apache httpcomponents - Error while trying to use an API. java.lang.NoSuchFieldError: INSTANCE

Question

I am trying to connect to the smartsheet api using a java program. Initially I had problems with the site certificate which was resolved by adding it to the java keystore. Now when I am trying to run my code, I get the following error.

Exception in thread "main" java.lang.NoSuchFieldError: INSTANCE
    at org.apache.http.conn.ssl.SSLConnectionSocketFactory.<clinit>(SSLConnectionSocketFactory.java:144)
    at org.apache.http.impl.client.HttpClientBuilder.build(HttpClientBuilder.java:955)
    at org.apache.http.impl.client.HttpClients.createDefault(HttpClients.java:58)
    at com.smartsheet.api.internal.http.DefaultHttpClient.<init>(DefaultHttpClient.java:64)
    at com.smartsheet.api.SmartsheetBuilder.build(SmartsheetBuilder.java:203)
    at SmartsheetConnection.main(SmartsheetConnection.java:13)

This is my code (I followed their documentation).

import com.smartsheet.api.*;
import com.smartsheet.api.models.*;
import com.smartsheet.api.models.enums.*;
import com.smartsheet.api.oauth.*;

public class SmartsheetConnection {
    public static void main(String[] args) throws SmartsheetException {
        // Set the access token.
        Token token = new Token();
        token.setAccessToken("foo");
        Smartsheet smartsheet = new SmartsheetBuilder().setAccessToken(token.getAccessToken()).build();
    }
}

The line that is throwing error is (line 144)

@Deprecated
    public static final X509HostnameVerifier ALLOW_ALL_HOSTNAME_VERIFIER
        = AllowAllHostnameVerifier.INSTANCE; 

but I am not sure what to make of it. I am using maven to get the dependencies. Does it have something to do with the version of the Apache HttpComponents?

Here is the pom.xml

    <build>
        <sourceDirectory>src</sourceDirectory>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.4</version>
                <configuration>
                    <warSourceDirectory>WebContent</warSourceDirectory>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <dependency>
            <groupId>com.smartsheet</groupId>
            <artifactId>smartsheet-sdk-java</artifactId>
            <version>2.0.2</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.sun.jersey.contribs</groupId>
            <artifactId>jersey-apache-client</artifactId>
            <version>1.9</version>
        </dependency>
    </dependencies>

Answer 1

Other posts about this error seem to suggest that it's typically caused by conflicting versions of httpcore jar. i.e., an older version of httpcore on the classpath.

For more information, I'd suggest you checkout the following posts:

• java.lang.NoSuchFieldError: org.apache.http.message.BasicLineFormatter.INSTANCE from Mashape Unirest in Java application

• java.lang.NoSuchFieldError: INSTANCE