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Java example source code file (InternetHeaders.java)

This example Java source code file (InternetHeaders.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

content\-description, error, finalarraylist, hdr, header, i\'m, internetheaders, ioexception, nosuchelementexception, override, rfc822, string, stringbuilder, stringindexoutofboundsexception, util

The InternetHeaders.java Java example source code

/*
 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.xml.internal.org.jvnet.mimepull;

import java.io.IOException;
import java.util.NoSuchElementException;
import java.util.List;

/**
 * InternetHeaders is a utility class that manages RFC822 style
 * headers. Given an RFC822 format message stream, it reads lines
 * until the blank line that indicates end of header. The input stream
 * is positioned at the start of the body. The lines are stored
 * within the object and can be extracted as either Strings or
 * {@link Header} objects. <p>
 * <p/>
 * This class is mostly intended for service providers. MimeMessage
 * and MimeBody use this class for holding their headers. <p>
 * <p/>
 * <hr> A note on RFC822 and MIME headers

* <p/> * RFC822 and MIME header fields <strong>must contain only * US-ASCII characters. If a header contains non US-ASCII characters, * it must be encoded as per the rules in RFC 2047. The MimeUtility * class provided in this package can be used to to achieve this. * Callers of the <code>setHeader, addHeader, and * <code>addHeaderLine methods are responsible for enforcing * the MIME requirements for the specified headers. In addition, these * header fields must be folded (wrapped) before being sent if they * exceed the line length limitation for the transport (1000 bytes for * SMTP). Received headers may have been folded. The application is * responsible for folding and unfolding headers as appropriate. <p> * * @author John Mani * @author Bill Shannon */ final class InternetHeaders { private final FinalArrayList<Hdr> headers = new FinalArrayList(); /** * Read and parse the given RFC822 message stream till the * blank line separating the header from the body. Store the * header lines inside this InternetHeaders object. <p> * <p/> * Note that the header lines are added into this InternetHeaders * object, so any existing headers in this object will not be * affected. * * @param lis RFC822 input stream */ InternetHeaders(MIMEParser.LineInputStream lis) { // Read header lines until a blank line. It is valid // to have BodyParts with no header lines. String line; String prevline = null; // the previous header line, as a string // a buffer to accumulate the header in, when we know it's needed StringBuilder lineBuffer = new StringBuilder(); try { //while ((line = lis.readLine()) != null) { do { line = lis.readLine(); if (line != null && (line.startsWith(" ") || line.startsWith("\t"))) { // continuation of header if (prevline != null) { lineBuffer.append(prevline); prevline = null; } lineBuffer.append("\r\n"); lineBuffer.append(line); } else { // new header if (prevline != null) { addHeaderLine(prevline); } else if (lineBuffer.length() > 0) { // store previous header first addHeaderLine(lineBuffer.toString()); lineBuffer.setLength(0); } prevline = line; } } while (line != null && line.length() > 0); } catch (IOException ioex) { throw new MIMEParsingException("Error in input stream", ioex); } } /** * Return all the values for the specified header. The * values are String objects. Returns <code>null * if no headers with the specified name exist. * * @param name header name * @return array of header values, or null if none */ List<String> getHeader(String name) { // XXX - should we just step through in index order? FinalArrayList<String> v = new FinalArrayList(); // accumulate return values int len = headers.size(); for( int i=0; i<len; i++ ) { Hdr h = (Hdr) headers.get(i); if (name.equalsIgnoreCase(h.name)) { v.add(h.getValue()); } } return (v.size() == 0) ? null : v; } /** * Return all the headers as an Enumeration of * {@link Header} objects. * * @return Header objects */ FinalArrayList<? extends Header> getAllHeaders() { return headers; // conceptually it should be read-only, but for performance reason I'm not wrapping it here } /** * Add an RFC822 header line to the header store. * If the line starts with a space or tab (a continuation line), * add it to the last header line in the list. <p> * <p/> * Note that RFC822 headers can only contain US-ASCII characters * * @param line raw RFC822 header line */ void addHeaderLine(String line) { try { char c = line.charAt(0); if (c == ' ' || c == '\t') { Hdr h = (Hdr) headers.get(headers.size() - 1); h.line += "\r\n" + line; } else { headers.add(new Hdr(line)); } } catch (StringIndexOutOfBoundsException e) { // line is empty, ignore it } catch (NoSuchElementException e) { // XXX - vector is empty? } } } /* * A private utility class to represent an individual header. */ class Hdr implements Header { String name; // the canonicalized (trimmed) name of this header // XXX - should name be stored in lower case? String line; // the entire RFC822 header "line" /* * Constructor that takes a line and splits out * the header name. */ Hdr(String l) { int i = l.indexOf(':'); if (i < 0) { // should never happen name = l.trim(); } else { name = l.substring(0, i).trim(); } line = l; } /* * Constructor that takes a header name and value. */ Hdr(String n, String v) { name = n; line = n + ": " + v; } /* * Return the "name" part of the header line. */ @Override public String getName() { return name; } /* * Return the "value" part of the header line. */ @Override public String getValue() { int i = line.indexOf(':'); if (i < 0) { return line; } int j; if (name.equalsIgnoreCase("Content-Description")) { // Content-Description should retain the folded whitespace after header unfolding - // rf. RFC2822 section 2.2.3, rf. RFC2822 section 3.2.3 for (j = i + 1; j < line.length(); j++) { char c = line.charAt(j); if (!(/*c == ' ' ||*/c == '\t' || c == '\r' || c == '\n')) { break; } } } else { // skip whitespace after ':' for (j = i + 1; j < line.length(); j++) { char c = line.charAt(j); if (!(c == ' ' || c == '\t' || c == '\r' || c == '\n')) { break; } } } return line.substring(j); } }

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