RESTEasy – Could not find message body reader for type: multipart/form-data

Note
Tested with Eclipse 3.6, Maven 3 and RESTEasy 2.2.1.GA

Question

Developing file upload feature with RESTEasy, see following RESTEasy multipart file upload example :

public class FileUploadForm {
 
	private byte[] data;
 
	@FormParam("file")
	public void setData(byte[] data) {
		this.data = data;
	}
 
	//...code omitted
}

@Path("/file")
public class UploadFileService {
 
	@POST
	@Path("/upload")
	@Consumes("multipart/form-data")
	public Response uploadFile(@MultipartForm FileUploadForm form) {
		//...code omitted
	}
 
}

Above file upload example is able to compile without any error. However, it prompts following scary error message during when upload file to the deployed service.

HTTP Status 500 - Bad arguments passed to public javax.ws.rs.core.Response 
com.mkyong.rest.UploadFileService.uploadFile(com.mkyong.rest.FileUploadForm) 
( org.jboss.resteasy.spi.BadRequestException org.jboss.resteasy.spi.BadRequestException: 
Could not find message body reader for type: 
class com.mkyong.rest.FileUploadForm of content type: multipart/form-data;
boundary="---------------------------98942870323811" )

Solution

RESTEasy is unable to find message body reader for “multipart/form-data“, it should be included in “resteasy-multipart-provider.jar“.

To fix it, make sure follow 2 steps are checked.

1. Declared resteasy-multipart-provider

Make sure “resteasy-multipart-provider.jar” is declared. See Maven example :

File : pom.xml

	<dependency>
		<groupId>org.jboss.resteasy</groupId>
		<artifactId>resteasy-multipart-provider</artifactId>
		<version>2.2.0.GA</version>
	</dependency>

2. mvn eclipse:eclipse -Dwtpversion=2.0

For web application project in Eclipse, you need to use following command to make sure all dependencies are deployed correctly.

mvn eclipse:eclipse -Dwtpversion=2.0

After that, check your Eclipse “Web Deployment Assembly“, make sure all required dependencies are included.

Remember -Dwtpversion=2.0
In Eclipse (web project), the classic “mvn eclipse:eclipse” is unable to get all dependencies deployed, instead, you should use “mvn eclipse:eclipse -Dwtpversion=2.0“.