psdi.app.workorder.virtual

Class OrderBy

java.lang.Object

psdi.app.workorder.virtual.OrderBy

All Implemented Interfaces:

java.lang.Comparable, java.util.Comparator

public class OrderBy
extends java.lang.Object
implements java.lang.Comparable, java.util.Comparator

This helper class parses order by clauses and reorders internal Mbo vectors using the order by clause given. It also compares other order by clauses.

Author:

John Neville

Constructor Summary

Constructors

Constructor and Description
OrderBy() Default constructor takes no parameters.
OrderBy(java.lang.String clause) Optional constructor takes a String for the initial order by.

Method Summary

Modifier and Type	Method and Description
int	compare(java.lang.Object o1, java.lang.Object o2) Compares two Mbos using the order by clause given earlier.
int	compareTo(java.lang.Object o) Compares this OrderBy object to another object.
java.lang.String	getOrderBy() Returns the order by clause in standard form.
boolean	isEmpty() Tests to see if any order by has been defined.
java.util.List	orderMboList(java.util.List mboList) Reorders the list of Mbos using the order by set earlier.
void	setOrderBy(java.lang.String clause) Parses the order by clause and stores the information internally.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Detail

OrderBy

public OrderBy()

Default constructor takes no parameters.

OrderBy

public OrderBy(java.lang.String clause)

Optional constructor takes a String for the initial order by.

Parameters:

clause -

Method Detail

setOrderBy

public void setOrderBy(java.lang.String clause)

Parses the order by clause and stores the information internally.

Parameters:

clause - The order by clause. Assumed to contain attribute names, commas, and optionally asc & desc tags. If null or the empty string, this order by is cleared.

Throws:

MXApplicationException - Thrown with "workorder", "OrderBy" if the clause can't be read

isEmpty

public boolean isEmpty()

Tests to see if any order by has been defined.

Returns:

true if there is no order by defined.

getOrderBy

public java.lang.String getOrderBy()

Returns the order by clause in standard form.

Returns:

The Order By clause. If no defined, the empty string will be returned.

orderMboList

public java.util.List orderMboList(java.util.List mboList)

Reorders the list of Mbos using the order by set earlier. If no order by was set, this does nothing.

compare

public int compare(java.lang.Object o1,
                   java.lang.Object o2)

Compares two Mbos using the order by clause given earlier. Depending on the order by given it likely that several Mbos will be found to be equal. The Mbo's Wonum attribute is used to tie-breaker in this case.

Specified by:

compare in interface java.util.Comparator

Parameters:

o1 - - the first object to be compared.

o2 - - the second object to be compared.

Returns:

A negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second. This comparison will only return zero if o1 and o2 are the same object.

Throws:

java.lang.ClassCastException - if the objects aren't both Mbos.

compareTo

public int compareTo(java.lang.Object o)

Compares this OrderBy object to another object.

Specified by:

compareTo in interface java.lang.Comparable

Parameters:

o - The other object to compare to

Returns:

A negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

Throws:

java.lang.ClassCastException - Is thrown if the parameter is not a String, representing an order by clause or another OrderBy object.