public Type getComponentType() {
    if (componentType == null) {
      if (descriptor.charAt(0) != '[') {
        throw new IllegalArgumentException("not an array type: " + descriptor);
      }
      componentType = intern(descriptor.substring(1));
    }

    return componentType;
  }
Gets the component type of this type. This method is only valid on array types.

@return {@code non-null;} the component type
android/android_framework/dex-maker/src/main/java/com/android/dx/rop/type/Type.java