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Project build error.Non resolvalbe parent POM in pom.xml in java

I am getting below error in pom.xml in springboot java application. I changed java version ,springboot version but error remains same. what should I do?
below is my 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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.13</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
I saw some of the answers and played with relativePath but did not work what should I do?

This is an common problem facing now a days. This error causes because your editor haven't installed the spring boot properly. This you have to install all the maven files properly. Just follow the below steps to solve the problem.
Right click your spring boot project (demo) and select the option maven.
2. From the maven option you will get list of options. There you select update project or select download source.
Then your editor will install all the maven files for your spring boot project. And your error will be resolved.
Or
If it does not work just uninstall your spring tool suite and reinstall properly.
Any clarification please don't hesitate to comment your issue.. I am waiting for your comment.. Thank you

Maven: why are dependencies declared in parent pom not inherited by child pom?

When I declare a dependency in a parent pom like -
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.demo</groupId>
<artifactId>deps</artifactId>
<packaging>pom</packaging>
<version>0.0.1-SNAPSHOT</version>
<dependencyManagement>
<dependencies>
<!-- not relevant for this question -->
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>5.3.12</version>
</dependency>
</dependencies>
</project>
above i have declared spring-core as a dependency for parent pom.
Now in child pom, i am importing the parent pom -
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.demo</groupId>
<artifactId>deps2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.demo</groupId>
<artifactId>deps</artifactId>
<version>0.0.1-SNAPSHOT</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<!-- not relevant for this question -->
</dependencies>
</project>
Now on looking at the dependencies inherited by child pom, there are none. Should NOT the spring-core jar be inherited by child project in all cases. As the parent pom directly depends on this jar and is it not passed on/inherited by child projects.
Note: This question is not about dependency management and versions
I understand dependencyManagement, which is to ensure that a set of projects have the same version and scope of a depencency.

There is a difference between placing a parent tag and Bill of materials (importing the pom in the dependency management section)
Using <parent> is a "real inheritance" in maven. You define this tag on the child pom and by that you will get all the dependencies defined in the parent pom automatically (also properties and plugins).
The Bill of Materials on the other hand (This is how its called in the official documentation) doesn't import any dependencies by itself, however it allows to avoid specifying the versions of the dependencies in the pom of your application, because you define them in this BOM.
So to answer your question, you should really rewrite the child pom as:
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.demo</groupId>
<artifactId>deps2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<parent>
<groupId>com.demo</groupId>
<artifactId>deps</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<dependencies>
<!-- not relevant for this question -->
</dependencies>
</project>

Your child pom is a standalone pom because you didn't specified a parent. You define a parent by adding this tag :
<parent>
<groupId>yourpackage</groupId>
<artifactId>yourartifactid</artifactId>
<version>version</version>
</parent>
In your case, this block should do the trick :
<parent>
<groupId>com.demo</groupId>
<artifactId>deps</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
I know that your question was not about depedencies management; but for people that would not know the difference I'll write some words about that.
Note that by importing your pom in <dependenciesManagement> you don't have any impact given that it only defines intentions of use but not concrete import. The <dependencies> contains the concrete imports and it's only its content that you can use in your application.

How to override the Spring Data Mongo version from Parent Project?

In my project, we've Parent module which is none of in our control and has using mongodb-driver-core-3.6.4.jar and spring-data-mongodb-2.0.11.RELEASE.jar. But somehow I want to use latest versions of both mongodb-driver-core and spring-data-mongodb. How to override this from Parent module ?
I already went through the link: https://spring.io/blog/2016/04/13/overriding-dependency-versions-with-spring-boot, but doesn't works for me.
I want to either override Spring Boot starter version or want to use somehow mongodb-driver-3.8.2.jar and spring-boot-2.1.4.RELEASE.jar
I've pom.xml file something like below:
<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>
<parent>
<groupId>com.example.ahr</groupId>
<artifactId>ahr-rest-api-starter-parent</artifactId>
<version>2.3.1</version>
</parent>
<groupId>com.example</groupId>
<artifactId>ahr-data</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>ahr-data</name>
<description>ahr Data Service </description>
<properties>
<java.version>1.8</java.version>
<mongo.version>2.1.4.RELEASE</mongo.version>
</properties>
............
..................
.................

We simply need to override the spring-boot-dependencies from the Parent module, so that Spring Data Mongo starter can pick up the latest versions of itself.
<dependencyManagement>
<dependencies>
<dependency>
<!-- Import dependency management from Spring Boot -->
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>2.1.4.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
Here is the one more change we need to make -
<properties>
<java.version>1.8</java.version>
<spring.boot.version>2.1.4.RELEASE</spring.boot.version>
</properties>

Why is Springs auto generated pom file un parsable?

I've been trying to setup a spring websocket server using the stat.spring.io generator which generates a pom file etc.
It seems that the generated pomfile is unparsable for some reason and i've spent hours trying to fix it.
I've tried using Java 1.7 with spring 2.. to no avail.
Please can someone help explain why it might not be parsing:
Here is my full pomfile:
<?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.example</groupId>
<artifactId>ws-analytics-gateway</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>ws-analytics-gateway</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.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-websocket</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>

The pom.xml you have posted is not valid XML. it is missing a closing tag for project as mentioned above. Also, you mention using java 1.7 with spring 2.
https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-2.0-Release-Notes#java-8-baseline-and-java-9-support states:
Spring Boot 2.0 requires Java 8 as a minimum version.
I checked your XMl by pasting it here: https://www.xmlvalidation.com/index.php?id=1&L=0 you may wish to have that check pass first.

pom use a common dependency for 3 applications Spring-mvc

I have a dependency called "general-lib" which will be modified and used by 3 teams.
Admin, Child-ABC and Child-XYZ are those 3 projects. Those 3 apps
deployed in same server.
Child-XYZ and Child-ABC are communicating to
Admin app frequently.
When we change general-lib version, I want
that Child apps also should use same version what admin app uses.
Finally that particular dependency version should be managed at super application.
is there any to do that ? Please let me know if I need to explain better.

You can define a BOM (Bills of Materials) where you can move the dependecyManagement for the common artifacts and then declare it as a parent in your 3 projects. This is an example of BOM:
<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>your.group.id</groupId>
<artifactId>whatever-BOM</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<properties>
<general-lib.version>1.0.2</general-lib.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>your.groupid</groupId>
<artifactId>general-lib</artifactId>
<version>${general-lib.version}</version>
</dependency>
</dependencies>
</dependencyManagement>
</project>
For more details on BOM, you can read the article Spring with Maven BOM that even if it's related to Spring, it will explain in a detailed way what are BOMs and how to use them.
Ohter possibility, is to define those 3 projects as a module of a higher level project and manage in this one the dependencyManagement.
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>your.group.id</groupId>
<artifactId>whatever</artifactId>
<version>1.0-SNAPSHOT</version>
<modules>
<module>Admin</module>
<module>Child-ABC</module>
<module>Child-XYZ</module>
</modules>
<packaging>pom</packaging>
<properties>
<general-lib.version>1.0.2</general-lib.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>your.groupid</groupId>
<artifactId>general-lib</artifactId>
<version>${general-lib.version}</version>
</dependency>
</dependencies>
</dependencyManagement>
</project>