| 1 | /**************************************************************** |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one * |
| 3 | * or more contributor license agreements. See the NOTICE file * |
| 4 | * distributed with this work for additional information * |
| 5 | * regarding copyright ownership. The ASF licenses this file * |
| 6 | * to you under the Apache License, Version 2.0 (the * |
| 7 | * "License"); you may not use this file except in compliance * |
| 8 | * with the License. You may obtain a copy of the License at * |
| 9 | * * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 * |
| 11 | * * |
| 12 | * Unless required by applicable law or agreed to in writing, * |
| 13 | * software distributed under the License is distributed on an * |
| 14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * |
| 15 | * KIND, either express or implied. See the License for the * |
| 16 | * specific language governing permissions and limitations * |
| 17 | * under the License. * |
| 18 | ****************************************************************/ |
| 19 | |
| 20 | package org.apache.james.jdkim.canon; |
| 21 | |
| 22 | import java.io.FilterOutputStream; |
| 23 | import java.io.IOException; |
| 24 | import java.io.OutputStream; |
| 25 | |
| 26 | /** |
| 27 | * Implements Relaxed canonicalization for the body as defined in RFC4871 - |
| 28 | * 3.4.4. The "relaxed" Body Canonicalization Algorithm |
| 29 | */ |
| 30 | public class RelaxedBodyCanonicalizer extends FilterOutputStream { |
| 31 | |
| 32 | private boolean pendingSpaces; |
| 33 | |
| 34 | public RelaxedBodyCanonicalizer(OutputStream out) { |
| 35 | super(new SimpleBodyCanonicalizer(out)); |
| 36 | pendingSpaces = false; |
| 37 | } |
| 38 | |
| 39 | public void write(byte[] buffer, int off, int len) throws IOException { |
| 40 | int start = off; |
| 41 | int end = len + off; |
| 42 | for (int k = off; k < end; k++) { |
| 43 | if (pendingSpaces) { |
| 44 | if (buffer[k] != ' ' && buffer[k] != '\t') { |
| 45 | if (buffer[k] != '\r') |
| 46 | out.write(' '); |
| 47 | pendingSpaces = false; |
| 48 | len = len - k + start; |
| 49 | start = k; |
| 50 | } |
| 51 | } else { |
| 52 | if (buffer[k] == ' ' || buffer[k] == '\t') { |
| 53 | if (k + 1 < end && buffer[k] == ' ' && buffer[k + 1] != ' ' |
| 54 | && buffer[k + 1] != '\t' && buffer[k + 1] != '\r') { |
| 55 | // optimization: we skip single spaces |
| 56 | // make sure we optimize only when we are on a space. |
| 57 | } else { |
| 58 | // compute everything from start to end; |
| 59 | out.write(buffer, start, k - start); |
| 60 | pendingSpaces = true; |
| 61 | } |
| 62 | } |
| 63 | } |
| 64 | } |
| 65 | if (!pendingSpaces) { |
| 66 | out.write(buffer, start, len); |
| 67 | } |
| 68 | } |
| 69 | |
| 70 | public void write(int b) throws IOException { |
| 71 | if (pendingSpaces) { |
| 72 | if (b != ' ' && b != '\t') { |
| 73 | if (b != '\r') |
| 74 | out.write(' '); |
| 75 | pendingSpaces = false; |
| 76 | out.write(b); |
| 77 | } |
| 78 | } else { |
| 79 | if (b == ' ' || b == '\t') { |
| 80 | pendingSpaces = true; |
| 81 | } else { |
| 82 | out.write(b); |
| 83 | } |
| 84 | } |
| 85 | } |
| 86 | |
| 87 | public void close() throws IOException { |
| 88 | complete(); |
| 89 | super.close(); |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * Called internally to make sure we output the buffered whitespace if any. |
| 94 | */ |
| 95 | private void complete() throws IOException { |
| 96 | if (pendingSpaces) |
| 97 | out.write(' '); |
| 98 | } |
| 99 | |
| 100 | } |