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Batch operations in JAX-RS

Context
I am currently working on a JavaEE project with a lot of existing resource based JAX-RS services. For this project we would like to have batch processing to prevent a lot of separate calls and, most importantly, to execute these different methods in a transactional context for rollback purposes with the native MongoDB driver. We want to avoid manually creating new methods for all possible combinations. I could not find any solution to this issue on Stack Overflow so I started analyzing the implementation of RESTEasy and I came up with the following solution.
Below a simplified/pseudo version of my code:
JAX-RS method
#POST
#Consumes(MediaType.APPLICATION_JSON)
#Produces(MediaType.APPLICATION_JSON)
#Path("execute")
public Response executeBatch(BatchRequestWrapper batchRequestWrapper) throws UnsupportedEncodingException
{
// Retrieve information from context
HttpServletRequest httpServletRequest = ResteasyProviderFactory.getContextData(HttpServletRequest.class);
HttpServletResponse httpServletResponse = ResteasyProviderFactory.getContextData(HttpServletResponse.class);
ServletContext servletContext = ResteasyProviderFactory.getContextData(ServletContext.class);
HttpResponse httpResponse = ResteasyProviderFactory.getContextData(HttpResponse.class);
SynchronousDispatcher dispatcher = (SynchronousDispatcher) ResteasyProviderFactory.getContextData(Dispatcher.class);
ResteasyHttpHeaders httpHeaders = (ResteasyHttpHeaders) ResteasyProviderFactory.getContextData(HttpHeaders.class);
ResteasyUriInfo uriInfo = (ResteasyUriInfo) ResteasyProviderFactory.getContextData(UriInfo.class);
// Create Mongo Client Session object and save it in a Singleton which contains a ThreadLocal object so that DAO layer can reuse the client session object for all methods.
// Iterate over all the methods and invoke dispatcher
for (BatchRequest batchRequest : batchRequestWrapper.getBatchRequests())
{
// Update URI based on specific endpoint
uriInfo.setRequestUri(URI.create(batchRequest.getUri()));
// Temporary use mock response for the response
MockHttpResponse response = new MockHttpResponse();
// Create httpservletinput message from RESTEasy lib to pass to the dispatcher. It will automatically resolve all parameters/methods etc.
HttpServletInputMessage request = new HttpServletInputMessage(httpServletRequest, httpServletResponse, servletContext, httpResponse, httpHeaders, uriInfo, batchRequest.getHttpMethod(), dispatcher);
// Set body in input stream if body is specified. This will inject the correct 'body' parameters in the methods. Query and Path parameters are already resolved in the method above.
if(!Strings.isNullOrEmpty(batchRequest.getBody()))
{
InputStream targetStream = new ByteArrayInputStream(batchRequest.getBody().getBytes(StandardCharsets.UTF_8));
request.setInputStream(targetStream);
}
// Actual invoke
dispatcher.invoke(request, response);
// Do something with response object
}
// Clean or abort session based on invoke result
return Response.ok().entity(null).build();
}
Request Object
public class BatchRequestWrapper
{
private List<BatchRequest> batchRequests;
public List<BatchRequest> getBatchRequests()
{
return batchRequests;
}
public void setBatchRequests(List<BatchRequest> batchRequests)
{
this.batchRequests = batchRequests;
}
}
public class BatchRequest
{
private String uri;
private String httpMethod;
private String body;
public String getUri()
{
return uri;
}
public void setUri(String uri)
{
this.uri = uri;
}
public String getHttpMethod()
{
return httpMethod;
}
public void setHttpMethod(String httpMethod)
{
this.httpMethod = httpMethod;
}
public String getBody()
{
return body;
}
public void setBody(String body)
{
this.body = body;
}
}
My solution works with one new REST method and let's me reuse all the existing JAX-RS annotated methods in the project. Before I actually fully implement this and bring it to production, I would like to know if this is the way to actually do this or are there better alternatives? I am not a big fan of the hard dependency on RESTEasy though.

How to log RequestBody in async spring controller?

I added an async endpoint to a existing spring-mvc application:
#RestController
public class MyController {
#PostMapping("/")
public Mono<String> post(Object body) {
return Mono.just("test");
//webClient.retrieve().bodyToMono(String.class);
}
}
I want to create a global interceptor/filter that will log the request body payload. But how can I get access to it?
I tried adding a HandlerInterceptorAdapter, but the payload is always empty:
static class LoggingInterceptor extends HandlerInterceptorAdapter {
#Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
ContentCachingRequestWrapper wrapper = new ContentCachingRequestWrapper(request);
byte[] buf = wrapper.getContentAsByteArray();
System.out.println(buf);
System.out.println(buf.length);
return true;
}
}
Maybe the payload is not yet present in the request, or has already been read. So how can I access the body in this async case?

Unfortunately in Webflux you cannot use HandlerInterceptorAdapter because it came from web mvc module and works only with the servlets.
I found a good article with solutions.
P.S. You must to remove spring-mvc dependencies if going to use reactive endpoins.

is it possible to call one jax-rs method from another?

suppose i have some jax-rs resource class:
#Consumes(MediaType.APPLICATION_JSON)
#Produces(MediaType.APPLICATION_JSON)
public class ResourceA {
#GET
public Something get(#Context UriInfo uriInfo) {
if (...) {
//how to get to ResourceB ?
}
}
}
and i want to conditionally redirect the call to some other jax-rs resource:
public class ResourceB {
#GET
#Path("{identifier}")
public Other get(#PathParam("identifier")String someArg) {
}
}
how do i do this?
note that i dont want this to be visible to the client (so no http redirects) and generally the resource methods i want to redirect to dont share the same signature (they may have path params etc as in the example i gave).
im running jersey 2.6 under apache tomcat (its a spring app, if thats any help)
EDIT - im looking for a jax-rs equivalent of servlet forward. i dont want to do an extra http hop or worry abour instantiating resource classes myself

You can get it using ResourceContext as follows:
#Context
ResourceContext resourceContext;
This will inject the ResourceContext into your Resource. You then get the resource you want using:
ResourceB b = resourceContext.getResource(ResourceB.class);
The Javadoc for ResourceContext is here. You can find a similar question here

I'm not aware of any possibility to do this from a resource method, but if it fits your use case, what you could do is implement your redirect logic in a pre matching request filter, for example like so:
#Provider
#PreMatching
public class RedirectFilter implements ContainerRequestFilter {
#Override
public void filter(ContainerRequestContext requestContext) {
UriInfo uriInfo = requestContext.getUriInfo();
String prefix = "/redirect";
String path = uriInfo.getRequestUri().getPath();
if (path.startsWith(prefix)) {
String newPath = path.substring(prefix.length());
URI newRequestURI = uriInfo.getBaseUriBuilder().path(newPath).build();
requestContext.setRequestUri(newRequestURI);
}
}
}
This will redirect every request to /redirect/some/resource to /some/resource (or whatever you pass to requestContext.setRequestUri()) internally, before the resource method has been matched to the request and is executed and without http redirects or an additional internal http request.

Java - Rich logging in web services

I have a simple web service like this:
#WebService
public class MyWebService
{
#WebMethod
public String ProcessQuery(#WebParam(name="query") String q)
{
// Logging here: User IP, etc.
}
public static void main(String[] args) throws Exception
{
String address = "http://127.0.0.1:8023/_WebServiceDemo";
Endpoint.publish(address, new MyWebService());
new DocumentServer();
System.out.println("Listening: " + address);
}
}
I want to add a logging method for my service to extract information. I've heard about NCSA format and Log4J but I don't know how to use them in the service. I want to log user's ip and other info. How can I do it?
Thanks.
Edit: I should note that the main part of my question is how can I retrieve some data such as user's IP, client, etc. in the web method.

Add WebServiceContext to your class, so you can get the HttpServletRequest:
#WebService
public class MyWebService
{
#Resource
WebServiceContext wsContext;
#WebMethod
public String ProcessQuery(#WebParam(name="query") String q)
{
MessageContext messageContext = wsContext.getMessageContext();
HttpServletRequest request = (HttpServletRequest) messageContext.get(SOAPMessageContext.SERVLET_REQUEST);
// now you can get anything you want from the request
}
}

Porting a servlet to a web service - accessing the context?

Consider a simply servlet:
// MyServlet.java
protected void doGet(HttpServletRequest request, HttpServletResponse response)
{
UtilClass.doSomething(getServletContext().getRealPath(SOME_FILE));
}
And the utility class does something with the file:
// UtilClass.java
public String doSomething(String filePath)
{
File f = new File(filePath);
String s = readWhateverFrom(f);
return s;
}
I am now porting the doSomething() function to a web service running under Tomcat and Axis2. How would I port it so that I can still access the context and get access to a file under the servlet?

You should get ahold of your (jax-ws) MessageContext. This would depend on your configuration, but perhaps using
#Resource
private WebServiceContext wsCtx;
and in your method:
MessageContext messageContext = wsCtx.getMessageContext()
ServletContext ctx = (ServletContext)
messageContext.getProperty(MessageContext.SERVLET_CONTEXT);
Edit: Seems like Axis2 (as well as Axis) support the following:
HttpServlet servlet = (HttpServlet)
MessageContext.getCurrentContext().getProperty(HTTPConstants.MC_HTTP_SERVLET);
ServletContext ctx = servlet.getServletContext();
With the following imports:
import org.apache.axis2.context.MessageContext;
import org.apache.axis2.transport.http.HTTPConstants;

Sounds like a job for a Servlet Filter and a ThreadLocal. Axis is running within a Servlet Context, too. So all you have to do is to implement a custom javax.servlet.Filter, stuffing in the ServletRequest into a ThreadLocal where you can access it from within your utility class. You can get the ServletContext from the FilterConfig.