Java Code Examples for javax.lang.model.element.TypeParameterElement#getBounds()

/**
 * Make a TypeVariableName for the given TypeMirror. This form is used internally to avoid
 * infinite recursion in cases like {@code Enum<E extends Enum<E>>}. When we encounter such a
 * thing, we will make a TypeVariableName without bounds and add that to the {@code typeVariables}
 * map before looking up the bounds. Then if we encounter this TypeVariable again while
 * constructing the bounds, we can just return it from the map. And, the code that put the entry
 * in {@code variables} will make sure that the bounds are filled in before returning.
 */
static TypeVariableName get(
    TypeVariable mirror, Map<TypeParameterElement, TypeVariableName> typeVariables) {
  TypeParameterElement element = (TypeParameterElement) mirror.asElement();
  TypeVariableName typeVariableName = typeVariables.get(element);
  if (typeVariableName == null) {
    // Since the bounds field is public, we need to make it an unmodifiableList. But we control
    // the List that that wraps, which means we can change it before returning.
    List<TypeName> bounds = new ArrayList<>();
    List<TypeName> visibleBounds = Collections.unmodifiableList(bounds);
    typeVariableName = new TypeVariableName(element.getSimpleName().toString(), visibleBounds);
    typeVariables.put(element, typeVariableName);
    for (TypeMirror typeMirror : element.getBounds()) {
      bounds.add(TypeName.get(typeMirror, typeVariables));
    }
    bounds.remove(OBJECT);
  }
  return typeVariableName;
}
 

/**
 * The type parameters to place on the builder, with the "extends ..." bounds.
 */
String alligatorWithBounds() {
  List<TypeParameterElement> allParameters = allParameters();
  if (allParameters.isEmpty()) {
    return "";
  }

  StringBuilder alligator = new StringBuilder("<");
  String separator = "";
  for (TypeParameterElement param : allParameters) {
    alligator.append(separator);
    separator = ", ";
    alligator.append(param.toString());
    for (TypeMirror bound : param.getBounds()) {
      alligator.append(" extends ").append(bound);
    }
  }
  return alligator.append(">").toString();
}
 

@Test
public void testMultipleTypeParameters() throws IOException {
  compile("class Foo<T, U extends java.lang.CharSequence> { }");

  TypeMirror objectType = elements.getTypeElement("java.lang.Object").asType();
  TypeMirror charSequenceType = elements.getTypeElement("java.lang.CharSequence").asType();

  TypeElement fooElement = elements.getTypeElement("Foo");
  List<? extends TypeParameterElement> typeParameters = fooElement.getTypeParameters();
  assertSame(2, typeParameters.size());

  TypeParameterElement tParam = typeParameters.get(0);
  List<? extends TypeMirror> bounds = tParam.getBounds();
  assertSame(1, bounds.size());
  assertSameType(objectType, bounds.get(0));

  TypeParameterElement uParam = typeParameters.get(1);
  bounds = uParam.getBounds();
  assertSame(1, bounds.size());
  assertSameType(charSequenceType, bounds.get(0));
}
 

private Map<TypeParameterElement, TypeMirror> getChildInstanceOfClassFromGeneric(final TypeElement typeElement, final Class<?> aClass) {
	Map<TypeParameterElement, TypeMirror> result = new HashMap<>();
	for (TypeParameterElement element : typeElement.getTypeParameters()) {
		List<? extends TypeMirror> bounds = element.getBounds();
		for (TypeMirror bound : bounds) {
			if (bound instanceof DeclaredType && ((DeclaredType) bound).asElement() instanceof TypeElement) {
				Collection<TypeMirror> viewsType = getViewsType((TypeElement) ((DeclaredType) bound).asElement());
				boolean isViewType = false;
				for (TypeMirror viewType : viewsType) {
					if (((DeclaredType) viewType).asElement().toString().equals(aClass.getCanonicalName())) {
						isViewType = true;
					}
				}

				if (isViewType) {
					result.put(element, bound);
					break;
				}
			}
		}
	}

	return result;
}
 

/**
 * FormalTypeParameter ::= Ident ClassBound {InterfaceBound}.
 */
private void genFormalTypeParameter(TypeParameterElement typeParam, StringBuilder sb) {
  sb.append(ElementUtil.getName(typeParam));
  List<? extends TypeMirror> bounds = typeParam.getBounds();
  if (bounds.isEmpty()) {
    sb.append(':').append(JAVA_OBJECT_SIGNATURE);
  } else {
    if (TypeUtil.isInterface(bounds.get(0))) {
      sb.append(':');
    }
    for (TypeMirror bound : bounds) {
      sb.append(':');
      genTypeSignature(bound, sb);
    }
  }
}
 

/**
 * Make a TypeVariableName for the given TypeMirror. This form is used internally to avoid
 * infinite recursion in cases like {@code Enum<E extends Enum<E>>}. When we encounter such a
 * thing, we will make a TypeVariableName without bounds and add that to the {@code typeVariables}
 * map before looking up the bounds. Then if we encounter this TypeVariable again while
 * constructing the bounds, we can just return it from the map. And, the code that put the entry
 * in {@code variables} will make sure that the bounds are filled in before returning.
 */
static TypeVariableName get(
    TypeVariable mirror, Map<TypeParameterElement, TypeVariableName> typeVariables) {
  TypeParameterElement element = (TypeParameterElement) mirror.asElement();
  TypeVariableName typeVariableName = typeVariables.get(element);
  if (typeVariableName == null) {
    // Since the bounds field is public, we need to make it an unmodifiableList. But we control
    // the List that that wraps, which means we can change it before returning.
    List<TypeName> bounds = new ArrayList<>();
    List<TypeName> visibleBounds = Collections.unmodifiableList(bounds);
    typeVariableName = new TypeVariableName(element.getSimpleName().toString(), visibleBounds);
    typeVariables.put(element, typeVariableName);
    for (TypeMirror typeMirror : element.getBounds()) {
      bounds.add(TypeName.get(typeMirror, typeVariables));
    }
    bounds.remove(OBJECT);
  }
  return typeVariableName;
}
 

/** Returns type variable equivalent to {@code element}. */
public static TypeVariableName get(TypeParameterElement element) {
  String name = element.getSimpleName().toString();
  List<? extends TypeMirror> boundsMirrors = element.getBounds();

  List<TypeName> boundsTypeNames = new ArrayList<>();
  for (TypeMirror typeMirror : boundsMirrors) {
    boundsTypeNames.add(TypeName.get(typeMirror));
  }

  return TypeVariableName.of(name, boundsTypeNames);
}
 

@Test
public void testUnboundedTypeParameter() throws IOException {
  compile("class Foo<T> { }");

  TypeElement fooElement = elements.getTypeElement("Foo");
  TypeMirror objectType = elements.getTypeElement("java.lang.Object").asType();
  List<? extends TypeParameterElement> typeParameters = fooElement.getTypeParameters();

  assertSame(1, typeParameters.size());
  TypeParameterElement typeParam = typeParameters.get(0);
  List<? extends TypeMirror> bounds = typeParam.getBounds();

  assertSame(1, bounds.size());
  assertSameType(objectType, bounds.get(0));
}
 

void validateInheritedEntityListener(
    TypeElement classElement, EntityMeta entityMeta, TypeElement inheritedListenerElement) {
  EntityAnnot entityAnnot = entityMeta.getEntityAnnot();
  List<? extends TypeParameterElement> typeParams =
      inheritedListenerElement.getTypeParameters();
  if (typeParams.size() == 0) {
    throw new AptException(
        Message.DOMA4230,
        classElement,
        entityAnnot.getAnnotationMirror(),
        new Object[] {
          inheritedListenerElement.getQualifiedName(), classElement.getQualifiedName()
        });
  }
  TypeParameterElement typeParam = typeParams.get(0);
  for (TypeMirror bound : typeParam.getBounds()) {
    if (!ctx.getMoreTypes().isAssignableWithErasure(classElement.asType(), bound)) {
      throw new AptException(
          Message.DOMA4231,
          classElement,
          entityAnnot.getAnnotationMirror(),
          new Object[] {
            inheritedListenerElement.getQualifiedName(),
            typeParam.getSimpleName(),
            bound,
            classElement.getQualifiedName()
          });
    }
  }
}
 

private List<Type.Defined> getBounds(Type.Parameters parameters, TypeParameterElement p) {
  List<Type.Defined> bounds = new ArrayList<>();
  for (TypeMirror b : p.getBounds()) {
    bounds.add((Type.Defined) b.accept(converter, parameters));
  }
  return bounds;
}
 

void validateGenericEntityListener(
    TypeElement classElement, EntityMeta entityMeta, TypeElement listenerElement) {
  EntityAnnot entityAnnot = entityMeta.getEntityAnnot();
  List<? extends TypeParameterElement> typeParams = listenerElement.getTypeParameters();
  if (typeParams.size() == 0) {
    throw new AptIllegalStateException("typeParams size should be more than 0");
  }
  if (typeParams.size() > 1) {
    throw new AptException(
        Message.DOMA4227,
        classElement,
        entityAnnot.getAnnotationMirror(),
        entityAnnot.getListener(),
        new Object[] {});
  }
  TypeParameterElement typeParam = typeParams.get(0);
  for (TypeMirror bound : typeParam.getBounds()) {
    if (!ctx.getMoreTypes().isAssignableWithErasure(classElement.asType(), bound)) {
      throw new AptException(
          Message.DOMA4229,
          classElement,
          entityAnnot.getAnnotationMirror(),
          entityAnnot.getListener(),
          new Object[] {typeParam.getSimpleName(), bound, classElement.getQualifiedName()});
    }
  }
  if (findListenerTypeParam(listenerElement, 0) == null) {
    throw new AptException(
        Message.DOMA4228,
        classElement,
        entityAnnot.getAnnotationMirror(),
        entityAnnot.getListener(),
        new Object[] {typeParam.getSimpleName()});
  }
}
 

@Override
public Integer visitTypeVariable(TypeVariable t, Set<Element> visiting) {
  int result = hashKind(HASH_SEED, t);
  result *= HASH_MULTIPLIER;
  result += t.getLowerBound().accept(this, visiting);
  TypeParameterElement element = (TypeParameterElement) t.asElement();
  for (TypeMirror bound : element.getBounds()) {
    result *= HASH_MULTIPLIER;
    result += bound.accept(this, visiting);
  }
  return result;
}
 

private void appendTypeParameterWithBounds(StringBuilder sb, TypeParameterElement typeParameter) {
  sb.append(typeParameter.getSimpleName());
  String sep = " extends ";
  for (TypeMirror bound : typeParameter.getBounds()) {
    if (!bound.toString().equals("java.lang.Object")) {
      sb.append(sep);
      sep = " & ";
      bound.accept(TO_STRING_TYPE_VISITOR, sb);
    }
  }
}
 

public List<? extends TypeMirror> getBounds(TypeParameterElement tpe) {
    List<? extends TypeMirror> bounds = tpe.getBounds();
    if (!bounds.isEmpty()) {
        TypeMirror upperBound = bounds.get(bounds.size() - 1);
        if (ignoreBounds(upperBound)) {
            return Collections.emptyList();
        }
    }
    return bounds;
}
 

public TypeParamDef apply(TypeParameterElement item) {
    List<ClassRef> typeRefs = new ArrayList();

    for (TypeMirror typeMirror : item.getBounds()) {
        //TODO: Fix this
        //typeRefs.add(toTypeRef.apply(typeMirror));
    }

    return new TypeParamDefBuilder()
            .withName(item.getSimpleName().toString())
            .withBounds(typeRefs)
            .build();
}
 

private void appendTypeParameterWithBounds(StringBuilder sb, TypeParameterElement typeParameter) {
  sb.append(typeParameter.getSimpleName());
  String sep = " extends ";
  for (TypeMirror bound : typeParameter.getBounds()) {
    if (!bound.toString().equals("java.lang.Object")) {
      sb.append(sep);
      sep = " & ";
      bound.accept(TO_STRING_TYPE_VISITOR, sb);
    }
  }
}
 

private static String createHtmlHeader(boolean deprecated, TypeElement e) {
    StringBuilder sb = new StringBuilder();
    sb.append("<html>");
    if (deprecated) sb.append("<s>");
    sb.append(e.getSimpleName());
    if (deprecated) sb.append("</s>");
    List<? extends TypeParameterElement> typeParams = e.getTypeParameters();
    if (typeParams != null && !typeParams.isEmpty()) {
        sb.append("&lt;"); // NOI18N
        for(Iterator<? extends TypeParameterElement> it = typeParams.iterator(); it.hasNext();) {
            TypeParameterElement tp = it.next();
            sb.append(tp.getSimpleName());
            try {
                List<? extends TypeMirror> bounds = tp.getBounds();
                if (!bounds.isEmpty()) {
                    sb.append(translateToHTML(printBounds(bounds)));
                }
            }
            catch (NullPointerException npe) {
            }                    
            if (it.hasNext()) {
                sb.append(", "); // NOI18N
            }
        }
        sb.append("&gt;"); // NOI18N
    }
    return sb.toString();
}
 

private static void appendTypeParameterWithBounds(
    TypeParameterElement typeParameter, StringBuilder sb) {
  appendAnnotations(typeParameter.getAnnotationMirrors(), sb);
  sb.append(typeParameter.getSimpleName());
  String sep = " extends ";
  for (TypeMirror bound : typeParameter.getBounds()) {
    if (!isUnannotatedJavaLangObject(bound)) {
      sb.append(sep);
      sep = " & ";
      sb.append(encodeWithAnnotations(bound));
    }
  }
}
 

/**
 * Returns a representation of the given {@code @RetroWeibo.Builder} class or interface. If the
 * class or interface has abstract methods that could not be part of any builder, emits error
 * messages and returns null.
 */
private Optional<Builder> builderFrom(
    TypeElement builderTypeElement, Optional<ExecutableElement> validateMethod) {

  // We require the builder to have the same type parameters as the @RetroWeibo class, meaning the
  // same names and bounds. In principle the type parameters could have different names, but that
  // would be confusing, and our code would reject it anyway because it wouldn't consider that
  // the return type of Foo<U> build() was really the same as the declaration of Foo<T>. This
  // check produces a better error message in that case and similar ones.

  boolean ok = true;
  int nTypeParameters = autoValueClass.getTypeParameters().size();
  if (nTypeParameters != builderTypeElement.getTypeParameters().size()) {
    ok = false;
  } else {
    for (int i = 0; i < nTypeParameters; i++) {
      TypeParameterElement autoValueParam = autoValueClass.getTypeParameters().get(i);
      TypeParameterElement builderParam = builderTypeElement.getTypeParameters().get(i);
      if (!autoValueParam.getSimpleName().equals(builderParam.getSimpleName())) {
        ok = false;
        break;
      }
      Set<TypeMirror> autoValueBounds = new TypeMirrorSet(autoValueParam.getBounds());
      Set<TypeMirror> builderBounds = new TypeMirrorSet(builderParam.getBounds());
      if (!autoValueBounds.equals(builderBounds)) {
        ok = false;
        break;
      }
    }
  }
  if (!ok) {
    errorReporter.reportError(
        "Type parameters of " + builderTypeElement + " must have same names and bounds as "
            + "type parameters of " + autoValueClass, builderTypeElement);
    return Optional.absent();
  }

  String typeParams = TypeSimplifier.actualTypeParametersString(autoValueClass);

  List<ExecutableElement> buildMethods = new ArrayList<ExecutableElement>();
  List<ExecutableElement> setterMethods = new ArrayList<ExecutableElement>();
  // For each abstract method (in builderTypeElement or inherited), check that it is either
  // a setter method or a build method. A setter method has one argument and returns
  // builderTypeElement. A build method has no arguments and returns the @RetroWeibo class.
  // Record each method in one of the two lists.
  for (ExecutableElement method : abstractMethods(builderTypeElement)) {
    boolean thisOk = false;
    int nParameters = method.getParameters().size();
    if (nParameters == 0
        && TYPE_EQUIVALENCE.equivalent(method.getReturnType(), autoValueClass.asType())) {
      buildMethods.add(method);
      thisOk = true;
    } else if (nParameters == 1
        && TYPE_EQUIVALENCE.equivalent(method.getReturnType(), builderTypeElement.asType())) {
      setterMethods.add(method);
      thisOk = true;
    }
    if (!thisOk) {
      errorReporter.reportError(
          "Builder methods must either have no arguments and return "
              + autoValueClass + typeParams + " or have one argument and return "
              + builderTypeElement + typeParams,
          method);
      ok = false;
    }
  }
  if (buildMethods.isEmpty()) {
    errorReporter.reportError(
        "Builder must have a single no-argument method returning "
            + autoValueClass + typeParams,
        builderTypeElement);
    ok = false;
  } else if (buildMethods.size() > 1) {
    // More than one eligible build method. Emit an error for each one, that is attached to
    // that build method.
    for (ExecutableElement buildMethod : buildMethods) {
      errorReporter.reportError(
          "Builder must have a single no-argument method returning "
              + autoValueClass + typeParams,
          buildMethod);
    }
    ok = false;
  }

  if (ok) {
    return Optional.of(new Builder(
        builderTypeElement,
        Iterables.getOnlyElement(buildMethods),
        setterMethods,
        validateMethod));
  } else {
    return Optional.absent();
  }
}
 

private String createHtmlHeader(CompilationInfo info, TypeElement e, boolean isDeprecated, boolean isInherited, boolean fqn) {

        StringBuilder sb = new StringBuilder();            
        if ( isDeprecated ) {
            sb.append("<s>"); // NOI18N
        }
        if( isInherited ) {
            sb.append( "<font color=" + ui.getInheritedColor() + ">" ); // NOI18N
        }
        sb.append(Utils.escape(
            fqn?
            e.getQualifiedName().toString():
            e.getSimpleName().toString()));
        if ( isDeprecated ) {
            sb.append("</s>"); // NOI18N
        }
        // sb.append(print(info, e.asType()));
        List<? extends TypeParameterElement> typeParams = e.getTypeParameters();

        //System.out.println("Element " + e + "type params" + typeParams.size() );

        if ( typeParams != null && !typeParams.isEmpty() ) {
            sb.append("&lt;"); // NOI18N

            for( Iterator<? extends TypeParameterElement> it = typeParams.iterator(); it.hasNext(); ) {
                TypeParameterElement tp = it.next();
                sb.append( Utils.escape(tp.getSimpleName().toString()) );                    
                try { // XXX Verry ugly -> file a bug against Javac?
                    List<? extends TypeMirror> bounds = tp.getBounds();
                    //System.out.println( tp.getSimpleName() + "   bounds size " + bounds.size() );
                    if ( !bounds.isEmpty() ) {
                        sb.append(printBounds(info, bounds, fqn));
                    }
                }
                catch ( NullPointerException npe ) {
                    System.err.println("El " + e );
                    npe.printStackTrace();
                }                    
                if ( it.hasNext() ) {
                    sb.append(", "); // NOI18N
                }
            }

            sb.append("&gt;"); // NOI18N
        }

        // Add superclass and implemented interfaces

        TypeMirror sc = e.getSuperclass();
        String scName = print(info, sc, fqn);

        if ( sc == null || 
             e.getKind() == ElementKind.ENUM ||
             e.getKind() == ElementKind.ANNOTATION_TYPE ||
             "Object".equals(scName) || // NOI18N
             "<none>".equals(scName)) { // NOI18N
            scName = null;
        }

        List<? extends TypeMirror> ifaces = e.getInterfaces();

        if ( ( scName != null || !ifaces.isEmpty() ) &&
              e.getKind() != ElementKind.ANNOTATION_TYPE ) {
            sb.append( " :: " ); // NOI18N
            if (scName != null) {                
                sb.append( "<font color=" + ui.getTypeColor() + ">" ); // NOI18N
                sb.append( scName );
                sb.append("</font>"); // NOI18N
            }
            if ( !ifaces.isEmpty() ) {
                if ( scName != null ) {
                    sb.append( " : " ); // NOI18N
                }
                for (Iterator<? extends TypeMirror> it = ifaces.iterator(); it.hasNext();) {
                    TypeMirror typeMirror = it.next();
                    sb.append( "<font color=" + ui.getTypeColor() + ">" ); // NOI18N
                    sb.append( print(info, typeMirror, fqn) );
                    sb.append("</font>"); // NOI18N
                    if ( it.hasNext() ) {
                        sb.append(", "); // NOI18N
                    }
                }

            }
        }

        return sb.toString();            
    }