Spring MVC的Post请求参数中文乱码的原因&处理
一、项目配置:
- Spring 4.4.1-RELEASE
- Jetty 9.3.5
- JDK 1.8
- Servlet 3.1.0
- web.xml文件中没有配置编解码Filter
二、实际遇到的问题:
客户端(比如java)发送post请求访问接口,数据放在body里面,每个参数utf-8编码。
从body里面取出的中文参数是乱码。
下面是发送请求的代码和服务端接收请求的代码。
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客户端代码。
这是一个真实的第三方访问API的案例,这段代码请求到PHP系统正常,请求到java系统就会出现乱码。
但是中文参数放到URL中解码正常,放到请求体中就是乱码。
通过httpclient4.1发送Post请求如下:public static void postData(String sign, String timestamp) { // 创建默认的httpClient实例. CloseableHttpClient httpclient=null; String result=""; try { httpclient = HttpClients.createDefault(); String url = "http://example/api/entry"; HttpPost httpPost = new HttpPost(url); //设置请求和传输超时时间 RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(6000).setConnectTimeout(6000).build(); httpPost.setConfig(requestConfig); MultipartEntity entity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE); entity.addPart("app_id", new StringBody("c5eb3ba8c0e7326559", Charset.forName("utf-8"))); entity.addPart("method", new StringBody("kdt.item.add", Charset.forName("utf-8"))); entity.addPart("timestamp", new StringBody(timestamp)); entity.addPart("format", new StringBody("json", Charset.forName("utf-8"))); entity.addPart("v", new StringBody("1.0", Charset.forName("utf-8"))); entity.addPart("sign", new StringBody(sign, Charset.forName("utf-8"))); entity.addPart("sign_method", new StringBody("md5", Charset.forName("utf-8"))); entity.addPart("cid", new StringBody("5000000", Charset.forName("utf-8"))); entity.addPart("tag_ids", new StringBody("0", Charset.forName("utf-8"))); entity.addPart("price", new StringBody("0.01", Charset.forName("utf-8"))); entity.addPart("title", new StringBody("测试", Charset.forName("utf-8"))); entity.addPart("desc", new StringBody("test1", Charset.forName("utf-8"))); //是否是虚拟商品。0为否,1为是。目前不支持虚拟商品 entity.addPart("is_virtual", new StringBody("0", Charset.forName("utf-8"))); entity.addPart("post_fee", new StringBody("0.0", Charset.forName("utf-8"))); //Sku的属性串。格式:pText:vText;pText:vText,多个sku之间用逗号分隔,如:颜色:黄色;尺寸:M,颜色:黄色;尺寸:S。pText和vText文本中不可以存在冒号和分号以及逗号 entity.addPart("sku_properties", new StringBody("color:white", Charset.forName("utf-8"))); entity.addPart("sku_quantities", new StringBody("998,999", Charset.forName("utf-8"))); entity.addPart("sku_prices", new StringBody("0.01,0.02", Charset.forName("utf-8"))); entity.addPart("sku_outer_ids", new StringBody("null,null", Charset.forName("utf-8"))); //该商品的外部购买地址。当用户购买环境不支持微信或微博支付时会跳转到此地址 entity.addPart("buy_url", new StringBody("http://img.cdn.sb.hongware.com/1461836641703511.gif", Charset.forName("utf-8"))); entity.addPart("quantity", new StringBody("1998", Charset.forName("utf-8"))); //宝贝修改的时候需要这个参数 httpPost.setEntity(entity); CloseableHttpResponse response = httpclient.execute(httpPost); try { HttpEntity httpEntity = response.getEntity(); System.out.println(httpEntity.getContent()); InputStream content = httpEntity.getContent(); BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(content)); String line; while ( (line=bufferedReader.readLine()) != null) { System.out.println(line); } } catch (Exception e) { e.printStackTrace(); } finally { response.close(); } } catch (Exception e) { e.printStackTrace(); } finally { try { httpclient.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
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服务端代码如下
为了简化演示,我把参数提取代码Map<String, String[]> parameterMap = request.getParameterMap()冗余在这个入口函数中,以便说明问题:@RequestMapping(value = "/api/entry", produces = "application/json;charset=utf-8") public DeferredResult<Object> sign(HttpServletRequest request,HttpServletResponse response) { DeferredResult<Object> deferredResult = new DeferredResult<>(); Map<String, String[]> parameterMap = request.getParameterMap(); String method = request.getParameter("method"); if (StringUtils.isEmpty(method)) { ResponseEntity<String> responseEntity = new ResponseEntity<String>( String.format(Constants.ERROR_RESPONSE, 50000, "service or method is null"), HttpStatus.valueOf(200)); deferredResult.setResult(responseEntity); return deferredResult; } int lastIndex = method.lastIndexOf("."); String service = method.substring(0, lastIndex); method = method.substring(lastIndex + 1); event.setService(service); event.setMethod(method); event.setResult(deferredResult); proxy.doAction(request,response,event); return deferredResult; }
服务端通过Map<String, String[]> parameterMap = request.getParameterMap()取出所有参数,传进来title参数是乱码!!
三、根本原因
Servlet 3.0规范中有关请求数据编码的解释如下:
当前很多浏览器并不发送带Content-Type头部的字符编码标识符,它会把字符编码的决定留在读取HTTP请求的时候。如果客户端没有指明编码,容器用来创建请求读和解析POST数据的默认编码必须是"ISO-8859-1"。然而,为了提示开发者客户端没有成功发送一个字符编码,容器中getCharacterEncoding方法会返回null。
如果客户端没有设置字符编码,并且请求数据使用了不同编码而不是上述的默认编码,程序将会出现中断。为了纠正这种状态,一个新的方法setCharacterEncoding(String enc) 被添加到ServletRequest接口。开发者调用这个方法能重写容器提供的字符编码。这个方法必须在解析request中任何post数据或者读任何输入之前调用。一旦数据已经被读取,调用这个方法不会影响它的编码。
另外一种相同的解释:
![](http://upload-images.jianshu.io/upload_images/1465919-0859fdb232d5dd75.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
四、3种解决方法
- 在web.xml中配置编解码Filter
关于这段配置需要强调两点:<filter> <filter-name>encodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> <init-param> <param-name>forceEncoding</param-name> <param-value>true</param-value> </init-param> <async-supported>true</async-supported> </filter> <filter-mapping> <filter-name>encodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
- web.xml中,这段配置要放在所有filter的最前面,否则会不生效,根本原因请见上述第三点的解释。
- 两个初始化参数的作用,其实看这个Filter的源码就一目了然,这两个参数是用来决定是否要设置request和response中的编码。源码很简洁:
public class CharacterEncodingFilter extends OncePerRequestFilter { private String encoding; private boolean forceEncoding = false; public CharacterEncodingFilter() { } public void setEncoding(String encoding) { this.encoding = encoding; } public void setForceEncoding(boolean forceEncoding) { this.forceEncoding = forceEncoding; } protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException { if(this.encoding != null && (this.forceEncoding || request.getCharacterEncoding() == null)) { request.setCharacterEncoding(this.encoding); if(this.forceEncoding) { response.setCharacterEncoding(this.encoding); } } filterChain.doFilter(request, response); } }
- 设置Content-Type
如果post请求方式是x-www-form-urlencoded,那么设置如下:
Content-Type=application/x-www-form-urlencoded;charset=utf-8
这样通过request对象取body体里面的中文是正常的。
这种方式有一点需要注意: 如果请求方式是multipart/form-data,如上设置会导致request取不到参数。Content-Type要与传递数据匹配(本文data) - 手动编解码
比如参数title="测试",这样取出来就是"测试"。String str = new String(request.getParameter("title").getBytes("iso-8859-1"), "utf-8");
综上所有,最优雅的方式是第一种解决方案--通过框架的Filter去处理。
你仅专注于业务代码就好。
参考资料
- ajax post data获取不到数据
- Servlet 3.0规范
- HTTP Content-Type常用对照表
- Spring官网--Consumable Media Types章节
- ISO-8859-1
- ISO-8859-1为何能显示中文
- 字符编码
- Media Type