001/* 002 * Copyright (C) 2009 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 005 * in compliance with the License. You may obtain a copy of the License at 006 * 007 * http://www.apache.org/licenses/LICENSE-2.0 008 * 009 * Unless required by applicable law or agreed to in writing, software distributed under the License 010 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 011 * or implied. See the License for the specific language governing permissions and limitations under 012 * the License. 013 */ 014 015package com.google.common.io; 016 017import com.google.common.annotations.Beta; 018import com.google.common.annotations.GwtIncompatible; 019import com.google.errorprone.annotations.CanIgnoreReturnValue; 020import java.io.IOException; 021 022/** 023 * A callback to be used with the streaming {@code readLines} methods. 024 * 025 * <p>{@link #processLine} will be called for each line that is read, and should return {@code 026 * false} when you want to stop processing. 027 * 028 * @author Miles Barr 029 * @since 1.0 030 */ 031@Beta 032@GwtIncompatible 033public interface LineProcessor<T> { 034 035 /** 036 * This method will be called once for each line. 037 * 038 * @param line the line read from the input, without delimiter 039 * @return true to continue processing, false to stop 040 */ 041 @CanIgnoreReturnValue // some uses know that their processor never returns false 042 boolean processLine(String line) throws IOException; 043 044 /** Return the result of processing all the lines. */ 045 T getResult(); 046}