1 /* Licensed to the Apache Software Foundation (ASF) under one or more 2 * contributor license agreements. See the NOTICE file distributed with 3 * this work for additional information regarding copyright ownership. 4 * The ASF licenses this file to You under the Apache License, Version 2.0 5 * (the "License"); you may not use this file except in compliance with 6 * the License. You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package java.util; 18 19 /** 20 * Classes that handle custom formatting for the 's' specifier of {@code Formatter} 21 * should implement the {@code Formattable} interface. It gives basic control over 22 * formatting objects. 23 * 24 * @see Formatter 25 */ 26 27 public interface Formattable { 28 29 /** 30 * Formats the object using the specified {@code Formatter}. 31 * 32 * @param formatter 33 * the {@code Formatter} to use. 34 * @param flags 35 * the flags applied to the output format, which is a bitmask 36 * that is any combination of {@code FormattableFlags.LEFT_JUSTIFY}, 37 * {@code FormattableFlags.UPPERCASE}, and {@code FormattableFlags.ALTERNATE}. If 38 * no such flag is set, the output is formatted by the default 39 * formatting of the implementation. 40 * @param width 41 * the minimum number of characters that should be written to the 42 * output. If the length of the converted value is less than {@code width} 43 * Additional space characters (' ') are added to the output if the 44 * as needed to make up the difference. These spaces are added at the 45 * beginning by default unless the flag 46 * FormattableFlags.LEFT_JUSTIFY is set, which denotes that 47 * padding should be added at the end. If width is -1, then 48 * minimum length is not enforced. 49 * @param precision 50 * the maximum number of characters that can be written to the 51 * output. The length of the output is trimmed down to this size 52 * before the width padding is applied. If the precision 53 * is -1, then maximum length is not enforced. 54 * @throws IllegalFormatException 55 * if any of the parameters is not supported. 56 */ formatTo(Formatter formatter, int flags, int width, int precision)57 void formatTo(Formatter formatter, int flags, int width, int precision) 58 throws IllegalFormatException; 59 } 60