pom.xml

...
<build>
  <plugins>
    ...
    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-source-plugin</artifactId>
        <version>3.0.1</version>
        <executions>
            <execution>
                <id>attach-sources</id>
                <goals>
                    <goal>jar</goal>
                </goals>
            </execution>
        </executions>
    </plugin>
    ...
  </plugins>
</build>
...
<profiles>
  <profile>
    <id>release</id>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-javadoc-plugin</artifactId>
                <version>2.10.4</version>
                <executions>
                    <execution>
                        <id>attach-javadocs</id>
                        <goals>
                            <goal>jar</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-gpg-plugin</artifactId>
                <version>1.5</version>
                <executions>
                    <execution>
                        <id>sign-artifacts</id>
                        <phase>verify</phase>
                          <goals>
                              <goal>sign</goal>
                          </goals>
                      </execution>
                  </executions>
              </plugin>
              <plugin>
                  <groupId>org.sonatype.plugins</groupId>
                  <artifactId>nexus-staging-maven-plugin</artifactId>
                  <version>1.6.7</version>
                  <extensions>true</extensions>
                  <configuration>
                      <serverId>ossrh</serverId>
                      <nexusUrl>https://oss.sonatype.org/</nexusUrl>
                      <autoReleaseAfterClose>true</autoReleaseAfterClose>
                  </configuration>
              </plugin>
          </plugins>
      </build>
  </profile>
</profiles>
...