Summary: Fields | Ctors | Methods | Inherited Methods | [Expand All]

Added in API level 1

public class

Properties

extends Hashtable<Object, Object>

java.lang.Object
↳	java.util.Dictionary<java.lang.Object, java.lang.Object>
	↳	java.util.Hashtable<java.lang.Object, java.lang.Object>
		↳	java.util.Properties

Known Direct Subclasses

Provider

Known Indirect Subclasses

AuthProvider

Class Overview

A Properties object is a Hashtable where the keys and values must be Strings. Each property can have a default Properties list which specifies the default values to be used when a given key is not found in this Properties instance.

Character Encoding

Note that in some cases Properties uses ISO-8859-1 instead of UTF-8. ISO-8859-1 is only capable of representing a tiny subset of Unicode. Use either the loadFromXML/storeToXML methods (which use UTF-8 by default) or the load/store overloads that take an OutputStreamWriter (so you can supply a UTF-8 instance) instead.

Summary

Fields
protected Properties	defaults	The default values for keys not found in this `Properties` instance.

Public Constructors
	Properties() Constructs a new `Properties` object.
	Properties(Properties properties) Constructs a new `Properties` object using the specified default `Properties`.

Public Methods
String	getProperty(String name, String defaultValue) Searches for the property with the specified name.
String	getProperty(String name) Searches for the property with the specified name.
void	list(PrintStream out) Lists the mappings in this `Properties` to `out` in a human-readable form.
void	list(PrintWriter out) Lists the mappings in this `Properties` to `out` in a human-readable form.
synchronized void	load(InputStream in) Loads properties from the specified `InputStream`, assumed to be ISO-8859-1.
synchronized void	load(Reader in) Loads properties from the specified `Reader`.
synchronized void	loadFromXML(InputStream in) Loads the properties from an `InputStream` containing the properties in XML form.
Enumeration<?>	propertyNames() Returns all of the property names (keys) in this `Properties` object.
void	save(OutputStream out, String comment) This method was deprecated in API level 1. This method ignores any `IOException` thrown while writing — use `store(OutputStream, String)` instead for better exception handling.
Object	setProperty(String name, String value) Maps the specified key to the specified value.
synchronized void	store(OutputStream out, String comment) Stores properties to the specified `OutputStream`, using ISO-8859-1.
synchronized void	store(Writer writer, String comment) Stores the mappings in this `Properties` object to `out`, putting the specified comment at the beginning.
synchronized void	storeToXML(OutputStream os, String comment, String encoding) Writes all properties stored in this instance into the `OutputStream` in XML representation.
void	storeToXML(OutputStream os, String comment) Writes all properties stored in this instance into the `OutputStream` in XML representation.
Set<String>	stringPropertyNames() Returns those property names (keys) in this `Properties` object for which both key and value are strings.

[Expand]

Inherited Methods

From class java.util.Hashtable

synchronized void	clear() Removes all key/value pairs from this `Hashtable`, leaving the size zero and the capacity unchanged.
synchronized Object	clone() Returns a new `Hashtable` with the same key/value pairs, capacity and load factor.
boolean	contains(Object value) Returns true if this `Hashtable` contains the specified object as the value of at least one of the key/value pairs.
synchronized boolean	containsKey(Object key) Returns true if this `Hashtable` contains the specified object as a key of one of the key/value pairs.
synchronized boolean	containsValue(Object value) Searches this `Hashtable` for the specified value.
synchronized Enumeration<Object>	elements() Returns an enumeration on the values of this `Hashtable`.
synchronized Set<Entry<Object, Object>>	entrySet() Returns a set of the mappings contained in this `Hashtable`.
synchronized boolean	equals(Object object) Compares this `Hashtable` with the specified object and indicates if they are equal.
synchronized Object	get(Object key) Returns the value associated with the specified key in this `Hashtable`.
synchronized int	hashCode() Returns an integer hash code for this object.
synchronized boolean	isEmpty() Returns true if this `Hashtable` has no key/value pairs.
synchronized Set<Object>	keySet() Returns a set of the keys contained in this `Hashtable`.
synchronized Enumeration<Object>	keys() Returns an enumeration on the keys of this `Hashtable` instance.
synchronized Object	put(Object key, Object value) Associate the specified value with the specified key in this `Hashtable`.
synchronized void	putAll(Map<? extends K, ? extends V> map) Copies every mapping to this `Hashtable` from the specified map.
void	rehash() Increases the capacity of this `Hashtable`.
synchronized Object	remove(Object key) Removes the key/value pair with the specified key from this `Hashtable`.
synchronized int	size() Returns the number of key/value pairs in this `Hashtable`.
synchronized String	toString() Returns the string representation of this `Hashtable`.
synchronized Collection<Object>	values() Returns a collection of the values contained in this `Hashtable`.

From class java.util.Dictionary

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

From interface java.util.Map

abstract void	clear() Removes all elements from this `Map`, leaving it empty.
abstract boolean	containsKey(Object key) Returns whether this `Map` contains the specified key.
abstract boolean	containsValue(Object value) Returns whether this `Map` contains the specified value.
abstract Set<Entry<Object, Object>>	entrySet() Returns a `Set` containing all of the mappings in this `Map`.
abstract boolean	equals(Object object) Compares the argument to the receiver, and returns `true` if the specified object is a `Map` and both `Map`s contain the same mappings.
abstract Object	get(Object key) Returns the value of the mapping with the specified key.
abstract int	hashCode() Returns an integer hash code for the receiver.
abstract boolean	isEmpty() Returns whether this map is empty.
abstract Set<Object>	keySet() Returns a set of the keys contained in this `Map`.
abstract Object	put(Object key, Object value) Maps the specified key to the specified value.
abstract void	putAll(Map<? extends K, ? extends V> map) Copies every mapping in the specified `Map` to this `Map`.
abstract Object	remove(Object key) Removes a mapping with the specified key from this `Map`.
abstract int	size() Returns the number of mappings in this `Map`.
abstract Collection<Object>	values() Returns a `Collection` of the values contained in this `Map`.

Fields

protected Properties defaults

Added in API level 1

The default values for keys not found in this Properties instance.

Public Constructors

public Properties ()

Added in API level 1

Constructs a new Properties object.

public Properties (Properties properties)

Added in API level 1

Constructs a new Properties object using the specified default Properties.

Parameters

properties	the default `Properties`.

Public Methods

public String getProperty (String name, String defaultValue)

Added in API level 1

Searches for the property with the specified name. If the property is not found, it looks in the default Properties. If the property is not found in the default Properties, it returns the specified default.

Parameters

name	the name of the property to find.
defaultValue	the default value.

Returns

the named property value.

public String getProperty (String name)

Added in API level 1

Searches for the property with the specified name. If the property is not found, the default Properties are checked. If the property is not found in the default Properties, null is returned.

Parameters

name	the name of the property to find.

Returns

the named property value, or null if it can't be found.

public void list (PrintStream out)

Added in API level 1

Lists the mappings in this Properties to out in a human-readable form. Note that values are truncated to 37 characters, so this method is rarely useful.

public void list (PrintWriter out)

Added in API level 1

Lists the mappings in this Properties to out in a human-readable form. Note that values are truncated to 37 characters, so this method is rarely useful.

public synchronized void load (InputStream in)

Added in API level 1

Loads properties from the specified InputStream, assumed to be ISO-8859-1. See "Character Encoding".

Parameters

in	the `InputStream`

Throws

IOException

public synchronized void load (Reader in)

Added in API level 9

Loads properties from the specified Reader. The properties file is interpreted according to the following rules:

Empty lines are ignored.
Lines starting with either a "#" or a "!" are comment lines and are ignored.
A backslash at the end of the line escapes the following newline character ("\r", "\n", "\r\n"). If there's whitespace after the backslash it will just escape that whitespace instead of concatenating the lines. This does not apply to comment lines.
A property line consists of the key, the space between the key and the value, and the value. The key goes up to the first whitespace, "=" or ":" that is not escaped. The space between the key and the value contains either one whitespace, one "=" or one ":" and any amount of additional whitespace before and after that character. The value starts with the first character after the space between the key and the value.
Following escape sequences are recognized: "\ ", "\\", "\r", "\n", "\!", "\#", "\t", "\b", "\f", and "\uXXXX" (unicode character).

Parameters

in	the `Reader`

Throws

	IOException
IOException

public synchronized void loadFromXML (InputStream in)

Added in API level 1

Loads the properties from an InputStream containing the properties in XML form. The XML document must begin with (and conform to) following DOCTYPE:

 <!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">

Also the content of the XML data must satisfy the DTD but the xml is not validated against it. The DTD is not loaded from the SYSTEM ID. After this method returns the InputStream is not closed.

Parameters

in	the InputStream containing the XML document.

Throws

IOException	in case an error occurs during a read operation.
InvalidPropertiesFormatException	if the XML data is not a valid properties file.

public Enumeration<?> propertyNames ()

Added in API level 1

Returns all of the property names (keys) in this Properties object.

public void save (OutputStream out, String comment)

Added in API level 1

This method was deprecated in API level 1.
This method ignores any IOException thrown while writing — use store(OutputStream, String) instead for better exception handling.

Saves the mappings in this Properties to the specified OutputStream, putting the specified comment at the beginning. The output from this method is suitable for being read by the load(InputStream) method.

Parameters

out	the `OutputStream` to write to.
comment	the comment to add at the beginning.

Throws

ClassCastException	if the key or value of a mapping is not a String.

public Object setProperty (String name, String value)

Added in API level 1

Maps the specified key to the specified value. If the key already exists, the old value is replaced. The key and value cannot be null.

Parameters

name	the key.
value	the value.

Returns

the old value mapped to the key, or null.

public synchronized void store (OutputStream out, String comment)

Added in API level 1

Stores properties to the specified OutputStream, using ISO-8859-1. See "Character Encoding".

Parameters

out	the `OutputStream`
comment	an optional comment to be written, or null

Throws

	IOException
ClassCastException	if a key or value is not a string
IOException

public synchronized void store (Writer writer, String comment)

Added in API level 9

Stores the mappings in this Properties object to out, putting the specified comment at the beginning.

Parameters

writer	the `Writer`
comment	an optional comment to be written, or null

Throws

	IOException
ClassCastException	if a key or value is not a string
IOException

public synchronized void storeToXML (OutputStream os, String comment, String encoding)

Added in API level 1

Writes all properties stored in this instance into the OutputStream in XML representation. The DOCTYPE is

 <!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">

If the comment is null, no comment is added to the output. The parameter encoding defines which encoding should be used. The OutputStream is not closed at the end.

Parameters

os	the `OutputStream` to write to.
comment	the comment to add. If null, no comment is added.
encoding	the code identifying the encoding that should be used to write into the `OutputStream`.

Throws

IOException	if an error occurs during writing to the output.

public void storeToXML (OutputStream os, String comment)

Added in API level 1

Writes all properties stored in this instance into the OutputStream in XML representation. The DOCTYPE is

 <!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">

If the comment is null, no comment is added to the output. UTF-8 is used as the encoding. The OutputStream is not closed at the end. A call to this method is the same as a call to

storeToXML(os,
 comment, "UTF-8")

Parameters

os	the `OutputStream` to write to.
comment	the comment to add. If null, no comment is added.

Throws

IOException	if an error occurs during writing to the output.

public Set<String> stringPropertyNames ()

Added in API level 9

Returns those property names (keys) in this Properties object for which both key and value are strings.

Returns

a set of keys in the property list

Results

Interfaces

Classes

Enums

Exceptions

Errors

Properties

Class Overview

Character Encoding

See Also

Summary

Fields

protected Properties defaults

Public Constructors

public Properties ()

public Properties (Properties properties)

Parameters

Public Methods

public String getProperty (String name, String defaultValue)

Parameters

Returns

public String getProperty (String name)

Parameters

Returns

public void list (PrintStream out)

public void list (PrintWriter out)

public synchronized void load (InputStream in)

Parameters

Throws

public synchronized void load (Reader in)

Parameters

Throws

public synchronized void loadFromXML (InputStream in)

Parameters

Throws

public Enumeration<?> propertyNames ()

public void save (OutputStream out, String comment)

Parameters

Throws

public Object setProperty (String name, String value)

Parameters

Returns

public synchronized void store (OutputStream out, String comment)

Parameters

Throws

public synchronized void store (Writer writer, String comment)

Parameters

Throws

public synchronized void storeToXML (OutputStream os, String comment, String encoding)

Parameters

Throws

public void storeToXML (OutputStream os, String comment)

Parameters

Throws

public Set<String> stringPropertyNames ()

Returns