com.moz.fiji.schema.util.JavaIdentifiers.java Source code

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Here is the source code for com.moz.fiji.schema.util.JavaIdentifiers.java

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/**
 * (c) Copyright 2012 WibiData, Inc.
 *
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.moz.fiji.schema.util;

import org.apache.commons.lang.StringUtils;

import com.moz.fiji.annotations.ApiAudience;

/**
 * A utility class for dealing with identifiers in the Java language.
 */
@ApiAudience.Private
public final class JavaIdentifiers {
    /** Disable constructor for this utility class. */
    private JavaIdentifiers() {
    }

    /**
     * Determines whether a string is a valid Java identifier.
     *
     * <p>A valid Java identifier may not start with a number, but may contain any
     * combination of letters, digits, underscores, or dollar signs.</p>
     *
     * <p>See the <a href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#3.8">
     * Java Language Specification</a></p>
     *
     * @param identifier The identifier to test for validity.
     * @return Whether the identifier was valid.
     */
    public static boolean isValidIdentifier(String identifier) {
        if (identifier.isEmpty() || !Character.isJavaIdentifierStart(identifier.charAt(0))) {
            return false;
        }
        for (int i = 1; i < identifier.length(); i++) {
            if (!Character.isJavaIdentifierPart(identifier.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    /**
     * Determines whether a string could be the name of a Java class.
     *
     * <p>If this method returns true, it does not necessarily mean that the Java class with
     * <code>className</code> exists; it only means that one could write a Java class with
     * that fully-qualified name.</p>
     *
     * @param className A string to test.
     * @return Whether the class name was valid.
     */
    public static boolean isValidClassName(String className) {
        // A valid class name is a bunch of valid Java identifiers separated by dots.
        for (String part : StringUtils.splitByWholeSeparatorPreserveAllTokens(className, ".")) {
            if (!isValidIdentifier(part)) {
                return false;
            }
        }
        return true;
    }
}