java.lang.Object
- com.mckoi.database.jdbcserver.JDBCProcessor

All Implemented Interfaces:

ProtocolConstants

Direct Known Subclasses:

StreamJDBCServerConnection
```
abstract class JDBCProcessor
extends java.lang.Object
implements ProtocolConstants
```
This processes JDBC commands from a JDBC client and dispatches the commands to the database. This is a state based class. There is a single processor for each JDBC client connected. This class is designed to be flexible enough to handle packet based protocols as well as stream based protocols.

Field Summary

Fields
Modifier and Type	Field	Description
`private int`	`authentication_tries`	Number of authentications tried.
`private DatabaseCallBack`	`db_call_back`	The database call back method that sends database events back to the client.
`private DatabaseInterface`	`db_interface`	The interface to the database.
`private DebugLogger`	`debug`	An object the debug information can be logged to.
`private static int`	`SERVER_VERSION`	The version of the server protocol.
`private int`	`state`	The current state we are in.

Fields inherited from interface com.mckoi.database.jdbc.ProtocolConstants
ACKNOWLEDGEMENT, AUTHENTICATION_ERROR, CLOSE, DATABASE_EVENT, DISPOSE_RESULT, DISPOSE_STREAMABLE_OBJECT, EXCEPTION, FAILED, PING, PUSH_STREAMABLE_OBJECT_PART, QUERY, RESULT_SECTION, SERVER_REQUEST, STREAMABLE_OBJECT_SECTION, SUCCESS, USER_AUTHENTICATION_FAILED, USER_AUTHENTICATION_PASSED

Constructor Summary

Constructors
Constructor Description

JDBCProcessor(DatabaseInterface db_interface, DebugLogger logger)
Sets up the processor.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`abstract void`	`close()`	Closes the connection with the client.
`(package private) void`	`dispose()`	Disposes of this processor.
`private byte[]`	`disposeResult(int dispatch_id, byte[] command)`	Disposes of a result set we queries via the 'QUERY' command.
`private byte[]`	`disposeStreamableObject(int dispatch_id, byte[] command)`	Disposes of a streamable object.
`private byte[]`	`exception(int dispatch_id, java.sql.SQLException e)`	Creates a response that represents an SQL exception failure.
`void`	`finalize()`
`(package private) int`	`getState()`	Returns the state of the connection.
`abstract boolean`	`isClosed()`	Returns true if the connection to the client is closed.
`protected static void`	`printByteArray(byte[] array)`
`(package private) byte[]`	`processJDBCCommand(byte[] command)`	Processes a single JDBCCommand from the client.
`private byte[]`	`processQuery(byte[] command)`	Processes a query on the byte[] array and returns the result.
`private byte[]`	`pushStreamableObjectPart(int dispatch_id, byte[] command)`	Pushes a part of a streamable object onto the server.
`private byte[]`	`queryCommand(int dispatch_id, byte[] command)`	Executes a query and returns the header for the result in the response.
`private byte[]`	`resultSection(int dispatch_id, byte[] command)`	Responds with a part of the result set of a query made via the 'QUERY' command.
`abstract void`	`sendEvent(byte[] event_msg)`	Sends an event to the client.
`private byte[]`	`simpleSuccess(int dispatch_id)`	Creates a response that indicates a simple success of an operation with the given dispatch id.
`private byte[]`	`single(int val)`	Convenience, returns a single 4 byte array with the given int encoded into it.
`private byte[]`	`streamableObjectSection(int dispatch_id, byte[] command)`	Returns a section of a streamable object.

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - SERVER_VERSION
```
private static final int SERVER_VERSION
```
    The version of the server protocol.
    
    See Also:
    
    Constant Field Values
  - state
```
private int state
```
    The current state we are in. 0 indicates we haven't logged in yet. 100 indicates we are logged in.
  - authentication_tries
```
private int authentication_tries
```
    Number of authentications tried.
  - db_interface
```
private DatabaseInterface db_interface
```
    The interface to the database.
  - debug
```
private DebugLogger debug
```
    An object the debug information can be logged to.
  - db_call_back
```
private DatabaseCallBack db_call_back
```
    The database call back method that sends database events back to the client.
- Constructor Detail
  - JDBCProcessor
```
JDBCProcessor(DatabaseInterface db_interface,
              DebugLogger logger)
```
    Sets up the processor.
- Method Detail
  - printByteArray
```
protected static void printByteArray(byte[] array)
```
  - processJDBCCommand
```
byte[] processJDBCCommand(byte[] command)
                   throws java.io.IOException
```
    Processes a single JDBCCommand from the client. The command comes in as a byte[] array and the response is written out as a byte[] array. If it returns 'null' then it means the connection has been closed.
    
    Throws:
    
    java.io.IOException
  - getState
```
int getState()
```
    Returns the state of the connection. 0 = not logged in yet. 1 = logged in.
  - single
```
private byte[] single(int val)
```
    Convenience, returns a single 4 byte array with the given int encoded into it.
  - exception
```
private byte[] exception(int dispatch_id,
                         java.sql.SQLException e)
                  throws java.io.IOException
```
    Creates a response that represents an SQL exception failure.
    
    Throws:
    
    java.io.IOException
  - simpleSuccess
```
private byte[] simpleSuccess(int dispatch_id)
                      throws java.io.IOException
```
    Creates a response that indicates a simple success of an operation with the given dispatch id.
    
    Throws:
    
    java.io.IOException
  - processQuery
```
private byte[] processQuery(byte[] command)
                     throws java.io.IOException
```
    Processes a query on the byte[] array and returns the result.
    
    Throws:
    
    java.io.IOException
  - dispose
```
void dispose()
```
    Disposes of this processor.
  - queryCommand
```
private byte[] queryCommand(int dispatch_id,
                            byte[] command)
                     throws java.io.IOException
```
    Executes a query and returns the header for the result in the response. This keeps track of all result sets because sections of the result are later queries via the 'RESULT_SECTION' command.
    'dispatch_id' is the number we need to respond with.
    
    Throws:
    
    java.io.IOException
  - pushStreamableObjectPart
```
private byte[] pushStreamableObjectPart(int dispatch_id,
                                        byte[] command)
                                 throws java.io.IOException
```
    Pushes a part of a streamable object onto the server.
    'dispatch_id' is the number we need to respond with.
    
    Throws:
    
    java.io.IOException
  - resultSection
```
private byte[] resultSection(int dispatch_id,
                             byte[] command)
                      throws java.io.IOException
```
    Responds with a part of the result set of a query made via the 'QUERY' command.
    'dispatch_id' is the number we need to respond with.
    
    Throws:
    
    java.io.IOException
  - streamableObjectSection
```
private byte[] streamableObjectSection(int dispatch_id,
                                       byte[] command)
                                throws java.io.IOException
```
    Returns a section of a streamable object.
    'dispatch_id' is the number we need to respond with.
    
    Throws:
    
    java.io.IOException
  - disposeStreamableObject
```
private byte[] disposeStreamableObject(int dispatch_id,
                                       byte[] command)
                                throws java.io.IOException
```
    Disposes of a streamable object.
    'dispatch_id' is the number we need to respond with.
    
    Throws:
    
    java.io.IOException
  - disposeResult
```
private byte[] disposeResult(int dispatch_id,
                             byte[] command)
                      throws java.io.IOException
```
    Disposes of a result set we queries via the 'QUERY' command.
    'dispatch_id' is the number we need to respond with.
    
    Throws:
    
    java.io.IOException
  - sendEvent
```
public abstract void sendEvent(byte[] event_msg)
                        throws java.io.IOException
```
    Sends an event to the client. This is used to notify the client of trigger events, etc.
    SECURITY ISSUE: This is always invoked by the DatabaseDispatcher. We have to be careful that this method isn't allowed to block. Otherwise the DatabaseDispatcher thread will be out of operation. Unfortunately assuring this may not be possible until Java has non-blocking IO, or we use datagrams for transmission. I know for sure that the TCP implementation is vunrable. If the client doesn't 'read' what we are sending then this'll block when the buffers become full.
    
    Throws:
    
    java.io.IOException
  - close
```
public abstract void close()
                    throws java.io.IOException
```
    Closes the connection with the client.
    
    Throws:
    
    java.io.IOException
  - isClosed
```
public abstract boolean isClosed()
                          throws java.io.IOException
```
    Returns true if the connection to the client is closed.
    
    Throws:
    
    java.io.IOException
  - finalize
```
public final void finalize()
                    throws java.lang.Throwable
```
    Overrides:
    
    finalize in class java.lang.Object
    
    Throws:
    
    java.lang.Throwable

Class JDBCProcessor

Field Summary

Fields inherited from interface com.mckoi.database.jdbc.ProtocolConstants

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SERVER_VERSION

state

authentication_tries

db_interface

debug

db_call_back

Constructor Detail

JDBCProcessor

Method Detail

printByteArray

processJDBCCommand

getState

single

exception

simpleSuccess

processQuery

dispose

queryCommand

pushStreamableObjectPart

resultSection

streamableObjectSection

disposeStreamableObject

disposeResult

sendEvent

close

isClosed

finalize