org.jboss.netty.handler.codec.http

Class QueryStringDecoder

java.lang.Object

org.jboss.netty.handler.codec.http.QueryStringDecoder

public class QueryStringDecoder
extends java.lang.Object

Splits an HTTP query string into a path string and key-value parameter pairs. This decoder is for one time use only. Create a new instance for each URI:

 QueryStringDecoder decoder = new QueryStringDecoder("/hello?recipient=world&x=1;y=2");
 assert decoder.getPath().equals("/hello");
 assert decoder.getParameters().get("recipient").get(0).equals("world");
 assert decoder.getParameters().get("x").get(0).equals("1");
 assert decoder.getParameters().get("y").get(0).equals("2");
 

This decoder can also decode the content of an HTTP POST request whose content type is application/x-www-form-urlencoded:

 QueryStringDecoder decoder = new QueryStringDecoder("recipient=world&x=1;y=2", false);
 ...
 

HashDOS vulnerability fix

As a workaround to the HashDOS vulnerability, the decoder limits the maximum number of decoded key-value parameter pairs, up to 1024 by default, and you can configure it when you construct the decoder by passing an additional integer parameter.

See Also:

QueryStringEncoder

Field Summary

Fields

Modifier and Type	Field and Description
private java.nio.charset.Charset	charset
private static int	DEFAULT_MAX_PARAMS
private boolean	hasPath
private int	maxParams
private int	nParams
private java.util.Map<java.lang.String,java.util.List<java.lang.String>>	params
private java.lang.String	path
private java.lang.String	uri

Constructor Summary

Constructors

Constructor and Description
QueryStringDecoder(java.lang.String uri) Creates a new decoder that decodes the specified URI.
QueryStringDecoder(java.lang.String uri, boolean hasPath) Creates a new decoder that decodes the specified URI encoded in the specified charset.
QueryStringDecoder(java.lang.String uri, java.nio.charset.Charset charset) Creates a new decoder that decodes the specified URI encoded in the specified charset.
QueryStringDecoder(java.lang.String uri, java.nio.charset.Charset charset, boolean hasPath) Creates a new decoder that decodes the specified URI encoded in the specified charset.
QueryStringDecoder(java.lang.String uri, java.nio.charset.Charset charset, boolean hasPath, int maxParams) Creates a new decoder that decodes the specified URI encoded in the specified charset.
QueryStringDecoder(java.net.URI uri) Creates a new decoder that decodes the specified URI.
QueryStringDecoder(java.net.URI uri, java.nio.charset.Charset charset) Creates a new decoder that decodes the specified URI encoded in the specified charset.
QueryStringDecoder(java.net.URI uri, java.nio.charset.Charset charset, int maxParams) Creates a new decoder that decodes the specified URI encoded in the specified charset.

Method Summary

Modifier and Type	Method and Description
private boolean	addParam(java.util.Map<java.lang.String,java.util.List<java.lang.String>> params, java.lang.String name, java.lang.String value)
static java.lang.String	decodeComponent(java.lang.String s) Decodes a bit of an URL encoded by a browser.
static java.lang.String	decodeComponent(java.lang.String s, java.nio.charset.Charset charset) Decodes a bit of an URL encoded by a browser.
private static char	decodeHexNibble(char c) Helper to decode half of a hexadecimal number from a string.
private void	decodeParams(java.lang.String s)
java.util.Map<java.lang.String,java.util.List<java.lang.String>>	getParameters() Returns the decoded key-value parameter pairs of the URI.
java.lang.String	getPath() Returns the decoded path string of the URI.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_MAX_PARAMS

private static final int DEFAULT_MAX_PARAMS

See Also:

Constant Field Values

charset

private final java.nio.charset.Charset charset

uri

private final java.lang.String uri

hasPath

private final boolean hasPath

maxParams

private final int maxParams

path

private java.lang.String path

params

private java.util.Map<java.lang.String,java.util.List<java.lang.String>> params

nParams

private int nParams

Constructor Detail

QueryStringDecoder

public QueryStringDecoder(java.lang.String uri)

Creates a new decoder that decodes the specified URI. The decoder will assume that the query string is encoded in UTF-8.

QueryStringDecoder

public QueryStringDecoder(java.lang.String uri,
                          boolean hasPath)

Creates a new decoder that decodes the specified URI encoded in the specified charset.

QueryStringDecoder

public QueryStringDecoder(java.lang.String uri,
                          java.nio.charset.Charset charset)

Creates a new decoder that decodes the specified URI encoded in the specified charset.

QueryStringDecoder

public QueryStringDecoder(java.lang.String uri,
                          java.nio.charset.Charset charset,
                          boolean hasPath)

Creates a new decoder that decodes the specified URI encoded in the specified charset.

QueryStringDecoder

public QueryStringDecoder(java.lang.String uri,
                          java.nio.charset.Charset charset,
                          boolean hasPath,
                          int maxParams)

Creates a new decoder that decodes the specified URI encoded in the specified charset.

QueryStringDecoder

public QueryStringDecoder(java.net.URI uri)

Creates a new decoder that decodes the specified URI. The decoder will assume that the query string is encoded in UTF-8.

QueryStringDecoder

public QueryStringDecoder(java.net.URI uri,
                          java.nio.charset.Charset charset)

Creates a new decoder that decodes the specified URI encoded in the specified charset.

QueryStringDecoder

public QueryStringDecoder(java.net.URI uri,
                          java.nio.charset.Charset charset,
                          int maxParams)

Creates a new decoder that decodes the specified URI encoded in the specified charset.

Method Detail

getPath

public java.lang.String getPath()

Returns the decoded path string of the URI.

getParameters

public java.util.Map<java.lang.String,java.util.List<java.lang.String>> getParameters()

Returns the decoded key-value parameter pairs of the URI.

decodeParams

private void decodeParams(java.lang.String s)

addParam

private boolean addParam(java.util.Map<java.lang.String,java.util.List<java.lang.String>> params,
                         java.lang.String name,
                         java.lang.String value)

decodeComponent

public static java.lang.String decodeComponent(java.lang.String s)

Decodes a bit of an URL encoded by a browser.

This is equivalent to calling decodeComponent(String, Charset) with the UTF-8 charset (recommended to comply with RFC 3986, Section 2).

Parameters:

s - The string to decode (can be empty).

Returns:

The decoded string, or s if there's nothing to decode. If the string to decode is null, returns an empty string.

Throws:

java.lang.IllegalArgumentException - if the string contains a malformed escape sequence.

decodeComponent

public static java.lang.String decodeComponent(java.lang.String s,
                                               java.nio.charset.Charset charset)

Decodes a bit of an URL encoded by a browser.

The string is expected to be encoded as per RFC 3986, Section 2. This is the encoding used by JavaScript functions encodeURI and encodeURIComponent, but not escape. For example in this encoding, é (in Unicode U+00E9 or in UTF-8 0xC3 0xA9) is encoded as %C3%A9 or %c3%a9.

This is essentially equivalent to calling URLDecoder.decode(s, charset.name()) except that it's over 2x faster and generates less garbage for the GC. Actually this function doesn't allocate any memory if there's nothing to decode, the argument itself is returned.

Parameters:

s - The string to decode (can be empty).

charset - The charset to use to decode the string (should really be CharsetUtil.UTF_8.

Returns:

The decoded string, or s if there's nothing to decode. If the string to decode is null, returns an empty string.

Throws:

java.lang.IllegalArgumentException - if the string contains a malformed escape sequence.

decodeHexNibble

private static char decodeHexNibble(char c)

Helper to decode half of a hexadecimal number from a string.

Parameters:

c - The ASCII character of the hexadecimal number to decode. Must be in the range [0-9a-fA-F].

Returns:

The hexadecimal value represented in the ASCII character given, or Character.MAX_VALUE if the character is invalid.