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Class com.extropia.net.JavaCGIBridge

java.lang.Object
   |
   +----java.util.Observable
           |
           +----com.extropia.net.JavaCGIBridge

public class JavaCGIBridge
extends Observable
implements Runnable

This is a class that POSTS and GETS data from URLs using various helper methods. This class also provides the capability of timing out if the connection takes too long to transfer data by using threads to monitor whether the data is taking too long to transfer (implements Runnable).

Helper methods allow you to set up form variables, get setup information over a URL, get raw or pre-parsed HTML data, and more.

The getParsedData method relies on instance variables which tell the parser where the data begins and ends (top and bottom separators respectively). The field and row separators inform the parser where records and fields end.

The default start of data separator is \n
The default end of data separator is \n
The default field separator is | (pipe).
The default record separator is \n (newline).
If the data you are sending is likely to contain special characters such as newlines in database fields or | symbols, you can expand the record and field separators to be more restrictive. For example, you might consider making the field seperator ~|~ (tilde + pipe + tilde) if you think a stray pipe might appear somewhere.
Another strategy is to follow a MIME like strategy where you make very long separators that are very unlikely to appear randomly in binary or large database field data. An example separator string might be "__CabbageNeck_Peter_Joe_Erik_Mark_Anthony_David_987XxX". However, be aware that although longer separator strings provide more security against random stray characters matching, they will also increase the parsing time.

Version:: 2.00, 18 Jul 1998
Author:: Gunther Birznieks, Marty Hall

_endDataSeparator: The bottom of data separator.
_fetchCount: This lets us know at what point fetchNextRecord() needs to read the next Vector.
_fieldSeparator: The field separator.
_parseAsRaw: _parseAsRaw is a flag that indicates whether the Vector of Vectors will contain fields as traditional Java Strings (false, the default) or raw binary byte arrays (true).
_parseDataAsVector: _parseDataAsVector is a flag letting the HTTP parser know to parse data on the fly as it is coming in.
_parsedNotifyInterval: This is the number of parsed lines before notifying observers of the latest batch of parsed Vector records.
_processingStatus: This integer holds the current processing status of the class.
_rawNotifyInterval: This is the number of raw data bytes (usually HTML chars) before notifying observers of the latest batch of raw data.
_recordSeparator: The record separator.
_serialObjectStream: This is an object stream that contains a decorator for the byte stream which contains serialized objects for POSTing.
_serialStream: This is a byte stream that contains object serialization data in-memory.
_startDataSeparator: The top of data separator.
_thread: This is a handle to the currently running communications thread.
_threadBaseTime: This variable contains the base time that the thread last received valid data.
_threadCompleted: This is a flag indicating whether the URL data was retrieved inside the thread or not.
_threadFormVar: The HTML form data for the URL that data is retrieved from.
_threadIdleAtEnd: _threadIdleAtEnd sets the object in the IDLE state automatically when a callOneWay() is used to launch an HTTP session.
_threadOneWay: _threadOneWay tells the run() method whether it was launched from an asynchronous method such as callOneWay() or a synchronous method such as getRawData().
_threadRawData: This is the returned URL data.
_threadTimeOut: This is the actual CGI Timeout value in milliseconds for the instantiated object.
_threadURL: The URL That data is retrieved from.
_vectorParsedData: This is the vector of vectors of parsed data.
IDLE: IDLE indicates that the JavaCGIBridge object has finished processing and can move on to do something else.
PROCESSING: PROCESSING indicates that the JavaCGIBridge object is in the middle of processing a request.
SETUP: SETUP indicates that the processing status is in setup mode.

JavaCGIBridge(): Constructs the object with no initialization.
JavaCGIBridge(String, String, String, String): Constructs the object with new separator values

_getBytes(String): This private routine converts strings to byte arrays in a way that is more convenient than the traditional JDK 1.0.2 method.
_getData(URL, Hashtable): Starts up the communications thread and gets the data from it in a synchronous manner.
_getHttpRequestInThread(URL, Hashtable): Returns the HTTP Request data to the thread that was launched to GET/POST data for a URL.
_getIndex(ByteArrayOutputStream, byte[], int, int): Retrieves the index in the ByteArrayOutputStream of where a string to search for is located.
_initJavaCGIBridge(String, String, String, String): Initializes the object with new separator values.
_notifyObservers(Object, boolean): Notifies the observers of the data that is being parsed or received in the communications thread.
addFormValue(Hashtable, String, String): Adds a form variable, value pair to the passed Hashtable.
callOneWay(URL): Calls the URL but returns immediately.
callOneWay(URL, boolean): Calls the URL but returns immediately.
callOneWay(URL, Hashtable): Calls the URL but returns immediately.
callOneWay(URL, Hashtable, boolean): Calls the URL but returns immediately.
getEndDataSeparator(): Returns the end of data separator for the object.
getFieldSeparator(): Returns the field separator for the object.
getKeyValuePairs(Vector): Takes the parsed data returned from the getParsedData method and changes it to a Hashtable of key, value pairs where the first Vector entry of each Vector record is the key and the rest of the second Vector entry for each record is the value of the Hashtable.
getParseAsRaw(): Returns true or false depending on whether the JavaCGIBridge will parse the fields in the HTTP response as Strings (default) or as raw data byte arrays.
getParsedData(URL): Returns parsed data in the form of a Vector of Vectors containing the returned fields inside of a Vector of returned rows.
getParsedData(URL, Hashtable): Returns parsed data in the form of a Vector of Vectors containing the returned fields inside of a Vector of returned rows.
getParsedNotifyInterval(): Returns an integer indicating the number of records which will trigger a notification to observers with the contents of what has been parsed so far.
getRawData(URL): Returns raw HTML data as a String from the passed URL.
getRawData(URL, Hashtable): Returns raw HTML data as a String from the passed URL and list of Form variable/value pairs stored in a Hashtable.
getRawNotifyInterval(): Returns an integer indicating the number of raw content bytes from the HTTP response which will trigger a notification to observers with the contents of what has been read so far.
getRecordSeparator(): Returns the record separator for the object.
getStartDataSeparator(): Returns the start of data separator for the object.
getStatus(): Returns the processing status of the JavaCGIBridge objects.
getTimeOut(): Returns the actual communication time out in milliseconds for the object.
getURLEncodedHashtable(Hashtable): Returns the form variables inside the hashtable as a URL encoded string of parameters for a CGI based program to process.
run(): This run thread asynchronously POSTs and GETs data from a URL and places the contents into the _threadRawData variable.
setEndDataSeparator(String): Sets the end of data separator for the object.
setFieldSeparator(String): Sets the field separator for the object.
setParseAsRaw(boolean): Sets the flag that indicates whether the JavaCGIBridge will parse the HTTP response data as raw byte array or as String (default).
setParsedNotifyInterval(int): Sets an integer indicating the number of records which will trigger a notification to observers with the contents of what has been parsed so far.
setRawNotifyInterval(int): Sets an integer indicating the number of raw content bytes from the HTTP response which will trigger a notification to observers with the contents of what has been read so far.
setRecordSeparator(String): Sets the record separator for the object.
setStartDataSeparator(String): Sets the start of data separator for the object.
setStatus(int): Sets the processing status of the JavaCGIBridge object.
setTimeOut(int): Sets the actual communication time out in milliseconds for the object.

SETUP

 public static final int SETUP

SETUP indicates that the processing status is in setup mode. This means that no communications have been established yet. In otherwords, the programmer is still setting up defaults.

See Also:: getStatus, setStatus

PROCESSING

 public static final int PROCESSING

PROCESSING indicates that the JavaCGIBridge object is in the middle of processing a request.

See Also:: getStatus, setStatus

IDLE

 public static final int IDLE

IDLE indicates that the JavaCGIBridge object has finished processing and can move on to do something else. Usually this means that the JavaCGIBridgePool object can give this instance to another consumer now that it is done with the request.

See Also:: getStatus, setStatus

_vectorParsedData

 protected Vector _vectorParsedData

This is the vector of vectors of parsed data. It is protected so that fetchNextRecord() can peep it in the JavaCGIBridgeExtension class.

_threadTimeOut

 protected int _threadTimeOut

This is the actual CGI Timeout value in milliseconds for the instantiated object. Notice that the default value is a static class variable that applies across all instances of this class. This variable, on the other hand, is the actual value the object uses.

It is protected so that the other JavaCGIBridge-type classes can also detect whether a JavaCGIBridge object has timed out.

_threadCompleted

 protected boolean _threadCompleted

This is a flag indicating whether the URL data was retrieved inside the thread or not. It is protected so that other JavaCGIBridge-type classes can figure out if a JavaCGIBridge object has timed out.

_fetchCount

 protected int _fetchCount

This lets us know at what point fetchNextRecord() needs to read the next Vector. This variable is located here so that it can be manipulated by the communications thread as it parses Vector data for consumption by fetchNextRecord().

_threadBaseTime

 protected long _threadBaseTime

This variable contains the base time that the thread last received valid data. The base time basically tells the object how much time has past between successful communications when compared with System.currentTimeMillis(). It is protected so that other JavaCGIBridge-type objects can figure out whether a JavaCGIBridge object has timed out.

_thread

 protected Thread _thread

This is a handle to the currently running communications thread. It is protected so that the JavaCGIBridgePool objects can stop timed out threads in its clean up thread.

_serialStream

 protected ByteArrayOutputStream _serialStream

This is a byte stream that contains object serialization data in-memory. It is protected so that it can be accessed by the serialization API methods in JavaCGIBridgeExtension class.

_serialObjectStream

 protected ObjectOutputStream _serialObjectStream

This is an object stream that contains a decorator for the byte stream which contains serialized objects for POSTing. It is protected so that its contents can be accessed by the serialization API methods in the JavaCGIBridgeExtension class.

_fieldSeparator

 private byte _fieldSeparator[]

The field separator. When a CGI script or HTML file returns data, then the getParsedData() method will know how to separate fields by looking at this variable. The default value is "|" (pipe). This is considered sufficiently unlikely to appear inside of actual field data that it is a pretty good field separator to parse on. If the user of this class needs a different separator, it may be overridden by calling the appropriate method.

_recordSeparator

 private byte _recordSeparator[]

The record separator. When a CGI script or HTML file returns data, then the getParsedData() method will know how to separate returned rows by looking at this variable. The default value is "\n" (newline). This is considered sufficiently unlikely to appear inside of actual row data that it is a pretty good row separator to parse on. If the user of this class needs a different separator, it may be overridden by calling the appropriate method.

_startDataSeparator

 private byte _startDataSeparator[]

The top of data separator. When a CGI script or HTML file returns data, then the getParsedData() method will determine when to start parsing data by encountering this separator. The default value is "\n" including a a newline. That is, a newline is generally expected to follow this separator.

_endDataSeparator

 private byte _endDataSeparator[]

The bottom of data separator. When a CGI script or HTML file returns data, then the getParsedData() method will determine when to stop parsing data by encountering this separator. The default value is "\n" including a newline. That is, a newline is generally expected to follow this separator.

_threadURL

 private URL _threadURL

The URL That data is retrieved from. This is an instance variable rather than a parameter because the data retrieval is done from a launched thread which gets no parameters.

_threadFormVar

 private Hashtable _threadFormVar

The HTML form data for the URL that data is retrieved from. This is an instance variable rather than a parameter because the data retrieval is done from a launched thread which gets no parameters.

_threadRawData

 private byte _threadRawData[]

This is the returned URL data. It is an instance variable because the run() method of the thread cannot explicitly return data.

_parseDataAsVector

 private boolean _parseDataAsVector

_parseDataAsVector is a flag letting the HTTP parser know to parse data on the fly as it is coming in.

_parseAsRaw

 private boolean _parseAsRaw

_parseAsRaw is a flag that indicates whether the Vector of Vectors will contain fields as traditional Java Strings (false, the default) or raw binary byte arrays (true).

_threadIdleAtEnd

 private boolean _threadIdleAtEnd

_threadIdleAtEnd sets the object in the IDLE state automatically when a callOneWay() is used to launch an HTTP session. This value is generally set to true by default, but it will be set to false if the user calls the callOneWay() method by telling it that they intend to call fetchNextRecord(). The reason this is done is that it is possible, in a multi threaded environment that fetchNextRecord() might be called after the whole HTTP session has finished. In this case, another thread might easily reuse the JavaCGIBridge object in the IDLE state before fetchNextRecord() was called. Therefore, it is imperative that if you intend to use fetchNextRecord() that you tell the callOneWay() function you intend to do so.

_threadOneWay

 private boolean _threadOneWay

_threadOneWay tells the run() method whether it was launched from an asynchronous method such as callOneWay() or a synchronous method such as getRawData(). _threadOneWay == true if it was launched from an asynchronous method.

_parsedNotifyInterval

 private int _parsedNotifyInterval

This is the number of parsed lines before notifying observers of the latest batch of parsed Vector records. The default is 0 (no notification).

See Also:: getParsedNotifyInterval, setParsedNotifyInterval

_rawNotifyInterval

 private int _rawNotifyInterval

This is the number of raw data bytes (usually HTML chars) before notifying observers of the latest batch of raw data. The default is 0 (no notification).

See Also:: getRawNotifyInterval, setRawNotifyInterval

_processingStatus

 private int _processingStatus

This integer holds the current processing status of the class. Its value is either SETUP (1), PROCESSING (2), or IDLE (3).

JavaCGIBridge

 public JavaCGIBridge(String field,
                      String record,
                      String startData,
                      String endData)

Constructs the object with new separator values

JavaCGIBridge

 public JavaCGIBridge()

Constructs the object with no initialization. This is the default (empty) constructor.

addFormValue

 public void addFormValue(Hashtable ht,
                          String formKey,
                          String formValue)

Adds a form variable, value pair to the passed Hashtable.

Parameters:: ht - the Hashtable that contains the form variable/value pairs; formKey - the String that contains the form variable to add; formValue - the String that contains the form value to add

getKeyValuePairs

 public Hashtable getKeyValuePairs(Vector vectorOfVectors)

Takes the parsed data returned from the getParsedData method and changes it to a Hashtable of key, value pairs where the first Vector entry of each Vector record is the key and the rest of the second Vector entry for each record is the value of the Hashtable.

Parameters:: vectorOfVectors - the Vector of Vectors for the parsed data
Returns:: Hashtable containing converted variable/value pairs
See Also:: getParsedData

getParsedData

 public Vector getParsedData(URL u) throws JavaCGIBridgeTimeOutException

Returns parsed data in the form of a Vector of Vectors containing the returned fields inside of a Vector of returned rows.

Parameters:: u - URL to get parsed data from.
Returns:: Vector (records) of vectors (fields) of parsed data
Throws: JavaCGIBridgeTimeOutException: If the retrieval times out
See Also:: getRawData, callOneWay, getParseAsRaw, setParseAsRaw, getParsedNotifyInterval, setParsedNotifyInterval

getParsedData

 public Vector getParsedData(URL u,
                             Hashtable ht) throws JavaCGIBridgeTimeOutException

Returns parsed data in the form of a Vector of Vectors containing the returned fields inside of a Vector of returned rows. This form POSTs the HTML Form variable data to the URL.

Parameters:: u - URL to get parsed data from.; ht - Hashtable contains form variables to POST
Returns:: Vector (records) of vectors (fields) of parsed data
Throws: JavaCGIBridgeTimeOutException: If the retrieval times out
See Also:: getRawData, callOneWay, getParseAsRaw, setParseAsRaw, getParsedNotifyInterval, setParsedNotifyInterval

getRawData

 public byte[] getRawData(URL u) throws JavaCGIBridgeTimeOutException

Returns raw HTML data as a String from the passed URL.

Parameters:: u - URL to get raw HTML from.
Returns:: String containing plain HTML text
Throws: JavaCGIBridgeTimeOutException: If the retrieval times out
See Also:: getParsedData, callOneWay, getRawNotifyInterval, setRawNotifyInterval

getRawData

 public byte[] getRawData(URL u,
                          Hashtable ht) throws JavaCGIBridgeTimeOutException

Returns raw HTML data as a String from the passed URL and list of Form variable/value pairs stored in a Hashtable. This form POSTs the HTML Form variable data to the URL.

Parameters:: u - URL to get raw HTML from.; ht - Hashtable contains form variables to POST
Returns:: String containing plain HTML text
Throws: JavaCGIBridgeTimeOutException: If the retrieval times out
See Also:: getParsedData, callOneWay, getRawNotifyInterval, setRawNotifyInterval

callOneWay

 public void callOneWay(URL u)

Calls the URL but returns immediately. This is called a ONEWAY operation. This method is used in one of three circumstances.

[1] You want to "fire and forget" an operation such as an update to a file or database on the web server without worrying about a return code or whether the operation even succedded.

[2] You want to set up an observer interface to the bridge to notify yourself as data comes in instead of blocking the whole program while waiting for the data.

[3] You want to call fetchNextRecord method in the JavaCGIBridgeExtension class. Basically, the callOneWay() operation returns immediately so that it leaves your program free to loop through the fetchNextRecord() method. Note that if you use callOneWay for this purpose, it is recommended that you call the version where you set "fetchData" equal to true so that the Object is not set to the IDLE state prematurely. This is discussed in further detail in the documentation for fetchNextRecord() in the JavaCGIBridgeExtension class.

Parameters:: u - URL to get raw HTML from.
See Also:: getRawData, getParsedData, getRawNotifyInterval, setRawNotifyInterval, getParsedNotifyInterval, setParsedNotifyInterval

callOneWay

 public void callOneWay(URL u,
                        boolean fetchData)

Calls the URL but returns immediately. This is called a ONEWAY operation. This method is used in one of three circumstances.

[1] You want to "fire and forget" an operation such as an update to a file or database on the web server without worrying about a return code or whether the operation even succedded.

[2] You want to set up an observer interface to the bridge to notify yourself as data comes in instead of blocking the whole program while waiting for the data.

Parameters:: u - URL to get raw HTML from.; fetchData - Set to true if you intend to use the fetchNextRecord() method. This avoids the thread automatically setting the state of the object to IDLE when the thread completes. This is necessary because it is possible that fetchNextRecord has not completed fetching all the records by the time the communications thread ends.
See Also:: getRawData, getParsedData, getRawNotifyInterval, setRawNotifyInterval, getParsedNotifyInterval, setParsedNotifyInterval

callOneWay

 public void callOneWay(URL u,
                        Hashtable ht)

Calls the URL but returns immediately. This is called a ONEWAY operation. This method is used in one of three circumstances.

[1] You want to "fire and forget" an operation such as an update to a file or database on the web server without worrying about a return code or whether the operation even succedded.

[2] You want to set up an observer interface to the bridge to notify yourself as data comes in instead of blocking the whole program while waiting for the data.

Parameters:: u - URL to get raw HTML from.; ht - Hashtable contains form variables to POST
See Also:: getRawData, getParsedData, getRawNotifyInterval, setRawNotifyInterval, getParsedNotifyInterval, setParsedNotifyInterval

callOneWay

 public void callOneWay(URL u,
                        Hashtable ht,
                        boolean fetchData)

Calls the URL but returns immediately. This is called a ONEWAY operation. This method is used in one of three circumstances.

[1] You want to "fire and forget" an operation such as an update to a file or database on the web server without worrying about a return code or whether the operation even succedded.

[2] You want to set up an observer interface to the bridge to notify yourself as data comes in instead of blocking the whole program while waiting for the data.

Parameters:: u - URL to get raw HTML from.; ht - Hashtable contains form variables to POST; fetchData - Set to true if you intend to use the fetchNextRecord() method. This avoids the thread automatically setting the state of the object to IDLE when the thread completes. This is necessary because it is possible that fetchNextRecord has not completed fetching all the records by the time the communications thread ends.
See Also:: getRawData, getParsedData, getRawNotifyInterval, setRawNotifyInterval, getParsedNotifyInterval, setParsedNotifyInterval

getTimeOut

 public int getTimeOut()

Returns the actual communication time out in milliseconds for the object. The default is 10 seconds. When the object retrieves data from a URL, it must get the data within timeout milliseconds or a JavaCGIBridgeTimeOutException is thrown.

Returns:: communication time out in milliseconds
See Also:: setTimeOut

setTimeOut

 public void setTimeOut(int t)

Sets the actual communication time out in milliseconds for the object. The default is 10 seconds. When the object retrieves data from a URL, it must get the data within timeout milliseconds or a JavaCGIBridgeTimeOutException is thrown.

Parameters:: t - communication time out in milliseconds
See Also:: getTimeOut

setFieldSeparator

 public void setFieldSeparator(String s)

Sets the field separator for the object. When getParsedData method is called, the object uses the field separator to determine where fields in a returned record of the raw HTML result set begin and end.

Parameters:: s - String containing new delimiting separator
See Also:: getParsedData, getFieldSeparator

getFieldSeparator

 public String getFieldSeparator()

Returns the field separator for the object. When getParsedData method is called, the object uses the field separator to determine where fields in a returned record of the raw HTML result set begin and end.

Returns:: Separator string
See Also:: getParsedData, setFieldSeparator

setRecordSeparator

 public void setRecordSeparator(String s)

Sets the record separator for the object. When getParsedData method is called, the object uses the record separator to determine where records/rows of the raw HTML result set begin and end.

Parameters:: s - String containing new delimiting separator
See Also:: getParsedData, getRecordSeparator

getRecordSeparator

 public String getRecordSeparator()

Returns the record separator for the object. When getParsedData method is called, the object uses the record separator to determine where records/rows of the raw HTML result set begin and end.

Returns:: Separator string
See Also:: getParsedData, setRecordSeparator

setStartDataSeparator

 public void setStartDataSeparator(String s)

Sets the start of data separator for the object. When getParsedData method is called, the object uses the start of data separator to determine where the rows of data inside the raw HTML output actually begin.

Parameters:: s - String containing new delimiting separator
See Also:: getParsedData, getStartDataSeparator

getStartDataSeparator

 public String getStartDataSeparator()

Returns the start of data separator for the object. When getParsedData method is called, the object uses the start of data separator to determine where the rows of data inside the raw HTML output actually begin.

Returns:: Separator string
See Also:: getParsedData, setStartDataSeparator

setEndDataSeparator

 public void setEndDataSeparator(String s)

Sets the end of data separator for the object. When getParsedData method is called, the object uses the end of data separator to determine where the rows of data inside the raw HTML output actually end.

Parameters:: s - String containing new delimiting separator
See Also:: getParsedData, getEndDataSeparator

getEndDataSeparator

 public String getEndDataSeparator()

Returns the end of data separator for the object. When getParsedData method is called, the object uses the end of data separator to determine where the rows of data inside the raw HTML output actually end.

Returns:: Separator string
See Also:: getParsedData, setEndDataSeparator

getParsedNotifyInterval

 public int getParsedNotifyInterval()

Returns an integer indicating the number of records which will trigger a notification to observers with the contents of what has been parsed so far. When this is set to a positive number, it will also notify when the records have finished being parsed at the end of the HTTP response. When this is set to a negative number, no periodic notifications will be sent, however one will be sent at the end of the HTTP response.

Returns:: int Number of records between parse notifications. Set to 0 to turn off parsing notification, Set to a negative number to only send notifications at the end.
See Also:: setParsedNotifyInterval

setParsedNotifyInterval

 public void setParsedNotifyInterval(int n)

Sets an integer indicating the number of records which will trigger a notification to observers with the contents of what has been parsed so far. When this is set to a positive number, it will also notify when the records have finished being parsed at the end of the HTTP response. When this is set to a negative number, no periodic notifications will be sent, however one will be sent at the end of the HTTP response.

Parameters:: n - Number of records between parse notifications. Set to 0 to turn off parsing notification, Set to a negative number to only send notifications at the end.
See Also:: getParsedNotifyInterval

getRawNotifyInterval

 public int getRawNotifyInterval()

Returns an integer indicating the number of raw content bytes from the HTTP response which will trigger a notification to observers with the contents of what has been read so far. When this is set to a positive number, it will also notify when the HTTP response has finished. When this is set to a negative number, no periodic notifications will be sent, however one will be sent at the end of the HTTP response.

Returns:: int Number of bytes between notifications. Set to 0 to turn off notification after lines of HTML sent in the HTTP response, Set to a negative number to only send notifications at the end.
See Also:: setRawNotifyInterval

setRawNotifyInterval

 public void setRawNotifyInterval(int n)

Sets an integer indicating the number of raw content bytes from the HTTP response which will trigger a notification to observers with the contents of what has been read so far. When this is set to a positive number, it will also notify when the HTTP response has finished. When this is set to a negative number, no periodic notifications will be sent, however one will be sent at the end of the HTTP response.

Parameters:: n - Number of bytes between notifications. Set to 0 to turn off notification after bytes of HTML sent in the HTTP response, Set to a negative number to only send notifications at the end.
See Also:: getRawNotifyInterval

getParseAsRaw

 public boolean getParseAsRaw()

Returns true or false depending on whether the JavaCGIBridge will parse the fields in the HTTP response as Strings (default) or as raw data byte arrays. Use byte arrays if you public void setRawNotifyInterval(int n) { _rawNotifyInterval = n; } /** Returns true or false depending on whether the JavaCGIBridge will parse the fields in the HTTP response as Strings (default) or as raw data byte arrays. Use byte arrays if you will be transferring binary data such as a jpeg or gif image.

Returns:: boolean Flag indicating parsing as raw byte array or as Strings
See Also:: setParseAsRaw

setParseAsRaw

 public void setParseAsRaw(boolean b)

Sets the flag that indicates whether the JavaCGIBridge will parse the HTTP response data as raw byte array or as String (default).

Parameters:: b - Flag indicating true or false
See Also:: getParseAsRaw

getStatus

 public int getStatus()

Returns the processing status of the JavaCGIBridge objects. It will be equal to SETUP (1), PROCESSING (2), or IDLE (3) public static class variables.

Returns:: int Status code
See Also:: setStatus

setStatus

 public void setStatus(int status)

Sets the processing status of the JavaCGIBridge object. You will set it to SETUP (1), PROCESSING (2), or IDLE (3) public static class variables.

Parameters:: status - Status code
See Also:: getStatus

run

 public void run()

This run thread asynchronously POSTs and GETs data from a URL and places the contents into the _threadRawData variable. Since Threads do not return or pass parameter values, instance variables in this object are used to maintain state. This method is only public so that the Thread class can launch the thread.

See Also:: getRawData

getURLEncodedHashtable

 public String getURLEncodedHashtable(Hashtable ht)

Returns the form variables inside the hashtable as a URL encoded string of parameters for a CGI based program to process.

Parameters:: ht - Hashtable containing form variables
Returns:: URLencoded string of HTML form variables & values
See Also:: addFormValue

_getHttpRequestInThread

 private byte[] _getHttpRequestInThread(URL u,
                                        Hashtable ht) throws JavaCGIBridgeTimeOutException

Returns the HTTP Request data to the thread that was launched to GET/POST data for a URL. This is a private method.

Parameters:: u - URL to retrieve and post data for; ht - Form variables to send to URL
Returns:: String containing retrieved HTML text
Throws: JavaCGIBridgeTimeOutException: If the retrieval times out
See Also:: run

_getIndex

 private int _getIndex(ByteArrayOutputStream baos,
                       byte toLookFor[],
                       int begin,
                       int end)

Retrieves the index in the ByteArrayOutputStream of where a string to search for is located. The current algorithm is based loosely off of the code in String.indexOf in the java.lang.String source code.

_notifyObservers

 private void _notifyObservers(Object o,
                               boolean endOfData) throws JavaCGIBridgeTimeOutException

Notifies the observers of the data that is being parsed or received in the communications thread. It constructs a JavaCGIBridgeNotify object to send the information including whether or not the JavaCGIBridge timed out or whether the end of data has been reached.

Parameters:: o - Object containing data to send out such as the latest Vector or the latest byte array of data.; endOfData - indicates whether the end of data was reached
Throws: JavaCGIBridgeTimeOutException: If the retrieval times out

_initJavaCGIBridge

 private void _initJavaCGIBridge(String field,
                                 String record,
                                 String startData,
                                 String endData)

Initializes the object with new separator values. It is called from the constructors of this object.

Parameters:: field - Field separator; record - Record separator; startData - Start of Data separator; endData - End of Data separator

_getData

 private void _getData(URL u,
                       Hashtable ht) throws JavaCGIBridgeTimeOutException

Starts up the communications thread and gets the data from it in a synchronous manner. Thus, this method blocks until it gets all the data. It also implements a timeout mechanism using wait() and notify(). It is basically the same as Thread.join() except that it fixes the broken Thread.join() implementation in Netscape browsers.

Parameters:: u - URL to get parsed data from.; ht - Hashtable contains form variables to POST
Throws: JavaCGIBridgeTimeOutException: If the retrieval times out
See Also:: getParsedData, getRawData

_getBytes

 private byte[] _getBytes(String s)

This private routine converts strings to byte arrays in a way that is more convenient than the traditional JDK 1.0.2 method. In otherwords, this is a wrapper for the more complex version of the String to byte array converter method.

Parameters:: s - String to convert to bytes
Returns:: byte[] converted byte array

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