包 org.springframework.boot 不存在答案

【问题标题】：package org.springframework.boot does not exist包 org.springframework.boot 不存在
【发布时间】：2018-07-28 14:42:38
【问题描述】：

我正在尝试在我的机器上运行一个小型基本 Spring 启动程序，当我在 maven 上运行 clean compile（甚至在尝试 spring-boot:run 之前）时，我收到以下错误：

[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] /C:/Users/hbenayed/eclipse-workspace/SpringBootPoc/src/main/java/com/benayed/spboot/poc/SpringBootPoc/SpringBootPocApplication.java:[3,32] package org.springframework.boot does not exist
[ERROR] /C:/Users/hbenayed/eclipse-workspace/SpringBootPoc/src/main/java/com/benayed/spboot/poc/SpringBootPoc/SpringBootPocApplication.java:[4,46] package org.springframework.boot.autoconfigure does not exist
[ERROR] /C:/Users/hbenayed/eclipse-workspace/SpringBootPoc/src/main/java/com/benayed/spboot/poc/SpringBootPoc/SpringBootPocApplication.java:[6,2] cannot find symbol
  symbol: class SpringBootApplication
[ERROR] /C:/Users/hbenayed/eclipse-workspace/SpringBootPoc/src/main/java/com/benayed/spboot/poc/SpringBootPoc/SpringBootPocApplication.java:[10,17] cannot find symbol
  symbol:   variable SpringApplication
  location: class com.benayed.spboot.poc.SpringBootPoc.SpringBootPocApplication
[INFO] 4 errors 
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 14.807 s
[INFO] Finished at: 2018-02-18T03:28:24+01:00
[INFO] Final Memory: 19M/167M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project SpringBootPoc: Compilation failure: Compilation failure:
[ERROR] /C:/Users/hbenayed/eclipse-workspace/SpringBootPoc/src/main/java/com/benayed/spboot/poc/SpringBootPoc/SpringBootPocApplication.java:[3,32] package org.springframework.boot does not exist
[ERROR] /C:/Users/hbenayed/eclipse-workspace/SpringBootPoc/src/main/java/com/benayed/spboot/poc/SpringBootPoc/SpringBootPocApplication.java:[4,46] package org.springframework.boot.autoconfigure does not exist
[ERROR] /C:/Users/hbenayed/eclipse-workspace/SpringBootPoc/src/main/java/com/benayed/spboot/poc/SpringBootPoc/SpringBootPocApplication.java:[6,2] cannot find symbol
[ERROR] symbol: class SpringBootApplication
[ERROR] /C:/Users/hbenayed/eclipse-workspace/SpringBootPoc/src/main/java/com/benayed/spboot/poc/SpringBootPoc/SpringBootPocApplication.java:[10,17] cannot find symbol
[ERROR] symbol:   variable SpringApplication
[ERROR] location: class com.benayed.spboot.poc.SpringBootPoc.SpringBootPocApplication
[ERROR] -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project SpringBootPoc: Compilation failure
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:212)
    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:116)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
    at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
    at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
    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:498)
    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.compiler.CompilationFailureException: Compilation failure
    at org.apache.maven.plugin.compiler.AbstractCompilerMojo.execute(AbstractCompilerMojo.java:858)
    at org.apache.maven.plugin.compiler.CompilerMojo.execute(CompilerMojo.java:129)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)
    ... 20 more
[ERROR] 
[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/MojoFailureException

这是我的 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>com.benayed.spboot.poc</groupId>
    <artifactId>SpringBootPoc</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>SpringBootPoc</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.10.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <!-- <dependency> -->
        <!-- <groupId>org.springframework.boot</groupId> -->
        <!-- <artifactId>spring-boot-starter-data-jpa</artifactId> -->
        <!-- </dependency> -->

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

这是我的 java 类：

package com.benayed.spboot.poc.SpringBootPoc;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringBootPocApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringBootPocApplication.class, args);
    }

}

我尝试了许多可以在 Internet 上找到的解决方案，例如删除 .m2 存储库，向 spring-boot-maven-plugin 插件添加不同的标签（版本、fork、...），我很确定这是其中的一部分导致问题

有什么建议吗？

【问题讨论】：

标签： java spring maven spring-boot

【解决方案1】：

此问题将使用

解决

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

如果还是不行，运行"maven clean install"

【讨论】：

【解决方案2】：

1) 关闭项目 2) 再次导入项目并勾选自动导入

这对我有用。也许也适合你。

【讨论】：

【解决方案3】：

你需要添加这个依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

然后它会工作。

【讨论】：

这行得通！除了 Darren Forsythe 的回答之外，我还有一个问题：为什么我需要添加该依赖项？因为我在我的 pom 中包含了一个父级，这意味着我需要的所有依赖项都是从该父级检索的，所以为什么我必须添加另一个依赖项才能编译我的项目？
如果父级声明了继承的依赖关系，那将是正确的。但是，Spring Boot parent 只声明了dependencyManagement，它只会管理版本和范围，而依赖项本身并没有添加到子项目中。

【解决方案4】：

在依赖管理之外添加以下部分并更新项目。然后是 maven 的全新安装。

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.10.RELEASE</version>
    </parent>

还有下面的依赖。

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

如果没有修复（不太可能发生）然后添加提到的其他依赖项here

【讨论】：

【解决方案5】：

您有 0 个编译依赖项，仅定义了测试编译依赖项，因为您已注释掉 spring-boot-starter-data-jpa。 Spring starter 引入其他依赖项（包括其他启动器）以在编译时创建所需的一切。取消注释 spring-boot-starter-data-jpa 依赖项，和/或重新评估您真正想要的依赖项。

【讨论】：

这行得通！除了 Do Nhu Vy 的回答之外，我还有一个问题：为什么我需要添加该依赖项？因为我在我的 pom 中包含了一个父级，这意味着我需要的所有依赖项都是从该父级检索的，所以为什么我必须添加另一个依赖项才能编译我的项目？
父 POM 用于管理依赖关系，它们都是可选的，因此您需要明确并自己定义它们。