org.apache.aurora.common.base.MorePreconditions.java Source code

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Here is the source code for org.apache.aurora.common.base.MorePreconditions.java

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/**
 * 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 org.apache.aurora.common.base;

import com.google.common.base.Preconditions;
import com.google.common.collect.Iterables;

import org.apache.commons.lang.StringUtils;

/**
 * A utility helpful in concisely checking preconditions on arguments.  This utility is a complement
 * to {@link com.google.common.base.Preconditions}.
 *
 * @author John Sirois
 */
public final class MorePreconditions {

    private static final String ARG_NOT_BLANK_MSG = "Argument cannot be blank";

    private MorePreconditions() {
        // utility
    }

    /**
     * Checks that a string is both non-null and non-empty.
     *
     * @see #checkNotBlank(String, String, Object...)
     */
    public static String checkNotBlank(String argument) {
        return checkNotBlank(argument, ARG_NOT_BLANK_MSG);
    }

    /**
     * Checks that a string is both non-null and non-empty.
     *
     * @param argument the argument to validate
     * @param message the message template for validation exception messages where %s serves as the
     *     sole argument placeholder
     * @param args any arguments needed by the message template
     * @return the argument if it is valid
     * @throws NullPointerException if the argument is null
     * @throws IllegalArgumentException if the argument is the empty string or a pure whitespace
     *    string
     */
    public static String checkNotBlank(String argument, String message, Object... args) {
        Preconditions.checkNotNull(argument, message, args);
        Preconditions.checkArgument(!StringUtils.isBlank(argument), message, args);
        return argument;
    }

    /**
     * Checks that an Iterable is both non-null and non-empty.  This method does not check individual
     * elements in the Iterable.
     *
     * @see #checkNotBlank(Iterable, String, Object...)
     */
    public static <S, T extends Iterable<S>> T checkNotBlank(T argument) {
        return checkNotBlank(argument, ARG_NOT_BLANK_MSG);
    }

    /**
     * Checks that an Iterable is both non-null and non-empty.  This method does not check individual
     * elements in the Iterable, it just checks that the Iterable has at least one element.
     *
     * @param argument the argument to validate
     * @param message the message template for validation exception messages where %s serves as the
     *     sole argument placeholder
     * @param args any arguments needed by the message template
     * @return the argument if it is valid
     * @throws NullPointerException if the argument is null
     * @throws IllegalArgumentException if the argument has no iterable elements
     */
    public static <S, T extends Iterable<S>> T checkNotBlank(T argument, String message, Object... args) {
        Preconditions.checkNotNull(argument, message, args);
        Preconditions.checkArgument(!Iterables.isEmpty(argument), message, args);
        return argument;
    }
}