Package net.sourceforge.pmd.lang.java.types

Class TypesFromReflection

  • public final class TypesFromReflection
extends Object
    Builds type mirrors from Type instances.

    This is intended as a public API to help rules build types.

    • Method Detail

      • fromReflect

        public static JTypeMirror fromReflect​(org.apache.commons.lang3.reflect.Typed<?> reflected,
                                      TypeSystem ts)
        Builds a type from reflection. This overload expects a ground type, ie it will fail if the given type mentions type variables. This can be used to get a type quickly, eg: 
        

 // note the anonymous class body
 JTypeMirror streamOfInt = fromReflect(new TypeLiteral<Stream<Integer>>() {}, node.getTypeSystem());

 if (node.getTypeMirror().equals(streamOfInt))
   addViolation(node, "Use IntStream instead of Stream<Integer>");

 // going the long way:
 TypeSystem ts = node.getTypeSystem();
 JTypeMirror streamOfInt = ts.typeOf(ts.getClassSymbol(Stream.class), false)
                             .withTypeParameters(listOf(ts.INT.box()));
        Parameters:
        ts - Type system that will build the type
        reflected - A Typed instance, eg a TypeLiteral.
        Throws:
        IllegalArgumentException - If the given type mentions type variables
        NullPointerException - If the type, or the type system, are null

      • fromReflect

        public static @Nullable JTypeMirror fromReflect​(TypeSystem ts,
                                                @NonNull Type reflected,
                                                LexicalScope lexicalScope,
                                                Substitution subst)
        Builds a type from reflection. This takes care of preserving the identity of type variables.
        Parameters:
        ts - Type system
        reflected - A type instance obtained from reflection
        lexicalScope - An index for the in-scope type variables. All type variables occurring in the type must be referenced.
        subst - Substitution to apply to tvars
        Returns:
        A type, or null if the type system's symbol resolver cannot map the types to its own representation
        Throws:
        IllegalArgumentException - If there are free type variables in the type. Any type variable should be accessible in the lexical scope parameter.
        NullPointerException - If any parameter is null

      • loadType

        public static @Nullable JTypeMirror loadType​(TypeSystem ctr,
                                             String className)
        Load a class. Supports loading array types like 'java.lang.String[]' and converting a canonical name to a binary name (eg 'java.util.Map.Entry' -> 'java.util.Map$Entry').

      • loadType

        public static @Nullable JTypeMirror loadType​(TypeSystem ctr,
                                             String className,
                                             net.sourceforge.pmd.lang.java.symbols.internal.UnresolvedClassStore unresolvedStore)
        Load a class. Supports loading array types like 'java.lang.String[]' and converting a canonical name to a binary name (eg 'java.util.Map.Entry' -> 'java.util.Map$Entry'). Types that are not on the classpath may be replaced by placeholder types if the UnresolvedClassStore parameter is non-null.