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/*
* RequestConsumer.java February 2001
*
* Copyright (C) 2001, Niall Gallagher
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
package org.simpleframework.http.message;
import java.util.List;
import org.simpleframework.http.Address;
import org.simpleframework.http.Path;
import org.simpleframework.http.Query;
import org.simpleframework.http.parse.AddressParser;
/**
* The RequestConsumer object is used to parse the HTTP
* request line followed by the HTTP message headers. This parses the
* request URI such that the query parameters and path are extracted
* and normalized. It performs this using external parsers, which
* will remove and escaped characters and normalize the path segments.
* Finally this exposes the HTTP version used using the major and
* minor numbers sent with the HTTP request.
*
* @author Niall Gallagher
*/
public class RequestConsumer extends HeaderConsumer {
/**
* This is the address parser used to parse the request URI.
*/
protected AddressParser parser;
/**
* This is the method token send with the HTTP request header.
*/
protected String method;
/**
* This represents the raw request URI in an unparsed form.
*/
protected String target;
/**
* This is the major version number of the HTTP request header.
*/
protected int major;
/**
* This is the minor version number of the HTTP request header.
*/
protected int minor;
/**
* Constructor for the RequestConsumer object. This
* is used to create a consumer which can consume a HTTP request
* header and provide the consumed contents via a known interface.
* This also further breaks down the request URI for convenience.
*/
public RequestConsumer() {
super();
}
/**
* This can be used to get the target specified for this HTTP
* request. This corresponds to the URI sent in the request
* line. Typically this will be the path part of the URI, but
* can be the full URI if the request is a proxy request.
*
* @return the target URI that this HTTP request specifies
*/
public String getTarget() {
return target;
}
/**
* This is used to acquire the address from the request line.
* An address is the full URI including the scheme, domain,
* port and the query parts. This allows various parameters
* to be acquired without having to parse the target.
*
* @return this returns the address of the request line
*/
public Address getAddress() {
if(parser == null) {
parser = new AddressParser(target);
}
return parser;
}
/**
* This method is used to acquire the query part from the
* HTTP request URI target. This will return only the values
* that have been extracted from the request URI target.
*
* @return the query associated with the HTTP target URI
*/
public Query getQuery() {
return getAddress().getQuery();
}
/**
* This is used to acquire the path as extracted from the
* the HTTP request URI. The Path object that is
* provided by this method is immutable, it represents the
* normalized path only part from the request URI.
*
* @return this returns the normalized path for the request
*/
public Path getPath() {
return getAddress().getPath();
}
/**
* This can be used to get the HTTP method for this request. The
* HTTP specification RFC 2616 specifies the HTTP request methods
* in section 9, Method Definitions. Typically this will be a
* GET or POST method, but can be any valid alphabetic token.
*
* @return the HTTP method that this request has specified
*/
public String getMethod() {
return method;
}
/**
* This can be used to get the major number from a HTTP version.
* The major version corrosponds to the major protocol type, that
* is the 1 of a HTTP/1.0 version string. Typically the major
* type is 1, by can be 0 for HTTP/0.9 clients.
*
* @return the major version number for the HTTP message
*/
public int getMajor() {
return major;
}
/**
* This can be used to get the minor number from a HTTP version.
* The minor version corrosponds to the minor protocol type, that
* is the 0 of a HTTP/1.0 version string. This number is typically
* used to determine whether persistent connections are supported.
*
* @return the minor version number for the HTTP message
*/
public int getMinor() {
return minor;
}
/**
* This can be used to get the date of the first message header
* that has the specified name. This is a convenience method that
* avoids having to deal with parsing the value of the requested
* HTTP message header. This returns -1 if theres no HTTP header
* value for the specified name.
*
* @param name the HTTP message header to get the value from
*
* @return this returns the date as a long from the header value
*/
public long getDate(String name) {
return header.getDate(name);
}
/**
* This can be used to get the integer of the first message header
* that has the specified name. This is a convenience method that
* avoids having to deal with parsing the value of the requested
* HTTP message header. This returns -1 if theres no HTTP header
* value for the specified name.
*
* @param name the HTTP message header to get the value from
*
* @return this returns the date as a long from the header value
*/
public int getInteger(String name) {
return header.getInteger(name);
}
/**
* This method is used to get a List of the names
* for the headers. This will provide the original names for the
* HTTP headers for the message. Modifications to the provided
* list will not affect the header, the list is a simple copy.
*
* @return this returns a list of the names within the header
*/
public List getNames() {
return header.getNames();
}
/**
* This method is invoked after the terminal token has been read.
* It is used to process the consumed data and is typically used to
* parse the input such that it can be used by the subclass for
* some useful puropse. This is called only once by the consumer.
*/
@Override
protected void process() {
method();
target();
version();
end();
headers();
}
/**
* This will parse URI target from the first line of the header
* and store the parsed string internally. The target token is
* used to create an Address object which provides
* all the details of the target including the query part.
*/
private void target() {
Token token = new Token(array, pos, 0);
while(pos < count){
if(white(array[pos])){
pos++;
break;
}
token.size++;
pos++;
}
target = token.toString();
}
/**
* This will parse HTTP method from the first line of the header
* and store the parsed string internally. The method is used to
* determine what action to take with the request, it also acts
* as a means to determine the semantics of the request.
*/
private void method() {
Token token = new Token(array, pos, 0);
while(pos < count){
if(white(array[pos])){
pos++;
break;
}
token.size++;
pos++;
}
method = token.toString();
}
/**
* This will parse HTTP version from the first line of the header
* and store the parsed string internally. The method is used to
* determine what version of HTTP is being used. Typically this
* will be HTTP/1.1 however HTTP/1.0 must be supported and this
* has different connection semantics with regards to pipelines.
*/
protected void version() {
pos += 5; /* "HTTP/" */
major(); /* "1" */
pos++; /* "." */
minor(); /* "1" */
}
/**
* This will parse the header from the current offset and convert
* the bytes found into an int as it parses the digits it comes
* accross. This will cease to parse bytes when it encounters a
* non digit byte or the end of the readable bytes.
*/
private void major() {
while(pos < count){
if(!digit(array[pos])){
break;
}
major *= 10;
major += array[pos];
major -= '0';
pos++;
}
}
/**
* This will parse the header from the current offset and convert
* the bytes found into an int as it parses the digits it comes
* accross. This will cease to parse bytes when it encounters a
* non digit byte or the end of the readable bytes.
*/
private void minor() {
while(pos < count){
if(!digit(array[pos])){
break;
}
minor *= 10;
minor += array[pos];
minor -= '0';
pos++;
}
}
/**
* This is used to determine if a given ISO-8859-1 byte is a digit
* character, between an ISO-8859-1 0 and 9. If it is, this will
* return true otherwise it returns false.
*
* @param octet this is to be checked to see if it is a digit
*
* @return true if the byte is a digit character, false otherwise
*/
protected boolean digit(byte octet) {
return octet >= '0' && octet <= '9';
}
/**
* This method returns a CharSequence holding the data
* consumed for the request. A character sequence is returned as it
* can provide a much more efficient means of representing the header
* data by just wrapping the consumed byte array.
*
* @return this returns the characters consumed for the header
*/
public CharSequence getHeader() {
return new Token(array, 0, count);
}
/**
* This is used to convert the byte range to a string. This
* will use UTF-8 encoding for the string which is compatible
* with the HTTP default header encoding of ISO-8859-1.
*
* @return the encoded string representing the token
*/
public String toString() {
return getHeader().toString();
}
/**
* This is a sequence of characters representing the header data
* consumed. Here the internal byte buffer is simply wrapped so
* that it can be a represented as a CharSequence.
* Wrapping the consumed array in this manner ensures that no
* further memory allocation is required.
*/
private static class Token implements CharSequence {
/**
* This is the array that contains the header bytes.
*/
public byte[] array;
/**
* This is the number of bytes to use from the array.
*/
public int size;
/**
* This is the offset in the array the token begins at.
*/
public int off;
/**
* Constructor for the ByteSequence object. This
* is used to represent the data that has been consumed by
* the header. It acts as a light weight wrapper for the data
* and avoids having to create new strings for each event.
*
* @param array this is the array representing the header
* @param off the starting offset for the token range
* @param size the number of bytes used for the token
*/
private Token(byte[] array, int off, int size) {
this.array = array;
this.size = size;
this.off = off;
}
/**
* This returns the length of the header in bytes. The length
* includes the request line and all of the control characters
* including the carriage return and line feed at the end of
* the request header.
*
* @return this returns the number of bytes for the header
*/
public int length() {
return size;
}
/**
* This is used to acquire the character at the specified index.
* Characters returned from this method are simply the bytes
* casted to a character. This may not convert the character
* correctly and a more sensible method should be used.
*
* @param index the index to extract the character from
*
* @return this returns the character found at the index
*/
public char charAt(int index) {
return (char) array[index];
}
/**
* This returns a section of characters within the specified
* range. Acquiring a section in this manner is simply done by
* setting a start and end offset within the internal array.
*
* @param start this is the start index to be used
* @param end this is the end index to be used
*
* @return this returns a new sequence within the original
*/
public CharSequence subSequence(int start, int end) {
return new Token(array, start, end - start);
}
/**
* This is used to create a string from the header bytes. This
* converts the header bytes to a string using a compatible
* encoding. This may produce different results depending on
* the time it is invoked, as the header consumes more data.
*
* @return this returns an encoded version of the header
*/
public String toString() {
return toString("UTF-8");
}
/**
* This is used to create a string from the header bytes. This
* converts the header bytes to a string using a compatible
* encoding. This may produce different results depending on
* the time it is invoked, as the header consumes more data.
*
* @param charset this is the encoding to use for the header
*
* @return this returns an encoded version of the header
*/
public String toString(String charset) {
try {
return new String(array, off, size, charset);
} catch(Exception e) {
return null;
}
}
}
}