Question

在根文件夹上运行gradle build命令时出现以下错误。

E:\Code\mdh>gradle build

> Task :multidemo:compileKotlin FAILED
e: E:\Code\mdh\multidemo\src\main\kotlin\com\simbalarry\multidemo\SampleController.kt: (3, 23): Unresolved reference: somelib
e: E:\Code\mdh\multidemo\src\main\kotlin\com\simbalarry\multidemo\SampleController.kt: (18, 12): Unresolved reference: Tester

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':multidemo:compileKotlin'.
> Compilation error. See log for more details

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 5s
4 actionable tasks: 1 executed, 3 up-to-date

下面是我的项目结构，multidemo项目正在使用somelib的某些功能。另外，我特意保留了somelib作为spring boot项目，因为稍后我将添加更多与spring boot相关的功能。

Root Project
  |
  |---settings.gradle
  |---somelib
  |       |
  |       |---build.gradle
  |       |---settings.gradle
  |       |---src/main/kotlin/somepackage/Tester.kt
  |       |---src/main/kotlin/somepackage/SomeLibApplication.kt
  |
  |---multidemo
  |       |---build.gradle
  |       |---settings.gradle
  |       |---src/main/kotlin/somepackage/SampleController.kt
  |       |---src/main/kotlin/somepackage/MultidemoApplication.kt

下面是每个文件的内容

Root / settings.gradle

include ':somelib', ':multidemo'

somelib / build.gradle

plugins {
    id 'org.springframework.boot' version '2.1.3.RELEASE'
    id 'org.jetbrains.kotlin.jvm' version '1.3.21'
    id 'org.jetbrains.kotlin.plugin.spring' version '1.3.21'
}

apply plugin: 'io.spring.dependency-management'

group = 'com.simbalarry'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '1.8'

repositories {
    mavenCentral()
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation 'com.fasterxml.jackson.module:jackson-module-kotlin'
    implementation 'org.jetbrains.kotlin:kotlin-reflect'
    implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk8'
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

compileKotlin {
    kotlinOptions {
        freeCompilerArgs = ['-Xjsr305=strict']
        jvmTarget = '1.8'
    }
}

compileTestKotlin {
    kotlinOptions {
        freeCompilerArgs = ['-Xjsr305=strict']
        jvmTarget = '1.8'
    }
}

somelib / settings.gradle

pluginManagement {
    repositories {
        gradlePluginPortal()
    }
}
rootProject.name = 'somelib'

somelib / src / main / kotlin / somepackage / Tester.kt

package com.simbalarry.somelib


/*
 * Created on : 17-03-2019
 * Author     : Nayan Kurude
 */

object Tester {
  fun getOutputText(): String {
    return "Sample Text"
  }
}

somelib / src / main / kotlin / somepackage / SomelibApplication.kt

package com.simbalarry.somelib

import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication

@SpringBootApplication
class SomelibApplication

fun main(args: Array<String>) {
    runApplication<SomelibApplication>(*args)
}

multidemo / build.gradle

plugins {
    id 'org.springframework.boot' version '2.1.3.RELEASE'
    id 'org.jetbrains.kotlin.jvm' version '1.3.21'
    id 'org.jetbrains.kotlin.plugin.spring' version '1.3.21'
}

apply plugin: 'io.spring.dependency-management'

group = 'com.simbalarry'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '1.8'

repositories {
    mavenCentral()
    mavenLocal()
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation 'com.fasterxml.jackson.module:jackson-module-kotlin'
    implementation 'org.jetbrains.kotlin:kotlin-reflect'
    implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk8'
    compile project(':somelib')
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

compileKotlin {
    kotlinOptions {
        freeCompilerArgs = ['-Xjsr305=strict']
        jvmTarget = '1.8'
    }
}

compileTestKotlin {
    kotlinOptions {
        freeCompilerArgs = ['-Xjsr305=strict']
        jvmTarget = '1.8'
    }
}

multidemo / settings.gradle

pluginManagement {
    repositories {
        gradlePluginPortal()
    }
}
rootProject.name = 'multidemo'

multidemo / src / main / kotlin / somepackage / MultiDemoApplication.kt

package com.simbalarry.multidemo

import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication

@SpringBootApplication
class MultidemoApplication

fun main(args: Array<String>) {
    runApplication<MultidemoApplication>(*args)
}

multidemo / src / main / kotlin / somepackage / SampleController.kt

package com.simbalarry.multidemo

import com.simbalarry.somelib.Tester
import org.springframework.web.bind.annotation.RequestMapping
import org.springframework.web.bind.annotation.RestController


/*
 * Created on : 17-03-2019
 * Author     : Nayan Kurude
 */

@RestController
class SampleController {

  @RequestMapping("/hello")
  fun hello(): String {
    return Tester.getOutputText()
  }
}

谁能告诉我我在哪里做错了事。

Answer 1

正如我在评论中所说：somelib应该是一个库。因此，它不应应用spring boot插件，该插件的作用是创建Spring Boot 应用。

您用于somelib的build.gradle文件应如下所示：

plugins {
    id 'java-library' // 1
    id 'org.springframework.boot' version '2.1.3.RELEASE' apply false // 2
    id 'io.spring.dependency-management' version '1.0.6.RELEASE' //3
    id 'org.jetbrains.kotlin.jvm' version '1.3.21'
    id 'org.jetbrains.kotlin.plugin.spring' version '1.3.21'
}

group = 'com.simbalarry'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '1.8'

repositories {
    mavenCentral()
}

dependencyManagement { // 4
    imports {
        mavenBom org.springframework.boot.gradle.plugin.SpringBootPlugin.BOM_COORDINATES
    }
}

ext['kotlin.version'] = '1.3.21' // 5

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation 'com.fasterxml.jackson.module:jackson-module-kotlin'
    implementation 'org.jetbrains.kotlin:kotlin-reflect'
    implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk8'
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

compileKotlin {
    kotlinOptions {
        freeCompilerArgs = ['-Xjsr305=strict']
        jvmTarget = '1.8'
    }
}

compileTestKotlin {
    kotlinOptions {
        freeCompilerArgs = ['-Xjsr305=strict']
        jvmTarget = '1.8'
    }
}

一些说明（请参见代码中的注释）：

应用Java库gradle插件，因为这就是您要创建的：一个可以在其他项目中使用的库
将Spring Boot插件添加到构建的类路径中而不应用它，以便以后可以使用其BOM。参见https://docs.spring.io/spring-boot/docs/2.1.3.RELEASE/gradle-plugin/reference/html/#managing-dependencies-using-in-isolation
通过使用spring boot BOM中指定的版本号，应用spring依赖性管理插件来指定没有版本的依赖性
配置依赖项管理插件以使用Spring Boot BOM
用要使用的BOM替代BOM（1.2.71）中使用的kotlin版本。参见https://docs.spring.io/dependency-management-plugin/docs/current-SNAPSHOT/reference/html/#dependency-management-configuration-bom-import-override-property

Gradle，Kotlin，多模块项目：在编译该项目时遇到构建错误

1 个答案: