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/*
 * Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0, which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package 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. 

*

* This class is mostly intended for service providers. MimeMessage * and MimeBody use this class for holding their headers.

*

*


A note on RFC822 and MIME headers

*

* RFC822 and MIME header fields 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 setHeader, addHeader, and * 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.

* * @author John Mani * @author Bill Shannon */ final class InternetHeaders { private final FinalArrayList 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.

*

* 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 null * if no headers with the specified name exist. * * @param name header name * @return array of header values, or null if none */ List getHeader(String name) { // XXX - should we just step through in index order? FinalArrayList v = new FinalArrayList(); // accumulate return values int len = headers.size(); for( int i=0; i 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.

*

* 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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