I'm doing some performance testing, and I want to be able to call a resource method without going through the network. I already have a framework for generating URLs, and I'd like to be able to reuse it.
For example, given the URL: www.example.com:8080/resource/method, I want to get a reference to the resource method that it calls, so that I can run it without making a network-level HTTP request. I.e., in the example below, I want to use the URL "www.frimastudio.com:8080/time" to get a reference to the method getServerTime() that I can then call directly.
Does Jersey (or something else?) provide a way to do this, or do I have to import the specific Resource class I want to call, instantiate it, etc.? Thanks in advance!
Yes jersey is RESTful API that allow routes configuration (only with annotations)
Example :
package com.frimastudio.webservice.controller.route;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import org.joda.time.DateTime;
import com.frimastudio.webservice.controller.representation.Time;
#Path("/time")
#Produces(MediaType.APPLICATION_JSON)
public class TimeResource
{
public TimeResource()
{
}
#GET
public Time getServerDate()
{
return new Time(new DateTime());
}
}
with Time being a Jackson representation :
package com.frimastudio.webservice.controller.representation;
import org.hibernate.validator.constraints.NotEmpty;
import org.joda.time.DateTime;
import com.fasterxml.jackson.annotation.JsonProperty;
public class Time
{
#NotEmpty
#JsonProperty
private String date;
public Time()
{
// Jackson deserialization
}
public Time(String date)
{
super();
this.date = date;
}
public Time(DateTime date)
{
super();
this.date = date.toString();
}
}
This doesn't seem to be possible, based on looking at the Jersey code. The lookup is performed by HttpMethodRule.Matcher, which is a private class used only to implement HttpMethodRule.accept.
Seems to me everything in accept up to if (s == MatchStatus.MATCH) { could be pulled into its own method and exposed to the user.
Related
I'm new in REST and tried to search for how do I transfer my header which I get via service to other service via code or properties file.
Please help
You can use Filter to get the header. Below is the example:
import java.io.IOException;
import javax.ws.rs.container.ContainerRequestContext;
import javax.ws.rs.container.ContainerRequestFilter;
public class ExtensionContainerRequestFilter implements ContainerRequestFilter {
public void filter(ContainerRequestContext reqCtx) throws IOException {
MultivaluedMap<String, String> headers = reqCtx.getHeaders();
//TODO continue with your logic
}
}
Im using wildfly 9.0 to deploy my war file. I have java LocalDateTime, Java Money types defined in my REST GET endpoints.
When i deploy my war file, i get following error[1]. Based on this answer [2] I have written "ParamConverterProvider" implementations for both types.
It was working fine( I haven't seen same issue again till now) and now i get same issue.
Any clue?
[1]
Caused by: java.lang.RuntimeException: Unable to find a constructor that takes a String param or a valueOf() or fromString() method for javax.ws.rs.QueryParam(\"totalMoneyVolumeForPeriod\") on public javax.ws.rs.core.Response com.test.rest.StockEndpoint.getItems(java.lang.Integer,java.lang.Integer,java.lang.String,java.lang.String,java.lang.Long,org.javamoney.moneta.Money,java.util.Set,java.lang.String) for basetype: org.javamoney.moneta.Money"}}}}
[2]
jaxrs could not find my custom (de)serializers for joda.money type
Sample code
package com.test;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.math.BigDecimal;
import javax.money.Monetary;
import javax.ws.rs.ext.ParamConverter;
import javax.ws.rs.ext.ParamConverterProvider;
import javax.ws.rs.ext.Provider;
import org.javamoney.moneta.Money;
#Provider
public class MoneyConverterProvider implements ParamConverterProvider {
private final MoneyConverter converter = new MoneyConverter();
#Override
public <T> ParamConverter<T> getConverter(Class<T> rawType, Type genericType, Annotation[] annotations) {
if (!rawType.equals(Money.class)) return null;
return (ParamConverter<T>) converter;
}
public class MoneyConverter implements ParamConverter<Money> {
public Money fromString(String value) {
if (value == null ||value.isEmpty()) return null; // change this for production
return Money.of(new BigDecimal(value), Monetary.getCurrency("AUD"));
}
public String toString(Money value) {
if (value == null) return "";
return value.toString(); // change this for production
}
}
}
Application claas
package com.test;
import javax.ws.rs.core.Application;
import com.test.autogen*;
import io.swagger.jaxrs.config.BeanConfig;
import java.util.HashSet;
import java.util.Set;
import javax.ws.rs.ApplicationPath;
#ApplicationPath("/rest")
public class RestApplication extends Application {
public RestApplication() {
BeanConfig beanConfig = new BeanConfig();
//beanConfig.setVersion("1.0");
beanConfig.setSchemes(new String[] { "http" });
beanConfig.setTitle("My API");
beanConfig.setBasePath("/rest");
beanConfig.setResourcePackage("com.test.autogen");
beanConfig.setScan(true);
}
#Override
public Set<Class<?>> getClasses() {
HashSet<Class<?>> set = new HashSet<Class<?>>();
set.add(EmailEndpoint.class);
set.add(StockEndpoint.class);
set.add(io.swagger.jaxrs.listing.ApiListingResource.class);
set.add(io.swagger.jaxrs.listing.SwaggerSerializers.class);
return set;
}
}
When you are using classpath scanning, JAX-RS components annotated with #Path or #Provider will get picked up and registered. There are a couple way to use classpath scanning. The most common way is to just have an empty Application class annotated with #ApplicationPath
#ApplicationPath("/api")
public class MyApplication extends Application {}
This is enough for a JAX-RS application to be loaded, and to have the application's classpath scanned to components to register.
But, per the specification, once we override any of the Set<Object> getSingletons or Set<Class> getClasses methods of the Application class, and return a non-empty set, this automatically disables classpath scanning, as it is assumed we want to register everything ourselves.
So in previous cases, you were probably just using classpath scanning. In this case, you need to explicitly add the provider to the set of classes in your getClasses method, since you overrode the method to add other component classes.
The code i am trying is showing Null pointer Exception because it is not extracting parameter value from path and i am not getting why? if any one could help me out with this ??
The path value extracted from pathparam i.e is name is extracted as null and why this is happening am not getting please help me out with the same.
I am not getting at all what the problem actually is I tried and I only got that parameter value for name is not getting extracted in path param, I checked out on the different sites still am not able to get the solution. I hope posting over here helps me to find a solution
My resource class is:
package resource;
import javax.websocket.server.PathParam;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import dao.CustomerDao;
import dao.CustomerDaoImpl;
import entity.Customer;
#Path("/customer")
public class CustomerResource {
CustomerDaoImpl dao = new CustomerDaoImpl();
#GET
#Path("/greet")
public String greet(){
return("Hello World");
}
#GET
#Path("/{name}")
public String getCustomerByName(#PathParam("name") String name){
System.out.println("the name is : "+name);
return dao.getCustomerByName(name).toString();
}
}
and service class is below:
package dao;
import java.util.ArrayList;
import java.util.List;
import entity.Customer;
public class CustomerDaoImpl implements CustomerDao {
static private List<Customer> customerList = new ArrayList<Customer>();
static {
customerList.add(new Customer("John",101,"7757945607"));
customerList.add(new Customer("Joe", 102,"8857833518"));
customerList.add(new Customer("James",103,"8177998482"));
customerList.add(new Customer("Roy",104,"8149038984"));
customerList.add(new Customer("Dev",105,"9503257180"));
}
#Override
public Customer getCustomerByName(String name) {
for (Customer c : customerList) {
if (c.getCustomerName().equalsIgnoreCase(name)) {
return c;
}
}
return null;
}
}
although i am using the correct path
http://localhost:8080/CustomerWebApp/rest/customer/Roy
You are using the wrong PathParam. You should use javax.ws.rs.PathParam.
yes PathParam you have to use provided by jar-rs specification .
you have used wrong one javax.websocket.server.PathParam;
for more Details how to use #PathParam and #path annotation plz refer:http://entityclass.in/rest/jaxRsAnnotationPath.htm
I've inherited a web project that a contractor started. I and my coworkers are unfamiliar with the technology used, and have a number of questions. From what we can tell, this appears to be some sort of RESTful Java server code, but my understanding is there are lots of different types of Java RESTful services. Which one is this? Specific questions:
1) Where can we read more (particularly introductory information) about this specific service?
2) The code creates and returns a JSON through some kind of "magic"... I merely return a model class (code below) that has getter and setter methods for its fields, and it's automagically converted into a JSON. I'd like to learn more about how this is done automagically.
3) We already have some code that creates a JSON. We need to return this using this framework. If I already have a JSON, how do I return that? I tried something like this:
String testJSON = "{\"menu\": {\"id\": \"file\", \"value\": \"Hello there\"}}";
return testJSON;
instead of returning a model object with getters/setters, but this returns a literal text string, not a JSON. Is there a way to return an actual JSON that's already a JSON string, and have it be sent as a JSON?
You don't have to be able to answer all of the questions above. Any/all pointers in a helpful direction appreciated!
CODE
First, the view controller that returns the JSON:
package com.aimcloud.server;
import com.aimcloud.util.MySqlConnection;
import javax.ws.rs.GET;
import javax.ws.rs.PUT;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.QueryParam;
import javax.ws.rs.FormParam;
import javax.ws.rs.HeaderParam;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import com.aimcloud.models.SubscriptionTierModel;
#Path("subscription_tier")
public class SubscriptionTierController
{
// this method will return a list of subscription_tier table entries that are currently active
#GET
#Produces({ MediaType.APPLICATION_JSON })
public String/*ArrayList<SubscriptionTierModel>*/ getSubscriptionTiers(#QueryParam("includeActiveOnly") Boolean includeActiveOnly)
{
MySqlConnection mysql = MySqlConnection.getConnection();
ArrayList<SubscriptionTierModel> subscriptionTierArray = new ArrayList<SubscriptionTierModel>();
String queryString;
if (includeActiveOnly)
queryString = "SELECT * FROM subscription_tier WHERE active=1";
else
queryString = "SELECT * FROM subscription_tier";
List<Map<String, Object>> resultList = mysql.query(queryString, null);
for (Map<String, Object> subscriptionRow : resultList)
subscriptionTierArray.add( new SubscriptionTierModel(subscriptionRow) );
// String testJSON = "{\"menu\": {\"id\": \"file\", \"value\": \"Hello there\"}}";
// return testJSON;
return subscriptionTierArray;
}
}
Next, the model the code above returns:
package com.aimcloud.models;
// NOTE this does NOT import Globals
import java.sql.Types;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.Map;
import org.json.JSONObject;
import com.aimcloud.util.LoggingUtils;
public class SubscriptionTierModel extends ModelPrototype
{
private String name;
private Integer num_studies;
private Integer cost_viewing;
private Integer cost_processing;
private Integer active;
protected void setupFields()
{
this.fields.add("name");
this.fields.add("num_studies");
this.fields.add("cost_viewing");
this.fields.add("cost_processing");
this.fields.add("active");
}
public SubscriptionTierModel()
{
super("subscription");
this.setupFields();
}
public SubscriptionTierModel(Map<String, Object> map)
{
super("subscription");
this.setupFields();
this.initFromMap(map);
}
public void setName(String name) {
this.name = name;
}
public String getName() {
return this.name;
}
public void setNum_Studies(Integer num_studies) {
this.num_studies = num_studies;
}
public Integer getNum_studies() {
return this.num_studies;
}
public void setCost_viewing(Integer cost_viewing) {
this.cost_viewing = cost_viewing;
}
public Integer getCost_viewing() {
return this.cost_viewing;
}
public void setCost_processing(Integer cost_processing) {
this.cost_processing = cost_processing;
}
public Integer getCost_processing() {
return this.cost_processing;
}
public void setActive(Integer active) {
this.active = active;
}
public Integer getActive() {
return this.active;
}
}
public abstract class ModelPrototype {
protected MySqlConnection mysql;
protected ArrayList<String> fields;
protected String table;
protected Integer id = null;
public Integer getId() {
return this.id;
}
public void setId(Integer id) {
this.id = id;
}
abstract protected void setupFields();
public ModelPrototype() {
mysql = MySqlConnection.getConnection();
this.fields = new ArrayList<String>();
this.fields.add("id");
}
public void initFromDbResult(List<Map<String, Object>> result) {
if (result.size() >= 1)
{
Map<String, Object> userRow = result.get(0);
this.initFromMap(userRow);
if (result.size() > 1)
{
Thread.dumpStack();
}
}
else
{
throw new WebApplicationException(ServerUtils.generateResponse(Response.Status.NOT_FOUND, "resource not found"));
}
}
protected void initFromMap(Map<String, Object> map) {
for (Map.Entry<String, Object> entry : map.entrySet()) {
Object value = entry.getValue();
// LoggingUtils.log(entry.getKey() + " " + entry.getValue().toString());
if (value != null && this.fields.contains(entry.getKey())) {
this.setField(entry.getKey(), value);
}
}
}
....
1) Where can we read more (particularly introductory information)
about this specific service?
This is a RESTful service that uses basic jax-rs annotations to build the service. I suggest looking at a tutorial like "REST using jersey" or "REST using CXF".
2) The code creates and returns a JSON through some kind of "magic"...
The restful framework used usually takes care of this. #Produces({ MediaType.APPLICATION_JSON }) annotation indicates the framework to do this conversion.This will be defined somewhere in the configuration. Check the spring config files if you are using spring to define the beans. Usually a mapper or a provider will be defined that converts the object to json.
3) We already have some code that creates a JSON. We need to return this using this framework. If I already have a JSON, how do I return that? I tried something like this:
If you already have a json just return that json from the method. Remember to still have the #Produces({ MediaType.APPLICATION_JSON }) annotation on the method.
but this returns a literal text string, not a JSON
A json is a string. That is what you will see in the response, unless you deserialize it back to an object.
I suggest you read up on JAX-RS, the Java specification for RESTful web services. All of the "javax.ws.rs.*" classes/annotations come from JAX-RS
As JAX-RS, is just a specification, there needs to be something that implements the spec. There is probably a third-party, JAX-RS component that is used to run this service. Jersey in one popular implementation. Apache CXF is another.
Now back to JAX-RS. When you read up on this, you will see that the annotations on your class determine the REST characteristics of your service. For example,
#Path("subscription_tier")
defines your class as the resource with URI BASE_PATH/subscription_tier, where BASE_PATH is propbably defined in a configuration file for your web service framework.
As for how the objects are "automagically" converted into a JSON response: that is the role of the web service framework as well. It probably uses some kind of standard object-to-JSON mapping to accomplish this. (I have worked with CXF and XML resources. In that case JAXB was the mapping mechanism). This is a good thing, as the web service developer does not have to worry about this mapping, and can focus on coding just the implementation of service itself.
In my gwt application, I've implemented this method:
#Service("carService")
#Path("/cars")
#Scope("request")
public class CarServiceImpl implements CarService {
#Autowired
private CarDAO carDAO;
#Override
#GET #Path("{type}/{start}/{end}")
#Produces({MediaType.APPLICATION_XML})
public List<Car> findByType(#PathParam("type") CarType type,
#PathParam("start") Date start,
#PathParam("end") Date end) {
return carDAO.findByType(type, start, end);
}
where findByType is a method in the carDAO asking to databases (in a peer-to-peer architecture) for available cars to rent.
Now I have to implement its rest client and I have:
package it.unibo.ronf.server.rest;
import java.util.Date;
import java.util.List;
import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.GenericType;
import com.sun.jersey.api.client.UniformInterfaceException;
import com.sun.jersey.api.client.WebResource;
import it.unibo.ronf.shared.entities.Car;
import it.unibo.ronf.shared.entities.CarType;
public class ClientRestCars {
public List<Car> findAvailableCar(CarType type, Date start, Date end) {
Client client = Client.create();
WebResource webResource = client
.resource("http://localhost:8080/RONF/rest/cars");
}
}
and I don't know how to go on, how to pass the parameters to the url and get the list of cars as results.
Can help?
If you don't have a framework to send your request, you should look at restygwt. It allows to create such requests in this way :
#PUT
#Path("{type}/{start}/{end}")
public void updateOrder(#PathParam("type") CarType carType,
#PathParam("start") Date start,
#PathParam("end") Date end,
MethodCallback<OrderConfirmation> callback);
Note : If you are using gwtp, you should note that they will soon provide this type of interface out-of-the-box.
Here is a quick example but you still should read the user guide
First, create a service (an interface which extends RestService):
#Path("/test/method")
public interface CarService extends RestService {
/*
* With #PathParam, you can specify the name of the attribute in the request.
* Without PathParam, the name of the attribute takes the name of the argument.
* The parameter type T of MethodCallBack<T> is the type you expect in the success method of the callback (see above)
*/
#GET
public void get(CarType carType,#PathParam("start")Date myStartDateWithASillyName, Date end,MethodCallback<List<Car>> callback);
/*
* Another method just to show that you are not limited to one...
* Here, the request have car parameter and is intended to save a car.
* As REST norms expect in this case, the resulting car is returned from server (with potentially the id updated after insert in database)
*/
#POST
public void post(Car car,MethodCallback<Car> callback);
}
Now, from anywhere in your code, you can call your service like this:
CarService service = GWT.create(CarService.class);
service.get(carType,dateFrom,dateTo,new MethodCallback<List<Car>>() {
/*
*This method is called if a problems occurs (server not reachable, 404,403 etc)
*/
public void onFailure(Method method, Throwable exception) {
Window.alert("Error x: " + exception);
}
/*
* In case of success, this method is called and you obtain
* the expected List<Car> as the response parameter
*/
public void onSuccess(Method method, List<Car> response) {
...
}
});