CmdLineProcessor.java 文件源码

@Nullable
private TypeMirror getTypeArgument(TypeMirror annotatedType, final TypeElement baseType) {
  for (TypeMirror type : getAllTypes(annotatedType)) {
    TypeMirror typeArgument = type.accept(new SimpleTypeVisitor6<TypeMirror, Void>() {
      @Override public TypeMirror visitDeclared(DeclaredType t, Void aVoid) {
        if (isAssignable(t, baseType)) {
          List<? extends TypeMirror> typeArguments = t.getTypeArguments();
          if (!typeArguments.isEmpty()) {
            return typeUtils.erasure(typeArguments.get(0));
          }
        }
        return null;
      }
    }, null);

    if (typeArgument != null) {
      return typeArgument;
    }
  }
  error("Failed to find a type argument for %s in %s", baseType, annotatedType);
  return null;
}