Java tutorial
/** * *************************************************************************** * Copyright (c) 2010 Qcadoo Limited * Project: Qcadoo Framework * Version: 1.2.0 * * This file is part of Qcadoo. * * Qcadoo is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published * by the Free Software Foundation; either version 3 of the License, * or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * *************************************************************************** */ package com.qcadoo.model.internal.api; import java.util.Arrays; import org.apache.commons.lang.ArrayUtils; /** * Immutable class representing value and error */ public final class ValueAndError { private static final ValueAndError EMPTY_VALUE_AND_ERROR = new ValueAndError(null, null); private final Object value; private final String message; private final String[] args; private ValueAndError(final Object value, final String message, final String... args) { this.value = value; this.message = message; if (ArrayUtils.isEmpty(args)) { this.args = ArrayUtils.EMPTY_STRING_ARRAY; } else { this.args = args; } } /** * Build and returns new instance of {@link ValueAndError} with given * * @param value * @return new instance of {@link ValueAndError} */ public static ValueAndError withoutError(final Object value) { return new ValueAndError(value, null); } /** * Returns empty {@link ValueAndError} object * * @return empty {@link ValueAndError} object */ public static ValueAndError empty() { return EMPTY_VALUE_AND_ERROR; } /** * Build and returns new instance of {@link ValueAndError} with given message and args * * @param message * error message * @param args * error message arguments (values which will replace message's place holders) * @return new instance of {@link ValueAndError} */ public static ValueAndError withError(final String message, final String... args) { return new ValueAndError(null, message, args); } /** * Checks if value is valid. * * @return true if field value is valid. Otherwise false. */ public boolean isValid() { return message == null; } /** * Returns parsed value * * @return parsed value */ public Object getValue() { return value; } /** * Returns error message arguments (values which will replace message's place holders) * * @return error message arguments (values which will replace message's place holders) */ public String[] getArgs() { return Arrays.copyOf(args, args.length); } /** * Returns error message * * @return error message */ public String getMessage() { return message; } }