ClassLookupCache

java.lang.Object
- org.onemind.commons.java.datastructure.LookupCache
- - org.onemind.commons.java.lang.reflect.ClassLookupCache

```
public class ClassLookupCache
extends LookupCache
```
A class lookup cache can lookup non-fully-qualified name classes for a given set of packages and will cache the lookup for later use. For example,
```
      ClassLookupCache cache = new ClassLookupCache();
      cache.addPackage("*"); //default package
      cache.addPackage("java.io.*");
  
      Class c = cache.getClass("File"); //c = java.io.File
      c = cache.getClass("File1"); //c = null
 
```
NOTE: 1. The cache is static for all instances of the lookup cache. 2. The packages is instance specific 3. It will cache only positive and negative response of fully qualified name thus lookup of non-fully-qualified has some performance hit, but for the sake of correctness
Version:

$Id: ClassLookupCache.java,v 1.6 2006/10/29 17:02:38 thlee Exp $ $Name: $

Author:

TiongHiang Lee (thlee@onemindsoft.org)

Field Summary

Fields
Modifier and Type Field and Description

private static java.util.logging.Logger _logger
the logger *

private java.util.HashSet _packages
the packages *

Fields
Modifier and Type	Field and Description
`private static java.util.logging.Logger`	`_logger` the logger *
`private java.util.HashSet`	`_packages` the packages *

Constructor Summary

Constructors
Constructor and Description

ClassLookupCache()

Constructors
Constructor and Description
`ClassLookupCache()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addImport(java.lang.String importName)` Add a new package.
`protected void`	`clearNegCache()` Clear all the negative cache
`java.lang.Class`	`getClass(java.lang.String className)` Get the class given by the fully-qualified or non-fully qualified java class name
`java.util.Set`	`getPackages()` Get all the import packages in this lookup cache.
`protected boolean`	`isInCache(java.lang.Object o)` Test if the key is in cache
`protected boolean`	`isInNegCache(java.lang.Object o)` Get whether the object is in negative cache
`java.lang.Object`	`produce(java.lang.Object key)` Produce the class given the key Produce the object given the key.
`protected void`	`setDoNegativeCache(boolean b)` Turn on/off the negative cache

Methods inherited from class org.onemind.commons.java.datastructure.LookupCache
lookup

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

- Field Detail
  - _packages
```
private final java.util.HashSet _packages
```
    the packages *
  - _logger
```
private static final java.util.logging.Logger _logger
```
    the logger *
- Constructor Detail
  - ClassLookupCache
```
public ClassLookupCache()
```
- Method Detail
  - addImport
```
public void addImport(java.lang.String importName)
```
    Add a new package.
    
    Parameters:
    
    packageName - the package name
  - getClass
```
public java.lang.Class getClass(java.lang.String className)
```
    Get the class given by the fully-qualified or non-fully qualified java class name
    
    Parameters:
    
    className - the class name
    
    Returns:
    
    the class or null
  - produce
```
public java.lang.Object produce(java.lang.Object key)
```
    Produce the class given the key Produce the object given the key. This is assumed to be an expensive operation and it will be called by the lookup method. The result will be cached by the lookup method and negative result also will be cached to if the doNegCache is turned on.
    
    Specified by:
    
    produce in class LookupCache
    
    Parameters:
    
    key - the key
    
    Returns:
    
    the result or null if no result
  - getPackages
```
public java.util.Set getPackages()
```
    Get all the import packages in this lookup cache.
    
    Returns:
    
    the packages
  - clearNegCache
```
protected void clearNegCache()
```
    Clear all the negative cache
    
    Overrides:
    
    clearNegCache in class LookupCache
  - isInCache
```
protected boolean isInCache(java.lang.Object o)
```
    Test if the key is in cache
    
    Overrides:
    
    isInCache in class LookupCache
    
    Parameters:
    
    o - the object
    
    Returns:
    
    true if is in cache
  - isInNegCache
```
protected boolean isInNegCache(java.lang.Object o)
```
    Get whether the object is in negative cache
    
    Overrides:
    
    isInNegCache in class LookupCache
    
    Parameters:
    
    o - the object
    
    Returns:
    
    true if is in negative cache
  - setDoNegativeCache
```
protected void setDoNegativeCache(boolean b)
```
    Turn on/off the negative cache
    
    Overrides:
    
    setDoNegativeCache in class LookupCache
    
    Parameters:
    
    b - true to turn on the neg cache

Class ClassLookupCache

Field Summary

Constructor Summary

Method Summary

Methods inherited from class org.onemind.commons.java.datastructure.LookupCache

Methods inherited from class java.lang.Object

Field Detail

_packages

_logger

Constructor Detail

ClassLookupCache

Method Detail

addImport

getClass

produce

getPackages

clearNegCache

isInCache

isInNegCache

setDoNegativeCache