michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.message;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.ProtocolVersion;
michael@0: import ch.boye.httpclientandroidlib.RequestLine;
michael@0: import ch.boye.httpclientandroidlib.StatusLine;
michael@0: import ch.boye.httpclientandroidlib.Header;
michael@0: import ch.boye.httpclientandroidlib.FormattedHeader;
michael@0: import ch.boye.httpclientandroidlib.util.CharArrayBuffer;
michael@0: 
michael@0: /**
michael@0:  * Interface for formatting elements of the HEAD section of an HTTP message.
michael@0:  * This is the complement to {@link LineParser}.
michael@0:  * There are individual methods for formatting a request line, a
michael@0:  * status line, or a header line. The formatting does <i>not</i> include the
michael@0:  * trailing line break sequence CR-LF.
michael@0:  * The formatted lines are returned in memory, the formatter does not depend
michael@0:  * on any specific IO mechanism.
michael@0:  * Instances of this interface are expected to be stateless and thread-safe.
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public class BasicLineFormatter implements LineFormatter {
michael@0: 
michael@0:     /**
michael@0:      * A default instance of this class, for use as default or fallback.
michael@0:      * Note that {@link BasicLineFormatter} is not a singleton, there can
michael@0:      * be many instances of the class itself and of derived classes.
michael@0:      * The instance here provides non-customized, default behavior.
michael@0:      */
michael@0:     public final static BasicLineFormatter DEFAULT = new BasicLineFormatter();
michael@0: 
michael@0: 
michael@0: 
michael@0:     // public default constructor
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Obtains a buffer for formatting.
michael@0:      *
michael@0:      * @param buffer    a buffer already available, or <code>null</code>
michael@0:      *
michael@0:      * @return  the cleared argument buffer if there is one, or
michael@0:      *          a new empty buffer that can be used for formatting
michael@0:      */
michael@0:     protected CharArrayBuffer initBuffer(CharArrayBuffer buffer) {
michael@0:         if (buffer != null) {
michael@0:             buffer.clear();
michael@0:         } else {
michael@0:             buffer = new CharArrayBuffer(64);
michael@0:         }
michael@0:         return buffer;
michael@0:     }
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Formats a protocol version.
michael@0:      *
michael@0:      * @param version           the protocol version to format
michael@0:      * @param formatter         the formatter to use, or
michael@0:      *                          <code>null</code> for the
michael@0:      *                          {@link #DEFAULT default}
michael@0:      *
michael@0:      * @return  the formatted protocol version
michael@0:      */
michael@0:     public final static
michael@0:         String formatProtocolVersion(final ProtocolVersion version,
michael@0:                                      LineFormatter formatter) {
michael@0:         if (formatter == null)
michael@0:             formatter = BasicLineFormatter.DEFAULT;
michael@0:         return formatter.appendProtocolVersion(null, version).toString();
michael@0:     }
michael@0: 
michael@0: 
michael@0:     // non-javadoc, see interface LineFormatter
michael@0:     public CharArrayBuffer appendProtocolVersion(final CharArrayBuffer buffer,
michael@0:                                                  final ProtocolVersion version) {
michael@0:         if (version == null) {
michael@0:             throw new IllegalArgumentException
michael@0:                 ("Protocol version may not be null");
michael@0:         }
michael@0: 
michael@0:         // can't use initBuffer, that would clear the argument!
michael@0:         CharArrayBuffer result = buffer;
michael@0:         final int len = estimateProtocolVersionLen(version);
michael@0:         if (result == null) {
michael@0:             result = new CharArrayBuffer(len);
michael@0:         } else {
michael@0:             result.ensureCapacity(len);
michael@0:         }
michael@0: 
michael@0:         result.append(version.getProtocol());
michael@0:         result.append('/');
michael@0:         result.append(Integer.toString(version.getMajor()));
michael@0:         result.append('.');
michael@0:         result.append(Integer.toString(version.getMinor()));
michael@0: 
michael@0:         return result;
michael@0:     }
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Guesses the length of a formatted protocol version.
michael@0:      * Needed to guess the length of a formatted request or status line.
michael@0:      *
michael@0:      * @param version   the protocol version to format, or <code>null</code>
michael@0:      *
michael@0:      * @return  the estimated length of the formatted protocol version,
michael@0:      *          in characters
michael@0:      */
michael@0:     protected int estimateProtocolVersionLen(final ProtocolVersion version) {
michael@0:         return version.getProtocol().length() + 4; // room for "HTTP/1.1"
michael@0:     }
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Formats a request line.
michael@0:      *
michael@0:      * @param reqline           the request line to format
michael@0:      * @param formatter         the formatter to use, or
michael@0:      *                          <code>null</code> for the
michael@0:      *                          {@link #DEFAULT default}
michael@0:      *
michael@0:      * @return  the formatted request line
michael@0:      */
michael@0:     public final static String formatRequestLine(final RequestLine reqline,
michael@0:                                                  LineFormatter formatter) {
michael@0:         if (formatter == null)
michael@0:             formatter = BasicLineFormatter.DEFAULT;
michael@0:         return formatter.formatRequestLine(null, reqline).toString();
michael@0:     }
michael@0: 
michael@0: 
michael@0:     // non-javadoc, see interface LineFormatter
michael@0:     public CharArrayBuffer formatRequestLine(CharArrayBuffer buffer,
michael@0:                                              RequestLine reqline) {
michael@0:         if (reqline == null) {
michael@0:             throw new IllegalArgumentException
michael@0:                 ("Request line may not be null");
michael@0:         }
michael@0: 
michael@0:         CharArrayBuffer result = initBuffer(buffer);
michael@0:         doFormatRequestLine(result, reqline);
michael@0: 
michael@0:         return result;
michael@0:     }
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Actually formats a request line.
michael@0:      * Called from {@link #formatRequestLine}.
michael@0:      *
michael@0:      * @param buffer    the empty buffer into which to format,
michael@0:      *                  never <code>null</code>
michael@0:      * @param reqline   the request line to format, never <code>null</code>
michael@0:      */
michael@0:     protected void doFormatRequestLine(final CharArrayBuffer buffer,
michael@0:                                        final RequestLine reqline) {
michael@0:         final String method = reqline.getMethod();
michael@0:         final String uri    = reqline.getUri();
michael@0: 
michael@0:         // room for "GET /index.html HTTP/1.1"
michael@0:         int len = method.length() + 1 + uri.length() + 1 +
michael@0:             estimateProtocolVersionLen(reqline.getProtocolVersion());
michael@0:         buffer.ensureCapacity(len);
michael@0: 
michael@0:         buffer.append(method);
michael@0:         buffer.append(' ');
michael@0:         buffer.append(uri);
michael@0:         buffer.append(' ');
michael@0:         appendProtocolVersion(buffer, reqline.getProtocolVersion());
michael@0:     }
michael@0: 
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Formats a status line.
michael@0:      *
michael@0:      * @param statline          the status line to format
michael@0:      * @param formatter         the formatter to use, or
michael@0:      *                          <code>null</code> for the
michael@0:      *                          {@link #DEFAULT default}
michael@0:      *
michael@0:      * @return  the formatted status line
michael@0:      */
michael@0:     public final static String formatStatusLine(final StatusLine statline,
michael@0:                                                 LineFormatter formatter) {
michael@0:         if (formatter == null)
michael@0:             formatter = BasicLineFormatter.DEFAULT;
michael@0:         return formatter.formatStatusLine(null, statline).toString();
michael@0:     }
michael@0: 
michael@0: 
michael@0:     // non-javadoc, see interface LineFormatter
michael@0:     public CharArrayBuffer formatStatusLine(final CharArrayBuffer buffer,
michael@0:                                             final StatusLine statline) {
michael@0:         if (statline == null) {
michael@0:             throw new IllegalArgumentException
michael@0:                 ("Status line may not be null");
michael@0:         }
michael@0: 
michael@0:         CharArrayBuffer result = initBuffer(buffer);
michael@0:         doFormatStatusLine(result, statline);
michael@0: 
michael@0:         return result;
michael@0:     }
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Actually formats a status line.
michael@0:      * Called from {@link #formatStatusLine}.
michael@0:      *
michael@0:      * @param buffer    the empty buffer into which to format,
michael@0:      *                  never <code>null</code>
michael@0:      * @param statline  the status line to format, never <code>null</code>
michael@0:      */
michael@0:     protected void doFormatStatusLine(final CharArrayBuffer buffer,
michael@0:                                       final StatusLine statline) {
michael@0: 
michael@0:         int len = estimateProtocolVersionLen(statline.getProtocolVersion())
michael@0:             + 1 + 3 + 1; // room for "HTTP/1.1 200 "
michael@0:         final String reason = statline.getReasonPhrase();
michael@0:         if (reason != null) {
michael@0:             len += reason.length();
michael@0:         }
michael@0:         buffer.ensureCapacity(len);
michael@0: 
michael@0:         appendProtocolVersion(buffer, statline.getProtocolVersion());
michael@0:         buffer.append(' ');
michael@0:         buffer.append(Integer.toString(statline.getStatusCode()));
michael@0:         buffer.append(' '); // keep whitespace even if reason phrase is empty
michael@0:         if (reason != null) {
michael@0:             buffer.append(reason);
michael@0:         }
michael@0:     }
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Formats a header.
michael@0:      *
michael@0:      * @param header            the header to format
michael@0:      * @param formatter         the formatter to use, or
michael@0:      *                          <code>null</code> for the
michael@0:      *                          {@link #DEFAULT default}
michael@0:      *
michael@0:      * @return  the formatted header
michael@0:      */
michael@0:     public final static String formatHeader(final Header header,
michael@0:                                             LineFormatter formatter) {
michael@0:         if (formatter == null)
michael@0:             formatter = BasicLineFormatter.DEFAULT;
michael@0:         return formatter.formatHeader(null, header).toString();
michael@0:     }
michael@0: 
michael@0: 
michael@0:     // non-javadoc, see interface LineFormatter
michael@0:     public CharArrayBuffer formatHeader(CharArrayBuffer buffer,
michael@0:                                         Header header) {
michael@0:         if (header == null) {
michael@0:             throw new IllegalArgumentException
michael@0:                 ("Header may not be null");
michael@0:         }
michael@0:         CharArrayBuffer result = null;
michael@0: 
michael@0:         if (header instanceof FormattedHeader) {
michael@0:             // If the header is backed by a buffer, re-use the buffer
michael@0:             result = ((FormattedHeader)header).getBuffer();
michael@0:         } else {
michael@0:             result = initBuffer(buffer);
michael@0:             doFormatHeader(result, header);
michael@0:         }
michael@0:         return result;
michael@0: 
michael@0:     } // formatHeader
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Actually formats a header.
michael@0:      * Called from {@link #formatHeader}.
michael@0:      *
michael@0:      * @param buffer    the empty buffer into which to format,
michael@0:      *                  never <code>null</code>
michael@0:      * @param header    the header to format, never <code>null</code>
michael@0:      */
michael@0:     protected void doFormatHeader(final CharArrayBuffer buffer,
michael@0:                                   final Header header) {
michael@0:         final String name = header.getName();
michael@0:         final String value = header.getValue();
michael@0: 
michael@0:         int len = name.length() + 2;
michael@0:         if (value != null) {
michael@0:             len += value.length();
michael@0:         }
michael@0:         buffer.ensureCapacity(len);
michael@0: 
michael@0:         buffer.append(name);
michael@0:         buffer.append(": ");
michael@0:         if (value != null) {
michael@0:             buffer.append(value);
michael@0:         }
michael@0:     }
michael@0: 
michael@0: 
michael@0: } // class BasicLineFormatter