java - .proto 文件导入时出错

Question

我有一个 MyResponse.proto 文件，它导入两个 .proto 文件 Alternative.proto 和 Index.proto >.

MyResponse.proto 文件:

import "Alternative.proto";
import "Index.proto";
message MyResponse {
  repeated AlternativeV1 alternativeV1 = 1;
  required IndexV1 indexV1 = 2;
}

Alternative.proto 文件:

import "Reference.proto";
message AlternativeV1 {
  required string name = 1;
  required string id = 2;
}

Index.proto 文件:

message IndexV1 {
  required string name = 1;
}

使用 maven 编译 proto 文件时收到错误“AlternativeV1”未定义。我使用 Intellij 作为 IDE。类型 AlternativeV1 和 IndexV1 在 IDE 中显示为“未解析的引用”。谁能帮我解决这个问题？

Answer 1

下面是一个小的工作示例。因此您可以将其与您的项目设置进行比较。

假设以下文件和目录结构。

pom.xml
src/main/proto/Alternative.proto
src/main/proto/Index.proto
src/main/proto/MyResponse.proto

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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">
    <modelVersion>4.0.0</modelVersion>
    <groupId>sub.optimal</groupId>
    <artifactId>ProtoExample</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <dependencies>
        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java</artifactId>
            <version>2.6.1</version>
        </dependency>
    </dependencies>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<!--        <maven.compiler.source>1.7</maven.compiler.source>
        <maven.compiler.target>1.7</maven.compiler.target>-->
    </properties>

    <pluginRepositories>
        <pluginRepository>
            <releases>
                <updatePolicy>never</updatePolicy>
            </releases>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
            <id>central</id>
            <name>Central Repository</name>
            <url>https://repo.maven.apache.org/maven2</url>
        </pluginRepository>
        <pluginRepository>
            <id>protoc-plugin</id>
            <url>https://dl.bintray.com/sergei-ivanov/maven/</url>
        </pluginRepository>
    </pluginRepositories>

    <build>
        <plugins>
            <plugin>
                <groupId>com.google.protobuf.tools</groupId>
                <artifactId>maven-protoc-plugin</artifactId>
                <version>0.4.4</version>
                <configuration>
                    <protocExecutable>protoc</protocExecutable>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                            <goal>test-compile</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

Alternative.proto

package sub.optimal;
message AlternativeV1 {
    required string name = 1;
    required string id = 2;
}

Index.proto

package sub.optimal;
message IndexV1 {
    required string name = 1;
}

MyResponse.proto

package sub.optimal;
option java_outer_classname = "MyResponseProtos";
import "Alternative.proto";
import "Index.proto";
message MyResponse {
    repeated AlternativeV1 alternativeV1 = 1;
    required IndexV1 indexV1 = 2;
}

以下内容已添加到 *.proto 文件

• 包 - 生成有效的 Java 源代码
• 选项 java_outer_classname - 否则 protoc 编译器将生成默认类 MyResponseOuterClass.java

运行mvncompile将生成target/classes/sub/optimal/下面的类。