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

问题

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>

回答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

回答2:

I know its I am replying a bit late actually I am also struggling the same problem and I found the solution by using Maven Shade plugin.

The Problem is the JAR conflict probably your project is using a different Version Of HTTPclient then your container over which your Appliaction is running.

To resolve this use the Below Maven Shade Plugin which will change the package name of HttpClient to the specified one which packaging the JAR. This will also refactor all the usage in your code.

<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>2.4.1</version>
<executions>
    <execution>
        <phase>package</phase>
        <goals>
            <goal>shade</goal>
        </goals>
        <configuration>
            <relocations>
              <relocation>
                <pattern>org.apache.http</pattern>
                <shadedPattern>org.shaded.apache.http</shadedPattern>
              </relocation>
            </relocations>
        </configuration>
    </execution>
</executions>
</plugin>

The Above sample will change HttpClient Package with org.shaded.apache.http from org.apache.http

Maven Shade will also create a fat/uber jar so your final package size get increased and will have all the classes which you have mentioned in the Dependency in POM.

If you don't want to include the all your dependency jar in your final jar then add the Scope for the Dependency as <scope>provided</scope>.

回答3:

I was using intellij for both android and spring development. In my case, I accidentally chose Android sdk as the module SDK.

After choosing JDK 1.8 and rebuilding the project fixed the issue for me

来源：https://stackoverflow.com/questions/32793830/error-while-trying-to-use-an-api-java-lang-nosuchfielderror-instance

标签

java-7

apache-httpcomponents

smartsheet-api