ExpressionTree Class — spring-boot Architecture

Source Code

configuration-metadata/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/fieldvalues/javac/ExpressionTree.java lines 29–103

class ExpressionTree extends ReflectionWrapper {

	private final Class<?> literalTreeType = findClass("com.sun.source.tree.LiteralTree");

	private final Method literalValueMethod = findMethod(this.literalTreeType, "getValue");

	private final Class<?> methodInvocationTreeType = findClass("com.sun.source.tree.MethodInvocationTree");

	private final Method methodInvocationArgumentsMethod = findMethod(this.methodInvocationTreeType, "getArguments");

	private final Class<?> memberSelectTreeType = findClass("com.sun.source.tree.MemberSelectTree");

	private final Method memberSelectTreeExpressionMethod = findMethod(this.memberSelectTreeType, "getExpression");

	private final Method memberSelectTreeIdentifierMethod = findMethod(this.memberSelectTreeType, "getIdentifier");

	private final Class<?> newArrayTreeType = findClass("com.sun.source.tree.NewArrayTree");

	private final Method arrayValueMethod = findMethod(this.newArrayTreeType, "getInitializers");

	ExpressionTree(Object instance) {
		super("com.sun.source.tree.ExpressionTree", instance);
	}

	String getKind() throws Exception {
		return findMethod("getKind").invoke(getInstance()).toString();
	}

	Object getLiteralValue() throws Exception {
		if (this.literalTreeType.isAssignableFrom(getInstance().getClass())) {
			return this.literalValueMethod.invoke(getInstance());
		}
		return null;
	}

	Object getFactoryValue() throws Exception {
		if (this.methodInvocationTreeType.isAssignableFrom(getInstance().getClass())) {
			List<?> arguments = (List<?>) this.methodInvocationArgumentsMethod.invoke(getInstance());
			if (arguments.size() == 1) {
				return new ExpressionTree(arguments.get(0)).getLiteralValue();
			}
		}
		return null;
	}

	Member getSelectedMember() throws Exception {
		if (this.memberSelectTreeType.isAssignableFrom(getInstance().getClass())) {
			String expression = this.memberSelectTreeExpressionMethod.invoke(getInstance()).toString();
			String identifier = this.memberSelectTreeIdentifierMethod.invoke(getInstance()).toString();
			if (expression != null && identifier != null) {
				return new Member(expression, identifier);
			}
		}
		return null;
	}

	List<? extends ExpressionTree> getArrayExpression() throws Exception {
		if (this.newArrayTreeType.isAssignableFrom(getInstance().getClass())) {
			List<?> elements = (List<?>) this.arrayValueMethod.invoke(getInstance());
			List<ExpressionTree> result = new ArrayList<>();
			if (elements == null) {
				return result;
			}
			for (Object element : elements) {
				result.add(new ExpressionTree(element));
			}
			return result;
		}
		return null;
	}

	record Member(String expression, String identifier) {
	}

}