Spring Tool Suite: Cannot Execute a Simple Demo because of Spring Boot Build Path ERROR - spring

Question

The Error is as follows:
Description Resource Path Location Type The project was not built
since its build path is incomplete. Cannot find the class file for
org.springframework.context.ConfigurableApplicationContext. Fix the
build path then try building this project springbootdemo Unknown Java
Problem
2 ERROR items:
Description Resource Path Location Type The type
org.springframework.context.ConfigurableApplicationContext cannot be
resolved. It is indirectly referenced from required .class
files MainActivity.java /springbootdemo/src/main/java/springbootdemo line
10 Java Problem
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
#SpringBootApplication
public class MainActivity {
public MainActivity() {
// TODO Auto-generated constructor stub
}
public static void main(String[] args) {
//this is where the ERROR happens beginning at
// "SpringApplication.run(MainActivity.class, args);"
ApplicationContext ctx = SpringApplication.run(MainActivity.class, args);
}
}
pom.xml
<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>labs.noogui.springbootquickstart</groupId>
<artifactId>course-api</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springboot course-api</name>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
<properties>
<java.version>1.8</java.version>
</properties>
</project>
Project Structure:
**Spring Tool Suite**
Version: 3.9.4.RELEASE
Build Id: 201804120921
Platform: Eclipse Oxygen.3a (4.7.3a)
I'm following the Spring Boot tutorial from Edureka!
How do I fix this build path error? I mean, this is like a spring boot hello world and I'm already running into errors?

Answer 1

Just use below code,
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
#SpringBootApplication
public class MainActivity {
public static void main(String[] args) {
SpringApplication.run(MainActivity.class, args);
}
}
or if you want to use ApplicationContext to start the application then use below line but both are almost same.
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
#SpringBootApplication
public class MainActivity {
public static void main(String[] args) {
ApplicationContext ctx = SpringApplication.run(MainActivity.class, args);
}
}

Answer 2

You are using ApplicationContext from org.apache.catalina.core.
Import and use this org.springframework.context.ApplicationContext instead.
Your IDE is showing compile errors. Error message should probably lead you to the right direction.

Answer 3

Thanks for the folks who tried to help but I found out that the problem is with maven's 'corrupted' repository (again). So as always, deleting the .m2/repository and updating your maven project resolves the issue.
Related post in this github forum. This is a recurring issue with maven.