java.lang.NoClassDefFoundError: org/apache/http/client/HttpClient
JavaJsonGwtServletsJava Problem Overview
I am trying to make a get request from the GWT servlet to get JSON response from a web service. Following is the code in my servlet :
public String getQueData() throws IllegalArgumentException {
String message = null;
try {
HttpClient httpclient = new DefaultHttpClient();
JSONParser parser = new JSONParser();
String url = "working - url";
HttpResponse response = null;
response = httpclient.execute(new HttpGet(url));
JSONObject json_data = null;
json_data = (JSONObject)parser.parse(EntityUtils.toString(response.getEntity()));
JSONArray results = (JSONArray)json_data.get("result");
for (Object queid : results) {
message = message.concat((String) ((JSONObject)queid).get("id"));
message = message.concat("\t");
message = message.concat((String) ((JSONObject)queid).get("owner"));
message = message.concat("\n");
}
} catch (Exception e) {
message = e.toString();
}
return message;
}
Getting the following exception on trying to make get request from a GWT servlet.
java.lang.NoClassDefFoundError: org/apache/http/client/HttpClient
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2389)
at java.lang.Class.getConstructor0(Class.java:2699)
at java.lang.Class.newInstance0(Class.java:326)
at java.lang.Class.newInstance(Class.java:308)
at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153)
at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:428)
at org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:339)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:35)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:60)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:122)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:78)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:362)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.lang.ClassNotFoundException: org.apache.http.client.HttpClient
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at com.google.appengine.tools.development.IsolatedAppClassLoader.loadClass(IsolatedAppClassLoader.java:176)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
What could be the possible cause of this exception? How it could be removed?
I am using jdk1.6.0_30 on ubuntu 10.04.
Java Solutions
Solution 1 - Java
If its a maven project, add the below dependency in your pom file
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.3.4</version>
</dependency>
Solution 2 - Java
>What could be the possible cause of this exception?
You may not have appropriate Jar in your class path.
>How it could be removed?
By putting HTTPClient jar in your class path. If it's a webapp, copy Jar into WEB-INF/lib
if it's standalone, make sure you have this jar in class path or explicitly set using -cp
option
as the doc says,
>Thrown if the Java Virtual Machine or a ClassLoader instance tries to load in the definition of a class (as part of a normal method call or as part of creating a new instance using the new expression) and no definition of the class could be found. > The searched-for class definition existed when the currently executing class was compiled, but the definition can no longer be found.
Edit:
If you are using a dependency management like Maven/Gradle (see the answer below) or SBT please use it to bring the httpclient jar for you.
Solution 3 - Java
I solved this issue for myself, I found there's was two files of http-client with different version of other dependent jar files. So there may version were collapsing between libraries files so remove all old/previous libraries files and re-add are jar files from lib folder of this zip file:
Solution 4 - Java
I was facing the same issue. In my case, I had a dependency of httpclient with an older version while sendgrid required a newer version of httpclient. Just make sure that the version of httpclient is correct in your dependencies and it would work fine.
Solution 5 - Java
This problem occurs if there are different jar versions. Especially versions of httpcore and httpclient. Use same versions of httpcore and httpclient.
Solution 6 - Java
I have solved this problem by importing the following dependency. you must manually import httpclient
<dependency>
<groupId>commons-httpclient</groupId>
<artifactId>commons-httpclient</artifactId>
<version>3.1</version>
<exclusions>
<exclusion>
<groupId>commons-logging</groupId>
<artifactId>*</artifactId>
</exclusion>
</exclusions>
</dependency>
Solution 7 - Java
After Creating Artifact Jar I was facing this Problem. What I do that, I create a new Artifact > With Module Dependency >
And then Leave Blank the Main Class. In that way, after creating the artifact jar, the jar was running Ok. I, think the problem was, http-client from org.apache and from network - this two types of class used for different libraries at the same Time in my first Artifact and the problem arises. So, When I created new Artifact, and leaving unnecessary libraries and duplicate libraries, the problem gone.
Solution 8 - Java
I faced the same issue, later I found I was using wrong gradle dependency.,
Wrong:
compileOnly 'org.apache.httpcomponents:httpclient:4.5.3'
Correct:
implementation group: 'org.apache.httpcomponents', name: 'httpclient', version: '4.5.3'
Once I changed it, it was working fine.