Erro ao criar um novo projeto(blog).

Aparentemente no diretório que você está executando o comando do maven (C:\Users\Jean\Desktop\Alura\Cursos Alura\Java\Java Maven), não há nenhum arquivo POM. Você precisa executar este comando no diretório ao qual o POM se encontra.

Não consigo encontrar esse arquivo . Quando tento compilar o projeto apresenta o seguinte aviso:

[WARNING] Using platform encoding (Cp1252 actually) to copy filtered resources, i.e. build is platform dependent!

Pode me ajudar a resolver isso? Não consigo compilar pelo cmder por conta desses errros.

Isso não seria o motivo do erro ao meu ver, pois é um WARNING do Maven. Você precisa criar um arquivo POM para conseguir compilar o seu projeto maven, pois é pelo arquivo que ele irá compilar baixando as dependências contidas nele.

Este é o código do pom mais básico (crie o arquivo pom.xml no diretorio e tenta executar o maven, depois me diz o que o cmd devolve pra vc):

<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.mycompany.app</groupId>
  <artifactId>my-app</artifactId>
  <version>1.0-SNAPSHOT</version>

  <properties>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>

Aprece o seguinte:

C:\Users\Jean\Desktop\Alura\Cursos Alura\Java\Java Maven\produtos
λ mvn archetype:generate -DartifactId=blog -DgroupId=br.com.alura.maven -Dinteractive Mode=false -DarchetypeArtifactId=maven-archetype-quickstart
[INFO] Scanning for projects...
[INFO]
[INFO] --------------------< br.com.alura.maven:produtos >---------------------
[INFO] Building produtos 1.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] >>> maven-archetype-plugin:3.0.1:generate (default-cli) > generate-sources @ produtos >>>
[INFO]
[INFO] <<< maven-archetype-plugin:3.0.1:generate (default-cli) < generate-sources @ produtos <<<
[INFO]
[INFO]
[INFO] --- maven-archetype-plugin:3.0.1:generate (default-cli) @ produtos ---
[INFO] Generating project in Interactive mode
[INFO] Using property: groupId = br.com.alura.maven
[INFO] Using property: artifactId = blog
Define value for property 'version' 1.0-SNAPSHOT: : 1.
[INFO] Using property: package = br.com.alura.maven
Confirm properties configuration:
groupId: br.com.alura.maven
artifactId: blog
version:

Se eu coloco versão pede:

[INFO] Using property: groupId = br.com.alura.maven
[INFO] Using property: artifactId = blog
Define value for property 'version' 1.0-SNAPSHOT: : 1
Define value for property 'package' br.com.alura.maven: : 1
Confirm properties configuration:
groupId: br.com.alura.maven
artifactId: blog
version: 1
package: 1
 Y: :

Fica repetindo as informações.

Preencha Y: : com y

Ele está apenas pedindo sua confirmação para terminar de criar. Acredito que esteja dando certo.

Apresentou outro erro agora

[INFO] ----------------------------------------------------------------------------
[INFO] Using following parameters for creating project from Old (1.x) Archetype: maven-archetype-quickstart:1.0
[INFO] ----------------------------------------------------------------------------
[INFO] Parameter: basedir, Value: C:\Users\Jean\Desktop\Alura\Cursos Alura\Java\Java Maven
[INFO] Parameter: package, Value: br.com.alura.maven
[INFO] Parameter: groupId, Value: br.com.alura.maven
[INFO] Parameter: artifactId, Value: blog
[INFO] Parameter: packageName, Value: br.com.alura.maven
[INFO] Parameter: version, Value: 1
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Skipping my-app
[INFO] This project has been banned from the build due to previous failures.
[INFO] ------------------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  29.406 s
[INFO] Finished at: 2019-02-20T21:54:55-03:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-archetype-plugin:3.0.1:generate (default-cli) on project my-app: Unable to add module to the current project as it is not of packaging type 'pom' -> [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

Antes da tag

 </project>

adicione

<packaging>pom</packaging> 

Deu erro porque coloquei a tag packaging.

C:\Users\Jean\Desktop\Alura\Cursos Alura\Java\Java Maven
λ mvn archetype:generate -DartifactId=blog -DgroupId=br.com.alura.maven -Dinteractive Mode=false -DarchetypeArtifactId=maven-archetype-quickstart
[INFO] Scanning for projects...
[ERROR] [ERROR] Some problems were encountered while processing the POMs:
[FATAL] Non-parseable POM C:\Users\Jean\Desktop\Alura\Cursos Alura\Java\Java Maven\pom.xml: Expected root element 'project' but found 'packaging' (position: START_TAG seen <packaging>... @1:11)  @ line 1, column 11
 @
[ERROR] The build could not read 1 project -> [Help 1]
[ERROR]
[ERROR]   The project  (C:\Users\Jean\Desktop\Alura\Cursos Alura\Java\Java Maven\pom.xml) has 1 error
[ERROR]     Non-parseable POM C:\Users\Jean\Desktop\Alura\Cursos Alura\Java\Java Maven\pom.xml: Expected root element 'project' but found 'packaging' (position: START_TAG seen <packaging>... @1:11)  @ line 1, column 11 -> [Help 2]
[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/ProjectBuildingException
[ERROR] [Help 2] http://cwiki.apache.org/confluence/display/MAVEN/ModelParseException

Talvez vc tenha colocado essa tag fora do project... tenta colocar nessa estrutura aqui, por favor:

<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.mycompany.app</groupId>
  <artifactId>my-app</artifactId>
  <version>1.0-SNAPSHOT</version>

  <properties>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
<packaging>pom</packaging> 
</project>

É um erro atrás do outro, vou tentar esvaziar a pasta .m2/repository pra ver se da certo.

C:\Users\Jean\Desktop\Alura\Cursos Alura\Java\Java Maven
λ mvn archetype:generate -DartifactId=blog -DgroupId=br.com.alura.maven -Dinteractive Mode=false -DarchetypeArtifactId=maven-archetype-quickstart
[INFO] Scanning for projects...
[INFO]
[INFO] ----------------------< com.mycompany.app:my-app >----------------------
[INFO] Building my-app 1.0-SNAPSHOT
[INFO] --------------------------------[ pom ]---------------------------------
[INFO]
[INFO] >>> maven-archetype-plugin:3.0.1:generate (default-cli) > generate-sources @ my-app >>>
[INFO]
[INFO] <<< maven-archetype-plugin:3.0.1:generate (default-cli) < generate-sources @ my-app <<<
[INFO]
[INFO]
[INFO] --- maven-archetype-plugin:3.0.1:generate (default-cli) @ my-app ---
[INFO] Generating project in Interactive mode
[INFO] Using property: groupId = br.com.alura.maven
[INFO] Using property: artifactId = blog
Define value for property 'version' 1.0-SNAPSHOT: : 1
[INFO] Using property: package = br.com.alura.maven
Confirm properties configuration:
groupId: br.com.alura.maven
artifactId: blog
version: 1
package: br.com.alura.maven
 Y: : y
[INFO] ----------------------------------------------------------------------------
[INFO] Using following parameters for creating project from Old (1.x) Archetype: maven-archetype-quickstart:1.0
[INFO] ----------------------------------------------------------------------------
[INFO] Parameter: basedir, Value: C:\Users\Jean\Desktop\Alura\Cursos Alura\Java\Java Maven
[INFO] Parameter: package, Value: br.com.alura.maven
[INFO] Parameter: groupId, Value: br.com.alura.maven
[INFO] Parameter: artifactId, Value: blog
[INFO] Parameter: packageName, Value: br.com.alura.maven
[INFO] Parameter: version, Value: 1
[INFO] project created from Old (1.x) Archetype in dir: C:\Users\Jean\Desktop\Alura\Cursos Alura\Java\Java Maven\blog
[INFO]
[INFO] ----------------------< com.mycompany.app:my-app >----------------------
[INFO] Building my-app 1.0-SNAPSHOT
[INFO] --------------------------------[ pom ]---------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  44.930 s
[INFO] Finished at: 2019-02-20T22:11:30-03:00
[INFO] ------------------------------------------------------------------------
[ERROR] Unknown lifecycle phase "Mode=false". You must specify a valid lifecycle phase or a goal in the format <plugin-prefix>:<goal> or <plugin-group-id>:<plugin-artifact-id>[:<plugin-version>]:<goal>. Available lifecycle phases are: validate, initialize, generate-sources, process-sources, generate-resources, process-resources, compile, process-classes, generate-test-sources, process-test-sources, generate-test-resources, process-test-resources, test-compile, process-test-classes, test, prepare-package, package, pre-integration-test, integration-test, post-integration-test, verify, install, deploy, pre-clean, clean, post-clean, pre-site, site, post-site, site-deploy. -> [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/LifecyclePhaseNotFoundException

Consegui resolver.

Primeiro inseri o comando abaixo na pasta do projeto

mvn clean verify

Depois:

mvn install

Assim consegui criar o projeto.

Obrigado pela ajuda Raquel Natali Mariz!

De nada, fico feliz por vc ter conseguido. :)