编译Java运行时库时Protobuf错误

Question

我正在尝试为Protocol Buffers构建 Java 运行时库。通过遵循 Protocol Buffers 项目（从https://github.com/google/protobuf克隆）中 Java 目录下的 README 指令，我在 Windows 和 OS X 上都遇到了错误。

mvn test我在protobuf/java目录下运行时出现以下错误。

OS X 中的错误

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-antrun-plugin:1.8:run (generate-sources) on project protobuf-java: An Ant BuildException has occured: The following error occurred while executing this line:
[ERROR] /Users/wangsa/Work/ProtoBuffer/protobuf/java/core/generate-sources-build.xml:4: Execute failed: java.io.IOException: Cannot run program "/Users/wangsa/Work/ProtoBuffer/protobuf/java/core/../../src/protoc" (in directory "/Users/wangsa/Work/ProtoBuffer/protobuf/java/core"): error=2, No such file or directory

来自 Windows 的错误

[INFO] Scanning for projects...
[WARNING]
[WARNING] Some problems were encountered while building the effective model for com.google.protobuf:protobuf-java:bundle:2.6.1
[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-compiler-plugin is missing. @ line 57, column 15
[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-surefire-plugin is missing. @ line 64, column 15
[WARNING] 'build.plugins.plugin.version' for org.apache.felix:maven-bundle-plugin is missing. @ line 143, column 15
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING]
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building Protocol Buffer Java API 2.6.1
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-antrun-plugin:1.3:run (generate-sources) @ protobuf-java ---
[INFO] Executing tasks
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.030 s
[INFO] Finished at: 2016-06-07T10:03:48+12:00
[INFO] Final Memory: 11M/245M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-antrun-plugin:1.3:run (generate-sources) on project protobuf-java: An Ant BuildException has occured: Execute failed: java.io.IOException: Cannot run program "..\src\protoc": CreateProcess error=2, The system cannot find the file specified -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[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/MojoExecutionException

更多细节

• Maven已正确安装（版本3.3.9）
• Java JDK 已正确安装（OS X 版本为 1.7，Windows 版本为 1.8）
• Protobuf 已正确安装。我可以使用该protoc命令将 .proto 文件转换为 .java 文件。
• 对于已安装的二进制文件和我尝试构建的 Java 包，protobuf 的版本都是 2.6.1。

任何人都可以看到可能出了什么问题吗？

编辑：执行此构建过程对我来说是相当新的，我假设如果此过程成功完成，我将获得一个 .jar 文件，我可以将其包含在我的 android 程序中，以便使用从我的 proto 文件生成的 protobuf 方法来序列化数据并通过 TCP 发送，这是我的最终目标。

Answer 1

最终通过以下更改使其正常工作：

更改 1：我更改为使用https://github.com/google/protobuf/releases/tag/v2.6.1中的 java 源，而不是https://github.com/google/protobuf/tree/v2.6.1/爪哇

更改 2：对于 Windows 计算机，我需要将 protoc.exe 复制到src位于java 文件夹的父文件夹中的文件夹。以前我将 protoc.exe 复制到srcjava 文件夹内，但不起作用。

之后我mvn test在java文件夹中运行，一切正常。我能够使用mvn install然后mvn package基于 README 文件生成 .jar 文件。

注意：我不明白为什么 protobuf/tree/v2.6.1 中的代码不起作用，但因为在 github 上，构建状态也显示失败（截至 6 月 7 日），所以我认为这就是原因。