com.goldencode.p2j.util

Class SourceLob

java.lang.Object

com.goldencode.p2j.util.LobCopyInput

com.goldencode.p2j.util.SourceLob

All Implemented Interfaces:

LobCopyParameter

public class SourceLob
extends LobCopyInput

Concrete implementation of a converted COPY-LOB source parameter, corresponding with the FROM [ OBJECT ] source-lob phrase.

Field Summary

Fields

Modifier and Type	Field and Description
private LargeObject	lob Large object which is the source of the copy operation

Fields inherited from class com.goldencode.p2j.util.LobCopyInput

offset

Fields inherited from interface com.goldencode.p2j.util.LobCopyParameter

TYPE_BLOB, TYPE_CHAR_BIT, TYPE_CLOB, TYPE_FIELD_BIT, TYPE_FILE, TYPE_LONGCHAR, TYPE_MEMPTR, TYPE_UNKNOWN

Constructor Summary

Constructors

Constructor and Description
SourceLob(LargeObject lob) Constructor which takes a LOB.
SourceLob(java.lang.Object lob) Constructor which takes an object that is expected to be a LOB.

Method Summary

Modifier and Type	Method and Description
java.lang.String	getCodePage() Get the code page of this parameter, if any.
int	getObjectType() Obtain the type of the object wrapped by this parameter
protected int	getSize() Get the size of the object to be copied.
boolean	isCharacterData() Indicate whether the large object represented by this parameter natively represents encoded character data, as opposed to binary data.
boolean	isLargeObject() Indicate whether this object is a valid large object data type.
protected byte[]	readBytes() Read the content of the backing LOB from the starting offset up to the length and return it as a byte buffer.
protected java.lang.String	readString(java.lang.String codePage) Read the content of the backing LOB from the starting offset up to the length and return it as a string using the given encoding.
boolean	validateOffset(int targetType) Checks if the optional offset is valid.

Methods inherited from class com.goldencode.p2j.util.LobCopyInput

getLength, getOffset, length, length, offset, offset, validate

Methods inherited from class java.lang.Object

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

Field Detail

lob

private final LargeObject lob

Large object which is the source of the copy operation

Constructor Detail

SourceLob

public SourceLob(LargeObject lob)

Constructor which takes a LOB.

Parameters:

lob - Large object which is the source of the copy operation.

SourceLob

public SourceLob(java.lang.Object lob)

Constructor which takes an object that is expected to be a LOB. Intended to handle the converted POLY case.

Parameters:

lob - Large object which is the source of the copy operation.

Throws:

ConditionException - if lob is not an instance of @LargeObject@.

Method Detail

validateOffset

public boolean validateOffset(int targetType)

Checks if the optional offset is valid.

Parameters:

targetType - The type of the target object. The error messages are different in some cases.

Returns:

true if the optional offset is valid.

isLargeObject

public boolean isLargeObject()

Indicate whether this object is a valid large object data type. It is possible to pass a POLY which is not a valid LOB type as a COPY-LOB parameter, and this error must be determined at runtime.

Returns:

true if valid, else false. The default implementation assumes validity; implementors which must handle runtime type verification must override this method.

getObjectType

public int getObjectType()

Obtain the type of the object wrapped by this parameter

Returns:

The numerical id of a type declared as one of the TYPE static constants from LobCopyParameter interface.

isCharacterData

public boolean isCharacterData()

Indicate whether the large object represented by this parameter natively represents encoded character data, as opposed to binary data.

Returns:

true if character data; false if binary data.

getSize

protected int getSize()

Get the size of the object to be copied.

Specified by:

getSize in class LobCopyInput

Returns:

Size of object, in bytes or characters, as appropriate to the object type.

getCodePage

public java.lang.String getCodePage()

Get the code page of this parameter, if any.

Returns:

4GL code page name or null if parameter represents non-character data.

readString

protected java.lang.String readString(java.lang.String codePage)

Read the content of the backing LOB from the starting offset up to the length and return it as a string using the given encoding.

Specified by:

readString in class LobCopyInput

Parameters:

codePage - Name of the 4GL code page to be used to encode the read string. If null, the large object's explicit code page (if any) will be used. If none, the value of -cpinternal will be used.

Returns:

The data as described above.

readBytes

protected byte[] readBytes()

Read the content of the backing LOB from the starting offset up to the length and return it as a byte buffer.

Note that the returned buffer must not be modified, as it could either be a copy of the LOB's data or its real backing data.

Specified by:

readBytes in class LobCopyInput

Returns:

The data as described above.