我写了这么个代码, 用来测试使用 spring 提供 Json 数据

Controller

package controller;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;import service.json.FileService;@Controller
public class IndexController {@ResponseBody@RequestMapping(value = "index", method = RequestMethod.GET, produces = "text/html; charset=utf-8")public String index(HttpServletRequest request, HttpServletResponse response) {System.out.println("请求内容: " + request.getHeader("Accept"));response.setContentType("text/html); charset=utf-8");return FileService.INSTANCE.getResList();}}

Kotlin 处理逻辑

package service.jsonimport java.io.File
import my.kotlin.getFileSizeobject FileService {fun getResList() : String {val dir = File("C:\\")var list = ""for (f in (dir.listFiles() ?: return "{}")) {list +=  """|   {"$f", "${ if (f.isFile()) "文件" else "目录" }", ${ f.getFileSize() }}|""".trimMargin()}return """|{|$list|}""".trimMargin()}
}fun main() = Unit

请求结果

$ curl http://abc.com:8080/Json/index.html
{{"C:\$Recycle.Bin", "??", 0 Byte}{"C:\AppData", "??", 0 Byte}{"C:\Boot", "??", 4 KB}{"C:\bootmgr", "??", 374.79 KB}{"C:\CYGWIN_SYSLOG.TXT", "??", 876 Byte}{"C:\Documents and Settings", "??", 0 Byte}{"C:\dosh", "??", 0 Byte}{"C:\DownLoadRecord.ini", "??", 19 Byte}{"C:\GHLDR", "??", 265.78 KB}{"C:\hsrv.txt", "??", 0 Byte}{"C:\mypath_config.txt", "??", 2.7 KB}{"C:\my_path_eve_var.txt", "??", 2.8 KB}{"C:\OEMSF", "??", 317.54 KB}{"C:\pagefile.sys", "??", 7.93 GB}{"C:\perflogs", "??", 0 Byte}{"C:\ping.jpg", "??", 1.51 MB}{"C:\Program Files", "??", 8 KB}{"C:\Program Files (x86)", "??", 12 KB}{"C:\ProgramData", "??", 8 KB}{"C:\Sandbox", "??", 0 Byte}{"C:\System Volume Information", "??", 0 Byte}{"C:\Users", "??", 4 KB}{"C:\windmdll", "??", 0 Byte}{"C:\Windows", "??", 48 KB}}  [15:30:56] Administrator@ ~

很明显, response.setContentType("text/html; charset=utf-8");这句代码是没有起到作用的, 在 Github 上我终于找到了问题的原因:

我想知道为什么这会有用？我认为客户有责任发送他们可以接受的contentType。然后消息转换器可以响应它。

设置 Accept 为 utf-8 编码

$ telnet abc.com 8080
GET /Json/index.html HTTP/1.1
Host: abc.com
Accept: text/json;charset=utf-8HTTP/1.1 200
Content-Type: text/json;charset=utf-8
Content-Length: 924
Date: Thu, 05 Sep 2019 07:47:22 GMT{{"C:\$Recycle.Bin", "目录", 0 Byte}{"C:\AppData", "目录", 0 Byte}{"C:\Boot", "目录", 4 KB}{"C:\bootmgr", "文件", 374.79 KB}{"C:\CYGWIN_SYSLOG.TXT", "文件", 876 Byte}{"C:\Documents and Settings", "目录", 0 Byte}{"C:\dosh", "目录", 0 Byte}{"C:\DownLoadRecord.ini", "文件", 19 Byte}{"C:\GHLDR", "文件", 265.78 KB}{"C:\hsrv.txt", "文件", 0 Byte}{"C:\mypath_config.txt", "文件", 2.7 KB}{"C:\my_path_eve_var.txt", "文件", 2.8 KB}{"C:\OEMSF", "文件", 317.54 KB}{"C:\pagefile.sys", "文件", 7.93 GB}{"C:\perflogs", "目录", 0 Byte}{"C:\ping.jpg", "文件", 1.51 MB}{"C:\Program Files", "目录", 8 KB}{"C:\Program Files (x86)", "目录", 12 KB}{"C:\ProgramData", "目录", 8 KB}{"C:\Sandbox", "目录", 0 Byte}{"C:\System Volume Information", "目录", 0 Byte}{"C:\Users", "目录", 4 KB}{"C:\windmdll", "目录", 0 Byte}{"C:\Windows", "目录", 48 KB}}Connection closed by foreign host

设置 Accept 为 bgk 编码