com.marringtons.database
Class Index

java.lang.Object
  com.marringtons.database.Index

Direct Known Subclasses:

Session.PersistentData.index

public class Index

extends Object

DAO object interfaces recognise indexes by looking for inner classes that have extend this base class. Only this and DAO are visible outside the database package. Names in the Index class must have the same names as fields in the DAO. You will only need to instantiate an index for a non string/integer or for an aggregate index to retrieve the first matching record.

  static class MyDAO extends DAO
   {
     int integer; // can contain any form of primative
     String string; // and Strings
     MyOtherClass myOtherClass; // and any other class you have defined to any depth
     HashMap nameValuePairs; // Maps are saved and NVP for more efficient storage
     DAO anotherDAO; // normalised - committed and saved as a database pointer only
     ArrayList myList; // as are Collections
     static class PrimaryIndex extends Index { int integer; String string; }
     static class SecondaryIndex extends Index( String string; }
   }
 ...
 TestDAO.TertiaryIndex index = new MyDAO.PrimaryIndex();
 index.integer = 1962;
 index.string = "test string testFirst";
 found = (MyDAO) dao.first( index);
 

Author:

Paul Marrington

See Also:

DAO

Constructor Summary

Index()

Method Summary

boolean	equals(Object to) Compare to Index objects using the class directory mapping.
int	hashCode() Generates the hashCode for a known DAO object.

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Index

public Index()

Method Detail

equals

public boolean equals(Object to)

Compare to Index objects using the class directory mapping. Used by DAO.java for searches and by in-memory cache of indexes.

Parameters:

to - compare to.

Returns:

try if logically equals.

See Also:

Object.equals(java.lang.Object)

hashCode

public int hashCode()

Generates the hashCode for a known DAO object. Does not cache 'cause user might reload index. Used by DAO.java for searches and by in-memory cache of indexes.

Returns:

hash code.

See Also:

Object.hashCode()