I was able to get rid of it.
Actually, the jar of Mechanize (version 0.11.1) contains pom.xml, which I referred and got enlightened about its usage on HttpClient jars. I used the HTTPClient jars of version 4.2.1 in my web application and it is working now.
The point to note here is: the pom.xml has a dependency:
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.0.1</version>
<dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.0.1</version>
<dependency>
</dependencies>
<profiles>
<profile>
<id>latestHttpClient</id>
<dependencies>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.2.1</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.2.1</version>
</dependency>
</dependencies>
<profile>
<profiles>
This seems to be a bottleneck now because on one environment, the old versioned jars are working and on other environment, new ones. :(