要点：
JobClient 接口
public interface JobClient

1、EmbeddedJobClient (org.apache.flink.client.deployment.application)
public class EmbeddedJobClient implements JobClient, CoordinationRequestGateway
    private final JobID jobId;
    private final DispatcherGateway dispatcherGateway;
    private final ScheduledExecutor retryExecutor;
    private final Time timeout;
    private final ClassLoader classLoader;

2、MiniClusterJobClient (org.apache.flink.runtime.minicluster)
public final class MiniClusterJobClient implements JobClient, CoordinationRequestGateway
    private final JobID jobID;
    private final MiniCluster miniCluster;
    private final ClassLoader classLoader;
    private final CompletableFuture<JobResult> jobResultFuture;

3、WebSubmissionJobClient (org.apache.flink.client.deployment.application)
public class WebSubmissionJobClient implements JobClient
    private final JobID jobId;

4、ClusterClientJobClientAdapter (org.apache.flink.client.deployment)
public class ClusterClientJobClientAdapter<ClusterID> implements JobClient, CoordinationRequestGateway
    private final ClusterClientProvider<ClusterID> clusterClientProvider;
    private final JobID jobID;
    private final ClassLoader classLoader;