Maven & Protobuf compile error: Cannot find symbol in package com.google.protobuf

Question

I'm new to Linux and Protobuf.. I need help.

I'm trying to "mvn package" a project that contains many ".proto" files, and a pom.xml file of course...

I'm working on Ubuntu

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ERROR

When I run "mvn package", I receive this error:

after

... Compiling 11 source files to .../target/classes ... 

I get a bunch of these errors:

[ERROR] .../target/generated-sources/...java:[16457,30] cannot find symbol [ERROR] symbol  : class Parser [ERROR] location: package com.google.protobuf [ERROR]  [ERROR] .../target/generated-sources/...java:[17154,37] cannot find symbol [ERROR] symbol  : class Parser [ERROR] location: package com.google.protobuf [ERROR]  [ERROR] .../target/generated-sources/...java:[17165,30] cannot find symbol [ERROR] symbol  : class Parser [ERROR] location: package com.google.protobuf [ERROR]  [ERROR] .../target/generated-sources/...java:[17909,37] cannot find symbol [ERROR] symbol  : class Parser [ERROR] location: package com.google.protobuf [ERROR] 

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POM

Here is the pom.xml file, with groupId & artifactId taken out:

<project>   <modelVersion>4.0.0</modelVersion>   <parent>      <groupId>*****</groupId>      <artifactId>*****</artifactId>      <version>1.0-SNAPSHOT</version>   </parent>   <artifactId>*****</artifactId>   <version>1.0-SNAPSHOT</version>   <properties>       <proto.cas.path>${project.basedir}/src</proto.cas.path>       <target.gen.source.path>${project.basedir}/target/generated-sources</target.gen.source.path>   </properties>  <dependencies>       <dependency>                 <groupId>com.google.protobuf</groupId>                 <artifactId>protobuf-java</artifactId>                 <version>2.4.1</version>                 <scope>compile</scope>             </dependency>   </dependencies>   <build>     <sourceDirectory>${project.basedir}/src</sourceDirectory>         <plugins>             <plugin>                <artifactId>maven-compiler-plugin</artifactId>                <version>2.0.2</version>                <configuration>                         <source>1.6</source>                         <target>1.6</target>                     <includes><include>**/commonapps/**</include></includes>                 </configuration>                          </plugin>              <plugin>                     <artifactId>maven-antrun-plugin</artifactId>                     <executions>                         <execution>                             <id>generate-sources</id>                             <phase>generate-sources</phase>                             <configuration>                                 <tasks>                                     <mkdir dir="${target.gen.source.path}" />                                         <path id="proto.path.files">                                         <fileset dir="${proto.cas.path}">                                             <include name="*.proto" />                                         </fileset>                                       </path>                                     <pathconvert pathsep=" " property="proto.files" refid="proto.path.files" />                                      <exec executable="protoc">                                          <arg value="--java_out=${target.gen.source.path}" />                                          <arg value="--proto_path=${proto.cas.path}" />                                             <arg line="${proto.files}" />                                     </exec>                                 </tasks>                                 <sourceRoot>${target.gen.source.path}</sourceRoot>                             </configuration>                             <goals>                                 <goal>run</goal>                             </goals>                         </execution>                     </executions>                 </plugin>          </plugins>      </build> </project> 

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PROTOBUF INSTALLATION

I've done

./configure make make check make install 

in protobuf/,

and

mvn test mvn install mvn package 

in protobuf/java.

I took the jar in protobuf/java/target

and added it to my maven repo by running:

mvn install:install-file -Dpackaging=jar -DgeneratePom=true  -DgroupId=com.google.protobuf   -DartifactId=protobuf-java   -Dfile=protobuf-java-2.4.1.jar -Dversion=2.4.1 

Note that I've messed around with $LD_LIBRARY_PATH. Currently when I run echo it, I get:

/usr/local/lib/:/usr/:/usr/lib/:/usr/local/ 

yeah.... as you can tell I don't have a clue about setting $LD_LIBRARY_PATH

I also ran:

apt-get install protobuf-compiler 

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PROTOC INSTALLATION

I forgot what I did to make protoc work, but when I run

protoc --version 

I get

libprotoc 2.5.0 

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MY QUESTION IS SIMILAR TO:

Problems using protobufs with java and scala

maven compilation failure

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POSSIBLE RELEVANCE?

still not find package, after 'mvn install'

http://www.scriptol.com/programming/protocol-buffers-tutorial.php

Can anyone help?

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PROGRESS

Apparently it's a plugin failure:

https://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.0.2:compile (default-compile) on project casprotobuf: Compilation failure: Compilation failure: 

Answer 1

I had the same problem. building the protobuf sources from google directly (I used 2.5.0) and doing

mvn install:install-file -Dpackaging=jar -DgeneratePom=true  -DgroupId=com.google.protobuf   -DartifactId=protobuf-java   -Dfile=protobuf-java-2.5.0.jar -Dversion=2.5.0 

fixed the problem for me.

In my earlier trials I noticed, that the jar-file in /root/.m2/repository/com/google/protobuf/protobuf-java/2.5.0/ was missing.

Maybe try to use version 2.5.0 in the pom.xml and/or copying the jarfile manually.

cheers

Answer 2

I had this problem when there was a mismatch between the protoc version installed and the version listed in the pom. Matching the versions fixed the problem. In my case, I had to switch my protoc version back to 2.4.1 to match the POM.