Can we write simple boot application with using "spring-boot-starter-parent" - maven

Question

I have starting working on Spring-boot. I was trying to check whether "spring-boot-starter-parent" is mandatory to include as a parent in our pom,xml or not.
I tried to use to "Spring-boot-starter-web" as parent pom but it's still giving some error regarding filtering resource which may be due to inability to find out application.properties.
Is it mandatory to have a parent in pom file ?
Thanks

Answer 1

Yes you can, but you need to manage things at your own.
Like
* Turn on filtering by default for application properties,
* Apply more sensible defaults for user projects(test configs.. etc)
* Spring boot plugins etc
Here is parent pom file of 1.5.6
<?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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>1.5.6.RELEASE</version>
<relativePath>../../spring-boot-dependencies</relativePath>
</parent>
<artifactId>spring-boot-starter-parent</artifactId>
<packaging>pom</packaging>
<name>Spring Boot Starter Parent</name>
<description>Parent pom providing dependency and plugin management for applications
built with Maven</description>
<url>http://projects.spring.io/spring-boot/</url>
<organization>
<name>Pivotal Software, Inc.</name>
<url>http://www.spring.io</url>
</organization>
<properties>
<java.version>1.6</java.version>
<resource.delimiter>#</resource.delimiter> <!-- delimiter that doesn't clash with Spring ${} placeholders -->
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<maven.compiler.source>${java.version}</maven.compiler.source>
<maven.compiler.target>${java.version}</maven.compiler.target>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
<exclusions>
<exclusion>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<!-- Turn on filtering by default for application properties -->
<resources>
<resource>
<directory>${basedir}/src/main/resources</directory>
<filtering>true</filtering>
<includes>
<include>**/application*.yml</include>
<include>**/application*.yaml</include>
<include>**/application*.properties</include>
</includes>
</resource>
<resource>
<directory>${basedir}/src/main/resources</directory>
<excludes>
<exclude>**/application*.yml</exclude>
<exclude>**/application*.yaml</exclude>
<exclude>**/application*.properties</exclude>
</excludes>
</resource>
</resources>
<pluginManagement>
<plugins>
<!-- Apply more sensible defaults for user projects -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-failsafe-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>integration-test</goal>
<goal>verify</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>${start-class}</mainClass>
<addDefaultImplementationEntries>true</addDefaultImplementationEntries>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<configuration>
<includes>
<include>**/*Tests.java</include>
<include>**/*Test.java</include>
</includes>
<excludes>
<exclude>**/Abstract*.java</exclude>
</excludes>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
<archive>
<manifest>
<mainClass>${start-class}</mainClass>
<addDefaultImplementationEntries>true</addDefaultImplementationEntries>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<configuration>
<mainClass>${start-class}</mainClass>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>2.6</version>
<configuration>
<delimiters>
<delimiter>${resource.delimiter}</delimiter>
</delimiters>
<useDefaultDelimiters>false</useDefaultDelimiters>
</configuration>
</plugin>
<plugin>
<groupId>pl.project13.maven</groupId>
<artifactId>git-commit-id-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>revision</goal>
</goals>
</execution>
</executions>
<configuration>
<verbose>true</verbose>
<dateFormat>yyyy-MM-dd'T'HH:mm:ssZ</dateFormat>
<generateGitPropertiesFile>true</generateGitPropertiesFile>
<generateGitPropertiesFilename>${project.build.outputDirectory}/git.properties</generateGitPropertiesFilename>
</configuration>
</plugin>
<!-- Support our own plugin -->
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
<configuration>
<mainClass>${start-class}</mainClass>
</configuration>
</plugin>
<!-- Support shade packaging (if the user does not want to use our plugin) -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>1.5.6.RELEASE</version>
</dependency>
</dependencies>
<configuration>
<keepDependenciesWithProvidedScope>true</keepDependenciesWithProvidedScope>
<createDependencyReducedPom>true</createDependencyReducedPom>
<filters>
<filter>
<artifact>*:*</artifact>
<excludes>
<exclude>META-INF/*.SF</exclude>
<exclude>META-INF/*.DSA</exclude>
<exclude>META-INF/*.RSA</exclude>
</excludes>
</filter>
</filters>
</configuration>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<transformers>
<transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
<resource>META-INF/spring.handlers</resource>
</transformer>
<transformer implementation="org.springframework.boot.maven.PropertiesMergingResourceTransformer">
<resource>META-INF/spring.factories</resource>
</transformer>
<transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
<resource>META-INF/spring.schemas</resource>
</transformer>
<transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
<transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
<mainClass>${start-class}</mainClass>
</transformer>
</transformers>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
you can see it setup spring-core, application properties and another common required plugins, which is basically required in any spring application,
If you don't want this default stuff then no need to add starter parent. (It totally depends on your application, if you don't required them just leave it, but if you required them you don't want to suffer to your self manage all stuff your own, stater parent pom is best friend for it )

Answer 2

You include spring-boot-starter-parent as parent and spring-boot-starter-web as dependency;
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.0.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
The Spring Boot Quick Start cannot be more clearer how to get started with Maven. Did you read it?
https://projects.spring.io/spring-boot/#quick-start
Also the Getting Started documentation section provides a complete starting pom.xml for web app.
<?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>myproject</artifactId>
<version>0.0.1-SNAPSHOT</version>
<!-- Inherit defaults from Spring Boot -->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.0.RELEASE</version>
</parent>
<!-- Add typical dependencies for a web application -->
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<!-- Package as an executable jar -->
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>