Spring webMVC 使用FastJsonHttpMessageConverter时出现如下异常该怎么处理？

 java.lang.IllegalArgumentException: Content-Type cannot contain wildcard type '*'
	at org.springframework.util.Assert.isTrue(Assert.java:118)
	at org.springframework.http.HttpHeaders.setContentType(HttpHeaders.java:949)
	at org.springframework.http.converter.AbstractHttpMessageConverter.addDefaultHeaders(AbstractHttpMessageConverter.java:256)
	at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:211)
	at com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter.write(FastJsonHttpMessageConverter.java:244)
	at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:290)
	at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:181)
	at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:82)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:125)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:889)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:792)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1048)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:946)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1047)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:950)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:924)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:668)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:770)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)

在使用FastJsonHttpMessageConverter 时出现异常java.lang.IllegalArgumentException: Content-Type cannot contain wildcard type ‘*’，查看源码知道异常由HttpHeaders类中的setContextType方法抛出的

	public void setContentType(@Nullable MediaType mediaType) {
		if (mediaType != null) {
			Assert.isTrue(!mediaType.isWildcardType(), "Content-Type cannot contain wildcard type '*'");
			Assert.isTrue(!mediaType.isWildcardSubtype(), "Content-Type cannot contain wildcard subtype '*'");
			set(CONTENT_TYPE, mediaType.toString());
		}
		else {
			remove(CONTENT_TYPE);
		}
	}

这里检测了mediaType中是不是包含了*，所以需要查看mediaType是怎么来的，往上跟源码，知道这个方法由下边这段代码调用：

protected void addDefaultHeaders(HttpHeaders headers, T t, @Nullable MediaType contentType) throws IOException {
		if (headers.getContentType() == null) {
			MediaType contentTypeToUse = contentType;
			if (contentType == null || contentType.isWildcardType() || contentType.isWildcardSubtype()) {
				contentTypeToUse = getDefaultContentType(t);
			}
			else if (MediaType.APPLICATION_OCTET_STREAM.equals(contentType)) {
				MediaType mediaType = getDefaultContentType(t);
				contentTypeToUse = (mediaType != null ? mediaType : contentTypeToUse);
			}
			if (contentTypeToUse != null) {
				if (contentTypeToUse.getCharset() == null) {
					Charset defaultCharset = getDefaultCharset();
					if (defaultCharset != null) {
						contentTypeToUse = new MediaType(contentTypeToUse, defaultCharset);
					}
				}
                //设置contextType
				headers.setContentType(contentTypeToUse);
			}
		}
		if (headers.getContentLength() < 0 && !headers.containsKey(HttpHeaders.TRANSFER_ENCODING)) {
			Long contentLength = getContentLength(t, headers.getContentType());
			if (contentLength != null) {
				headers.setContentLength(contentLength);
			}
		}
	}

可以看到headers.setContentType(contentTypeToUse);方法调用，而抛出异常出检验的mediaType也是由这里传过去的，而从这段代码中我们可以知道，最终mediaType由contentTypeToUse = getDefaultContentType(t);决定；我们跟踪getDefaultContentType方法，最终发现这个mediaType由HttpMessageConverter提供，这个时候我们查看FastJsonHttpMessageConverter的构造方法可以发现：

    public FastJsonHttpMessageConverter() {

        super(MediaType.ALL);
    }

这里FastJsonHttpMessageConverter提供MediaType.ALL, 查看这个MediaType.ALL的值

	/**
	 * Public constant media type that includes all media ranges (i.e. "*/*").
	 */
	public static final MediaType ALL;

	/**
	 * A String equivalent of {@link MediaType#ALL}.
	 */
	public static final String ALL_VALUE = "*/*";

到这里，出现这个异常的原因我们分析清楚了，既然FastJsonHttpMessageConverter提供了这个MediaType会出现异常，那么我们自己做一个调整就可以了

解决办法：

在WebMvcConfigurer的实现类中自己做MediaType设置，如下

	@Override
	public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
		FastJsonHttpMessageConverter converter = new FastJsonHttpMessageConverter();
		List<MediaType> mediaTypes = new ArrayList<>(16);
		mediaTypes.add(MediaType.APPLICATION_ATOM_XML);
		mediaTypes.add(MediaType.APPLICATION_CBOR);
		mediaTypes.add(MediaType.APPLICATION_FORM_URLENCODED);
		mediaTypes.add(MediaType.APPLICATION_JSON);
		mediaTypes.add(MediaType.APPLICATION_OCTET_STREAM);
		converter.setSupportedMediaTypes(mediaTypes);
		converters.add(converter);
	}