I am trying to build a REST webservice using an asynchronous response.
I have looked around this error on the web, however, none of the solutions have worked for me. I am not sure on how to go about it.
This is the code for the REST service, it has AsyncResponse, and @Suspended
which are taken from jar file specified in the pom.xml
, which I will provide below. The problem is, on deploying the war, I get an exception:
java.lang.AbstractMethodError: javax.ws.rs.core.UriBuilder.uri(Ljava/lang/String;)Ljavax/ws/rs/core/UriBuilder;
javax.ws.rs.core.UriBuilder.fromUri(UriBuilder.java:119)
com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:651)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.50 logs
My class is as follows:
package com.crudapp;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import javax.annotation.Generated;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.Response;
//import javax.ws.rs.core.UriBuilder;
import org.json.JSONArray;
import org.json.JSONObject;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.google.gson.Gson;
import com.mysql.jdbc.StringUtils;
import dao.User;
import dao.UserDAO;
import dao.UserDAOImpl;
import javax.ws.rs.container.AsyncResponse;
import javax.ws.rs.container.Suspended;
@Path("/crudpath")
public class EntityResource {
private final ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("/spring.xml");
UserDAO userdao = null;
private final int numOfThreads = 10;
private final ExecutorService executorService = Executors.newFixedThreadPool(numOfThreads);
// userdao.getUsers("118");
//ctx.close();
@GET
@Produces("application/json")
public Response getTupleFromDBasJSON(@QueryParam("param1") String userid, @Suspended final AsyncResponse asyncresponse ){
if(StringUtils.isNullOrEmpty(userid))
throw new ServiceException("Userid passed to the REST service /crudpath is null or empty");
userdao = (userdao==null)?
ctx.getBean("userDAO", UserDAOImpl.class)
: userdao;
Gson gson = new Gson();
Future<List<User>> futures = executorService.submit(new DAOTaskHandlerThread(userid));
List <User> users = new ArrayList<User>();
if(futures.isDone())
{
try{
users = futures.get();
if(users!= null)
return Response.status(200).entity( gson.toJson(users).toString()).build();
}
catch(Exception ex)
{
throw new ServiceException(ex);
}
}
return Response.status(200).entity(new ArrayList<User>().toString()).build();
/*// crrate a new thread.. call the DAO .. returns the result from here.
JSONObject jsonObject = new JSONObject();
jsonObject.put("key", "value");
return Response.status(200).entity( jsonObject.toString()).build();*/
}
private class DAOTaskHandlerThread implements Callable<List<User>>{
//private UserDAO userDAO;
private String userid;
private DAOTaskHandlerThread(//UserDAO userDAO,
String useridpassed){
///this.userDAO= userDAO;
userid= useridpassed;
}
@Override
public List<User> call() throws Exception {
// TODO Auto-generated method stub
return userdao.getUsers(userid);
}
}
}
My pom.xml
file for maven is as follow:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>RESTJerseyExample</groupId>
<artifactId>RESTJerseyExample</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>2.4</version>
<configuration>
<warSourceDirectory>WebContent</warSourceDirectory>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
<!-- spring framework just added -->
<properties>
<java-version>1.7</java-version>
<org.springframework-version>4.0.3.RELEASE</org.springframework-version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${org.springframework-version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${org.springframework-version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>${org.springframework-version}</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<!-- spring framework just added ends here -->
<dependency>
<groupId>asm</groupId>
<artifactId>asm</artifactId>
<version>3.3.1</version>
</dependency>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-bundle</artifactId>
<version>1.19</version>
</dependency>
<dependency>
<groupId>org.json</groupId>
<artifactId>json</artifactId>
<version>20140107</version>
</dependency>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-server</artifactId>
<version>1.19</version>
</dependency>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-core</artifactId>
<version>1.19</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-dbcp2</artifactId>
<version>2.0</version>
</dependency>
<!-- used for httpclient library -->
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.4</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.3.2</version>
</dependency>
<!-- for async response -->
<dependency>
<groupId>javax.ws.rs</groupId>
<artifactId>javax.ws.rs-api</artifactId>
<version>2.0-m12</version>
</dependency>
</dependencies>
</project>
AbstractMethodError
are thrown when an application tries to call an abstract method.
uri
is an abstract method in UriBuilder
, so you need an implementation of this. This method (with String
parameter) is from version 2.0
of JAX-RS specification.
You're trying to use JAX-RS 2.0 with Jersey 1.*. Instead, you need to use Jersey 2.* that implements JAX-RS 2.0 and contains an implementation to uri
method.
In your pom.xml
you may remove these dependencies:
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-bundle</artifactId>
<version>1.19</version>
</dependency>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-server</artifactId>
<version>1.19</version>
</dependency>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-core</artifactId>
<version>1.19</version>
</dependency>
<dependency>
<groupId>javax.ws.rs</groupId>
<artifactId>javax.ws.rs-api</artifactId>
<version>2.0-m12</version>
</dependency>
And use these dependencies:
<dependency>
<groupId>org.glassfish.jersey.core</groupId>
<artifactId>jersey-server</artifactId>
<version>2.17</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.containers</groupId>
<artifactId>jersey-container-servlet-core</artifactId>
<version>2.17</version>
</dependency>
Using this, uri
method is implemented in JerseyUriBuilder
class from jersey-common
.
EDIT:
You need to change, in your web.xml
, servlet com.sun.jersey.spi.container.servlet.ServletContainer
to org.glassfish.jersey.servlet.ServletContainer
and init-param
from com.sun.jersey.config.property.packages
to jersey.config.server.provider.packages