com.myjavatools.lib
Class Web

java.lang.Object
  com.myjavatools.lib.Web

public class Web
extends java.lang.Object

Field Summary

protected static java.util.regex.Pattern	HTML_CHARSET_PATTERN
protected static java.util.regex.Pattern	XML_CHARSET_PATTERN

Constructor Summary

Web()

Method Summary

static java.lang.String	downloadFile(java.lang.String url, java.lang.String filename) Downloads a file from a specified URL
static java.lang.String	downloadFile(java.net.URL url, java.lang.String filename) Downloads a file from a specified URL
static java.lang.String	getCharsetByEncoding(java.lang.String encoding) Deprecated. should use java.nio.Charset
static java.lang.String	getEncodingByCharset(java.lang.String charset) gets Java encoding given an IANA charset
static java.lang.String	getHtmlCharset(java.lang.CharSequence s) Detects charset from html contents
static java.lang.String	getHtmlEncoding(java.lang.CharSequence s) gets Java encoding of HTML contents
static java.io.InputStream	getUrlInputStream(java.net.URL url) gets an input stream for a given url
static java.lang.String	getXmlCharset(java.lang.CharSequence s) Detects charset from xml contents
static java.lang.String	getXmlEncoding(java.lang.CharSequence s) gets Java encoding of XML data
static java.lang.String	quote(java.lang.String s) surrounds a string with single quotes (apostrophes), which is convenient for generating Javascript code, but just senseless otherwise.
static void	sendMail(java.lang.String from, java.lang.String to, java.lang.String subj, java.lang.String message) sendMail sends emails.
static java.lang.String	toWebReadable(java.lang.String s) converts a string into something that could be literally placed into a web page, that is, replaces CR with CRLF (to be polite with browser's 'view source'), replaces all '<' with "<", and html-encodes (&#dddd;) characters above low-ascii.
static java.lang.String	url(java.lang.String href, java.util.Collection nvPairList) produces a GET request string for a uri and a collection of parameters
static java.lang.String	url(java.lang.String uri, java.lang.String... paramvalue) produces a GET request string for a uri and request parameters
static java.lang.String	urlEncode(java.lang.String name, java.lang.String value) converts a name-value pair into an element of url string

Methods inherited from class java.lang.Object

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

Field Detail

HTML_CHARSET_PATTERN

protected static java.util.regex.Pattern HTML_CHARSET_PATTERN

XML_CHARSET_PATTERN

protected static java.util.regex.Pattern XML_CHARSET_PATTERN

Constructor Detail

Web

public Web()

Method Detail

getHtmlCharset

public static java.lang.String getHtmlCharset(java.lang.CharSequence s)

Detects charset from html contents

Parameters:

s - the char sequence with html content

Returns:

charset name

Examples:

getHtmlCharset("") returns "shift-jis".

getXmlCharset

public static java.lang.String getXmlCharset(java.lang.CharSequence s)

Detects charset from xml contents

Parameters:

s - the char sequence with html content

Returns:

charset name

Examples:

getXmlCharset("<?xml version=\"1.0\" encoding=\"UTF-8\"?>") returns "utf-8".

getCharsetByEncoding

public static java.lang.String getCharsetByEncoding(java.lang.String encoding)

Deprecated. should use java.nio.Charset

gets IANA charset given Java encoding

Parameters:

encoding - the Java charset

Returns:

encoding name

getEncodingByCharset

public static java.lang.String getEncodingByCharset(java.lang.String charset)

gets Java encoding given an IANA charset

Parameters:

charset - the IANA charset

Returns:

encoding name

getHtmlEncoding

public static java.lang.String getHtmlEncoding(java.lang.CharSequence s)

gets Java encoding of HTML contents

Parameters:

s - HTML data

Returns:

its most probable Java encoding

Examples:

getHtmlCharset("") returns "SJIS".

getXmlEncoding

public static java.lang.String getXmlEncoding(java.lang.CharSequence s)

gets Java encoding of XML data

Parameters:

s - XML data (first line is enough)

Returns:

Java encoding to decode the data

Example:

getXmlEncoding("?xml version=\"1.0\" encoding=\"UTF-8"?>") will return "UTF8".

getUrlInputStream

public static java.io.InputStream getUrlInputStream(java.net.URL url)
                                             throws java.io.IOException,
                                                    java.lang.InstantiationException

gets an input stream for a given url

Parameters:

url - the universal resource locator

Returns:

the input stream

Throws:

java.io.IOException

java.lang.InstantiationException -

Example:

getUrlInputStream(new URL("http://www.google.com/images/logo.gif")) will return an input stream that contains the Google gif.

downloadFile

public static java.lang.String downloadFile(java.net.URL url,
                                            java.lang.String filename)

Downloads a file from a specified URL

Parameters:

url - URL that points to a resource

filename - the name of the file to store the contents

Returns:

error message; an empty string if none

Example:

downloadFile(new URL("http://www.google.com/images/logo.gif"), "googlelogo.gif") will download the gif, store it into the file, and return an empty string.

downloadFile

public static java.lang.String downloadFile(java.lang.String url,
                                            java.lang.String filename)

Downloads a file from a specified URL

Parameters:

url - URL string that points to a resource

filename - the name of the file to store the contents

Returns:

error message; an empty string if none

Example:

downloadFile("http://www.google.com/images/logo.gif", "googlelogo.gif") will download the gif, store it into the file, and return an empty string.

sendMail

public static void sendMail(java.lang.String from,
                            java.lang.String to,
                            java.lang.String subj,
                            java.lang.String message)
                     throws java.net.MalformedURLException,
                            java.io.IOException

sendMail sends emails. Borrowed from Slavik Dimitrovich, Richmond, Virginia

Parameters:

from - sender address

to - receiver address

subj - message subject

message - message body

Throws:

java.io.MalformedURLException

java.io.IOException

java.net.MalformedURLException

See Also:

The original article

urlEncode

public static final java.lang.String urlEncode(java.lang.String name,
                                               java.lang.String value)

converts a name-value pair into an element of url string

Parameters:

name - parameter name

value - parameter value

Returns:

a string like "name=value", where value is url-encoded
returns an empty string if value is empty

Example:

urlEncode("dir", "C:\\Program Files"") will return "dir=C%3A%5CProgram+Files".

url

public static final java.lang.String url(java.lang.String href,
                                         java.util.Collection nvPairList)

produces a GET request string for a uri and a collection of parameters

Parameters:

href - url where to send the request

nvPairList - a collection of (already url-encoded) name-value pair strings that look like "name=value"

Returns:

formatted url string, see example

Example:

urlEncode("http://example.myjavatools.com/mycomputer", new ArrayList(new String[] {"dir=C%3A%5CProgram+Files", "cmd=dir+*"})) will return "http://example.myjavatools.com/mycomputer?dir=C%3A%5CProgram+Files&cmd=dir+*".

url

public static final java.lang.String url(java.lang.String uri,
                                         java.lang.String... paramvalue)

produces a GET request string for a uri and request parameters

Parameters:

uri - where to send the request

paramvalue - String... (etc)

Returns:

formatted url string, see examples

Examples:

urlEncode("http://example.myjavatools.com/mycomputer", "dir, "C:\Program Files")) will return "http://example.myjavatools.com/mycomputer?dir=C%3A%5CProgram+Files".

urlEncode("http://example.myjavatools.com/mycomputer", "dir, "C:\Program Files", "cmd", "dir *") will return "http://example.myjavatools.com/mycomputer?dir=C%3A%5CProgram+Files&cmd=dir+*".

urlEncode("http://mycomputer", "dir, "C:\Program Files", "cmd", "dir *", "login", "root", "password", "urowned") will return "http://mycomputer?dir=C%3A%5CProgram+Files&cmd=dir+*&login=root&password=urowned".

toWebReadable

public static final java.lang.String toWebReadable(java.lang.String s)

converts a string into something that could be literally placed into a web page, that is, replaces CR with CRLF (to be polite with browser's 'view source'), replaces all '<' with "<", and html-encodes (&#dddd;) characters above low-ascii.

Parameters:

s - string to convert

Returns:

converted string

quote

public static final java.lang.String quote(java.lang.String s)

surrounds a string with single quotes (apostrophes), which is convenient for generating Javascript code, but just senseless otherwise.

Parameters:

s - string to quote

Returns:

"'" + s + "'"