Package de.aristaflow.adept2.util.net

Class HttpTools

java.lang.Object

de.aristaflow.adept2.util.net.HttpTools

public class HttpTools
extends Object

Tool methods for simplifying life with HTTP.

Field Summary

Fields

Modifier and Type	Field	Description
protected static Pattern	charsetPattern	The pattern determining the character set from the Content-Type.
static String	HEADER_FORWARDED	The header name for forward information for HTTP requests through a proxy.
static String	HEADER_X_FORWARDED_HOST	The header name for the forward host for HTTP requests through a proxy.
static String	HEADER_X_FORWARDED_PORT	The header name for the forward port for HTTP requests through a proxy.
static String	HEADER_X_FORWARDED_PROTO	The header name for the forward protocol for HTTP requests through a proxy.
protected static Pattern	hostPattern	The pattern determining the host and port from the Forwarded header.
protected static Pattern	protoPattern	The pattern determining the protocol from the Forwarded header.

Constructor Summary

Constructors

Constructor	Description
HttpTools()

Method Summary

Modifier and Type	Method	Description
static String	adaptUrl(String url, Function<String,String> headers, Logger logger)	Adapts the designated URL by transforming the string to a URL, applying adaptUrl(URL, Function, Logger) and converting the URL back to String again.
static URL	adaptUrl(URL url, Function<String,String> headers, Logger logger)	Adapts the designated URL by setting protocol, host and port from the headers provided by the designated function.
static Charset	getCharset(URLConnection conn)	Gets the character set used for text content of the designated URLConnection.

Methods inherited from class java.lang.Object

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

Field Detail

HEADER_FORWARDED

public static final String HEADER_FORWARDED

The header name for forward information for HTTP requests through a proxy.

See Also:

Forwarded, Constant Field Values

HEADER_X_FORWARDED_HOST

public static final String HEADER_X_FORWARDED_HOST

The header name for the forward host for HTTP requests through a proxy.

See Also:

X-Forwarded-Host, Constant Field Values

HEADER_X_FORWARDED_PORT

public static final String HEADER_X_FORWARDED_PORT

The header name for the forward port for HTTP requests through a proxy.

See Also:

Constant Field Values

HEADER_X_FORWARDED_PROTO

public static final String HEADER_X_FORWARDED_PROTO

The header name for the forward protocol for HTTP requests through a proxy.

See Also:

X-Forwarded-Proto, Constant Field Values

hostPattern

protected static final Pattern hostPattern

The pattern determining the host and port from the Forwarded header.

protoPattern

protected static final Pattern protoPattern

The pattern determining the protocol from the Forwarded header.

charsetPattern

protected static final Pattern charsetPattern

The pattern determining the character set from the Content-Type.

Constructor Detail

HttpTools

public HttpTools()

Method Detail

adaptUrl

public static String adaptUrl(String url,
                              Function<String,String> headers,
                              Logger logger)

Adapts the designated URL by transforming the string to a URL, applying adaptUrl(URL, Function, Logger) and converting the URL back to String again.

Parameters:

url - The URL which may need to be adapted to a different protocol, host and/or port. This must not be null.

headers - The function providing HTTP request headers. This must not be null but it may return null.

logger - The logger for logging problems, e. g. the port cannot be converted to int. This must not be null.

Returns:

The URL with protocol, host and/or port changed to the values provided by the designated headers function for the corresponding HTTP headers.

See Also:

adaptUrl(URL, Function, Logger)

adaptUrl

public static URL adaptUrl(URL url,
                           Function<String,String> headers,
                           Logger logger)

Adapts the designated URL by setting protocol, host and port from the headers provided by the designated function. This allows to change the known values to the ones provided by the HTTP request which may be routed through a proxy. That is, the URL working for the requestor may need to be different from the URL known by our service.

This supports (in this order, i. e. if a value is provided, the corresponding alternative header will be ignored):

• Forwarded
• X-Forwarded-Host
• X-Forwarded-Port
• X-Forwarded-Proto

Parameters:

url - The URL which may need to be adapted to a different protocol, host and/or port. This must not be null.

headers - The function providing HTTP request headers. This must not be null but it may return null.

logger - The logger for logging problems, e. g. the port cannot be converted to int. This must not be null.

Returns:

The URL with protocol, host and/or port changed to the values provided by the designated headers function for the corresponding HTTP headers.

getCharset

public static Charset getCharset(URLConnection conn)

Gets the character set used for text content of the designated URLConnection. If the content is no text content or the character set is not specified, null will be returned.

Parameters:

conn - The URL connection for which to determine the character set of the text content.

Returns:

The character set used for text content of the designated URLConnection or null in case of no text content or no specified character set.