Jersey client exception: A message body writer was

问题:

I am using Jersey client to hit a PHP web service for image uploading functionality. I am getting the following exception:

Caused by: com.sun.jersey.api.client.ClientHandlerException: 
A message body writer for Java type, class 
com.sun.jersey.multipart.FormDataMultiPart, and MIME media type, 
multipart/form-data, was not found
    at com.sun.jersey.api.client.RequestWriter.writeRequestEntity(RequestWriter.java:288)
    at com.sun.jersey.client.urlconnection.URLConnectionClientHandler._invoke(URLConnectionClientHandler.java:204)
    at com.sun.jersey.client.urlconnection.URLConnectionClientHandler.handle(URLConnectionClientHandler.java:147)
    ... 63 more

This is the code I am using:

WebResource webResource = Client.create().resource(HTTP_REST_URI);
JSONObject jSONObj = webResource.queryParams(queryParams)
      .type(MediaType.MULTIPART_FORM_DATA)
      .post(JSONObject.class, formDataMultiPart);

How can this exception be resolved?

回答1:

Register the MultiPartWriter provider when creating the Client:

ClientConfig cc = new DefaultClientConfig();
Client client;

cc.getClasses().add(MultiPartWriter.class);
client = Client.create(cc);

If using Maven, these are the dependencies you need in your pom.xml:

<dependency>
    <groupId>com.sun.jersey</groupId>
    <artifactId>jersey-client</artifactId>
    <version>1.17.1</version>
</dependency>
<dependency>
    <groupId>com.sun.jersey.contribs</groupId>
    <artifactId>jersey-multipart</artifactId>
    <version>1.17.1</version>
</dependency>

回答2:

Jersey (server or client) has providers that support the conversion of a Java type to a stream and vice versa. Your code returns (or receives) a Java object and based on the type of the object and the content type you are using, Jersey looks for an appropriate provider to do the marshalling (or unmarshalling).

The providers implement the MessageBodyReader or MessageBodyWriter interfaces and for every Java type and content type combination your application uses you must have a provider that knows how to handle the combination.

The messages you are getting is telling you that Jersey can't find a provider that knows how to marshal a FormDataMultiPart object with a multipart/form-data mime type. You need to provide one, and if I'm not mistaken the default implementation is found in the jersey-multipart.jar and mimepull.jar files.

回答3:

I faced the same issue. It got solved by changing maven dependency for jersey-multipart jar from 1.0.2 to 1.8 version (Used the same dependency in client side as well as provider side.

             <dependency>
                <groupId>com.sun.jersey.contribs</groupId>
                <artifactId>jersey-multipart</artifactId>
                <version>1.8</version>
             </dependency>

Here's the complete piece of code I'm using

File file = new File("E:/Goodies/tmp/sparrow.jpg");
byte[] logo = FileUtils.readFileToByteArray(file);

MultiPart multiPart = new MultiPart().bodyPart(new BodyPart(logo, MediaType.APPLICATION_OCTET_STREAM_TYPE));

// POST the request
try{
ClientResponse response = service.type("multipart/mixed").post(ClientResponse.class, multiPart);
System.out.println("Response Status : " + response.getEntity(String.class));
}catch(Exception e){
    e.printStackTrace();
}

and in the webservice:

@POST
@Consumes("multipart/mixed")
@Path("/upload")
public Response post(MultiPart multiPart) {

    BodyPartEntity bpe = (BodyPartEntity) multiPart.getBodyParts().get(0)
            .getEntity();

    boolean isProcessed = false;
    String message = null;
    try {
        InputStream source = bpe.getInputStream();
        BufferedImage bi = ImageIO.read(source);

        File file = new File("E:/Goodies/tmp" + "123.jpg");

        // storing the image to file system.
        if (file.isDirectory()) {
            ImageIO.write(bi, "jpg", file);
        } else {
            file.mkdirs();
            ImageIO.write(bi, "jpg", file);
        }
        isProcessed = true;
    } catch (Exception e) {
        message = e.getMessage();
    }

回答4:

there are few things you need to check

add mimepull.jar to your lib or with Maven

`<dependency>
    <groupId>org.jvnet.mimepull</groupId>
    <artifactId>mimepull</artifactId>
    <version>1.9.5</version>
</dependency>`

And if you are working with file, make sure you send at the header the content-length content-type accept-encoding

回答5:

I added this in web.xml. Problem solved.

<init-param>
   <param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name>
   <param-value>true</param-value>
</init-param>

回答6:

Here's my work around:

        WebResource webResource =
                jerseyClient.resource("www.api.com");
        WebResource.Builder requestBuilder = webResource.getRequestBuilder();
        requestBuilder.header("content-type", "application/json");
        ClientResponse response = requestBuilder
                .post(ClientResponse.class, mObjectMapper.writeValueAsString(new RequestObject(longUrl)));
        String text = response.getEntity(String.class);
        ResponseObject outcome = mObjectMapper.readValue(text, ResponseObject.class);

I have used Jackson ObjectMapper to serialize the request payload and likewise deserialized the outcome into a ResponseObject instance using ObjectMapper.