponse response) throws IOException {
		String s="Mr_Li13的servlet数据传输到网页上;第一种方式";
		response.setCharacterEncoding("UTF-8");//设置输出编码格式
		response.setHeader("Content-Type", "text/html;charset=UTF-8");//设置页面显示编码格式
		PrintWriter out = response.getWriter();//拿到输出流对象
		out.write(s);//输出到web客户端
	}

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

}

以字节流用UTF-8编码向客户端响应中文数据

package com.dp.java.response;

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

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ResponseDom2 extends HttpServlet {
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		test3(response);
	}
	/**
	 * 以字节流用UTF-8编码向客户端响应中文数据
	 */
	private void test3(HttpServletResponse response) throws IOException {
		String s="幸福是我？";
		ServletOutputStream out=response.getOutputStream();
		out.write("<meta http-equiv='Content-Type' content='text/html;charset=UTF-8'>".getBytes());
		out.write(s.getBytes());
	}
	
	/**
	 * 以字节流用UTF-8编码向客户端响应中文数据
	 */
	private void test2(HttpServletResponse response) throws IOException {
		String s="幸福是你？";
		ServletOutputStream out=response.getOutputStream();
		response.setHeader("Content-Type", "text/html;charset=UTF-8");
		out.write(s.getBytes("UTF-8"));
	}
	
	/**
	 * 以字节流用UTF-8编码向客户端响应中文数据
	 */
	private void test1(HttpServletResponse response) throws IOException {
		String s="幸福是什么？";
		ServletOutputStream out=response.getOutputStream();
		out.write(s.getBytes());
	}

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

}