为什么在将Spring-Boot启动程序的父级项目更新到最后2.2.5.RELEASE后，我在构建Spring-Boot

Question

我是Spring Boot的新手，在尝试更新Spring Boot starter父项目时遇到了一些问题。

所以，一开始我有一个pom.xml文件(它运行良好，我可以构建项目，我没有问题(：

<?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.springboot</groupId>
<artifactId>excel-api</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>Excel API with Spring Boot</name>
<description>Spring Boot - working with Excel API</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.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-security</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-data</artifactId>
</dependency>
<!-- Start of excel dependencies -->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.11</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.11</version>
</dependency>
<!-- End of excel dependencies -->
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>

正如您所看到的，pom.xml文件包含部分：

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>

如果我做了错误的断言，请纠正我：根据我的理解，这意味着我的pom.xml文件是spring-boot-starter-parent项目的另一个pom.xml件的子文件，版本为1.5.9.RELEASE。这种推理正确吗？如果在哪里定义了pom.xml文件？

因此，目前我成功地使用了这个父项目的1.5.9。RELEASE版本。它很旧，我想把它更新到最后一个版本，即2.2.5.REASE，如下所示：

https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-parent

因此，我只更改了前一个pom.xml文件的部分：

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>

问题是，试图通过这个Maven命令来构建项目：

mvn clean install -DskipTests=true

我获得以下错误消息：

[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] /home/developer/git/SOC-dashboard/src/main/java/com/springboot/excelapi/Application.java:[6,44] package org.springframework.boot.web.support does not exist
[ERROR] /home/developer/git/SOC-dashboard/src/main/java/com/springboot/excelapi/Application.java:[9,34] cannot find symbol
symbol: class SpringBootServletInitializer
[ERROR] /home/developer/git/SOC-dashboard/src/main/java/com/springboot/excelapi/Application.java:[15,9] method does not override or implement a method from a supertype
[INFO] 3 errors 
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  2.349 s
[INFO] Finished at: 2020-03-20T05:48:14-07:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project excel-api: Compilation failure: Compilation failure: 
[ERROR] /home/developer/git/SOC-dashboard/src/main/java/com/springboot/excelapi/Application.java:[6,44] package org.springframework.boot.web.support does not exist
[ERROR] /home/developer/git/SOC-dashboard/src/main/java/com/springboot/excelapi/Application.java:[9,34] cannot find symbol
[ERROR]   symbol: class SpringBootServletInitializer
[ERROR] /home/developer/git/SOC-dashboard/src/main/java/com/springboot/excelapi/Application.java:[15,9] method does not override or implement a method from a supertype
[ERROR] -> [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/MojoFailureException

Answer 1

这是一次从1.x到2.x的主要春季版本升级。在这种主要版本升级过程中，通常会有一些突破性的更改，如包重组、删除不推荐使用的类/方法等。最好参阅某种迁移指南来进行此类升级。你可以参考官方的移民指南或其他一些博客，比如这个。

Spring提供了一个依赖模块，可以将其添加到您的pom文件中。该模块分析应用程序，并为所需的更改提供诊断输出。

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-properties-migrator</artifactId>
<scope>runtime</scope>
</dependency>

对于问题中提出的具体问题；

[ERROR] /home/developer/git/SOC-dashboard/src/main/java/com/springboot/excelapi/Application.java:[9,34] cannot find symbol
[ERROR]   symbol: class SpringBootServletInitializer

SpringBootServletInitializer现在可以从org.springframework.boot.web.servlet.support软件包中获得。