[6785] | 1 | /**************************************************************** |
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| 2 | * Licensed to the Apache Software Foundation (ASF) under one * |
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| 3 | * or more contributor license agreements. See the NOTICE file * |
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| 4 | * distributed with this work for additional information * |
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| 5 | * regarding copyright ownership. The ASF licenses this file * |
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| 6 | * to you under the Apache License, Version 2.0 (the * |
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| 7 | * "License"); you may not use this file except in compliance * |
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| 8 | * with the License. You may obtain a copy of the License at * |
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| 9 | * * |
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| 10 | * http://www.apache.org/licenses/LICENSE-2.0 * |
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| 11 | * * |
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| 12 | * Unless required by applicable law or agreed to in writing, * |
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| 13 | * software distributed under the License is distributed on an * |
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| 14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * |
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| 15 | * KIND, either express or implied. See the License for the * |
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| 16 | * specific language governing permissions and limitations * |
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| 17 | * under the License. * |
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| 18 | ****************************************************************/ |
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| 19 | |
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| 20 | package org.apache.james.mime4j.stream; |
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| 21 | |
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| 22 | import java.io.IOException; |
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| 23 | |
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| 24 | import org.apache.james.mime4j.MimeException; |
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| 25 | import org.apache.james.mime4j.codec.DecodeMonitor; |
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| 26 | import org.apache.james.mime4j.io.LineReaderInputStream; |
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| 27 | import org.apache.james.mime4j.io.MaxHeaderLimitException; |
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| 28 | import org.apache.james.mime4j.io.MaxLineLimitException; |
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| 29 | import org.apache.james.mime4j.util.ByteArrayBuffer; |
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| 30 | import org.apache.james.mime4j.util.CharsetUtil; |
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| 31 | |
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| 32 | /** |
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| 33 | * Abstract MIME entity. |
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| 34 | */ |
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| 35 | abstract class AbstractEntity implements EntityStateMachine { |
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| 36 | |
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| 37 | protected final EntityState startState; |
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| 38 | protected final EntityState endState; |
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| 39 | protected final MimeEntityConfig config; |
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| 40 | protected final DecodeMonitor monitor; |
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| 41 | protected final FieldBuilder fieldBuilder; |
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| 42 | protected final MutableBodyDescriptor body; |
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| 43 | |
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| 44 | private final ByteArrayBuffer linebuf; |
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| 45 | |
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| 46 | protected EntityState state; |
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| 47 | private int lineCount; |
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| 48 | private boolean endOfHeader; |
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| 49 | private int headerCount; |
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| 50 | private RawField field; |
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| 51 | |
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| 52 | AbstractEntity( |
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| 53 | MimeEntityConfig config, |
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| 54 | EntityState startState, |
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| 55 | EntityState endState, |
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| 56 | DecodeMonitor monitor, |
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| 57 | FieldBuilder fieldBuilder, |
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| 58 | MutableBodyDescriptor body) { |
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| 59 | this.config = config; |
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| 60 | this.state = startState; |
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| 61 | this.startState = startState; |
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| 62 | this.endState = endState; |
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| 63 | this.monitor = monitor; |
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| 64 | this.fieldBuilder = fieldBuilder; |
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| 65 | this.body = body; |
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| 66 | |
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| 67 | this.linebuf = new ByteArrayBuffer(64); |
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| 68 | this.lineCount = 0; |
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| 69 | this.endOfHeader = false; |
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| 70 | this.headerCount = 0; |
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| 71 | } |
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| 72 | |
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| 73 | public EntityState getState() { |
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| 74 | return state; |
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| 75 | } |
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| 76 | |
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| 77 | /** |
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| 78 | * Returns the current line number or <code>-1</code> if line number |
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| 79 | * information is not available. |
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| 80 | */ |
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| 81 | protected abstract int getLineNumber(); |
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| 82 | |
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| 83 | protected abstract LineReaderInputStream getDataStream(); |
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| 84 | |
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| 85 | private void readRawField() throws IOException, MimeException { |
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| 86 | if (endOfHeader) |
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| 87 | throw new IllegalStateException(); |
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| 88 | LineReaderInputStream instream = getDataStream(); |
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| 89 | try { |
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| 90 | for (;;) { |
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| 91 | // If there's still data stuck in the line buffer |
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| 92 | // copy it to the field buffer |
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| 93 | int len = linebuf.length(); |
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| 94 | if (len > 0) { |
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| 95 | fieldBuilder.append(linebuf); |
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| 96 | } |
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| 97 | linebuf.clear(); |
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| 98 | if (instream.readLine(linebuf) == -1) { |
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| 99 | monitor(Event.HEADERS_PREMATURE_END); |
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| 100 | endOfHeader = true; |
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| 101 | break; |
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| 102 | } |
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| 103 | len = linebuf.length(); |
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| 104 | if (len > 0 && linebuf.byteAt(len - 1) == '\n') { |
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| 105 | len--; |
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| 106 | } |
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| 107 | if (len > 0 && linebuf.byteAt(len - 1) == '\r') { |
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| 108 | len--; |
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| 109 | } |
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| 110 | if (len == 0) { |
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| 111 | // empty line detected |
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| 112 | endOfHeader = true; |
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| 113 | break; |
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| 114 | } |
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| 115 | lineCount++; |
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| 116 | if (lineCount > 1) { |
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| 117 | int ch = linebuf.byteAt(0); |
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| 118 | if (ch != CharsetUtil.SP && ch != CharsetUtil.HT) { |
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| 119 | // new header detected |
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| 120 | break; |
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| 121 | } |
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| 122 | } |
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| 123 | } |
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| 124 | } catch (MaxLineLimitException e) { |
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| 125 | throw new MimeException(e); |
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| 126 | } |
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| 127 | } |
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| 128 | |
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| 129 | protected boolean nextField() throws MimeException, IOException { |
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| 130 | int maxHeaderCount = config.getMaxHeaderCount(); |
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| 131 | // the loop is here to transparently skip invalid headers |
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| 132 | for (;;) { |
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| 133 | if (endOfHeader) { |
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| 134 | return false; |
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| 135 | } |
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| 136 | if (maxHeaderCount > 0 && headerCount >= maxHeaderCount) { |
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| 137 | throw new MaxHeaderLimitException("Maximum header limit exceeded"); |
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| 138 | } |
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| 139 | headerCount++; |
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| 140 | fieldBuilder.reset(); |
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| 141 | readRawField(); |
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| 142 | try { |
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| 143 | field = fieldBuilder.build(); |
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| 144 | if (field == null) { |
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| 145 | continue; |
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| 146 | } |
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| 147 | if (field.getDelimiterIdx() != field.getName().length()) { |
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| 148 | monitor(Event.OBSOLETE_HEADER); |
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| 149 | } |
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| 150 | body.addField(field); |
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| 151 | return true; |
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| 152 | } catch (MimeException e) { |
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| 153 | monitor(Event.INVALID_HEADER); |
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| 154 | if (config.isMalformedHeaderStartsBody()) { |
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| 155 | LineReaderInputStream instream = getDataStream(); |
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| 156 | ByteArrayBuffer buf = fieldBuilder.getRaw(); |
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| 157 | // Complain, if raw data is not available or cannot be 'unread' |
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| 158 | if (buf == null || !instream.unread(buf)) { |
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| 159 | throw new MimeParseEventException(Event.INVALID_HEADER); |
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| 160 | } |
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| 161 | return false; |
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| 162 | } |
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| 163 | } |
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| 164 | } |
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| 165 | } |
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| 166 | |
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| 167 | /** |
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| 168 | * <p>Gets a descriptor for the current entity. |
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| 169 | * This method is valid if {@link #getState()} returns:</p> |
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| 170 | * <ul> |
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| 171 | * <li>{@link EntityState#T_BODY}</li> |
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| 172 | * <li>{@link EntityState#T_START_MULTIPART}</li> |
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| 173 | * <li>{@link EntityState#T_EPILOGUE}</li> |
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| 174 | * <li>{@link EntityState#T_PREAMBLE}</li> |
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| 175 | * </ul> |
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| 176 | * @return <code>BodyDescriptor</code>, not nulls |
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| 177 | */ |
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| 178 | public BodyDescriptor getBodyDescriptor() { |
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| 179 | switch (getState()) { |
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| 180 | case T_BODY: |
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| 181 | case T_START_MULTIPART: |
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| 182 | case T_PREAMBLE: |
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| 183 | case T_EPILOGUE: |
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| 184 | case T_END_OF_STREAM: |
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| 185 | return body; |
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| 186 | default: |
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| 187 | throw new IllegalStateException("Invalid state :" + stateToString(state)); |
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| 188 | } |
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| 189 | } |
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| 190 | |
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| 191 | /** |
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| 192 | * This method is valid, if {@link #getState()} returns {@link EntityState#T_FIELD}. |
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| 193 | * @return String with the fields raw contents. |
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| 194 | * @throws IllegalStateException {@link #getState()} returns another |
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| 195 | * value than {@link EntityState#T_FIELD}. |
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| 196 | */ |
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| 197 | public RawField getField() { |
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| 198 | switch (getState()) { |
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| 199 | case T_FIELD: |
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| 200 | return field; |
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| 201 | default: |
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| 202 | throw new IllegalStateException("Invalid state :" + stateToString(state)); |
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| 203 | } |
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| 204 | } |
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| 205 | |
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| 206 | /** |
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| 207 | * Monitors the given event. |
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| 208 | * Subclasses may override to perform actions upon events. |
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| 209 | * Base implementation logs at warn. |
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| 210 | * @param event <code>Event</code>, not null |
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| 211 | * @throws MimeException subclasses may elect to throw this exception upon |
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| 212 | * invalid content |
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| 213 | * @throws IOException subclasses may elect to throw this exception |
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| 214 | */ |
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| 215 | protected void monitor(Event event) throws MimeException, IOException { |
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| 216 | if (monitor.isListening()) { |
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| 217 | String message = message(event); |
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| 218 | if (monitor.warn(message, "ignoring")) { |
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| 219 | throw new MimeParseEventException(event); |
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| 220 | } |
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| 221 | } |
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| 222 | } |
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| 223 | |
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| 224 | /** |
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| 225 | * Creates an indicative message suitable for display |
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| 226 | * based on the given event and the current state of the system. |
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| 227 | * @param event <code>Event</code>, not null |
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| 228 | * @return message suitable for use as a message in an exception |
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| 229 | * or for logging |
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| 230 | */ |
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| 231 | protected String message(Event event) { |
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| 232 | final String message; |
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| 233 | if (event == null) { |
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| 234 | message = "Event is unexpectedly null."; |
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| 235 | } else { |
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| 236 | message = event.toString(); |
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| 237 | } |
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| 238 | |
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| 239 | int lineNumber = getLineNumber(); |
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| 240 | if (lineNumber <= 0) |
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| 241 | return message; |
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| 242 | else |
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| 243 | return "Line " + lineNumber + ": " + message; |
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| 244 | } |
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| 245 | |
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| 246 | @Override |
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| 247 | public String toString() { |
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| 248 | return getClass().getName() + " [" + stateToString(state) |
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| 249 | + "][" + body.getMimeType() + "][" + body.getBoundary() + "]"; |
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| 250 | } |
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| 251 | |
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| 252 | /** |
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| 253 | * Renders a state as a string suitable for logging. |
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| 254 | * @param state |
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| 255 | * @return rendered as string, not null |
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| 256 | */ |
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| 257 | public static final String stateToString(EntityState state) { |
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| 258 | final String result; |
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| 259 | switch (state) { |
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| 260 | case T_END_OF_STREAM: |
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| 261 | result = "End of stream"; |
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| 262 | break; |
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| 263 | case T_START_MESSAGE: |
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| 264 | result = "Start message"; |
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| 265 | break; |
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| 266 | case T_END_MESSAGE: |
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| 267 | result = "End message"; |
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| 268 | break; |
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| 269 | case T_RAW_ENTITY: |
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| 270 | result = "Raw entity"; |
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| 271 | break; |
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| 272 | case T_START_HEADER: |
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| 273 | result = "Start header"; |
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| 274 | break; |
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| 275 | case T_FIELD: |
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| 276 | result = "Field"; |
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| 277 | break; |
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| 278 | case T_END_HEADER: |
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| 279 | result = "End header"; |
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| 280 | break; |
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| 281 | case T_START_MULTIPART: |
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| 282 | result = "Start multipart"; |
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| 283 | break; |
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| 284 | case T_END_MULTIPART: |
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| 285 | result = "End multipart"; |
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| 286 | break; |
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| 287 | case T_PREAMBLE: |
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| 288 | result = "Preamble"; |
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| 289 | break; |
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| 290 | case T_EPILOGUE: |
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| 291 | result = "Epilogue"; |
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| 292 | break; |
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| 293 | case T_START_BODYPART: |
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| 294 | result = "Start bodypart"; |
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| 295 | break; |
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| 296 | case T_END_BODYPART: |
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| 297 | result = "End bodypart"; |
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| 298 | break; |
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| 299 | case T_BODY: |
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| 300 | result = "Body"; |
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| 301 | break; |
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| 302 | default: |
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| 303 | result = "Unknown"; |
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| 304 | break; |
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| 305 | } |
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| 306 | return result; |
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| 307 | } |
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| 308 | |
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| 309 | } |
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