java - 如何使用 Spring RestController 返回 FileSystemResource 或 json？

Question

我有一种下载 zip 文件的方法，目前我使用 FileSystemResource 来执行此操作。问题在于扩展 Controller ，我检查文件是否确实是 zip 文件，如果不是，则抛出异常。此异常创建一个包含错误详细信息的 Json 对象并返回它。问题是 Rest api 的类型，因为现在我有:

@RequestMapping(value = "/zipDownload", produces="application/zip", method = RequestMethod.GET)
public FileSystemResource getZip(@RequestParam(value="filePath", required=true) String filePath ) throws FileExtensionException{
    return file.getZipFile(filePath);
}

和服务:

public FileSystemResource getZipFile(String fileName) throws FileExtensionException {
    String ext=FilenameUtils.getExtension(fileName);
    if (!ext.equals("zip"))
        throw new FileExtensionException(ext + " and not zip");
    return new FileSystemResource(new File(fileName));
}

异常

public class FileExtensionException extends Exception {

    private static final long serialVersionUID = 1L;

    public FileExtensionException(String message){
        super("The selected file has a different extension:" + message);
    }
}

和异常 Controller

@ControllerAdvice 
public class ErrorController {

    /**
     * 
     * @param e: exception thrown
     * @return ErroreResponse
     */
     @ExceptionHandler(value = Exception.class)
    public @ResponseBody ErrorResponse errorHandler(Exception e){   
        //Make the exception by buildErrorResponse
        return ErrorResponseBuilder.buildErrorResponse(e);
    }
}

Spring 启动的另一个异常覆盖了我的问题:

2015-09-21 09:09:05.197 ERROR 7500 --- [nio-8080-exec-2] .m.m.a.ExceptionHandlerExceptionResolver : Failed to invoke @ExceptionHandler method: public matlab.ErrorResponse matlab.ErrorController.errorHandler(java.lang.Exception)

org.springframework.web.HttpMediaTypeNotAcceptableException: Could not find acceptable representation at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:173) at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:101) at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:185) at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:71) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:126) at org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver.doResolveHandlerMethodException(ExceptionHandlerExceptionResolver.java:362) at org.springframework.web.servlet.handler.AbstractHandlerMethodExceptionResolver.doResolveException(AbstractHandlerMethodExceptionResolver.java:60) at org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver.resolveException(AbstractHandlerExceptionResolver.java:138) at org.springframework.web.servlet.handler.HandlerExceptionResolverComposite.resolveException(HandlerExceptionResolverComposite.java:74) at org.springframework.web.servlet.DispatcherServlet.processHandlerException(DispatcherServlet.java:1183) at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1020) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:971) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:967) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:858) at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843) at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:85) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.boot.context.web.ErrorPageFilter.doFilter(ErrorPageFilter.java:116) at org.springframework.boot.context.web.ErrorPageFilter.access$000(ErrorPageFilter.java:60) at org.springframework.boot.context.web.ErrorPageFilter$1.doFilterInternal(ErrorPageFilter.java:91) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) at org.springframework.boot.context.web.ErrorPageFilter.doFilter(ErrorPageFilter.java:109) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1526) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1482) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745)

2015-09-21 09:09:05.201 ERROR 7500 --- [nio-8080-exec-2] o.s.boot.context.web.ErrorPageFilter : Forwarding to error page from request [/ManagmentFile/zipDownload] due to exception [The selected file has a different extension:xlsx and not zip]

matlab.FileExtensionException: The selected file has a different extension:xlsx and not zip at matlab.FileServices.getZipFile(FileServices.java:46) at matlab.ws.FileManagerImpl.getZip(FileManagerImpl.java:38) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:497) at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:776) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:967) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:858) at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843) at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:85) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.boot.context.web.ErrorPageFilter.doFilter(ErrorPageFilter.java:116) at org.springframework.boot.context.web.ErrorPageFilter.access$000(ErrorPageFilter.java:60) at org.springframework.boot.context.web.ErrorPageFilter$1.doFilterInternal(ErrorPageFilter.java:91) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) at org.springframework.boot.context.web.ErrorPageFilter.doFilter(ErrorPageFilter.java:109) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1526) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1482) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745)

如何以相同的方法返回 Zip 文件或 json 消息？问题是，产生=“application/zip”，如果没有这个收到正确的错误json，但它不会下载文件，否则反之亦然谢谢

Answer 1

编辑

您可以按原样保留 Controller 中的 getZip ，只需这样更改您的 @ExceptionHandler 即可:

@ExceptionHandler(Exception.class)
@ResponseStatus(HttpStatus.BAD_REQUEST)
public @ResponseBody ErrorResponse errorHandler(Exception e, HttpServletRequest request) {
    request.setAttribute(HandlerMapping.PRODUCIBLE_MEDIA_TYPES_ATTRIBUTE, Collections.singleton(MediaType.APPLICATION_JSON));
    return ErrorResponseBuilder.buildErrorResponse(e);
}

在这里，我只是修改请求并重置 PRODUCIBLE_MEDIA_TYPES_ATTRIBUTE 参数，以明确告诉 Spring 我想要使用什么表示形式。