MethodAPI.java

package xxx;

import static xxx.Section.PHOTOS;
import static xxx.Section.WALL;

public enum MethodAPI {
  WALL_POST(WALL, "post"),
  WALL_POST_EDIT(WALL, "edit"),
  PHOTOS_UPLOAD_WALL(PHOTOS, "setWallUploadServer"),
  PHOTOS_SAVE_WALL(PHOTOS, "saveWallPhoto");

  private final Section section;
  private final String methodName;

  MethodAPI(Section section, String methodName) {
    this.section = section;
    this.methodName = methodName;
  }

  public String getMethod() {
    return String.join(".", section.getName(), methodName);
  }
}

Secion.java

package xxx;

public enum Section {
  WALL("wall"),
  PHOTOS("photos");

  private final String name;

  Section(String name) {
    this.name = name;
  }

  public String getName() {
    return name;
  }
}