SpringMVC框架
4.6 使用Servlet原生API作为参数
- MVC 的 Handler 方法可以接受哪些 ServletAPI 类型的参数
- HttpServletRequest
- HttpServletResponse
- HttpSession
- security.Principal
- Locale
- InputStream
- OutputStream
- Reader
- Writer
- 源码参考：AnnotationMethodHandlerAdapter L866
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@Override protected Object resolveStandardArgument(Class<?> parameterType, NativeWebRequest webRequest) throws Exception { HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class); HttpServletResponse response = webRequest.getNativeResponse(HttpServletResponse.class);
if (ServletRequest.class.isAssignableFrom(parameterType) || MultipartRequest.class.isAssignableFrom(parameterType)) { Object nativeRequest = webRequest.getNativeRequest(parameterType); if (nativeRequest == null) { throw new IllegalStateException( "Current request is not of type [" + parameterType.getName() + "]: " + request); } return nativeRequest; } else if (ServletResponse.class.isAssignableFrom(parameterType)) { this.responseArgumentUsed = true; Object nativeResponse = webRequest.getNativeResponse(parameterType); if (nativeResponse == null) { throw new IllegalStateException( "Current response is not of type [" + parameterType.getName() + "]: " + response); } return nativeResponse; } else if (HttpSession.class.isAssignableFrom(parameterType)) { return request.getSession(); } else if (Principal.class.isAssignableFrom(parameterType)) { return request.getUserPrincipal(); } else if (Locale.class.equals(parameterType)) { return RequestContextUtils.getLocale(request); } else if (InputStream.class.isAssignableFrom(parameterType)) { return request.getInputStream(); } else if (Reader.class.isAssignableFrom(parameterType)) { return request.getReader(); } else if (OutputStream.class.isAssignableFrom(parameterType)) { this.responseArgumentUsed = true; eturn response.getOutputStream(); } else if (Writer.class.isAssignableFrom(parameterType)) { this.responseArgumentUsed = true; return response.getWriter(); } return super.resolveStandardArgument(parameterType, webRequest); } |
4.6.1 实验代码
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/** * 可以使用 Serlvet 原生的 API 作为目标方法的参数 具体支持以下类型 * * HttpServletRequest * HttpServletResponse * HttpSession * java.security.Principal * Locale InputStream * OutputStream * Reader * Writer * @throws IOException */ @RequestMapping("/testServletAPI") public void testServletAPI(HttpServletRequest request,HttpServletResponse response, Writer out) throws IOException { System.out.println("testServletAPI, " + request + ", " + response); out.write("hello springmvc"); //return "success"; } |
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<!-- 测试 Servlet API 作为处理请求参数 --> <a href="springmvc/testServletAPI">testServletAPI</a> |
