Class 未找到 com/google/common/util/concurrent/FutureFallback

Question

当我尝试使用 DataStax Java Driver. I have read few answer on SO. Here 从 Java 连接到 Cassandra 时出现此错误，它在 Guava 19.0 中显示 com.google.common.util.concurrent.FutureFallback is deprecated 并自 Guava 20.0 后删除。因此，请勿使用 Guava 20.0 或更高版本。

此外，我正在使用 Pmml-Evaluator，它需要 Guava 20.0。如果我删除这段连接到 Cassandra 的代码，我的代码可以正常工作。那么，我现在该如何解决？

Pom.xml 依赖关系：

<dependencies>

    <dependency>
      <groupId>org.jpmml</groupId>
      <artifactId>pmml-model</artifactId>
      <version>1.3.4</version>
   </dependency>

     <dependency>
        <groupId>com.beust</groupId>
        <artifactId>jcommander</artifactId>
        <version>1.48</version>
      </dependency>

    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>3.8.1</version>
        <scope>test</scope>
    </dependency>

     <dependency>
        <groupId>org.jpmml</groupId>
        <artifactId>pmml-evaluator</artifactId>
        <version>1.3.4</version>
      </dependency>

   <dependency>
      <groupId>io.grpc</groupId>
      <artifactId>grpc-netty</artifactId>
      <version>1.1.2</version>
    </dependency>

  <dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-protobuf</artifactId>
    <version>1.1.2</version>
  </dependency>

  <dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-stub</artifactId>
    <version>1.1.2</version>
  </dependency>

  <dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-handler</artifactId>
    <version>4.1.8.Final</version>
</dependency>

  <dependency>
      <groupId>com.datastax.cassandra</groupId>
      <artifactId>cassandra-driver-core</artifactId>
      <version>3.1.4</version>
  </dependency>

  </dependencies>

Class :

package com.cw.predictive;

import com.datastax.driver.core.Session;
import com.datastax.driver.core.Cluster;

public class CassandraSession {

    private static Session session;

    private CassandraSession(){}

    public static Session getCassandraSessionInstance(String[] CONTACT_POINTS, int PORT){

        if(session == null){                    
            synchronized (Session.class) {
                if(session == null){                   
                    try{                                        
                         Cluster cluster = Cluster.builder()
                        .addContactPoints(CONTACT_POINTS).withPort(PORT)
                        .build();                                              
                         session = cluster.connect();
                    }
                    catch(Exception ex) {
                        System.out.println("Error occurred");
                        return null;            
                    }               
                }             
            }           
        }       
        return session;
    }
}

错误：

Exception in thread "grpc-default-executor-0" java.lang.NoClassDefFoundError: com/google/common/util/concurrent/FutureFallback
        at com.cw.predictive.CassandraSession.getCassandraSessionInstance(CassandraSession.java:18)
        at com.cw.predictive.PredictiveScore$LeadScoreImpl.getLeadScore(PredictiveScore.java:136)
        at com.cw.predicitivegrpc.LeadScoreGrpc$MethodHandlers.invoke(LeadScoreGrpc.java:234)
        at io.grpc.stub.ServerCalls.onHalfClose(ServerCalls.java:148)
        at io.grpc.internal.ServerCallImpl$ServerStreamListenerImpl.halfClosed(ServerCallImpl.java:263)
        at io.grpc.internal.ServerImpl$JumpToApplicationThreadServerStreamListener.runInContext(ServerImpl.java:586)
        at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:52)
        at io.grpc.internal.SerializingExecutor$TaskRunner.run(SerializingExecutor.java:152)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:745)
    Caused by: java.lang.ClassNotFoundException: com.google.common.util.concurrent.FutureFallback
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        ... 11 more

Answer 1

如您所见，Apache Cassandra 的 DataStax Java 驱动程序尚不支持 Guava 20 和 21（参见：JAVA-1328）。

但是，有一个 working PR 已经针对 Guava 16.01、17.0、18.0、19.0、20.0 和 21.0 进行了测试，我们的目标版本是 3.2.0 以进行此修复。

我刚注意到您分享的 pmml-evaluator 中的 pom.xml 显示支持的版本范围 [14.0, 20.0]:

<dependency>
  <groupId>com.google.guava</groupId>
  <artifactId>guava</artifactId>
  <version>[14.0, 20.0]</version>
</dependency>

你可以做的是在 org.jpmml 中排除番石榴作为依赖项，即：

<dependency>
  <groupId>org.jpmml</groupId>
  <artifactId>pmml-evaluator</artifactId>
  <version>1.3.4</version>
  <exclusions>
    <exclusion>
      <groupId>com.google.guava</groupId>
      <artifactId>guava</artifactId>
    </exclusion>
  </exclusions>
</dependency>

这应该可以防止 guava 20.0 因解决 pmml-evaluator 的依赖关系而被拉入，而 guava 16.01 将通过 java 驱动程序的传递依赖关系被拉入。

Class 未找到 com/google/common/util/concurrent/FutureFallback

Class not found com/google/common/util/concurrent/FutureFallback

java

guava

datastax-enterprise

datastax-java-driver

datastax