refactor: code inspection: 'size() == 0' replaceable with 'isEmpty()'

src/main/java/spoon/MavenLauncher.java

@@ -514,12 +514,12 @@ class RangeVersion {
 				includeStart = range.startsWith("[");
 				includeEnd = range.endsWith("]");
 				String[] splitRange = range.substring(1, range.length() - 1).split(",");
-				if (splitRange[0].length() == 0) {
+				if (splitRange[0].isEmpty()) {
 					start = new Version("0.0.0.0");
 				} else {
 					start = new Version(splitRange[0]);
 				}
-				if (splitRange.length == 1 || splitRange[1].length() == 0) {
+				if (splitRange.length == 1 || splitRange[1].isEmpty()) {
 					end = new Version("99999999.9999999.999999.99999");
 				} else {
 					end = new Version(splitRange[1]);

src/main/java/spoon/compiler/builder/SourceOptions.java

@@ -50,7 +50,7 @@ public T sources(String... sources) {
 
 	/** adds the given {@link spoon.compiler.SpoonFile} as sources */
 	public T sources(List<SpoonFile> sources) {
-		if (sources == null || sources.size() == 0) {
+		if (sources == null || sources.isEmpty()) {
 			args.add(".");
 			return myself;
 		}

src/main/java/spoon/metamodel/MMMethodKind.java

@@ -31,7 +31,7 @@ public enum MMMethodKind {
 	 * Getter.
 	 * T get()
 	 */
-	GET(-1, false, 1, m -> m.getParameters().size() == 0  && (m.getSimpleName().startsWith("get") || m.getSimpleName().startsWith("is"))),
+	GET(-1, false, 1, m -> m.getParameters().isEmpty() && (m.getSimpleName().startsWith("get") || m.getSimpleName().startsWith("is"))),
 	/**
 	 * Setter
 	 * void set(T)

src/main/java/spoon/metamodel/MetamodelProperty.java

@@ -256,7 +256,7 @@ public CtTypeReference<?> getTypeofItems() {
 
 	public MMMethod getMethod(MMMethodKind kind) {
 		List<MMMethod> ms = getMethods(kind);
-		return ms.size() > 0 ? ms.get(0) : null;
+		return !ms.isEmpty() ? ms.get(0) : null;
 	}
 
 	public List<MMMethod> getMethods(MMMethodKind kind) {
@@ -297,7 +297,7 @@ void sortByBestMatch(MMMethodKind key) {
 	 */
 	private int getIdxOfBestMatch(List<MMMethod> methods, MMMethodKind key) {
 		MMMethod mmMethod = methods.get(0);
-		if (mmMethod.getActualCtMethod().getParameters().size() == 0) {
+		if (mmMethod.getActualCtMethod().getParameters().isEmpty()) {
 			return getIdxOfBestMatchByReturnType(methods, key);
 		} else {
 			MMMethod mmGetMethod = getMethod(MMMethodKind.GET);
@@ -540,7 +540,7 @@ public String toString() {
 	 */
 	public MetamodelProperty getSuperProperty() {
 		List<MetamodelProperty> potentialRootSuperFields = new ArrayList<>();
-		if (roleMethods.size() > 0) {
+		if (!roleMethods.isEmpty()) {
 			potentialRootSuperFields.add(this);
 		}
 		superProperties.forEach(superField -> {

src/main/java/spoon/pattern/PatternBuilder.java

@@ -449,7 +449,7 @@ protected Factory getFactory() {
 		if (templateTypeRef != null) {
 			return templateTypeRef.getFactory();
 		}
-		if (patternModel.size() > 0) {
+		if (!patternModel.isEmpty()) {
 			return patternModel.get(0).getFactory();
 		}
 		throw new SpoonException("PatternBuilder has no CtElement to provide a Factory");

src/main/java/spoon/pattern/PatternParameterConfigurator.java

@@ -401,7 +401,7 @@ private void configureByTemplateParameter(CtType<?> templateType, Map<String, Ob
 				 * Use it as Pattern parameter
 				 */
 				String fieldName = typeMember.getSimpleName();
-				String stringMarker = (param.value() != null && param.value().length() > 0) ? param.value() : fieldName;
+				String stringMarker = (param.value() != null && !param.value().isEmpty()) ? param.value() : fieldName;
 				//for the compatibility reasons with Parameters.getNamesToValues(), use the proxy name as parameter name
 				String parameterName = stringMarker;
 

src/main/java/spoon/pattern/internal/DefaultGenerator.java

@@ -211,7 +211,7 @@ private void addGeneratedByComment(CtElement ele, String generatedBy) {
 		String EOL = System.getProperty("line.separator");
 		CtComment comment = getJavaDoc(ele);
 		String content = comment.getContent();
-		if (content.trim().length() > 0) {
+		if (!content.trim().isEmpty()) {
 			content += EOL + EOL;
 		}
 		content += generatedBy;

src/main/java/spoon/pattern/internal/PatternPrinter.java

@@ -144,7 +144,7 @@ private void addParameterCommentTo(CtElement ele, ParamOnElement... paramsOnElem
 				params.add(paramOnElement);
 			}
 		}
-		if (isCommentVisible(ele) && params.size() > 0) {
+		if (isCommentVisible(ele) && !params.isEmpty()) {
 			ele.addComment(ele.getFactory().Code().createComment(getSubstitutionRequestsDescription(ele, params), CommentType.BLOCK));
 			params.clear();
 		}

src/main/java/spoon/pattern/internal/ValueConvertorImpl.java

@@ -90,7 +90,7 @@ public <T> T getValueAs(Factory factory, String parameterName, Object value, Cla
 			}
 			if (value instanceof List) {
 				List list = (List) value;
-				if (list.size() == 0) {
+				if (list.isEmpty()) {
 					return null;
 				}
 				if (list.size() == 1) {

src/main/java/spoon/pattern/internal/matcher/MatchingScanner.java

@@ -68,7 +68,7 @@ public void scan(CtRole role, Collection<? extends CtElement> elements) {
 
 	private int searchMatchInList(CtRole role, List<? extends CtElement> list, boolean scanChildren) {
 		int matchCount = 0;
-		if (list.size() > 0) {
+		if (!list.isEmpty()) {
 			TobeMatched tobeMatched = TobeMatched.create(
 					new ImmutableMapImpl(),
 					ContainerKind.LIST,
@@ -77,7 +77,7 @@ private int searchMatchInList(CtRole role, List<? extends CtElement> list, boole
 				TobeMatched nextTobeMatched = pattern.matchAllWith(tobeMatched);
 				if (nextTobeMatched != null) {
 					List<?> matchedTargets = tobeMatched.getMatchedTargets(nextTobeMatched);
-					if (matchedTargets.size() > 0) {
+					if (!matchedTargets.isEmpty()) {
 						matchCount++;
 						//send information about match to client
 						matchConsumer.accept(new Match(matchedTargets, nextTobeMatched.getParameters()));
@@ -99,7 +99,7 @@ private int searchMatchInList(CtRole role, List<? extends CtElement> list, boole
 	}
 
 	private void searchMatchInSet(CtRole role, Set<? extends CtElement> set) {
-		if (set.size() > 0) {
+		if (!set.isEmpty()) {
 			//copy targets, because it might be modified by call of matchConsumer, when refactoring spoon model
 			//use List, because Spoon uses Sets with predictable order - so keep the order
 			TobeMatched tobeMatched = TobeMatched.create(
@@ -110,7 +110,7 @@ private void searchMatchInSet(CtRole role, Set<? extends CtElement> set) {
 				TobeMatched nextTobeMatched = pattern.matchAllWith(tobeMatched);
 				if (nextTobeMatched != null) {
 					List<?> matchedTargets = tobeMatched.getMatchedTargets(nextTobeMatched);
-					if (matchedTargets.size() > 0) {
+					if (!matchedTargets.isEmpty()) {
 						//send information about match to client
 						matchConsumer.accept(new Match(matchedTargets, nextTobeMatched.getParameters()));
 						//do not scan children of matched elements. They already matched, so we must not scan them again

src/main/java/spoon/pattern/internal/matcher/TobeMatched.java

@@ -155,7 +155,7 @@ private boolean containsSame(List<?> items, Object object) {
 	 * @return true if there is anything to match.
 	 */
 	public boolean hasTargets() {
-		return targets.size() > 0;
+		return !targets.isEmpty();
 	}
 
 	/**

src/main/java/spoon/pattern/internal/parameter/MapParameterInfo.java

@@ -51,7 +51,7 @@ protected String getWrappedName(String containerName) {
 		if (name == null) {
 			return containerName;
 		}
-		if (containerName.length() > 0) {
+		if (!containerName.isEmpty()) {
 			containerName += ".";
 		}
 		return containerName + name;

src/main/java/spoon/refactoring/Refactoring.java

@@ -86,7 +86,7 @@ public static CtMethod<?> copyMethod(final CtMethod<?> method) {
 		CtMethod<?> clone = method.clone();
 		String tentativeTypeName = method.getSimpleName() + "Copy";
 		CtType parent = method.getParent(CtType.class);
-		while (parent.getMethodsByName(tentativeTypeName).size() > 0) {
+		while (!parent.getMethodsByName(tentativeTypeName).isEmpty()) {
 			tentativeTypeName += "X";
 		}
 		final String cloneMethodName = tentativeTypeName;

src/main/java/spoon/reflect/factory/TypeFactory.java

@@ -462,7 +462,7 @@ public boolean matches(CtClass<T> element) {
 						return super.matches(element) && element.getQualifiedName().equals(qualifiedName);
 					}
 				});
-				if (enclosingClasses.size() == 0) {
+				if (enclosingClasses.isEmpty()) {
 					return null;
 				}
 				return enclosingClasses.get(0);
@@ -478,7 +478,7 @@ public boolean matches(CtNewClass element) {
 						return super.matches(element) && element.getAnonymousClass().getQualifiedName().equals(qualifiedName);
 					}
 				});
-				if (anonymousClasses.size() == 0) {
+				if (anonymousClasses.isEmpty()) {
 					return null;
 				}
 				return anonymousClasses.get(0).getAnonymousClass();

src/main/java/spoon/reflect/visitor/CommentHelper.java

@@ -81,7 +81,7 @@ static void printComment(PrinterHelper printer, CtComment.CommentType commentTyp
 							printer.writeln();
 						}
 					} else {
-						if (com.length() > 0) {
+						if (!com.isEmpty()) {
 							printer.write(COMMENT_STAR + com).writeln();
 						} else {
 							printer.write(" *" /* no trailing space */ + com).writeln();

src/main/java/spoon/reflect/visitor/CtIterator.java

@@ -40,7 +40,7 @@ public boolean addAll(Collection c) {
 			for (Object aC : c) {
 				this.addFirst((CtElement) aC);
 			}
-			return c.size() > 0;
+			return !c.isEmpty();
 		}
 	};
 
@@ -74,7 +74,7 @@ public void scan(CtElement element) {
 
 	@Override
 	public boolean hasNext() {
-		return deque.size() > 0;
+		return !deque.isEmpty();
 	}
 
 	/**

src/main/java/spoon/reflect/visitor/DefaultJavaPrettyPrinter.java

@@ -284,7 +284,7 @@ protected void enterCtStatement(CtStatement s) {
 	 * Exits an expression.
 	 */
 	protected void exitCtExpression(CtExpression<?> e) {
-		while ((context.parenthesedExpression.size() > 0) && e == context.parenthesedExpression.peek()) {
+		while ((!context.parenthesedExpression.isEmpty()) && e == context.parenthesedExpression.peek()) {
 			context.parenthesedExpression.pop();
 			printer.writeSeparator(")");
 		}
@@ -387,7 +387,7 @@ private static void addParentPath(StringBuilder sb, CtElement ele) {
 	}
 
 	private boolean shouldSetBracket(CtExpression<?> e) {
-		if (e.getTypeCasts().size() != 0) {
+		if (!e.getTypeCasts().isEmpty()) {
 			return true;
 		}
 		try {
@@ -416,7 +416,7 @@ public <A extends Annotation> void visitCtAnnotation(CtAnnotation<A> annotation)
 		elementPrinterHelper.writeAnnotations(annotation);
 		printer.writeSeparator("@");
 		scan(annotation.getAnnotationType());
-		if (annotation.getValues().size() > 0) {
+		if (!annotation.getValues().isEmpty()) {
 			elementPrinterHelper.printList(annotation.getValues().entrySet(),
 				null, false, "(", false, false, ",", true, false, ")",
 				e -> {
@@ -687,7 +687,7 @@ public <T> void visitCtConstructor(CtConstructor<T> constructor) {
 		elementPrinterHelper.visitCtNamedElement(constructor, sourceCompilationUnit);
 		elementPrinterHelper.writeModifiers(constructor);
 		elementPrinterHelper.writeFormalTypeParameters(constructor);
-		if (constructor.getFormalCtTypeParameters().size() > 0) {
+		if (!constructor.getFormalCtTypeParameters().isEmpty()) {
 			printer.writeSpace();
 		}
 		if (constructor.getDeclaringType() != null) {
@@ -730,7 +730,7 @@ public <T extends Enum<?>> void visitCtEnum(CtEnum<T> ctEnum) {
 		context.pushCurrentThis(ctEnum);
 		printer.writeSpace().writeSeparator("{").incTab().writeln();
 
-		if (ctEnum.getEnumValues().size() == 0) {
+		if (ctEnum.getEnumValues().isEmpty()) {
 			printer.writeSeparator(";").writeln();
 		} else {
 			elementPrinterHelper.printList(ctEnum.getEnumValues(),
@@ -1151,7 +1151,7 @@ public void visitCtFor(CtFor forLoop) {
 		enterCtStatement(forLoop);
 		printer.writeKeyword("for").writeSpace().writeSeparator("(");
 		List<CtStatement> st = forLoop.getForInit();
-		if (st.size() > 0) {
+		if (!st.isEmpty()) {
 			scan(st.get(0));
 		}
 		if (st.size() > 1) {
@@ -1215,7 +1215,7 @@ public <T> void visitCtInterface(CtInterface<T> intrface) {
 			elementPrinterHelper.writeFormalTypeParameters(intrface);
 		}
 
-		if (intrface.getSuperInterfaces().size() > 0) {
+		if (!intrface.getSuperInterfaces().isEmpty()) {
 			elementPrinterHelper.printList(intrface.getSuperInterfaces(),
 				"extends", false, null, false, true, ",", true, false, null,
 				ref -> scan(ref));
@@ -1335,7 +1335,7 @@ public <T> void visitCtMethod(CtMethod<T> m) {
 		elementPrinterHelper.visitCtNamedElement(m, sourceCompilationUnit);
 		elementPrinterHelper.writeModifiers(m);
 		elementPrinterHelper.writeFormalTypeParameters(m);
-		if (m.getFormalCtTypeParameters().size() > 0) {
+		if (!m.getFormalCtTypeParameters().isEmpty()) {
 			printer.writeSpace();
 		}
 		try (Writable _context = context.modify().ignoreGenerics(false)) {
@@ -1413,7 +1413,7 @@ public <T> void visitCtNewArray(CtNewArray<T> newArray) {
 				ref = ((CtArrayTypeReference) ref).getComponentType();
 			}
 		}
-		if (newArray.getDimensionExpressions().size() == 0) {
+		if (newArray.getDimensionExpressions().isEmpty()) {
 			elementPrinterHelper.printList(newArray.getElements(),
 				null, false, "{", true, false, ",", true, true, "}",
 				e -> scan(e));
@@ -1459,7 +1459,7 @@ private <T> void printConstructorCall(CtConstructorCall<T> ctConstructorCall) {
 
 			printer.writeKeyword("new").writeSpace();
 
-			if (ctConstructorCall.getActualTypeArguments().size() > 0) {
+			if (!ctConstructorCall.getActualTypeArguments().isEmpty()) {
 				elementPrinterHelper.writeActualTypeArguments(ctConstructorCall);
 			}
 
@@ -1493,7 +1493,7 @@ private <T> boolean hasDeclaringTypeWithGenerics(CtTypeReference<T> reference) {
 			return false;
 		}
 		// If declaring type have generics, we return true.
-		if (reference.getDeclaringType().getActualTypeArguments().size() != 0) {
+		if (!reference.getDeclaringType().getActualTypeArguments().isEmpty()) {
 			return true;
 		}
 		// Checks if the declaring type has generic types.

src/main/java/spoon/reflect/visitor/ElementPrinterHelper.java

@@ -152,7 +152,7 @@ public void writeExtendsClause(CtType<?> type) {
 
 	/** writes the implemented interfaces with a ListPrinter */
 	public void writeImplementsClause(CtType<?> type) {
-		if (type.getSuperInterfaces().size() > 0) {
+		if (!type.getSuperInterfaces().isEmpty()) {
 			printList(type.getSuperInterfaces(), "implements",
 				false, null, false, true, ",", true, false, null,
 				ref -> prettyPrinter.scan(ref));
@@ -167,7 +167,7 @@ public void writeExecutableParameters(CtExecutable<?> executable) {
 
 	/** writes the thrown exception with a ListPrinter */
 	public void writeThrowsClause(CtExecutable<?> executable) {
-		if (executable.getThrownTypes().size() > 0) {
+		if (!executable.getThrownTypes().isEmpty()) {
 			printList(executable.getThrownTypes(), "throws",
 				false, null, false, false, ",", true, false, null,
 				ref -> prettyPrinter.scan(ref));
@@ -244,7 +244,7 @@ public void writeFormalTypeParameters(CtFormalTypeDeclarer ctFormalTypeDeclarer)
 		if (parameters == null) {
 			return;
 		}
-		if (parameters.size() > 0) {
+		if (!parameters.isEmpty()) {
 			printList(parameters,
 				null,	false, "<", false, false, ",", true, false, ">",
 				parameter -> prettyPrinter.scan(parameter));
@@ -259,7 +259,7 @@ public void writeFormalTypeParameters(CtFormalTypeDeclarer ctFormalTypeDeclarer)
 	 */
 	public void writeActualTypeArguments(CtActualTypeContainer ctGenericElementReference) {
 		final Collection<CtTypeReference<?>> arguments = ctGenericElementReference.getActualTypeArguments();
-		if (arguments != null && arguments.size() > 0) {
+		if (arguments != null && !arguments.isEmpty()) {
 			printList(arguments.stream().filter(a -> !a.isImplicit())::iterator,
 				null, false, "<", false, false, ",", true, false, ">",
 				argument -> {
@@ -333,7 +333,7 @@ public void writeImports(Collection<CtImport> imports) {
 			printer.writeKeyword("import").writeSpace();
 			writeQualifiedName(importLine).writeSeparator(";").writeln();
 		}
-		if (setStaticImports.size() > 0) {
+		if (!setStaticImports.isEmpty()) {
 			if (isFirst) {
 				printer.writeln();
 			}

src/main/java/spoon/reflect/visitor/JavaIdentifiers.java

@@ -47,7 +47,7 @@ public enum JavaIdentifiers {
 	}
 
 	static boolean isJavaIdentifier(String s) {
-		if (s.length() == 0 || !Character.isJavaIdentifierStart(s.charAt(0))) {
+		if (s.isEmpty() || !Character.isJavaIdentifierStart(s.charAt(0))) {
 			return false;
 		}
 		for (int i = 1; i < s.length(); i++) {

src/main/java/spoon/reflect/visitor/ListPrinter.java

@@ -47,7 +47,7 @@ public ListPrinter(TokenWriter printerHelper, boolean startPrefixSpace, String s
 		if (startPrefixSpace) {
 			printerHelper.writeSpace();
 		}
-		if (start != null && start.length() > 0) {
+		if (start != null && !start.isEmpty()) {
 			printerTokenWriter.writeSeparator(start);
 		}
 		if (startSuffixSpace) {
@@ -71,7 +71,7 @@ public void printSeparatorIfAppropriate() {
 			if (nextPrefixSpace) {
 				printerTokenWriter.writeSpace();
 			}
-			if (separator != null && separator.length() > 0) {
+			if (separator != null && !separator.isEmpty()) {
 				printerTokenWriter.writeSeparator(separator);
 			}
 			if (nextSuffixSpace) {
@@ -85,7 +85,7 @@ public void close() {
 		if (endPrefixSpace) {
 			printerTokenWriter.writeSpace();
 		}
-		if (end != null && end.length() > 0) {
+		if (end != null && !end.isEmpty()) {
 			printerTokenWriter.writeSeparator(end);
 		}
 	}