I added the Gradle dependency, compile 'org.elasticsearch.client:transport:5.2.1'.
I got a list of warnings when the Gradle build was synced.
Warning:WARNING: Dependency commons-logging:commons-logging:1.1.3 is ignored for release as it may be conflicting with the internal version provided by Android.
Warning:WARNING: Dependency org.apache.httpcomponents:httpclient:4.5.2 is ignored for release as it may be conflicting with the internal version provided by Android.
Warning:WARNING: Dependency commons-logging:commons-logging:1.1.3 is ignored for release as it may be conflicting with the internal version provided by Android.
Warning:WARNING: Dependency org.apache.httpcomponents:httpclient:4.5.2 is ignored for release as it may be conflicting with the internal version provided by Android.
Warning:WARNING: Dependency commons-logging:commons-logging:1.1.3 is ignored for debug as it may be conflicting with the internal version provided by Android.
Warning:WARNING: Dependency org.apache.httpcomponents:httpclient:4.5.2 is ignored for debug as it may be conflicting with the internal version provided by Android.
Warning:WARNING: Dependency commons-logging:commons-logging:1.1.3 is ignored for debug as it may be conflicting with the internal version provided by Android.
Warning:WARNING: Dependency org.apache.httpcomponents:httpclient:4.5.2 is ignored for debug as it may be conflicting with the internal version provided by Android.
But the Gradle build was successful. Now I get an error at nodeBuilder() or NodeBuilder. The error is: Cannot resolve symbol. How do I fix this?