Module openj9.dtfj

Package com.ibm.dtfj.phd

Class PHDJavaObject.Builder

java.lang.Object

com.ibm.dtfj.phd.PHDJavaObject.Builder

Enclosing class:

PHDJavaObject

public static class PHDJavaObject.Builder
extends Object

The constructors for PHDJavaObject used to take up to 11 arguments, many of which were ints. This made it hard to tie up which argument corresponded to which parameter and invited errors since there can be no type checking.

This is now fixed by the use of the Builder pattern as described in Effective Java Second Edition by Joshua Bloch (http://cyclo.ps/books/Prentice.Hall.Effective.Java.2nd.Edition.May.2008.pdf), item 2 "Consider a builder when faced with many constructor parameters".

The only way to construct a PHDJavaObject is now using this Builder. Required arguments are set with a call to the Builder constructor, then optional arguments are set, then build() is called, usually all in one line using a fluent interface.

Constructor Summary

Constructors

Constructor	Description
Builder(com.ibm.dtfj.phd.PHDJavaHeap heap, long address, JavaClass cls, int flags, int hashCode)	Initialize a Builder for a PHDJavaClass with the five required parameters.

Method Summary

Modifier and Type	Method	Description
PHDJavaObject	build()	Build the PHDJavaObject using all the required and optional values given so far.
PHDJavaObject.Builder	instanceSize(long instanceSize)	Add the instance size attribute to a PHDJavaObject before building it.
PHDJavaObject.Builder	length(int length)	Add the length attribute to a PHDJavaObject before building it.
PHDJavaObject.Builder	refs(LongEnumeration refs, int skipped)	Add the refs attribute to a PHDJavaObject before building it.
PHDJavaObject.Builder	refsAsArray(long[] refs, int skipped)	Add the refs attribute to a PHDJavaObject before building it.

Methods declared in class java.lang.Object

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

Constructor Details

Builder

public Builder(com.ibm.dtfj.phd.PHDJavaHeap heap,
 long address,
 JavaClass cls,
 int flags,
 int hashCode)

Initialize a Builder for a PHDJavaClass with the five required parameters.

Parameters:

heap -

address -

cls -

flags -

hashCode -

Method Details

refs

public PHDJavaObject.Builder refs(LongEnumeration refs,
 int skipped)

Add the refs attribute to a PHDJavaObject before building it.

Parameters:

refs -

skipped -

Returns:

the builder for further attributes or a call to build()

refsAsArray

public PHDJavaObject.Builder refsAsArray(long[] refs,
 int skipped)

Add the refs attribute to a PHDJavaObject before building it.

Parameters:

refs -

skipped -

Returns:

the builder for further attributes or a call to build()

length

public PHDJavaObject.Builder length(int length)

Add the length attribute to a PHDJavaObject before building it.

Parameters:

length -

Returns:

instanceSize

public PHDJavaObject.Builder instanceSize(long instanceSize)

Add the instance size attribute to a PHDJavaObject before building it.

Parameters:

instance - size

Returns:

build

public PHDJavaObject build()

Build the PHDJavaObject using all the required and optional values given so far.

Returns:

the PHDJavaObject