CRest / How to configure to accecpt only JSON responce - java

I am using CRest to deserialize a JSON stream on Android. My first steps looks very promising.
To get the JSON stream from the server and not the XML one I use the following construct:
(Accept: application/json)
#EndPoint("http://localhost:8080/myserver/rest")
#Param(name = "Accept", value = "application/json", dest = Destination.HEADER)
public interface VersionService {
#ConnectionTimeout(10000)
#Path("/version")
VersionTO getVersion();
}
This works but it's a bit annoying to copy the "Param thing" for every service.
Is there a better way to configure all Services at one place only to return JSON?

Well I'm afraid there isn't any simple way in the current version, but feel free to open a request on the issue tracker.
Cheers,
Laurent

I faced a similar situation where I used a custom HTTP client. In your case it could look like as follows:
DefaultHttpClient client = new DefaultHttpClient();
client.addRequestInterceptor(new HttpRequestInterceptor() {
public void process(HttpRequest request, HttpContext context) throws HttpException, IOException {
request.addHeader("Accept", "application/json");
}
});
CRestBuilder builder = new CRestBuilder();
builder.expectsJson();
builder.setRestService(new HttpClientRestService(client));
Another option is to set default parameter for ClientPNames.DEFAULT_HEADERS of the custom HttpClient instance.
Details can be found on http://hc.apache.org/httpcomponents-client-ga/tutorial/html/httpagent.html.

Related

Adding a custom http header to a spring boot WS call (wstemplate)

I followed this guide "Consuming a SOAP web service", at
https://spring.io/guides/gs/consuming-web-service/
and changed it to call my own internal SOAP service, it makes the call
as expected, however now I need to pass an http header via the WsTemplate,
what is the easiest way to do this?
public class WsHttpHeaderCallback implements WebServiceMessageCallback
{
public WsHttpHeaderCallback()
{
super();
}
#Override
public void doWithMessage(WebServiceMessage message) throws IOException, TransformerException
{
String headerKey="headerkey";
String headerValue="headervalue";
addRequestHeader(headerKey, headerValue);
}
private void addRequestHeader(String headerKey, String headerValue) throws IOException
{
TransportContext context = TransportContextHolder.getTransportContext();
WebServiceConnection connection = context.getConnection();
if (connection instanceof HttpUrlConnection) {
HttpUrlConnection conn = (HttpUrlConnection) connection;
conn.addRequestHeader(headerKey, headerValue);
}
}
}
I'm not sure if this helps but found some documentation
For setting WS-Addressing headers on the client, you can use the org.springframework.ws.soap.addressing.client.ActionCallback. ...
webServiceTemplate.marshalSendAndReceive(o, new ActionCallback("http://samples/RequestOrder"));
I've faced the same problem. If it can help someone, I've found a solution here: Spring WS Add Soap Header in Client
The idea is to create a class implementing org.springframework.ws.client.core.WebServiceMessageCallback and override the doWithMessage() method.
The doItMessage() method takes a WebServiceMessage as argument and is invoqued by the springWs process before sending the request, allowing to modify it before it is send.
What is done in the exemple above is marschalling the object and adding it to the header of the request.
In my case I have to be carefull with XML annotions of the object to be set as header, especially the #XmlRootElement with the namespace attribute.
Once this is done, the WSClient has to be adjusted to use the marshalSendAndReceive() method that takes a request and an uri, a payload object, and a WebServiceMessageCallback.

(Android+Retrofit 2) - Is there a drawback on the usage of Static Headers with Interceptors?

Let's say I have 5 API endpoints and 4 of them require the #Header "Authorization"; the other one doesn't.
Is there a drawback or anything of the sort when I use an Interceptor to insert the header for all API calls even though one of the endpoints does not require it? :)
Probably would be better use a more customizable approach that's retrofit2 provides - dynamic headers. A dynamic header is passed like a parameter to the method. The provided parameter value gets mapped by Retrofit before executing the request. Example:
#GET("/yourEndpoint")
Call<List<Obj>> getSomth(#Header("Your-Header") String yourHeader);
But if you only worrying about extra header passing, I don't see any drawback in your particular case.
#Override
public okhttp3.Response intercept(Chain chain) throws IOException {
Request.Builder builder = chain.request().newBuilder();
Request request = chain.request();
if (!request.url().toString().contains("/tapi/login/login")) {
String cookie = SharedObj.getCookie();
builder.addHeader("Cookie", cookie);
}
return chain.proceed(builder.build());
}
This is my solution.All api need cookie except login api('/tapi/login/login') ,So I judge url to decide to wether to add cookie in request.
There is no problem using Interceptor with header for all API.
Set headers in interceptors and use to all API. If the API method is with or without auth it will be worked.
Like this - Create ones, use everywhere.
OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
httpClient.addInterceptor(chain -> {
Request original = chain.request();
Request.Builder requestBuilder = original.newBuilder();
//Add headers here using requestbuilder.
String authToken =//Your Authtoken
if (authToken != null)
requestBuilder.header("Authorization", authToken);
requestBuilder.method(original.method(), original.body());
return chain.proceed(requestBuilder.build());
});
In Retrofit
Retrofit retrofit= new Retrofit.Builder().baseUrl("baseUrl").client(httpClient.build()).build();

Retrofit queries without ampersand

I'm trying to send requests to an API that uses semicolon(;) instead of ampersand(&) for query parameters, The url request looks like this:
http://api.example.com/path/?param1=p1;param2=p2
The most similar post I found on the internet suggests to use another method that puts url parts together and then use #Url annotation.
Does retrofit contain any solution for these cases ?
Thanks.
It is possible to use an Interceptor to rewrite the URL from using '&' to ';'. The tricky part is doing it in a way that does not make the URL invalid.
new Interceptor() {
Response intercept(Chain chain) throws IOException {
HttpUrl originalUrl = chain.request().url();
String query = originalUrl.encodedQuery();
if (query == null) {
return chain.proceed(chain.request());
} else {
Request.Builder builder = chain.request().newBuilder();
builder.url(originalUrl.newBuilder()
.encodedQuery(query.replace('&', ';'))
.build());
return chain.proceed(builder.build());
}
}
};
This OkHttp (the networking library that powers Retrofit) Interceptor will check if the given URL has a query and replace any '&' in the query section with a ';'. In theory this should behave as you specified.
It can be applied by creating the OkHttpClient instance yourself and installing the abovementioned Interceptor while building it.

File upload along with other object in Jersey restful web service

I want to create an employee information in the system by uploading an image along with employee data. I am able to do it with different rest calls using jersey. But I want to achieve in one rest call.
I provide below the structure. Please help me how to do in this regard.
#POST
#Path("/upload2")
#Consumes({MediaType.MULTIPART_FORM_DATA,MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON})
public Response uploadFileWithData(
#FormDataParam("file") InputStream fileInputStream,
#FormDataParam("file") FormDataContentDisposition contentDispositionHeader,
Employee emp) {
//..... business login
}
Whenever I am trying to do, I get error in Chrome postman. The simple structure of my Employee json is given below.
{
"Name": "John",
"Age": 23,
"Email": "john#gmail.com",
"Adrs": {
"DoorNo": "12-A",
"Street": "Street-11",
"City": "Bangalore",
"Country": "Karnataka"
}
}
However I can do it by making two different call, but I want to achieve in one rest call so that I can receive the file as well as the actual data of the employee.
Request you to help in this regard.
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) {}
}
}
}
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.
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.,
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();
}

Getting redirected URL in Apache HttpComponents

I'm using Apache HttpComponents to GET some web pages for some crawled URLs. Many of those URLs actually redirect to different URLs (e.g. because they have been processed with a URL shortener). Additionally to downloading the content, I would like to resolve the final URLs (i.e. the URL which provided the downloaded content), or even better, all URLs in the redirect chain.
I have been looking through the API docs, but got no clue, where I could hook. Any hints would be greatly appreciated.
One way is to turn off automatic redirect handling by setting the relevant parameter, and do it yourself by checking for 3xx responses, and manually extracting the redirect location from the responses "Location" header.
Here's a full demo of how to do it using Apache HttpComponents.
Important Details
You'll need to extend DefaultRedirectStrategy like so:
class SpyStrategy extends DefaultRedirectStrategy {
public final Deque<URI> history = new LinkedList<>();
public SpyStrategy(URI uri) {
history.push(uri);
}
#Override
public HttpUriRequest getRedirect(
HttpRequest request,
HttpResponse response,
HttpContext context) throws ProtocolException {
HttpUriRequest redirect = super.getRedirect(request, response, context);
history.push(redirect.getURI());
return redirect;
}
}
expand method sends a HEAD request which causes client to collect URIs in spy.history deque as it follows redirects automatically:
public static Deque<URI> expand(String uri) {
try {
HttpHead head = new HttpHead(uri);
SpyStrategy spy = new SpyStrategy(head.getURI());
DefaultHttpClient client = new DefaultHttpClient();
client.setRedirectStrategy(spy);
// FIXME: the following completely ignores HTTP errors:
client.execute(head);
return spy.history;
}
catch (IOException e) {
throw new RuntimeException(e);
}
}
You may want to set maximum number of redirects followed to something reasonable (instead of the default of 100) like so:
BasicHttpParams params = new BasicHttpParams();
params.setIntParameter(ClientPNames.MAX_REDIRECTS, 5);
DefaultHttpClient client = new DefaultHttpClient(params);

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