title: GRPC client is not working
body: <p>when i'm running the grpc client i'm getting the following error.my grpc-server is working well ....................................................................................................................................................</p>
  
  <pre><code> mvn exec:java -Dexec.mainClass="com.example.grpc.client.MyGrpcClient.java" -e
  [INFO] Error stacktraces are turned on.
  [INFO] Scanning for projects...
  [INFO] ------------------------------------------------------------------------
  [INFO] Detecting the operating system and CPU architecture
  [INFO] ------------------------------------------------------------------------
  [INFO] os.detected.name: linux
  [INFO] os.detected.arch: x86_64
  [INFO] os.detected.release: ubuntu
  [INFO] os.detected.release.version: 14.04
  [INFO] os.detected.release.like.ubuntu: true
  [INFO] os.detected.release.like.debian: true
  [INFO] os.detected.classifier: linux-x86_64
  [WARNING] Failed to inject repository session properties.
  java.lang.NoSuchMethodError: org.apache.maven.execution.MavenSession.getRepositorySession()Lorg/eclipse/aether/RepositorySystemSession;
          at kr.motd.maven.os.RepositorySessionInjector.injectRepositorySession(RepositorySessionInjector.java:22)
          at kr.motd.maven.os.DetectExtension.injectSession(DetectExtension.java:148)
          at kr.motd.maven.os.DetectExtension.afterProjectsRead(DetectExtension.java:107)
          at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:274)
          at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
          at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
          at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
          at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
          at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
          at java.lang.reflect.Method.invoke(Method.java:497)
          at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
          at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
          at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
          at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
  [INFO]                                                                         
  [INFO] ------------------------------------------------------------------------
  [INFO] Building simple-grpc-client 1.0-SNAPSHOT
  [INFO] ------------------------------------------------------------------------
  [INFO] 
  [INFO] --- exec-maven-plugin:1.5.0:java (default-cli) @ simple-grpc-client ---
  [INFO] ------------------------------------------------------------------------
  [INFO] BUILD FAILURE
  [INFO] ------------------------------------------------------------------------
  [INFO] Total time: 1.591s
  [INFO] Finished at: Wed Mar 01 14:50:54 IST 2017
  [INFO] Final Memory: 10M/212M
  [INFO] ------------------------------------------------------------------------
  [ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.5.0:java (default-cli) on project simple-grpc-client: Execution default-cli of goal org.codehaus.mojo:exec-maven-plugin:1.5.0:java failed: Invalid classpath scope: tuomas -&gt; [Help 1]
  org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.5.0:java (default-cli) on project simple-grpc-client: Execution default-cli of goal org.codehaus.mojo:exec-maven-plugin:1.5.0:java failed: Invalid classpath scope: tuomas
          at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:225)
          at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
          at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
          at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
          at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
          at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
          at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
          at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320)
          at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
          at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
          at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
          at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
          at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
          at java.lang.reflect.Method.invoke(Method.java:497)
          at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
          at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
          at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
          at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
  Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default-cli of goal org.codehaus.mojo:exec-maven-plugin:1.5.0:java failed: Invalid classpath scope: tuomas
          at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:110)
          at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
          ... 19 more
  Caused by: java.lang.IllegalStateException: Invalid classpath scope: tuomas
          at org.codehaus.mojo.exec.AbstractExecMojo.collectProjectArtifactsAndClasspath(AbstractExecMojo.java:118)
          at org.codehaus.mojo.exec.ExecJavaMojo.addRelevantProjectDependenciesToClasspath(ExecJavaMojo.java:607)
          at org.codehaus.mojo.exec.ExecJavaMojo.getClassLoader(ExecJavaMojo.java:528)
          at org.codehaus.mojo.exec.ExecJavaMojo.execute(ExecJavaMojo.java:308)
          at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
          ... 20 more
  [ERROR] 
  [ERROR] Re-run Maven using the -X switch to enable full debug logging.
  [ERROR] 
  [ERROR] For more information about the errors and possible solutions, please read the following articles:
  [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginExecution
  </code></pre>
  
  <p>I am using maven here.I will be much appreciated if you can help me............ </p>
  
  <pre><code>here is my pom.xml
  &lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;!--
    ~ Copyright 2016 Google, Inc.
    ~
    ~ Licensed under the Apache License, Version 2.0 (the "License");
    ~ you may not use this file except in compliance with the License.
    ~ You may obtain a copy of the License at
    ~
    ~     http://www.apache.org/licenses/LICENSE-2.0
    ~
    ~ Unless required by applicable law or agreed to in writing, software
    ~ distributed under the License is distributed on an "AS IS" BASIS,
    ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    ~ See the License for the specific language governing permissions and
    ~ limitations under the License.
    --&gt;
  
  &lt;project xmlns="http://maven.apache.org/POM/4.0.0"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"&gt;
      &lt;parent&gt;
          &lt;artifactId&gt;grpc-demos&lt;/artifactId&gt;
          &lt;groupId&gt;com.example&lt;/groupId&gt;
          &lt;version&gt;1.0-SNAPSHOT&lt;/version&gt;
          &lt;relativePath&gt;..&lt;/relativePath&gt;
      &lt;/parent&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
  
      &lt;artifactId&gt;simple-grpc-client&lt;/artifactId&gt;
  
      &lt;dependencies&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;${project.groupId}&lt;/groupId&gt;
              &lt;artifactId&gt;simple-grpc-server&lt;/artifactId&gt;
              &lt;version&gt;${project.version}&lt;/version&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;io.reactivex&lt;/groupId&gt;
              &lt;artifactId&gt;rxjava&lt;/artifactId&gt;
              &lt;version&gt;1.1.5&lt;/version&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
  
  &lt;/project&gt;
  </code></pre>
  
  <p>it is taking dependencies from server. i changed it as follows to get dependencies by its own.</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;!--
    ~ Copyright 2016 Google, Inc.
    ~
    ~ Licensed under the Apache License, Version 2.0 (the "License");
    ~ you may not use this file except in compliance with the License.
    ~ You may obtain a copy of the License at
    ~
    ~     http://www.apache.org/licenses/LICENSE-2.0
    ~
    ~ Unless required by applicable law or agreed to in writing, software
    ~ distributed under the License is distributed on an "AS IS" BASIS,
    ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    ~ See the License for the specific language governing permissions and
    ~ limitations under the License.
    --&gt;
  
  &lt;project xmlns="http://maven.apache.org/POM/4.0.0"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"&gt;
      &lt;parent&gt;
          &lt;artifactId&gt;grpc-demos&lt;/artifactId&gt;
          &lt;groupId&gt;com.example&lt;/groupId&gt;
          &lt;version&gt;1.0-SNAPSHOT&lt;/version&gt;
          &lt;relativePath&gt;..&lt;/relativePath&gt;
      &lt;/parent&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
  
      &lt;artifactId&gt;simple-grpc-client&lt;/artifactId&gt;
  
      &lt;dependencies&gt;
  
          &lt;dependency&gt;
              &lt;groupId&gt;io.reactivex&lt;/groupId&gt;
              &lt;artifactId&gt;rxjava&lt;/artifactId&gt;
              &lt;version&gt;1.1.5&lt;/version&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
            &lt;groupId&gt;org.apache.tomcat.maven&lt;/groupId&gt;
            &lt;artifactId&gt;tomcat7-maven-plugin&lt;/artifactId&gt;
            &lt;version&gt;2.2&lt;/version&gt;
            &lt;type&gt;maven-plugin&lt;/type&gt;
          &lt;/dependency&gt;
           &lt;dependency&gt;
              &lt;groupId&gt;io.grpc&lt;/groupId&gt;
              &lt;artifactId&gt;grpc-netty&lt;/artifactId&gt;
              &lt;version&gt;1.0.0&lt;/version&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;io.grpc&lt;/groupId&gt;
              &lt;artifactId&gt;grpc-protobuf&lt;/artifactId&gt;
              &lt;version&gt;1.0.0&lt;/version&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;io.grpc&lt;/groupId&gt;
              &lt;artifactId&gt;grpc-stub&lt;/artifactId&gt;
              &lt;version&gt;1.0.0&lt;/version&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
  
       &lt;build&gt;
          &lt;extensions&gt;
              &lt;extension&gt;
                  &lt;groupId&gt;kr.motd.maven&lt;/groupId&gt;
                  &lt;artifactId&gt;os-maven-plugin&lt;/artifactId&gt;
                  &lt;version&gt;1.4.1.Final&lt;/version&gt;
              &lt;/extension&gt;
          &lt;/extensions&gt;
          &lt;plugins&gt;
              &lt;plugin&gt;
                  &lt;groupId&gt;org.xolstice.maven.plugins&lt;/groupId&gt;
                  &lt;artifactId&gt;protobuf-maven-plugin&lt;/artifactId&gt;
                  &lt;version&gt;0.5.0&lt;/version&gt;
                  &lt;configuration&gt;
                      &lt;!--
                        The version of protoc must match protobuf-java. If you don't depend on
                        protobuf-java directly, you will be transitively depending on the
                        protobuf-java version that grpc depends on.
                      --&gt;
                      &lt;protocArtifact&gt;com.google.protobuf:protoc:3.0.0:exe:${os.detected.classifier}&lt;/protocArtifact&gt;
                      &lt;pluginId&gt;grpc-java&lt;/pluginId&gt;
                      &lt;pluginArtifact&gt;io.grpc:protoc-gen-grpc-java:1.0.0:exe:${os.detected.classifier}&lt;/pluginArtifact&gt;
                  &lt;/configuration&gt;
                  &lt;executions&gt;
                      &lt;execution&gt;
                          &lt;goals&gt;
                              &lt;goal&gt;compile&lt;/goal&gt;
                              &lt;goal&gt;compile-custom&lt;/goal&gt;
                          &lt;/goals&gt;
                      &lt;/execution&gt;
                  &lt;/executions&gt;
              &lt;/plugin&gt;
  
          &lt;/plugins&gt;
      &lt;/build&gt;
  &lt;/project&gt;
  </code></pre>