com.mckoi.database
Class TObject

java.lang.Object
  extended by com.mckoi.database.TObject
All Implemented Interfaces:
java.io.Serializable

public final class TObject
extends java.lang.Object
implements java.io.Serializable

A TObject is a strongly typed object in a database engine. A TObject must maintain type information (eg. STRING, NUMBER, etc) along with the object value being represented itself.

Author:
Tobias Downer
See Also:
Serialized Form

Field Summary
static TObject BOOLEAN_FALSE
           
static TObject BOOLEAN_NULL
           
static TObject BOOLEAN_TRUE
           
static TObject NULL_OBJECT
           
 
Constructor Summary
TObject(TType type, java.lang.Object ob)
          Constructs the TObject as the given type.
 
Method Summary
 int approximateMemoryUse()
          Returns the approximate memory use of this object in bytes.
static TObject bigNumberVal(BigNumber val)
          Returns a TObject of numeric type that represents the given BigNumber value.
static TObject booleanVal(boolean b)
          Returns a TObject of boolean type that is either true or false.
 TObject castTo(TType cast_to_type)
          Casts this object to the given type and returns a new TObject.
 boolean comparableTypes(TObject ob)
          Returns true if the type of this object is logically comparable to the type of the given object.
 int compareTo(TObject tob)
          Compares this object with the given object (which is of a logically comparable type).
 int compareToNoNulls(TObject tob)
          Compares this object with the given object (which is of a logically comparable type).
static TObject createAndCastFromObject(TType type, java.lang.Object ob)
          Returns a TObject of the given type and with the given Java object.
static TObject dateVal(java.util.Date d)
          Returns a TObject of DATE type that represents the given time value.
static TObject doubleVal(double val)
          Returns a TObject of numeric type that represents the given double value.
 boolean equals(java.lang.Object ob)
          Equality test.
 java.lang.Object getObject()
          Returns a java.lang.Object that is the data behind this object.
 TType getTType()
          Returns the type of this object.
static TObject intVal(int val)
          Returns a TObject of numeric type that represents the given int value.
 boolean isNull()
          Returns true if the object is null.
static TObject longVal(long val)
          Returns a TObject of numeric type that represents the given long value.
static TObject nullVal()
          Returns a TObject of NULL type that represents a null value.
static TObject objectVal(java.lang.Object ob)
          Returns a TObject from the given Java value.
 TObject operatorAdd(TObject val)
          Mathematical addition of this object to the given object.
 TObject operatorConcat(TObject val)
          String concat of this object to the given object.
 TObject operatorDivide(TObject val)
          Mathematical division of this object to the given object.
 TObject operatorEquals(TObject val)
          Comparison of this object and the given object.
 TObject operatorGreater(TObject val)
          Comparison of this object and the given object.
 TObject operatorGreaterEquals(TObject val)
          Comparison of this object and the given object.
 TObject operatorIs(TObject val)
          Comparison of this object and the given object.
 TObject operatorLess(TObject val)
          Comparison of this object and the given object.
 TObject operatorLessEquals(TObject val)
          Comparison of this object and the given object.
 TObject operatorMultiply(TObject val)
          Mathematical multiply of this object to the given object.
 TObject operatorNot()
          Performs a logical NOT on this value.
 TObject operatorNotEquals(TObject val)
          Comparison of this object and the given object.
 TObject operatorOr(TObject val)
          Bitwise OR operation of this object with the given object.
 TObject operatorSubtract(TObject val)
          Mathematical subtraction of this object to the given object.
static TObject stringVal(java.lang.String str)
          Returns a TObject of VARCHAR type that represents the given String value.
static TObject stringVal(StringObject str)
          Returns a TObject of VARCHAR type that represents the given StringObject value.
 BigNumber toBigNumber()
          Returns the BigNumber of this object if this object is a numeric type.
 java.lang.Boolean toBoolean()
          Returns the Boolean of this object if this object is a boolean type.
 java.lang.String toString()
           
 java.lang.String toStringValue()
          Returns the String of this object if this object is a string type.
 boolean valuesEqual(TObject ob)
          Equality test.
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

BOOLEAN_TRUE

public static final TObject BOOLEAN_TRUE

BOOLEAN_FALSE

public static final TObject BOOLEAN_FALSE

BOOLEAN_NULL

public static final TObject BOOLEAN_NULL

NULL_OBJECT

public static final TObject NULL_OBJECT
Constructor Detail

TObject

public TObject(TType type,
               java.lang.Object ob)
Constructs the TObject as the given type.

Method Detail

getTType

public TType getTType()
Returns the type of this object.


isNull

public boolean isNull()
Returns true if the object is null. Note that we must still be able to determine type information for an object that is NULL.


getObject

public java.lang.Object getObject()
Returns a java.lang.Object that is the data behind this object.


approximateMemoryUse

public int approximateMemoryUse()
Returns the approximate memory use of this object in bytes. This is used when the engine is caching objects and we need a general indication of how much space it takes up in memory.


comparableTypes

public boolean comparableTypes(TObject ob)
Returns true if the type of this object is logically comparable to the type of the given object. For example, VARCHAR and LONGVARCHAR are comparable types. DOUBLE and FLOAT are comparable types. DOUBLE and VARCHAR are not comparable types.


toBigNumber

public BigNumber toBigNumber()
Returns the BigNumber of this object if this object is a numeric type. If the object is not a numeric type or is NULL then a null object is returned. This method can not be used to cast from a type to a number.


toBoolean

public java.lang.Boolean toBoolean()
Returns the Boolean of this object if this object is a boolean type. If the object is not a boolean type or is NULL then a null object is returned. This method must not be used to cast from a type to a boolean.


toStringValue

public java.lang.String toStringValue()
Returns the String of this object if this object is a string type. If the object is not a string type or is NULL then a null object is returned. This method must not be used to cast from a type to a string.


booleanVal

public static TObject booleanVal(boolean b)
Returns a TObject of boolean type that is either true or false.


intVal

public static TObject intVal(int val)
Returns a TObject of numeric type that represents the given int value.


longVal

public static TObject longVal(long val)
Returns a TObject of numeric type that represents the given long value.


doubleVal

public static TObject doubleVal(double val)
Returns a TObject of numeric type that represents the given double value.


bigNumberVal

public static TObject bigNumberVal(BigNumber val)
Returns a TObject of numeric type that represents the given BigNumber value.


stringVal

public static TObject stringVal(StringObject str)
Returns a TObject of VARCHAR type that represents the given StringObject value.


stringVal

public static TObject stringVal(java.lang.String str)
Returns a TObject of VARCHAR type that represents the given String value.


dateVal

public static TObject dateVal(java.util.Date d)
Returns a TObject of DATE type that represents the given time value.


nullVal

public static TObject nullVal()
Returns a TObject of NULL type that represents a null value.


objectVal

public static TObject objectVal(java.lang.Object ob)
Returns a TObject from the given Java value.


compareToNoNulls

public int compareToNoNulls(TObject tob)
Compares this object with the given object (which is of a logically comparable type). Returns 0 if the value of the objects are equal, < 0 if this object is smaller than the given object, and > 0 if this object is greater than the given object.

This can not be used to compare null values so it assumes that checks for null have already been made.


compareTo

public int compareTo(TObject tob)
Compares this object with the given object (which is of a logically comparable type). Returns 0 if the value of the objects are equal, < 0 if this object is smaller than the given object, and > 0 if this object is greater than the given object.

This compares NULL values before non null values, and null values are equal.


equals

public boolean equals(java.lang.Object ob)
Equality test. This will throw an exception if it is used. The reason for this is because it's not clear what we would be testing the equality of with this method. Equality of the object + the type or equality of the objects only?

Overrides:
equals in class java.lang.Object

valuesEqual

public boolean valuesEqual(TObject ob)
Equality test. Returns true if this object is equivalent to the given TObject. This means the types are the same, and the object itself is the same.


operatorOr

public TObject operatorOr(TObject val)
Bitwise OR operation of this object with the given object. If either numeric value has a scale of 1 or greater then it returns null. If this or the given object is not a numeric type then it returns null. If either this object or the given object is NULL, then the NULL object is returned.


operatorAdd

public TObject operatorAdd(TObject val)
Mathematical addition of this object to the given object. If this or the given object is not a numeric type then it returns null. If either this object or the given object is NULL, then the NULL object is returned.


operatorSubtract

public TObject operatorSubtract(TObject val)
Mathematical subtraction of this object to the given object. If this or the given object is not a numeric type then it returns null. If either this object or the given object is NULL, then the NULL object is returned.


operatorMultiply

public TObject operatorMultiply(TObject val)
Mathematical multiply of this object to the given object. If this or the given object is not a numeric type then it returns null. If either this object or the given object is NULL, then the NULL object is returned.


operatorDivide

public TObject operatorDivide(TObject val)
Mathematical division of this object to the given object. If this or the given object is not a numeric type then it returns null. If either this object or the given object is NULL, then the NULL object is returned.


operatorConcat

public TObject operatorConcat(TObject val)
String concat of this object to the given object. If this or the given object is not a string type then it returns null. If either this object or the given object is NULL, then the NULL object is returned.

This operator always returns an object that is a VARCHAR string type of unlimited size with locale inherited from either this or val depending on whether the locale information is defined or not.


operatorIs

public TObject operatorIs(TObject val)
Comparison of this object and the given object. The compared objects must be the same type otherwise it returns false. This is able to compare null values.


operatorEquals

public TObject operatorEquals(TObject val)
Comparison of this object and the given object. The compared objects must be the same type otherwise it returns null (doesn't know). If either this object or the given object is NULL then NULL is returned.


operatorNotEquals

public TObject operatorNotEquals(TObject val)
Comparison of this object and the given object. The compared objects must be the same type otherwise it returns null (doesn't know). If either this object or the given object is NULL then NULL is returned.


operatorGreater

public TObject operatorGreater(TObject val)
Comparison of this object and the given object. The compared objects must be the same type otherwise it returns null (doesn't know). If either this object or the given object is NULL then NULL is returned.


operatorGreaterEquals

public TObject operatorGreaterEquals(TObject val)
Comparison of this object and the given object. The compared objects must be the same type otherwise it returns null (doesn't know). If either this object or the given object is NULL then NULL is returned.


operatorLess

public TObject operatorLess(TObject val)
Comparison of this object and the given object. The compared objects must be the same type otherwise it returns null (doesn't know). If either this object or the given object is NULL then NULL is returned.


operatorLessEquals

public TObject operatorLessEquals(TObject val)
Comparison of this object and the given object. The compared objects must be the same type otherwise it returns null (doesn't know). If either this object or the given object is NULL then NULL is returned.


operatorNot

public TObject operatorNot()
Performs a logical NOT on this value.


createAndCastFromObject

public static TObject createAndCastFromObject(TType type,
                                              java.lang.Object ob)
Returns a TObject of the given type and with the given Java object. If the object is not of the right type then it is cast to the correct type.


castTo

public TObject castTo(TType cast_to_type)
Casts this object to the given type and returns a new TObject.


toString

public java.lang.String toString()
Overrides:
toString in class java.lang.Object