文件上传与其他对象一起在 Jersey 静止 Web 服务

You can't have two Content-Types (well technically that's what we're doing below, but they are separated with each part of the multipart, but the main type is multipart). That's basically what you are expecting with your method. You are expecting mutlipart and json together as the main media type. The Employee data needs to be part of the multipart. So you can add a @FormDataParam("emp") for the Employee.

@FormDataParam("emp") Employee emp) { ...

Here's the class I used for testing

@Path("/multipart")
public class MultipartResource {
    

@POST
@Path("/upload2")
@Consumes({MediaType.MULTIPART_FORM_DATA})
public Response uploadFileWithData(
@FormDataParam("file") InputStream fileInputStream,
@FormDataParam("file") FormDataContentDisposition cdh,
@FormDataParam("emp") Employee emp) throws Exception{
        

Image img = ImageIO.read(fileInputStream);
JOptionPane.showMessageDialog(null, new JLabel(new ImageIcon(img)));
System.out.println(cdh.getName());
System.out.println(emp);
        

return Response.ok("Cool Tools!").build();
}
}

First I just tested with the client API to make sure it works

@Test
public void testGetIt() throws Exception {
    

final Client client = ClientBuilder.newBuilder()
.register(MultiPartFeature.class)
.build();
WebTarget t = client.target(Main.BASE_URI).path("multipart").path("upload2");


FileDataBodyPart filePart = new FileDataBodyPart("file",
new File("stackoverflow.png"));
// UPDATE: just tested again, and the below code is not needed.
// It's redundant. Using the FileDataBodyPart already sets the
// Content-Disposition information
filePart.setContentDisposition(
FormDataContentDisposition.name("file")
.fileName("stackoverflow.png").build());


String empPartJson
= "{"
+ "  \"id\": 1234,"
+ "  \"name\": \"Peeskillet\""
+ "}";


MultiPart multipartEntity = new FormDataMultiPart()
.field("emp", empPartJson, MediaType.APPLICATION_JSON_TYPE)
.bodyPart(filePart);
          

Response response = t.request().post(
Entity.entity(multipartEntity, multipartEntity.getMediaType()));
System.out.println(response.getStatus());
System.out.println(response.readEntity(String.class));


response.close();
}

I just created a simple Employee class with an id and name field for testing. This works perfectly fine. It shows the image, prints the content disposition, and prints the Employee object.

I'm not too familiar with Postman, so I saved that testing for last :-)

It appears to work fine also, as you can see the response "Cool Tools". But if we look at the printed Employee data, we'll see that it's null. Which is weird because with the client API it worked fine.

If we look at the Preview window, we'll see the problem

There's no Content-Type header for the emp body part. You can see in the client API I explicitly set it

MultiPart multipartEntity = new FormDataMultiPart()
.field("emp", empPartJson, MediaType.APPLICATION_JSON_TYPE)
.bodyPart(filePart);

So I guess this is really only part of a full answer. Like I said, I am not familiar with Postman So I don't know how to set Content-Types for individual body parts. The image/png for the image was automatically set for me for the image part (I guess it was just determined by the file extension). If you can figure this out, then the problem should be solved. Please, if you find out how to do this, post it as an answer.

See UPDATE below for solution

And just for completeness...

• See here for more about MultiPart with Jersey.

Basic configurations:

Dependency:

<dependency>
<groupId>org.glassfish.jersey.media</groupId>
<artifactId>jersey-media-multipart</artifactId>
<version>${jersey2.version}</version>
</dependency>

Client config:

final Client client = ClientBuilder.newBuilder()
.register(MultiPartFeature.class)
.build();

Server config:

// Create JAX-RS application.
final Application application = new ResourceConfig()
.packages("org.glassfish.jersey.examples.multipart")
.register(MultiPartFeature.class);

If you're having problems with the server configuration, one of the following posts might help

• What exactly is the ResourceConfig class in Jersey 2?
• 152 MULTIPART_FORM_DATA: No injection source found for a parameter of type public javax.ws.rs.core.Response

UPDATE

So as you can see from the Postman client, some clients are unable to set individual parts' Content-Type, this includes the browser, in regards to it's default capabilities when using FormData (js).

We can't expect the client to find away around this, so what we can do, is when receiving the data, explicitly set the Content-Type before deserializing. For example

@POST
@Path("upload2")
@Consumes(MediaType.MULTIPART_FORM_DATA)
public Response uploadFileAndJSON(@FormDataParam("emp") FormDataBodyPart jsonPart,
@FormDataParam("file") FormDataBodyPart bodyPart) {
jsonPart.setMediaType(MediaType.APPLICATION_JSON_TYPE);
Employee emp = jsonPart.getValueAs(Employee.class);
}

It's a little extra work to get the POJO, but it is a better solution than forcing the client to try and find it's own solution.

Another option is to use a String parameter and use whatever JSON library you use to deserialze the String to the POJO (like Jackson ObjectMapper). With the previous option, we just let Jersey handle the deserialization, and it will use the same JSON library it uses for all the other JSON endpoints (which might be preferred).

Asides

• There is a conversation in these comments that you may be interested in if you are using a different Connector than the default HttpUrlConnection.

You can access the Image File and data from a form using MULTIPART FORM DATA By using the below code.

@POST
@Path("/UpdateProfile")
@Consumes(value={MediaType.APPLICATION_JSON,MediaType.MULTIPART_FORM_DATA})
@Produces(value={MediaType.APPLICATION_JSON,MediaType.APPLICATION_XML})
public Response updateProfile(
@FormDataParam("file") InputStream fileInputStream,
@FormDataParam("file") FormDataContentDisposition contentDispositionHeader,
@FormDataParam("ProfileInfo") String ProfileInfo,
@FormDataParam("registrationId") String registrationId) {


String filePath= "/filepath/"+contentDispositionHeader.getFileName();


OutputStream outputStream = null;
try {
int read = 0;
byte[] bytes = new byte[1024];
outputStream = new FileOutputStream(new File(filePath));


while ((read = fileInputStream.read(bytes)) != -1) {
outputStream.write(bytes, 0, read);
}


outputStream.flush();
outputStream.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (outputStream != null) {
try {
outputStream.close();
} catch(Exception ex) {}
}
}
}

Your ApplicationConfig should register the MultiPartFeature.class from the glassfish.jersey.media.. so as to enable file upload

@javax.ws.rs.ApplicationPath(ResourcePath.API_ROOT)
public class ApplicationConfig extends ResourceConfig {
public ApplicationConfig() {
//register the necessary headers files needed from client
register(CORSConfigurationFilter.class);
//The jackson feature and provider is used for object serialization
//between client and server objects in to a json
register(JacksonFeature.class);
register(JacksonProvider.class);
//Glassfish multipart file uploader feature
register(MultiPartFeature.class);
//inject and registered all resources class using the package
//not to be tempered with
packages("com.flexisaf.safhrms.client.resources");
register(RESTRequestFilter.class);
}

I used file upload example from,

http://www.mkyong.com/webservices/jax-rs/file-upload-example-in-jersey/

in my resource class i have below method

@POST
@Path("/upload")
@Consumes(MediaType.MULTIPART_FORM_DATA)
public Response  attachupload(@FormDataParam("file") byte[] is,
@FormDataParam("file") FormDataContentDisposition fileDetail,
@FormDataParam("fileName") String flename){
attachService.saveAttachment(flename,is);
}

in my attachService.java i have below method

 public void saveAttachment(String flename,  byte[] is) {
// TODO Auto-generated method stub
attachmentDao.saveAttachment(flename,is);


}

in Dao i have

attach.setData(is);
attach.setFileName(flename);

in my HBM mapping is like

<property name="data" type="binary" >
<column name="data" />
</property>

This working for all type of files like .PDF,.TXT, .PNG etc.,

When I tried @PaulSamsotha's solution with Jersey client 2.21.1, there was 400 error. It worked when I added following in my client code:

MediaType contentType = MediaType.MULTIPART_FORM_DATA_TYPE;
contentType = Boundary.addBoundary(contentType);


Response response = t.request()
.post(Entity.entity(multipartEntity, contentType));

instead of hardcoded MediaType.MULTIPART_FORM_DATA in POST request call.

The reason this is needed is because when you use a different Connector (like Apache) for the Jersey Client, it is unable to alter outbound headers, which is required to add a boundary to the Content-Type. This limitation is explained in the Jersey Client docs. So if you want to use a different Connector, then you need to manually create the boundary.

The request type is multipart/form-data and what you are sending is essentially form fields that go out as bytes with content boundaries separating different form fields.To send an object representation as form field (string), you can send a serialized form from the client that you can then deserialize on the server.

After all no programming environment object is actually ever traveling on the wire. The programming environment on both side are just doing automatic serialization and deserialization that you can also do. That is the cleanest and programming environment quirks free way to do it.

As an example, here is a javascript client posting to a Jersey example service,

submitFile(){


let data = new FormData();
let account = {
"name": "test account",
"location": "Bangalore"
}


data.append('file', this.file);
data.append("accountKey", "44c85e59-afed-4fb2-884d-b3d85b051c44");
data.append("device", "test001");
data.append("account", JSON.stringify(account));
    

let url = "http://localhost:9090/sensordb/test/file/multipart/upload";


let config = {
headers: {
'Content-Type': 'multipart/form-data'
}
}


axios.post(url, data, config).then(function(data){
console.log('SUCCESS!!');
console.log(data.data);
}).catch(function(){
console.log('FAILURE!!');
});
},

Here the client is sending a file, 2 form fields (strings) and an account object that has been stringified for transport. here is how the form fields look on the wire,

On the server, you can just deserialize the form fields the way you see fit. To finish this trivial example,

    @POST
@Path("/file/multipart/upload")
@Consumes({MediaType.MULTIPART_FORM_DATA})
public Response uploadMultiPart(@Context ContainerRequestContext requestContext,
@FormDataParam("file") InputStream fileInputStream,
@FormDataParam("file") FormDataContentDisposition cdh,
@FormDataParam("accountKey") String accountKey,
@FormDataParam("account") String json)  {
    



    

System.out.println(cdh.getFileName());
System.out.println(cdh.getName());
System.out.println(accountKey);
    

try {
Account account = Account.deserialize(json);
System.out.println(account.getLocation());
System.out.println(account.getName());
        

} catch (Exception e) {
e.printStackTrace();
}
    

return Response.ok().build();
    

}