001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.util;
018
019 import java.io.IOException;
020 import java.io.InputStream;
021 import java.io.OutputStream;
022 import java.io.UnsupportedEncodingException;
023 import java.nio.charset.Charset;
024
025 /**
026 * IO helper class.
027 *
028 * @version $Revision: 769303 $
029 */
030 public final class IOHelper {
031
032 private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;
033 private static final Charset UTF8_CHARSET = Charset.forName("utf-8");
034
035 private IOHelper() {
036 //Utility Class
037 }
038
039 /**
040 * Use this function instead of new String(byte[]) to avoid surprises from non-standard default encodings.
041 */
042 public static String newStringFromBytes(byte[] bytes) {
043 try {
044 return new String(bytes, UTF8_CHARSET.name());
045 } catch (UnsupportedEncodingException e) {
046 throw new RuntimeException("Impossible failure: Charset.forName(\"utf-8\") returns invalid name.", e);
047 }
048 }
049
050 /**
051 * Use this function instead of new String(byte[], int, int)
052 * to avoid surprises from non-standard default encodings.
053 */
054 public static String newStringFromBytes(byte[] bytes, int start, int length) {
055 try {
056 return new String(bytes, start, length, UTF8_CHARSET.name());
057 } catch (UnsupportedEncodingException e) {
058 throw new RuntimeException("Impossible failure: Charset.forName(\"utf-8\") returns invalid name.", e);
059 }
060 }
061
062 /**
063 * A factory method which creates an {@link IOException} from the given
064 * exception and message
065 */
066 public static IOException createIOException(Throwable cause) {
067 return createIOException(cause.getMessage(), cause);
068 }
069
070 /**
071 * A factory method which creates an {@link IOException} from the given
072 * exception and message
073 */
074 public static IOException createIOException(String message, Throwable cause) {
075 IOException answer = new IOException(message);
076 answer.initCause(cause);
077 return answer;
078 }
079
080 public static int copy(InputStream input, OutputStream output) throws IOException {
081 return copy(input, output, DEFAULT_BUFFER_SIZE);
082 }
083
084 public static int copy(final InputStream input, final OutputStream output, int bufferSize)
085 throws IOException {
086 int avail = input.available();
087 if (avail > 262144) {
088 avail = 262144;
089 }
090 if (avail > bufferSize) {
091 bufferSize = avail;
092 }
093 final byte[] buffer = new byte[bufferSize];
094 int n = 0;
095 n = input.read(buffer);
096 int total = 0;
097 while (-1 != n) {
098 output.write(buffer, 0, n);
099 total += n;
100 n = input.read(buffer);
101 }
102 output.flush();
103 return total;
104 }
105
106 public static void copyAndCloseInput(InputStream input, OutputStream output) throws IOException {
107 copy(input, output);
108 input.close();
109 }
110
111 public static void copyAndCloseInput(InputStream input, OutputStream output, int bufferSize) throws IOException {
112 copy(input, output, bufferSize);
113 }
114 }