ResponseUtils.java
package javax.utils;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.io.OutputStream;import java.io.PrintWriter;import java.net.URLEncoder;import javax.servlet.http.HttpServletResponse;import com.fasterxml.jackson.databind.ObjectMapper;/** * HTTP 输出响应内容工具类 * ?* @author Logan * @createDate 2019-02-13 * @version 1.0.0 * */public class ResponseUtils { ???/** ????* 发送HTTP响应信息 ????* ?????* @param response HTTP响应对象 ????* @param message 信息内容 ????* @throws IOException 抛出异常，由调用者捕获处理 ????*/ ???public static void write(HttpServletResponse response, String message) throws IOException { ???????response.setContentType("text/html;charset=UTF-8"); ???????try ( ???????????????PrintWriter writer = response.getWriter(); ???????) { ???????????writer.write(message); ???????????writer.flush(); ???????} ???} ???/** ????* 发送HTTP响应信息,JSON格式 ????* ?????* @param response HTTP响应对象 ????* @param message 输出对象 ????* @throws IOException 抛出异常，由调用者捕获处理 ????*/ ???public static void write(HttpServletResponse response, Object message) throws IOException { ???????response.setContentType("application/json;charset=UTF-8"); ???????ObjectMapper mapper = new ObjectMapper(); ???????try ( ???????????????PrintWriter writer = response.getWriter(); ???????) { ???????????writer.write(mapper.writeValueAsString(message)); ???????????writer.flush(); ???????} ???} ???/** ????* 下载文件 ????* ?????* @param response HTTP响应对象 ????* @param message 输出对象 ????* @throws IOException 抛出异常，由调用者捕获处理 ????*/ ???public static void write(HttpServletResponse response, File file) throws IOException { ???????String fileName = file.getName(); ???????try ( ???????????????OutputStream out = response.getOutputStream(); ???????????????FileInputStream in = new FileInputStream(file); ???????) { ???????????// 对文件名进行URL转义，防止中文乱码 ???????????fileName = URLEncoder.encode(fileName, "UTF-8"); ???????????// 空格用URLEncoder.encode转义后会变成"+"，所以要替换成"%20"，浏览器会解码回空格 ???????????fileName = fileName.replace("+", "%20"); ???????????// "+"用URLEncoder.encode转义后会变成"%2B"，所以要替换成"+"，浏览器不对"+"进行解码 ???????????fileName = fileName.replace("%2B", "+"); ???????????response.setContentType("application/x-msdownload;charset=UTF-8"); ???????????response.setHeader("Content-Disposition", "attachment; filename=" + fileName); ???????????byte[] bytes = new byte[4096]; ???????????int len = -1; ???????????while ((len = in.read(bytes)) != -1) { ???????????????out.write(bytes, 0, len); ???????????} ???????????out.flush(); ???????} ???}}.
HTTP 输出响应内容工具类
原文地址：https://www.cnblogs.com/jonban/p/10372033.html