I have a Maven Java project that uses Mashape Unirest for sending HTTP requests to other URLs. I am currently writing an integration test (using TestNG) that sends a normal HTTP request using Unirest. When I run the integration test through Maven (via the Failsafe plugin), the request is sent out successfully. However, when I try to run the integration test via Eclipse, I keep on getting the following error:
FAILED: getCurrentTimeTest
java.lang.NoSuchFieldError: INSTANCE
at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.<init>(DefaultHttpRequestWriterFactory.java:52)
at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.<init>(DefaultHttpRequestWriterFactory.java:56)
at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.<clinit>(DefaultHttpRequestWriterFactory.java:46)
at org.apache.http.impl.conn.ManagedHttpClientConnectionFactory.<init>(ManagedHttpClientConnectionFactory.java:72)
at org.apache.http.impl.conn.ManagedHttpClientConnectionFactory.<init>(ManagedHttpClientConnectionFactory.java:84)
at org.apache.http.impl.conn.ManagedHttpClientConnectionFactory.<clinit>(ManagedHttpClientConnectionFactory.java:59)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager$InternalConnectionFactory.<init>(PoolingHttpClientConnectionManager.java:487)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.<init>(PoolingHttpClientConnectionManager.java:147)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.<init>(PoolingHttpClientConnectionManager.java:136)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.<init>(PoolingHttpClientConnectionManager.java:112)
at org.apache.http.impl.client.HttpClientBuilder.build(HttpClientBuilder.java:726)
at com.mashape.unirest.http.options.Options.refresh(Options.java:41)
at com.mashape.unirest.http.options.Options.<clinit>(Options.java:27)
at com.mashape.unirest.http.HttpClientHelper.prepareRequest(HttpClientHelper.java:141)
at com.mashape.unirest.http.HttpClientHelper.requestAsync(HttpClientHelper.java:80)
at com.mashape.unirest.request.BaseRequest.asStringAsync(BaseRequest.java:56)
at ...
I am also able to reproduce this error using a basic Java application script.
I have made sure that the dependencies I am using in my pom.xml file are the latest and greatest, as seen below:
<dependency>
<groupId>com.mashape.unirest</groupId>
<artifactId>unirest-java</artifactId>
<version>1.3.5</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.3.2</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpasyncclient</artifactId>
<version>4.0</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.3.2</version>
</dependency>
<dependency>
<groupId>org.json</groupId>
<artifactId>json</artifactId>
<version>20140107</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.3.2</version>
</dependency>
I have also checked out the source code of BasicLineFormatter.java
, both from the source file downloaded to Eclipse and from Apache's Httpcore Github repo. In the Github repo, notice how the INSTANCE
field is defined for the 4.3.x branch and the trunk branch, but not in older branches like 4.2.x. However, I am indeed using version 4.3.2
in my project, so I should be using a JAR file for Httpcore that has the latest version of BasicLineFormatter
. I know that, based on the Maven Dependencies JAR files that are in my project, that I am indeed using the latest versions of these Apache dependencies, not the older versions specified as downstream dependencies of my project.
I have checked other various SOF and blog posts about this issue, such as Mashape Unirest Java : java.lang.NoClassDefFoundError and this blog post too, but they all seem to be talking about solving the NoSuchFieldError problem for Android. However, I'm dealing with a standalone Java application, not an Android application.
I am at a loss in determining how to troubleshoot this issue. Anyone have any idea what I need to do?
UPDATE
Instead of showing my test case, I will reduce the illustration of a reproduction of this problem to just a simple one-liner Java application, because the problem exists with any Java application or test case run through Eclipse, not just one particular test:
System.out.println(Unirest.get("http://www.google.com").asStringAsync().get().getBody());
Normally, this should print the HTML of the Google home page, but I instead get the NoSuchFieldError stack trace.
FIXED!
The problem was that the AWS SDK (it's on my classpath because I'm developing for Elastic Beanstalk) had a conflicting JAR file. Using Oleg's solution (thanks BTW), I printed the following output in a unit test:
jar:file:/some/path/aws-java-sdk/1.7.1/third-party/httpcomponents-client-4.2.3/httpcore-4.2.jar!/org/apache/http/message/BasicLineFormatter.class
I'll have to rearrange my classpath so that AWS SDK is no longer conflicting.
The only plausible explanation to this problem is there is an older version of HttpCore on the classpath (unless you also want to consider a possibility of green men from Mars messing with your computer remotely from a flying saucer).
You can add this snippet to your code to find out what jar the class gets picked up from. This might help find out why that jar is on your classpath in the first place.
ClassLoader classLoader = MyClass.class.getClassLoader();
URL resource = classLoader.getResource("org/apache/http/message/BasicLineFormatter.class");
System.out.println(resource);
This basically tells me that in my case the jar resides in the local maven repository and likely to have been added to the classpath by Maven
jar:file:/home/oleg/.m2/repository/org/apache/httpcomponents/httpcore/4.3.1/httpcore-4.3.1.jar!/org/apache/http/message/BasicLineFormatter.class
As already mentioned by previous comments, It's mainly because of the conflicting versions of httpcore
jar, the static field INSTANCE is been added to BasicLineFormatter
class in versions > 4.3.1
, Though you might have added the latest version of the httpcore
jar in your dependencies, but its highly possible that other (lower) version of jar is getting picked up.
So, first to confirm that, wrong jar is getting picked up, Use the following line of code -
ClassLoader classLoader = <Your Class>.class.getClassLoader();
URL resource = classLoader.getResource("org/apache/http/message/BasicLineFormatter.class");
System.out.println(resource);
If this prints, the lower version of the jar, then it's confirmed that it's picking the lower version of the httpcore jar (May be from other dependencies of your project),
Solution -
Add following maven/gradle dependencies at the top of dependency list (Or above the other project dependency which caused the conflict) -
<dependency>
<groupId>com.mashape.unirest</groupId>
<artifactId>unirest-java</artifactId>
<version>1.4.5</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.4.1</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.4.1</version>
</dependency>
I faced the same exception using unirest:
java.lang.NoSuchFieldError: INSTANCE
at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.<init>(DefaultHttpRequestWriterFactory.java:52)
at com.mashape.unirest.http.options.Options.refresh(Options.java:55)
at com.mashape.unirest.http.options.Options.<clinit>(Options.java:36)
And found it was due to DefaultConnectionKeepAliveStrategy.INSTANCE;
and the conflicting jar was apache-httpcomponents-httpclient.jar
in my classpath. Adding this post to help anyone who faces similar exception
I got this Exception: Caused by: java.lang.NoSuchFieldError: INSTANCE
Solution:
This happens if you have two different version classes in your classpath…. […], So I first find that class (one version of class), click that class, select build path, then I click remove from build path.
if you are using aws sdk this error occurs because of dependency mismatch. To avoid this error do the following: 1.Put the dependecies in the required order aws sdk and the end preferably 2.Add shade plugin to the project
This solved my problem
来源:https://stackoverflow.com/questions/21864521/java-lang-nosuchfielderror-org-apache-http-message-basiclineformatter-instance