SpringBoot pom.xml unknown error

参考：https://blog.csdn.net/yaowanliang/article/details/83185808

pom文件报Unknown error

pom.xml内容：

	4.0.0
	
		org.springframework.boot
		spring-boot-starter-parent
		2.1.9.RELEASE
		 
	
	com.example
	demo
	0.0.1-SNAPSHOT
	demo
	Demo project for Spring Boot

	
		1.8
	

	
		
			org.springframework.boot
			spring-boot-starter
		

		
			org.springframework.boot
			spring-boot-starter-test
			test
		
		
		
			org.springframework.boot
			spring-boot-starter-web
		
	

	
		
			
				org.springframework.boot
				spring-boot-maven-plugin
			
		
	

把maven项目重新clean,install后有接着提示下面的警告

[INFO] Scanning for projects...
[WARNING] 
[WARNING] Some problems were encountered while building the effective model for com.example:demo:jar:0.0.1-SNAPSHOT
[WARNING] 'dependencyManagement.dependencies.dependency.exclusions.exclusion.artifactId' for org.quartz-scheduler:quartz:jar with value '*' does not match a valid id pattern. @ org.springframework.boot:spring-boot-dependencies:2.1.9.RELEASE, D:\repos\org\springframework\boot\spring-boot-dependencies\2.1.9.RELEASE\spring-boot-dependencies-2.1.9.RELEASE.pom, line 2615, column 25
[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] 

网上提供的解决办法：

1. 降低spring-boot-starter-parent的版本，把2.1.9降低为2.1.1

2. 项目右键 - Maven - Update Project - 选中Force Update of Snapshots/Releases 进行强制更新

根据网上解决办法我也进行多次尝试，终于找到解决方法，方法如下：

1. 降低spring-boot-starter-parent的版本，把2.1.9降低为2.1.4

	org.springframework.boot
	spring-boot-starter-parent
	2.1.4.RELEASE
	 

2. 删除本地maven库repos里面org.springframework.boot对应的文件夹boot

3. 把maven项目重新clean,install （这个时候就可以看到项目对应的pom.xml不会报错）

4. 项目右键 - Maven - Update Project