I'm new to Play framework, and trying to use JavaWS to make a call to a RESTful API. I've been struggling a lot with it. This is what I have so far:
This code is based on the JavaWS documentation (which I found quite confusing), and is meant to make the request. I think it works by returing a completion stage of an 'ok' result which contains a string that is the result of converting the response to text.
import javax.inject.Inject;
import com.fasterxml.jackson.databind.JsonNode;
import play.mvc.*;
import play.libs.ws.*;
import java.util.concurrent.*;
import static play.mvc.Results.ok;
public class MyClient implements WSBodyReadables, WSBodyWritables {
private final WSClient ws;
#Inject
public MyClient() {
this.ws = ws;
}
public CompletionStage<Result> index() {
return ws.url("http://example.com").get().thenApply(response ->
ok(response.asText())
);
}
}
This code is then called from a controller:
public Result call(){
MyClient client = new MyClient();
try {
return client.index()
.toCompletableFuture()
.get();
} catch(Exception e){
Logger.error("ah fuck");
}
return internalServerError();
}
I'm currently getting an error which says "variable ws might not have been initialized" which makes sense because I did not initialize ws. I can't figure out how to properly initialize a WSClient instance, nor do I really understand what comes after that. Any help would be greatly appreciated.
Thanks.
Alternatively, you can use Feign library from Netflix to create Rest client.
#rkj had it right:
inject #Inject WSClient ws; in your controller and then pass ws instance to >MyClient class and access it from there. MyClient client = new MyClient(this.ws);
That plus a few little bugs and it worked. Thanks!
Related
I've been following this tutorial on how to create web services in Java. The code that I've followed are as follows:
import javax.jws.WebMethod;
import javax.jws.WebService;
import javax.jws.soap.SOAPBinding;
import javax.xml.ws.Endpoint;
#WebService
#SOAPBinding(style = SOAPBinding.Style.DOCUMENT)
public class TestService {
#WebMethod
public String sayHello(String msg){
return "Hello "+msg;
}
public static void main(String[] args){
Endpoint.publish("http://localhost:8888/testWS", new TestService());
}
}
The said tutorial instructed that I should just run the main method and I should be able to invoke it in the SoapUI. But each time I try to invoke the URL, I always get an error as mentioned in title. Am I missing something?
Your code looks OK, but it depends on how you're invoking the service. If you're using soapUI, create a new SOAP project and specify http://localhost:8888/testWS?wsdl as the initial WSDL:
Then, you can invoke the service by supplying a value in the request payload:
I am writing scheduler in my web application for notification purpose, the task of my scheduler is simple, It will hit the third party centralised database and look for the availability of data, if data is available then it returns true otherwise false.
But I am stuck here, I want to show the notification on based on the result (true/false)returning by my scheduler, but I am not able to think, how do I implement the same? I thought of bind the variable in session, but because it is time even so session is not possible here.
Suppose scheduler returning true, now I want this value inside my JSP page(Dashboard page) where I can able to show the message that "Data is available" in user's dashboard. I need this value to check condition
if(true)
"data is available"
else
no notification
Please see my code and suggest me.
package com.awzpact.uam.scheduler;
import com.awzpact.prayas.dao.HRMSPickSalaryDataDAO;
import com.awzpact.uam.domain.SalaryDetailReport;
import java.util.List;
import javax.servlet.http.HttpSession;
import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
#Component
public class PayrollDataNotificationScheduler {
private static boolean AVAIL_STATUS = false;
private static final Logger LOGGER = Logger.getLogger(PayrollDataNotificationScheduler.class);
public boolean checkDataAvailability() {
try {
List<SalaryDetailReport> list = salaryDataDAO.findAll();
if (list.size() > 0) {
AVAIL_STATUS = true;
return AVAIL_STATUS;
}
return false;
} catch (Exception e) {
e.printStackTrace();
LOGGER.info("Data is not available for migrate");
return false;
}
}
#Autowired
HRMSPickSalaryDataDAO salaryDataDAO;
}
You run your scheduled task periodically if there's some data retrieved - you save it to your DB.
// in your scheduled #Component
#Autowired
private SomeDataDAO someDataDAO;
#Scheduled(cron = "...")
public void fetchThirdPartyData() {
SomeData thirdPartyData = getThirdPartyData();
someDataDAO.save(thirdPartyData);
}
private SomeData getThirdPartyData() {
// calling their API...
}
Then you create a controller which is going to get the data from db (if exists, notice the Optional interface - you can use this in your DAO method)
// a rest controller
#RestController
#RequestMapping("/someData")
public class SomeController {
#Autowired
private SomeDataDAO someDataDAO;
#GetMapping
public SomeData getSomeData() {
return someDataDao.getSomeData().orElse(null);
}
}
Now, in your fronted you do some AJAX call, depending on what you're using there and then you can do your check and print the message.
Scheduling means that you want to make some actions on the schedule basis.
Waiting for response looks more like request/response communication between client and server.
To check that data is available - it's better to use simple method invocation via REST Controller and don't use a scheduler at all.
For development purposes, not everyone can install nginx on their machines (like our developers on Windows environments), but we want to be able to do a reverse proxy that behaves like nginx.
Here's our very specific case:
we have a spring boot REST service running on http://0.0.0.0:8081
we have spring boot web application running on http://0.0.0.0:8082
We would like to serve both services from http://0.0.0.0:8080
So we would like to map it like this:
requests to http://0.0.0.0:8080/ get proxied to http://0.0.0.0:8082
requests to http://0.0.0.0:8080/api get proxied to http://0.0.0.0:8081
That way it works like nginx with url rewrite reverse proxying.
I checked out the Undertow source code and examples, and even this specific example: Reverse Proxy Example, but this is a load balancer example, I haven't found any example that covers what I need.
Also, I know Undertow is capable of this, because we know we can configure WildFly to cover this specific case without issues through the Undertow component configuration, but we would like to implement it ourselves as a lightweight solution for local development.
Does anyone know of an example to do this? or any documentation that has enough info to implement this? because I've also read Undertow's documentation on reverse proxying and it's not helpful at all.
Thanks
This should do the job.
It's Java8 so some parts may not work on your setup.
You can start it in a similar way as the example you've mentioned in your question.
package com.company
import com.google.common.collect.ImmutableMap;
import io.undertow.client.ClientCallback;
import io.undertow.client.ClientConnection;
import io.undertow.client.UndertowClient;
import io.undertow.server.HttpServerExchange;
import io.undertow.server.ServerConnection;
import io.undertow.server.handlers.proxy.ProxyCallback;
import io.undertow.server.handlers.proxy.ProxyClient;
import io.undertow.server.handlers.proxy.ProxyConnection;
import org.xnio.IoUtils;
import org.xnio.OptionMap;
import java.io.IOException;
import java.net.URI;
import java.util.concurrent.TimeUnit;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Start the ReverseProxy with an ImmutableMap of matching endpoints and a default
*
* Example:
* mapping: ImmutableMap("api" -> "http://some-domain.com")
* default: "http://default-domain.com"
*
* Request 1: localhost:8080/foo -> http://default-domain.com/foo
* Request 2: localhost:8080/api/bar -> http://some-domain.com/bar
*/
public class ReverseProxyClient implements ProxyClient {
private static final ProxyTarget TARGET = new ProxyTarget() {};
private final UndertowClient client;
private final ImmutableMap<String, URI> mapping;
private final URI defaultTarget;
public ReverseProxyClient(ImmutableMap<String, URI> mapping, URI defaultTarget) {
this.client = UndertowClient.getInstance();
this.mapping = mapping;
this.defaultTarget = defaultTarget;
}
#Override
public ProxyTarget findTarget(HttpServerExchange exchange) {
return TARGET;
}
#Override
public void getConnection(ProxyTarget target, HttpServerExchange exchange, ProxyCallback<ProxyConnection> callback, long timeout, TimeUnit timeUnit) {
URI targetUri = defaultTarget;
Matcher matcher = Pattern.compile("^/(\\w+)(/.*)").matcher(exchange.getRequestURI());
if (matcher.find()) {
String firstUriSegment = matcher.group(1);
String remaininguri = matcher.group(2);
if (mapping.containsKey(firstUriSegment)) {
// If the first uri segment is in the mapping, update the targetUri
targetUri = mapping.get(firstUriSegment);
// Strip the request uri from the part that is used to map upon.
exchange.setRequestURI(remaininguri);
}
}
client.connect(
new ConnectNotifier(callback, exchange),
targetUri,
exchange.getIoThread(),
exchange.getConnection().getByteBufferPool(),
OptionMap.EMPTY);
}
private final class ConnectNotifier implements ClientCallback<ClientConnection> {
private final ProxyCallback<ProxyConnection> callback;
private final HttpServerExchange exchange;
private ConnectNotifier(ProxyCallback<ProxyConnection> callback, HttpServerExchange exchange) {
this.callback = callback;
this.exchange = exchange;
}
#Override
public void completed(final ClientConnection connection) {
final ServerConnection serverConnection = exchange.getConnection();
serverConnection.addCloseListener(serverConnection1 -> IoUtils.safeClose(connection));
callback.completed(exchange, new ProxyConnection(connection, "/"));
}
#Override
public void failed(IOException e) {
callback.failed(exchange);
}
}
}
As per M. Deinum's comment suggestion, I'll use Zuul Spring Boot component instead of trying to do this with Undertow, as it's more fit for this task.
Here's a link on a tutorial to do this:
https://spring.io/guides/gs/routing-and-filtering/
Hope this helps anyone else, as this is a pretty common case, and I didn't know about Zuul on Spring Boot.
I have a simple Dropwizard 0.8.1 REST service that pulls in Jersey 2.17. Upstream of the REST/Jetty service I have some authentication service that adds some nice authorization information to the HTTP Header that gets passed to my Dropwizard app.
I would love to be able to create a custom annotation in my Resource that hides all the messy header-parsing-to-POJO garbage. Something like this:
#Path("/v1/task")
#Produces(MediaType.APPLICATION_JSON)
#Consumes(MediaType.APPLICATION_JSON)
public class TaskResource {
#UserContext // <-- custom/magic annotation
private UserContextData userContextData; // <-- holds all authorization info
#GET
public Collection<Task> fetch() {
// use the userContextData to differentiate what data to return
}
I've spent the last day looking around stackoverflow and found several other people who had the same issue and appeared (?) to get some satisfaction, but I can't seem to avoid getting a "Not inside a request scope" stack trace when I try to do this.
So I stashed all my changes and tried to implement the example provided in sections 22.1 and 22.2 by the Jersey documentation directly: https://jersey.java.net/documentation/2.17/ioc.html
Following along with their example (but in my Dropwizard app), I'm trying to get a "#SessionInject" annotation in my Resource, but it also blows up with "Not inside a request scope" stack trace each time. What am I doing wrong here?
Resource:
#Path("/v1/task")
#Produces(MediaType.APPLICATION_JSON)
#Consumes(MediaType.APPLICATION_JSON)
public class TaskResource {
private final TaskDAO taskDAO;
#Context
private HttpServletRequest httpRequest;
#SessionInject
private HttpSession httpSession;
public TaskResource(TaskDAO taskDAO) {
this.taskDAO = taskDAO;
}
#GET
public Collection<Task> fetch(#SessionInject HttpSession httpSession) {
if (httpSession != null) {
logger.info("TOM TOM TOM httpSession isn't null: {}", httpSession);
}
else {
logger.error("TOM TOM TOM httpSession is null");
}
return taskDAO.findAllTasks();
}
The SessionInjectResolver:
package com.foo.admiral.integration.jersey;
import com.foo.admiral.integration.core.SessionInject;
import javax.inject.Inject;
import javax.inject.Named;
import javax.servlet.http.HttpSession;
import org.glassfish.hk2.api.Injectee;
import org.glassfish.hk2.api.InjectionResolver;
import org.glassfish.hk2.api.ServiceHandle;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class SessionInjectResolver implements InjectionResolver<SessionInject> {
private static final Logger logger = LoggerFactory.getLogger(HttpSessionFactory.class);
#Inject
#Named(InjectionResolver.SYSTEM_RESOLVER_NAME)
InjectionResolver<Inject> systemInjectionResolver;
#Override
public Object resolve(Injectee injectee, ServiceHandle<?> handle) {
if (HttpSession.class == injectee.getRequiredType()) {
return systemInjectionResolver.resolve(injectee, handle);
}
return null;
}
#Override
public boolean isConstructorParameterIndicator() {
return false;
}
#Override
public boolean isMethodParameterIndicator() {
return false;
}
}
The HttpSessionFactory:
package com.foo.admiral.integration.jersey;
import javax.inject.Inject;
import javax.inject.Singleton;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.glassfish.hk2.api.Factory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
#Singleton
public class HttpSessionFactory implements Factory<HttpSession> {
private static final Logger logger = LoggerFactory.getLogger(HttpSessionFactory.class);
private final HttpServletRequest request;
#Inject
public HttpSessionFactory(HttpServletRequest request) {
logger.info("Creating new HttpSessionFactory with request");
this.request = request;
}
#Override
public HttpSession provide() {
logger.info("Providing a new session if one does not exist");
return request.getSession(true);
}
#Override
public void dispose(HttpSession t) {
}
}
The annotation:
package com.foo.admiral.integration.core;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
#Retention(RetentionPolicy.RUNTIME)
#Target({ElementType.FIELD})
public #interface SessionInject {
}
And, finally, the binding in the Dropwizard Application class:
#Override
public void run(TodoConfiguration configuration, Environment environment) throws Exception {
...
environment.jersey().register(new AbstractBinder() {
#Override
protected void configure() {
bindFactory(HttpSessionFactory.class).to(HttpSession.class);
bind(SessionInjectResolver.class)
.to(new TypeLiteral<InjectionResolver<SessionInject>>() { })
.in(Singleton.class);
}
});
Ye old stack trace:
Caused by: java.lang.IllegalStateException: Not inside a request scope.
at jersey.repackaged.com.google.common.base.Preconditions.checkState(Preconditions.java:149)
at org.glassfish.jersey.process.internal.RequestScope.current(RequestScope.java:233)
at org.glassfish.jersey.process.internal.RequestScope.findOrCreate(RequestScope.java:158)
at org.jvnet.hk2.internal.MethodInterceptorImpl.invoke(MethodInterceptorImpl.java:74)
at org.jvnet.hk2.internal.MethodInterceptorInvocationHandler.invoke(MethodInterceptorInvocationHandler.java:62)
at com.sun.proxy.$Proxy72.getSession(Unknown Source)
at com.foo.admiral.integration.jersey.HttpSessionFactory.provide(HttpSessionFactory.java:29)
at com.foo.admiral.integration.jersey.HttpSessionFactory.provide(HttpSessionFactory.java:14)
Some clues that may be useful:
1) I'm noticing is that the logging statements in my HttpSessionFactory are never getting fired, so I don't think the Factory is correctly identified to DropWizard.
2) If I change the annotation to be a Parameter instead of a Field and move the use of the annotation into the fetch( ) method signature like this, it doesn't throw the stack trace (but the httpSession is still null, presumably because the Factory isn't firing...)
public Collection<Task> fetch(#SessionInject HttpSession httpSession) {
3) It doesn't appear to matter if I "register" the binder with environment.jersey().register() or environment.jersey().getResourceConfig().register()... they appear to do the same thing.
Do you see any obvious problems? Thanks in advance!
This is weird behavior. But what looks like is going on is the following
You have registered TaskResource as an instance and not as a .class. This I'm pretty sure of (though you have not mentioned).
register(new TaskResource());
/* instead of */
register(TaskResource.class);
Doing the former, it set the resource in a singleton scope. The latter in a request scope (unless annotated otherwise - see below)
When the resource model is loading it sees the TaskResource is a singleton, and that the HttpServletRequest is in a request scope. Either that or that the factory is in a per request scope. I'm guessing one of the two.
I thought that it might actually be a scope issue, as mentioned in the error message, but what I'm pretty sure of is that at runtime, it will get handled with a thread local proxy, because of the lesser scope.
You can see it fixed by registering the TaskResource as a class, and then annotating the TaskResource with #Singleton. This is if you actually do want the resource class to be a singleton. If not, then just leave off the #Singleton.
The odd thing to me is that it the fact that it fails on startup when the resource is explicitly instantiated on startup, but works when the framework loads on the first request (which is what happens when you register it as a class). They are both still in a singleton scope.
One thing you might want to take into consideration is whether you actually want the resource to be a singleton or not. You do have to worry about thread safety issues with singletons, and there are are some other limitations. Personally, I prefer to keep them in a request scope. You would have to do some performance testing to see if there is much of an impact for your application.
UPDATE
For parameter injection you may want to take a look at this post
UPDATE 2
See Also
jersey 2 context injection based upon HttpRequest without singleton. My answer should shed some more light.
This is the class I'm trying to test (it calculates the size of HTTP page):
import javax.ws.rs.core.MediaType;
import com.sun.jersey.api.client.*;
public class Loader {
private Client client;
public Loader(Client c) {
this.client = c;
}
public Integer getLength(URI uri) throws Exception {
return c.resource(uri) // returns WebResource
.accept(MediaType.APPLICATION_XML) // returns WebResource.Builder
.get(String.class) // returns String
.length();
}
}
Of course it just an example, not a real-life solution. Now I'm trying to test this class:
public class LoaderTest {
#Test public void shouldCalculateLength() throws Exception {
String mockPage = "test page"; // length is 9
Client mockedClient = /* ??? */;
Loader mockedLoader = new Loader(mockedClient);
assertEquals(
mockPage.length(),
mockedLoader.getLength(new URI("http://example.com"))
);
}
}
How should I mock com.sun.jersey.api.client.Client class? I'm trying to use Mockito, but any other framework will be OK, since I'm a newbie here..
Not really related to your question, but may come in handy later, is the Jersey Test Framework. Check out these blog entries by one of the Jersey contributors;
http://blogs.oracle.com/naresh/entry/jersey_test_framework_makes_it
http://blogs.oracle.com/naresh/entry/jersey_test_framework_re_visited
Back on topic, to test your Loader class you can simply instantiate it with a Client obtained from Client.create(). If you are using Maven you can create a dummy test endpoint (in src/test/java) to call and the Jersey Test framework will load it in Jetty.
You example is really complex, i wasnt able to run it with newest version of jersey, so i created those classes and here is how i mock it with EasyMock.
String mockPage = "test page"; // length is 9
RequestBuilder requestBuilderMock = createNiceControl().createMock(RequestBuilder.class);
expect(requestBuilderMock.get((Class < String >) anyObject())).andReturn("12345678").anyTimes();
replay(requestBuilderMock);
WebResource webResourcemock = createNiceControl().createMock(WebResource.class);
expect(webResourcemock.accept((String[]) anyObject())).andReturn(requestBuilderMock).anyTimes();
replay(webResourcemock);
Client clientMock = createNiceControl().createMock(Client.class);
expect(clientMock.resource((URI) anyObject())).andReturn(webResourcemock).anyTimes();
replay(clientMock);
Loader mockedLoader = new Loader(clientMock);
assertEquals((Integer) mockPage.length(), mockedLoader.getLength(new URI("http://example.com")));
If any of classes that you are trying to mock doesnt have default constructor then you should use
http://easymock.org/api/easymock/3.0/org/easymock/IMockBuilder.html#withConstructor%28java.lang.Class...%29