1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package tests.support; 19 20 import java.io.FilterReader; 21 import java.io.IOException; 22 import java.io.Reader; 23 24 /** 25 * A reader that always throws after a predetermined number of bytes have been 26 * read. 27 */ 28 public class ThrowingReader extends FilterReader { 29 30 private int total = 0; 31 private int throwAt; 32 33 public ThrowingReader(Reader in, int throwAt) { 34 super(in); 35 this.throwAt = throwAt; 36 } 37 38 @Override public int read() throws IOException { 39 explodeIfNecessary(); 40 int result = super.read(); 41 total++; 42 return result; 43 } 44 45 @Override public int read(char[] buf, int offset, int count) 46 throws IOException { 47 explodeIfNecessary(); 48 49 if (total < throwAt) { 50 count = Math.min(count, (throwAt - total)); 51 } 52 53 int returned = super.read(buf, offset, count); 54 total += returned; 55 return returned; 56 } 57 58 private void explodeIfNecessary() throws IOException { 59 if (total == throwAt) { 60 throwAt = Integer.MAX_VALUE; 61 throw new IOException(); 62 } 63 } 64 } 65
