ipworks
Class Dns

java.lang.Object
  |
  +--ipworks.Dns

public class Dns

extends java.lang.Object

The DNS bean is used to query DNS for record information.

The DNS bean queries a DNS server for records as specified in RFC 1035 and other relevant RFCs. The bean property QueryType indicates the record to be queried. Calling Query will initiate the query.

Once the query is complete, a single Response event will fire and the record properties will be filled. StatusCode is the server's success or fail code, and Status is a standard string interpretation of the code.

The records are contained in the Records collection. The programming interface is designed to allow a full walk of the records in the DNS response, including provisions for handling new record types. .

The bean operates synchronously by default (waits for a response before returning control to the caller), however, the bean may also operate asynchronously (return control immediately), by setting Timeout to 0. Please refer to the Timeout property for more information.

Field Summary

static int	qtAAAA
static int	qtAddress
static int	qtAFSDB
static int	qtCName
static int	qtHostInfo
static int	qtISDN
static int	qtMailBox
static int	qtMailGroup
static int	qtMailInfo
static int	qtMD
static int	qtMF
static int	qtMR
static int	qtMX
static int	qtNAPTR
static int	qtNS
static int	qtNULL
static int	qtPointer
static int	qtRevLookup
static int	qtRP
static int	qtRT
static int	qtSOA
static int	qtSRV
static int	qtText
static int	qtWKS
static int	qtX25
static int	rsAdditionalRecordsSection
static int	rsAnswerSection
static int	rsNameServerSection

Constructor Summary

Dns()

Method Summary

void	addDnsEventListener(ipworks.DnsEventListener l)
java.lang.String	config(java.lang.String configurationString) Sets or retrieves a beanconfiguration setting.
void	doEvents() Processes events from the internal message queue.
int	getDNSPort() The port to connect to on the DNS Server.
java.lang.String	getDNSServer() The address of the DNS Server.
int	getQueryType() The record type to query.
DNSRecordList	getRecords() Collection of records in the last response.
int	getRecordSource() The source of records provided in the Records collection.
int	getRequestId() The id of the current DNS request.
java.lang.String	getStatus() A standard string interpretation of StatusCode .
int	getStatusCode() The success or error code for the DNS query.
int	getTimeout() A timeout for the bean.
void	interrupt() Interrupt the current method.
boolean	isIdle() The current status of the component.
boolean	isRecursive() Determines whether to ask the DNSServer to recursively query other servers.
void	query(java.lang.String domain) Query a Domain.
void	removeDnsEventListener(ipworks.DnsEventListener l)
void	setDNSPort(int DNSPort) The port to connect to on the DNS Server.
void	setDNSServer(java.lang.String DNSServer) The address of the DNS Server.
void	setQueryType(int queryType) The record type to query.
void	setRecordSource(int recordSource) The source of records provided in the Records collection.
void	setRecursive(boolean recursive) Determines whether to ask the DNSServer to recursively query other servers.
void	setRequestId(int requestId) The id of the current DNS request.
void	setTimeout(int timeout) A timeout for the bean.

Methods inherited from class java.lang.Object

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

Field Detail

qtAddress

public static final int qtAddress

See Also:

Constant Field Values

qtNS

public static final int qtNS

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Constant Field Values

qtMD

public static final int qtMD

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qtMF

public static final int qtMF

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qtCName

public static final int qtCName

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qtSOA

public static final int qtSOA

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qtMailBox

public static final int qtMailBox

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qtMailGroup

public static final int qtMailGroup

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qtMR

public static final int qtMR

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qtNULL

public static final int qtNULL

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qtWKS

public static final int qtWKS

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qtPointer

public static final int qtPointer

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qtHostInfo

public static final int qtHostInfo

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qtMailInfo

public static final int qtMailInfo

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qtMX

public static final int qtMX

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qtText

public static final int qtText

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qtRP

public static final int qtRP

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qtAFSDB

public static final int qtAFSDB

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qtX25

public static final int qtX25

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qtISDN

public static final int qtISDN

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qtRT

public static final int qtRT

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qtAAAA

public static final int qtAAAA

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qtSRV

public static final int qtSRV

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qtNAPTR

public static final int qtNAPTR

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qtRevLookup

public static final int qtRevLookup

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rsAnswerSection

public static final int rsAnswerSection

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Constant Field Values

rsNameServerSection

public static final int rsNameServerSection

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Constant Field Values

rsAdditionalRecordsSection

public static final int rsAdditionalRecordsSection

See Also:

Constant Field Values

Constructor Detail

Dns

public Dns()

Method Detail

getDNSPort

public int getDNSPort()

The port to connect to on the DNS Server.

A valid port number (a value between 1 and 65535) is required for the connection to take place. The property must be set before a connection is attempted and cannot be changed once a connection is established. Any attempt to change this property while connected will fail with an error.

setDNSPort

public void setDNSPort(int DNSPort)
                throws IPWorksException

The port to connect to on the DNS Server.

A valid port number (a value between 1 and 65535) is required for the connection to take place. The property must be set before a connection is attempted and cannot be changed once a connection is established. Any attempt to change this property while connected will fail with an error.

IPWorksException

getDNSServer

public java.lang.String getDNSServer()

The address of the DNS Server.

The bean attempts to find the default DNS server for the machine where it is installed, and provide it in the DNSServer property. You may later change it to any particular DNS server you want to query. While any internet host running a DNS service will suffice, it is preferable to use either the DNS server for your network or the DNS server for the domain which you are querying.

If the bean cannot determine the default DNS server address, the property value will be an empty string.

setDNSServer

public void setDNSServer(java.lang.String DNSServer)
                  throws IPWorksException

The address of the DNS Server.

The bean attempts to find the default DNS server for the machine where it is installed, and provide it in the DNSServer property. You may later change it to any particular DNS server you want to query. While any internet host running a DNS service will suffice, it is preferable to use either the DNS server for your network or the DNS server for the domain which you are querying.

If the bean cannot determine the default DNS server address, the property value will be an empty string.

IPWorksException

isIdle

public boolean isIdle()

The current status of the component.

Idle will be False if the component is currently busy (communicating and/or waiting for an answer), and True at all other times.

getQueryType

public int getQueryType()

The record type to query.

Before a query is attempted, QueryType must be set to the desired record type. The records are defined as follows:

qtAddress (1)

Address Records

qtNS (2)

Name Server Records

qtMD (3)

Mail Destination Records

qtMF (4)

Mail Forwarder Records

qtCName (5)

Canonical Name Records

qtSOA (6)

Start Of Authority Records

qtMailBox (7)

MailBox Records

qtMailGroup (8)

Mail Group Records

qtMR (9)

MailBox Rename Records

qtNULL (10)

NULL Records

qtWKS (11)

Well Known Services Records

qtPointer (12)

Pointer Records

qtHostInfo (13)

Host Information Records

qtMailInfo (14)

Mail Information Records

qtMX (15)

Mail Exchange Records

qtText (16)

Text Records

qtRP (17)

Responsible Person Records

qtAFSDB (18)

Service Records

qtX25 (19)

X25 Records

qtISDN (20)

ISDN Records

qtRT (21)

Route Through Records

qtAAAA (28)

AAAA Record

qtSRV (33)

SRV Record (location of services)

qtNAPTR (35)

NAPTR Record (Naming Authority Pointer)

qtRevLookup (100)

Reverse Lookup (Reverse Lookup)

setQueryType

public void setQueryType(int queryType)
                  throws IPWorksException

The record type to query.

Before a query is attempted, QueryType must be set to the desired record type. The records are defined as follows:

qtAddress (1)

Address Records

qtNS (2)

Name Server Records

qtMD (3)

Mail Destination Records

qtMF (4)

Mail Forwarder Records

qtCName (5)

Canonical Name Records

qtSOA (6)

Start Of Authority Records

qtMailBox (7)

MailBox Records

qtMailGroup (8)

Mail Group Records

qtMR (9)

MailBox Rename Records

qtNULL (10)

NULL Records

qtWKS (11)

Well Known Services Records

qtPointer (12)

Pointer Records

qtHostInfo (13)

Host Information Records

qtMailInfo (14)

Mail Information Records

qtMX (15)

Mail Exchange Records

qtText (16)

Text Records

qtRP (17)

Responsible Person Records

qtAFSDB (18)

Service Records

qtX25 (19)

X25 Records

qtISDN (20)

ISDN Records

qtRT (21)

Route Through Records

qtAAAA (28)

AAAA Record

qtSRV (33)

SRV Record (location of services)

qtNAPTR (35)

NAPTR Record (Naming Authority Pointer)

qtRevLookup (100)

Reverse Lookup (Reverse Lookup)

IPWorksException

getRecords

public DNSRecordList getRecords()

Collection of records in the last response.

Once the query is complete, a single Response event will fire, and the following properties will contain the results:

StatusCode

The success or error code of the DNS query.

Status

A standard string interpretation of StatusCode .

Records

The Records in the last DNS response.

RecordSource

The source (type) of records being listed.

Example (Loop through all fields of all records)

 For i = 0 to records.Count
 \011For j = 0 to records.FieldCount(i)
 \011\011records.FieldIndex(i) = j
 \011\011DoSomethingWith(records.FieldName(i), records.RecordFieldValue(i))
 \011Next j
 Next i 

This collection is indexed from 0 to Count - 1.

getRecordSource

public int getRecordSource()

The source of records provided in the Records collection.

RecordSource can have one of the following values:

rsAnswerSection (0)

Records answering the question/query.

rsNameServerSection (1)

Records pointing toward an authoritative name server.

rsAdditionalRecordsSection (2)

Records holding additional information.

setRecordSource

public void setRecordSource(int recordSource)
                     throws IPWorksException

The source of records provided in the Records collection.

RecordSource can have one of the following values:

rsAnswerSection (0)

Records answering the question/query.

rsNameServerSection (1)

Records pointing toward an authoritative name server.

rsAdditionalRecordsSection (2)

Records holding additional information.

IPWorksException

isRecursive

public boolean isRecursive()

Determines whether to ask the DNSServer to recursively query other servers.

If Recursive is true, the component will tell the DNS server to perform the query recursively. This means that if the DNS server does not have information about the Domain being queried, it will send the request to another DNS server.

setRecursive

public void setRecursive(boolean recursive)
                  throws IPWorksException

Determines whether to ask the DNSServer to recursively query other servers.

If Recursive is true, the component will tell the DNS server to perform the query recursively. This means that if the DNS server does not have information about the Domain being queried, it will send the request to another DNS server.

IPWorksException

getRequestId

public int getRequestId()

The id of the current DNS request.

Each time the bean makes a DNS query, it generates a unique request id to track the response. RequestId is the id of the request that generated the current response values.

If a custom value is needed for RequestId , the property must be set before sending a request. The bean increments RequestId automatically after sending each request.

NOTE: The bean throws an IPWorksException raises an IPWorksException exception when a value that is not between 1 and 32,767 is specified.

setRequestId

public void setRequestId(int requestId)
                  throws IPWorksException

The id of the current DNS request.

Each time the bean makes a DNS query, it generates a unique request id to track the response. RequestId is the id of the request that generated the current response values.

If a custom value is needed for RequestId , the property must be set before sending a request. The bean increments RequestId automatically after sending each request.

NOTE: The bean throws an IPWorksException raises an IPWorksException exception when a value that is not between 1 and 32,767 is specified.

IPWorksException

getStatus

public java.lang.String getStatus()

A standard string interpretation of StatusCode .

For a list of valid error codes and their descriptions, please refer to the Error Messages section.

getStatusCode

public int getStatusCode()

The success or error code for the DNS query.

For a list of valid error codes and their descriptions, please refer to the Error Messages section.

getTimeout

public int getTimeout()

A timeout for the bean.

If the Timeout property is set to 0, all operations return immediately, potentially failing with an error if they can't be completed immediately.

If Timeout is set to a positive value, the bean will wait for the operation to complete before returning control.

The bean will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not "freeze" and remains responsive.

If Timeout expires, and the operation is not yet complete, the bean throws an IPWorksException raises an IPWorksException exception .

Please note that by default, all timeouts are inactivity timeouts , i.e. the timeout period is extended by Timeout seconds when data is successfully sent or received.

Optionally, the behaviour of the bean may be changed to absolute timeouts , i.e. the bean will wait for a maximum of Timeout seconds since the beginning of the operation, without extending the timeout period during communications.

This behavior is controlled by theAbsoluteTimeoutconfiguration setting.

The default value for the Timeout property is 60 seconds.

setTimeout

public void setTimeout(int timeout)
                throws IPWorksException

A timeout for the bean.

If the Timeout property is set to 0, all operations return immediately, potentially failing with an error if they can't be completed immediately.

If Timeout is set to a positive value, the bean will wait for the operation to complete before returning control.

The bean will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not "freeze" and remains responsive.

If Timeout expires, and the operation is not yet complete, the bean throws an IPWorksException raises an IPWorksException exception .

Please note that by default, all timeouts are inactivity timeouts , i.e. the timeout period is extended by Timeout seconds when data is successfully sent or received.

Optionally, the behaviour of the bean may be changed to absolute timeouts , i.e. the bean will wait for a maximum of Timeout seconds since the beginning of the operation, without extending the timeout period during communications.

This behavior is controlled by theAbsoluteTimeoutconfiguration setting.

The default value for the Timeout property is 60 seconds.

IPWorksException

config

public java.lang.String config(java.lang.String configurationString)
                        throws IPWorksException

Sets or retrieves a beanconfiguration setting.

Config is a generic method available in every bean. It is used to set and retrieveconfiguration settingsfor the bean.

Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the bean, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY , you must call Config("PROPERTY=VALUE") , where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY") . The value will be returned as a string.

IPWorksException

doEvents

public void doEvents()
              throws IPWorksException

Processes events from the internal message queue.

When DoEvents is called, the bean processes any available events. If no events are available, it waits for a preset period of time, and then returns.

IPWorksException

interrupt

public void interrupt()
               throws IPWorksException

Interrupt the current method.

If there is no method in progress, Interrupt simply returns doing nothing.

IPWorksException

query

public void query(java.lang.String domain)
           throws IPWorksException

Query a Domain.

The bean will query the host Domain for any records of the type in QueryType . Once the query is complete, a single Response event will fire, and the following properties will contain the results:

StatusCode

The success or error code of the DNS query.

Status

A standard string interpretation of StatusCode .

Records

The Records in the last DNS response.

RecordSource

The source (type) of records being listed.

IPWorksException

addDnsEventListener

public void addDnsEventListener(ipworks.DnsEventListener l)
                         throws java.util.TooManyListenersException

java.util.TooManyListenersException

removeDnsEventListener

public void removeDnsEventListener(ipworks.DnsEventListener l)