PersistentProperties (LSST Camera Control Software - configuration database definitions 1.0.14 API)

java.lang.Object
- org.lsst.ccs.config.utilities.PersistentProperties

All Implemented Interfaces:

Cloneable
```
public class PersistentProperties
extends Object
implements Cloneable
```
Stores as String various org.lsst.gruth.types in a property store.
The way these properties are stored is abstract: though the usual (and default) way is to use a file or a "preferences" system, it can be modified to use something else (such as a database). If you do not explicitly commit your changes to the properties this will done automatically when the JVM stops (but this delayed commit won't tell you about I/O problems).
The type of the stored data is not obvious and should be known the the caller code. That's why there are different method to store/retrieve data (each method for each type).

important note : once you have stored some data with a key you cannot re-use this key for another type. Or if you want to do that then put the property to null before.

Important note : for the time being (this may change later) instances of this class are not garbage collected

Author:

bamade

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`PersistentProperties.FileStore`
`static class`	`PersistentProperties.PreferenceStore`
`static interface`	`PersistentProperties.Store` this class defines the way the properties are made persistent and read.

Constructor Summary

Constructors
Constructor and Description
`PersistentProperties(String name)` uses a fileStore.
`PersistentProperties(String name, PersistentProperties.Store store)` creates a `PersistenProperties` with a specific store.

Method Summary

Methods
Modifier and Type	Method and Description
`PersistentProperties`	`clone()`
`<T> T`	`getArray(String key, Class<T> arrayClass)` returns a value stored in the properties as an array.
`Boolean`	`getBoolean(String key)` gets a Boolean value stored with this key
`Double`	`getDouble(String key)` get a double value associated with the key
`Float`	`getFloat(String key)` gets a Float from a value in the properties
`Integer`	`getInteger(String key)` get a Integer value from the Properties
`Set<Object>`	`getKeys()`
`List`	`getList(String key)` returns a list stored in the properties.
`Map`	`getMap(String key)` returns a `Map` stored in the properties.
`Object`	`getObject(String key)` tries to return an object out of a String.
`String`	`getString(String key)` gets a String associated with a key
`<T> T`	`getStruct(String key, Class<T> structClass)` returns an object stored with the `struct` convention from the properties.
`static PersistentProperties`	`preferencesFactory(String name)` creates a persistent properties object backed by User preferences.
`<T,V extends T> T`	`putArray(String key, Class<T> arrayClass, V value)` registers an array in the properties.
`Boolean`	`putBoolean(String key, boolean bool)` put a Boolean value in the properties
`Double`	`putDouble(String key, double val)` puts a Double value in the properties
`Float`	`putFloat(String key, float val)` registers a Float as a Property
`Integer`	`putInteger(String key, int value)` put an Integer value in the Properties
`List`	`putList(String key, List list)` registers a List to the properties.
`Map`	`putMap(String key, Map map)` stores a `Map` as a String in the properties.
`Object`	`putObject(String key, Object obj)` Puts an object with no type specification in the properties.
`String`	`putString(String key, String value)` registers a String in the properties
`<T> T`	`putStruct(String key, Class<T> structClass, T value)` This will store objects that stick to a convention (and known as `struct`.

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

- Constructor Detail
  - PersistentProperties
```
public PersistentProperties(String name,
                    PersistentProperties.Store store)
```
    creates a PersistenProperties with a specific store.
    
    Parameters:
    name - (beware should be consistent with that are legal for your store!)
    store -
  - PersistentProperties
```
public PersistentProperties(String name)
```
    uses a fileStore.
    
    Parameters:
    name - (beware should be consistent with a fileName)
- Method Detail
  - preferencesFactory
```
public static PersistentProperties preferencesFactory(String name)
```
    creates a persistent properties object backed by User preferences.
    
    Parameters:
    name -
    
    Returns:
  - putInteger
```
public Integer putInteger(String key,
                 int value)
```
    put an Integer value in the Properties
    
    Parameters:
    key -
    value -
    
    Returns:
    the previous Integer value or null
  - getInteger
```
public Integer getInteger(String key)
```
    get a Integer value from the Properties
    
    Parameters:
    key -
    
    Returns:
    the value or null if value is not set (or set to null)
  - putBoolean
```
public Boolean putBoolean(String key,
                 boolean bool)
```
    put a Boolean value in the properties
    
    Parameters:
    key -
    bool -
    
    Returns:
    the previous Boolean value or null
  - getBoolean
```
public Boolean getBoolean(String key)
```
    gets a Boolean value stored with this key
    
    Parameters:
    key -
    
    Returns:
  - putDouble
```
public Double putDouble(String key,
               double val)
```
    puts a Double value in the properties
    
    Parameters:
    key -
    val -
    
    Returns:
    previous double value or null
  - getDouble
```
public Double getDouble(String key)
```
    get a double value associated with the key
    
    Parameters:
    key -
    
    Returns:
    value or null if no such property
  - putFloat
```
public Float putFloat(String key,
             float val)
```
    registers a Float as a Property
    
    Parameters:
    key -
    val -
    
    Returns:
    previous value or null
  - getFloat
```
public Float getFloat(String key)
```
    gets a Float from a value in the properties
    
    Parameters:
    key -
    
    Returns:
  - putString
```
public String putString(String key,
               String value)
```
    registers a String in the properties
    
    Parameters:
    key -
    value -
    
    Returns:
    previous value or null if there was none
  - getString
```
public String getString(String key)
```
    gets a String associated with a key
    
    Parameters:
    key -
    
    Returns:
    value or null if none was found
  - putArray
```
public <T,V extends T> T putArray(String key,
                         Class<T> arrayClass,
                         V value)
```
    registers an array in the properties. You'll have to declare an array class which is compatible with the value argument : if the result is not null the returned Object will be of this type.
    So for example :
```
 Double[] arrDbl = {2.44, 6.66} ;
 Number[] arrNumber = myProperties.putArray("valueArray", Number[].class, arrDbl) ;
 
```
    Doing this:
```
 Number[] arrNumber = myProperties.putArray("valueArray", Double[].class, arrDbl) ;
 
```
    will work but you may end up with an ArrayStoreException when dealing later with arrNumber
    Type Parameters:
    T - type of Array with elements of type X
    V - array of any type Y that is assignment compatible to X
    Parameters:
    key -
    arrayClass - such as String[].class
    value - could be an array which is "assignable to" this array elements should be of a primitive type, wrapper org.lsst.gruth.types, String, BigDecimal or Arrays of arrays of these org.lsst.gruth.types. Arrays of other org.lsst.gruth.types of Objects are not supported (some "structs" -see below-would work)
    
    Returns:
  - getArray
```
public <T> T getArray(String key,
             Class<T> arrayClass)
```
    returns a value stored in the properties as an array.
    
    Type Parameters:
    T -
    Parameters:
    key -
    arrayClass -
    
    Returns:
    the array which is represented by the String stored or null if there is none
  - putStruct
```
public <T> T putStruct(String key,
              Class<T> structClass,
              T value)
```
    This will store objects that stick to a convention (and known as struct. The values are stored as a String version of a List or of a Map depending on the definition of the Object:
    - if the object has a full fledged constructor, then a List will be used
    - if the object is a bean with only getters/setters then a Map will be used (each pair will be : Name, value)
    In both cases the toString method of these object should exactly produce a List or Map litteral (with the conventions [1,'world',2.8] for lists and [number:1, name:'world', max:2.8] for Maps.
    Type Parameters:
    T -
    Parameters:
    key -
    structClass - the name of the class that will be used to analyse previous value
    value - any object that sticks to this struct convention
    
    Returns:
  - getStruct
```
public <T> T getStruct(String key,
              Class<T> structClass)
```
    returns an object stored with the struct convention from the properties.
    
    Type Parameters:
    T -
    Parameters:
    key -
    structClass -
    
    Returns:
  - putList
```
public List putList(String key,
           List list)
```
    registers a List to the properties. Note that the elements of the list can be only wrappers (Double, Integer,...), and String objects or List of these lists (or Maps of this simple data).
    Warning : a floating point value stored will be returned as a BigDecimal this may change in future releases (known feature)
    
    Parameters:
    key -
    list -
    
    Returns:
  - getList
```
public List getList(String key)
```
    returns a list stored in the properties.
    Warning : a floating point value stored will be returned as a BigDecimal this may change in future releases (known feature)
    
    Parameters:
    key -
    
    Returns:
  - putMap
```
public Map putMap(String key,
         Map map)
```
    stores a Map as a String in the properties. Note that the values of the map can be only wrappers (Double, Integer,...), and String objects (or lists or Maps of such objects).
    Warning : a floating point value stored will be returned as a BigDecimal this may change in future releases (known feature)
    
    Parameters:
    key -
    map -
    
    Returns:
  - getMap
```
public Map getMap(String key)
```
    returns a Map stored in the properties. Warning : a floating point value stored will be returned as a BigDecimal this may change in future releases (known feature)
    
    Parameters:
    key -
    
    Returns:
  - putObject
```
public Object putObject(String key,
               Object obj)
```
    Puts an object with no type specification in the properties. Without type specification some unwanted effect might happen when reading the previous value:
    - floating point values will be returned as BigDecimal
    - Strings that start with a numerical character will fire an attempt to create a number (which may fail if you have a String such as "200x300")
    - String that start with a "[" character will fire an attempt to read a List or Map (which may fail!)
    - String "true" or "false" will return a Boolean!
    - struct objects won't be analysed
    - arrays will be returned as Lists!
    Parameters:
    key -
    obj -
    
    Returns:
  - getObject
```
public Object getObject(String key)
```
    tries to return an object out of a String. See remarks with method putObject
    
    Parameters:
    key -
    
    Returns:
  - getKeys
```
public Set<Object> getKeys()
```
  - clone
```
public PersistentProperties clone()
```
    Overrides:
    
    clone in class Object

Class PersistentProperties

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

PersistentProperties

PersistentProperties

Method Detail

preferencesFactory

putInteger

getInteger

putBoolean

getBoolean

putDouble

getDouble

putFloat

getFloat

putString

getString

putArray

getArray

putStruct

getStruct

putList

getList

putMap

getMap

putObject

getObject

getKeys

clone