object (P2J - Progress 4GL to Java Conversion and Runtime)

java.lang.Object
- com.goldencode.p2j.util.LazyUndoable
- - com.goldencode.p2j.util.BaseDataType
  - - com.goldencode.p2j.util.object<T>

All Implemented Interfaces:

Undoable, java.io.Externalizable, java.io.Serializable, java.lang.Comparable

Direct Known Subclasses:

EnumObject, ObjectVar
```
public class object<T extends _BaseObject_>
extends BaseDataType
```
Wrapper class for all OO 4GL instance references. This is needed for compatibility with unknown value, assignment, parameter passing, DELETE, SESSION:FIRST-OBJECT/LAST-OBJECT and UNDO.
TODO: throwing errors from an appserver to the client will serialize the legacy instance.

See Also:

Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from class com.goldencode.p2j.util.BaseDataType
  BaseDataType.Type, BaseDataType.WrapperHandler

Field Summary

Fields
Modifier and Type	Field and Description
`protected ObjectOps.ObjectHelper`	`helper` Helper to use the ObjectOps without any context local lookups.
`protected T`	`ref` The contained object instance.
`private java.lang.Class<T>`	`type` The object's type.

Constructor Summary

Constructors
Constructor and Description
`object()` Default constructor.
`object(java.lang.Class<? extends _BaseObject_> type)` Initialize this object reference, allowing only assignment to objects compatible with the specified type.
`object(object<T> other)` Copy constructor.
`object(ObjectResource res)` Initialize this object with the reference from the specified resource.
`object(T ref)` Initialize this object with the given reference.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`_isValid()` Determines if this instance is valid (to be used).
`void`	`assign(_BaseObject_ ref)` Set this instance `ref` to the specified value, directly.
`void`	`assign(BaseDataType value)` Sets the state (data and unknown value) of this instance based on the state of the passed instance.
`void`	`assign(object<?> value)` Copy the reference from another object instance to this one.
`void`	`assign(Undoable old)` Modify the contained data of the instance to copy the instance data from the given instance.
`int`	`compareTo(java.lang.Object obj)` Compares this instance with the specified instance and returns -1 if this instance is less than the instance specified, 0 if the two instances are equal and 1 if this instance is greater than the specified instance.
`protected void`	`decrement()` Decrement the reference counter for this instance.
`java.lang.String`	`defaultFormatString()` Return the default display format string for this type.
`object<T>`	`duplicate()` Does the same as standard `clone()` method but returns an instance of `BaseDataType` and doesn't throw the `CloneNotSupportedException`.
`static object<? extends _BaseObject_>`	`fromResourceId(long resId)` Resolve the legacy instance and build an object referencing it.
`BaseDataType.Type`	`getType()` Get the type.
`int`	`hashCode()` A minimal implementation which satisfies the need for a concrete method.
`protected void`	`increment()` Increment the reference counter for this instance.
`private void`	`initialize(java.lang.Class<? extends _BaseObject_> type, T ref)` Initialize this object with the given reference.
`BaseDataType`	`instantiateDefault()` Creates a new instance of the same type that represents the default initialized value.
`BaseDataType`	`instantiateUnknown()` Creates a new instance of the same type that represents the `unknown value`.
`protected boolean`	`isIncompatibleTypesOnConversion(BaseDataType value)` Returns true if dynamic data type conversion should not be attempted, it can also throws in case of incompatible types for a POLY conversion.
`boolean`	`isTracked()` Reports if the given instance is managed as part of the legacy 4GL object life cycle.
`boolean`	`isUnknown()` Reports if this instance represents the `unknown value`.
`logical`	`isValid()` Determines if this instance is valid (to be used).
`void`	`readExternal(java.io.ObjectInput in)` The object implements the readExternal method to restore its contents by calling the methods of DataInput for primitive types and readObject for objects, strings and arrays.
`T`	`ref()` Return the wrapped reference if this instance is not set to unknown value.
`static long`	`resourceId(object<? extends _BaseObject_> obj)` Returns an ID for the resource-representation of this object's reference.
`(package private) void`	`set(_BaseObject_ ref)` Set this object's reference and type from the given instance.
`void`	`setUnknown()` Sets the state of this instance's `unknown value` flag or state to `true`.
`java.lang.String`	`toString()` Obtain a short description of the current object/state to be used in debugging.
`java.lang.String`	`toString(java.lang.String fmt)` Creates a string representation of the instance data using the given format string.
`java.lang.String`	`toStringExport()` Creates a string representation of the instance data using the 'export' format.
`java.lang.String`	`toStringMessage()` Creates a string representation of the instance data in a form that is compatible with the `MESSAGE` language statement.
`(package private) java.lang.Class<T>`	`type()` Get the object's declared class.
`void`	`writeExternal(java.io.ObjectOutput out)` The object implements the writeExternal method to save its contents by calling the methods of DataOutput for its primitive values or calling the writeObject method of ObjectOutput for objects, strings, and arrays.

Methods inherited from class com.goldencode.p2j.util.BaseDataType
assign, assign, calcFormatLength, createProxy, createProxy, deepCopy, elementsOfType, equals, fallback, formatLength, fromTypeName, generateDefault, generateUnknown, getAssigner, getSize, getTypeName, incompatibleTypesOnConversion, initialize, initializeDefaultExtent, instantiateDefaultExtent, invalidInitializer, isAllKnown, isAllKnown, isAssignDirect, isProxy, isUnknownValue, maximum, minimum, notUnknownValue, sameType, val, variable

Methods inherited from class com.goldencode.p2j.util.LazyUndoable
changed, checkUndoable, checkUndoable, checkUndoable, getTransLevel, isGlobal, isUndoable, markUndoable, popBlock, rollback, setGlobal

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - ref
```
protected T extends _BaseObject_ ref
```
    The contained object instance. null is unknown value.
  - type
```
private java.lang.Class<T extends _BaseObject_> type
```
    The object's type.
  - helper
```
protected ObjectOps.ObjectHelper helper
```
    Helper to use the ObjectOps without any context local lookups.
    WARNING: this instance is used only in _isValid() and isUnknown(). These methods are overridden in EnumObject. Any other usage must take care of this, as the enum must have no context saved when is created.
- Constructor Detail
  - object
```
public object()
```
    Default constructor.
  - object
```
public object(java.lang.Class<? extends _BaseObject_> type)
```
    Initialize this object reference, allowing only assignment to objects compatible with the specified type.
    
    Parameters:
    
    type - The type of references this object can hold.
  - object
```
public object(T ref)
```
    Initialize this object with the given reference.
    
    Parameters:
    
    ref - The reference.
  - object
```
public object(ObjectResource res)
```
    Initialize this object with the reference from the specified resource.
    
    Parameters:
    
    res - The object resource.
  - object
```
public object(object<T> other)
```
    Copy constructor.
    
    Parameters:
    
    other - The object from which to copy.
- Method Detail
  - resourceId
```
public static long resourceId(object<? extends _BaseObject_> obj)
```
    Returns an ID for the resource-representation of this object's reference.
    
    Parameters:
    
    obj - The object for which the resource ID is required.
    
    Returns:
    
    See above.
  - getType
```
public BaseDataType.Type getType()
```
    Get the type.
    
    Specified by:
    
    getType in class BaseDataType
    
    Returns:
    
    type
  - fromResourceId
```
public static object<? extends _BaseObject_> fromResourceId(long resId)
```
    Resolve the legacy instance and build an object referencing it.
    
    Parameters:
    
    resId - The resource ID.
    
    Returns:
    
    The object reference.
  - ref
```
public T ref()
```
    Return the wrapped reference if this instance is not set to unknown value.
    
    Returns:
    
    The contained reference or raise an error if this is unknown value.
  - compareTo
```
public int compareTo(java.lang.Object obj)
```
    Compares this instance with the specified instance and returns -1 if this instance is less than the instance specified, 0 if the two instances are equal and 1 if this instance is greater than the specified instance. This is the implementation of the Comparable interface.
    The algorithm will fail to give meaningful results in the case where one tries to sort against other objects that do not represent compatible values.
    
    Parameters:
    
    obj - The instance to compare against.
    
    Returns:
    
    -1, 0, or 1 depending on if this instance is less than, equal to or greater (respectively) than the specified instance obj.
  - hashCode
```
public int hashCode()
```
    A minimal implementation which satisfies the need for a concrete method.
    
    Specified by:
    
    hashCode in class BaseDataType
    
    Returns:
    
    The hash code for this object instance.
  - assign
```
public void assign(_BaseObject_ ref)
```
    Set this instance ref to the specified value, directly.
    If ref is null, it will be set to unknown.
    If the type is not compatible with ref, an error condition is raised.
    
    Parameters:
    
    ref - The instance to assign.
  - assign
```
public void assign(BaseDataType value)
```
    Sets the state (data and unknown value) of this instance based on the state of the passed instance.
    If the value is not of the same type, some form of automatic type conversion may occur, or an error will be raised.
    This variant is meant to handle the cases of built-in functions and methods in the 4GL which have polymorphic return types (e.g. DYNAMIC-FUNCTION()). This should NOT be used for non-polymorphic assignments.
    
    Specified by:
    
    assign in class BaseDataType
    
    Parameters:
    
    value - The instance from which to copy state.
  - assign
```
public void assign(object<?> value)
```
    Copy the reference from another object instance to this one.
    
    Parameters:
    
    value - The instance from which to copy state.
  - assign
```
public void assign(Undoable old)
```
    Modify the contained data of the instance to copy the instance data from the given instance. Generally, the class of the given instance must match the class upon which the assign method is called, although this is not a strict requirement.
    
    Parameters:
    
    old - The backup instance from which to copy data.
  - isUnknown
```
public boolean isUnknown()
```
    Reports if this instance represents the unknown value.
    
    Specified by:
    
    isUnknown in class BaseDataType
    
    Returns:
    
    true if this instance is set to the unknown value.
  - isValid
```
public logical isValid()
```
    Determines if this instance is valid (to be used).
    
    Returns:
    
    true if this instance can be used.
  - _isValid
```
public boolean _isValid()
```
    Determines if this instance is valid (to be used).
    
    Returns:
    
    true if this instance can be used.
  - isTracked
```
public boolean isTracked()
```
    Reports if the given instance is managed as part of the legacy 4GL object life cycle. This includes reference counting, linking in the SESSION object chain, managed construction and destruction.
    
    Returns:
    
    true if the instance is tracked and false if the instance exists outside of the OO 4GL life cycle mechanisms.
  - setUnknown
```
public void setUnknown()
```
    Sets the state of this instance's unknown value flag or state to true.
    Warning: the data stored in this instance will be invalid after calling this method.
    
    Specified by:
    
    setUnknown in class BaseDataType
  - duplicate
```
public object<T> duplicate()
```
    Does the same as standard clone() method but returns an instance of BaseDataType and doesn't throw the CloneNotSupportedException.
    
    Specified by:
    
    duplicate in class BaseDataType
    
    Returns:
    
    A clone of this instance.
  - instantiateUnknown
```
public BaseDataType instantiateUnknown()
```
    Creates a new instance of the same type that represents the unknown value.
    
    Specified by:
    
    instantiateUnknown in class BaseDataType
    
    Returns:
    
    An instance that represents the unknown value.
  - toString
```
public java.lang.String toString(java.lang.String fmt)
```
    Creates a string representation of the instance data using the given format string. If the instance represents the unknown value, a '?' will be returned.
    
    Specified by:
    
    toString in class BaseDataType
    
    Parameters:
    
    fmt - The format string to use.
    
    Returns:
    
    The formatted string.
  - toStringMessage
```
public java.lang.String toStringMessage()
```
    Creates a string representation of the instance data in a form that is compatible with the MESSAGE language statement. If the instance represents the unknown value, a '?' will be returned.
    
    Specified by:
    
    toStringMessage in class BaseDataType
    
    Returns:
    
    The 'message' formatted string.
  - toStringExport
```
public java.lang.String toStringExport()
```
    Creates a string representation of the instance data using the 'export' format. If the instance represents the unknown value, a '?' will be returned.
    
    Specified by:
    
    toStringExport in class BaseDataType
    
    Returns:
    
    The 'export' formatted string.
  - defaultFormatString
```
public java.lang.String defaultFormatString()
```
    Return the default display format string for this type.
    
    Specified by:
    
    defaultFormatString in class BaseDataType
    
    Returns:
    
    The default format string.
  - writeExternal
```
public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException
```
    The object implements the writeExternal method to save its contents by calling the methods of DataOutput for its primitive values or calling the writeObject method of ObjectOutput for objects, strings, and arrays.
    
    Parameters:
    
    out - the stream to write the object to
    
    Throws:
    
    java.io.IOException - Includes any I/O exceptions that may occur
  - readExternal
```
public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException
```
    The object implements the readExternal method to restore its contents by calling the methods of DataInput for primitive types and readObject for objects, strings and arrays. The readExternal method must read the values in the same sequence and with the same types as were written by writeExternal.
    
    Parameters:
    
    in - the stream to read data from in order to restore the object
    
    Throws:
    
    java.io.IOException - if I/O errors occur
    
    java.lang.ClassNotFoundException - If the class for an object being restored cannot be found.
  - set
```
void set(_BaseObject_ ref)
```
    Set this object's reference and type from the given instance.
    
    Parameters:
    
    ref - The object instance.
  - type
```
java.lang.Class<T> type()
```
    Get the object's declared class.
    
    Returns:
    
    The type.
  - instantiateDefault
```
public BaseDataType instantiateDefault()
```
    Creates a new instance of the same type that represents the default initialized value.
    
    Specified by:
    
    instantiateDefault in class BaseDataType
    
    Returns:
    
    An instance that represents the default value.
  - decrement
```
protected void decrement()
```
    Decrement the reference counter for this instance.
    No-op for internal object instances.
  - increment
```
protected void increment()
```
    Increment the reference counter for this instance.
    No-op for internal object instances.
  - initialize
```
private void initialize(java.lang.Class<? extends _BaseObject_> type,
                        T ref)
```
    Initialize this object with the given reference.
    
    Parameters:
    
    type - The type of references this object can hold. It is safe to pass null.
    
    ref - The reference. It is safe to pass null.
  - toString
```
public java.lang.String toString()
```
    Obtain a short description of the current object/state to be used in debugging.
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    a short description of the current object/state.
  - isIncompatibleTypesOnConversion
```
protected boolean isIncompatibleTypesOnConversion(BaseDataType value)
```
    Description copied from class: BaseDataType
    
    Returns true if dynamic data type conversion should not be attempted, it can also throws in case of incompatible types for a POLY conversion. (e.g. DYNAMIC-FUNCTION()).
    
    Overrides:
    
    isIncompatibleTypesOnConversion in class BaseDataType

Class object<T extends _BaseObject_>

Nested Class Summary

Nested classes/interfaces inherited from class com.goldencode.p2j.util.BaseDataType

Field Summary

Constructor Summary

Method Summary

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

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

Methods inherited from class java.lang.Object

Field Detail

ref

type

helper

Constructor Detail

object

object

object

object

object

Method Detail

resourceId

getType

fromResourceId

ref

compareTo

hashCode

assign

assign

assign

assign

isUnknown

isValid

_isValid

isTracked

setUnknown

duplicate

instantiateUnknown

toString

toStringMessage

toStringExport

defaultFormatString

writeExternal

readExternal

set

type

instantiateDefault

decrement

increment

initialize

toString

isIncompatibleTypesOnConversion