java.util
Class Properties

java.lang.Object
  java.util.Dictionary<K,V>
      java.util.Hashtable<Object,Object>
          java.util.Properties

All Implemented Interfaces:

Serializable, Cloneable, Map<Object,Object>

Direct Known Subclasses:

Provider

public class Properties
extends Hashtable<Object,Object>

Properties is a Hashtable where the keys and values must be Strings. Each Properties can have a default Properties which specifies the default values which are used if the key is not in this Properties.

See Also:

Hashtable, System.getProperties(), Serialized Form

Field Summary

protected Properties

defaults The default values for this Properties.

Constructor Summary

Properties()
Constructs a new Properties object.

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

Method Summary

String	getProperty(String name) Searches for the property with the specified name.
String	getProperty(String name, String defaultValue) Searches for the property with the specified name.
void	list(PrintStream out) Lists the mappings in this Properties to the specified PrintStream in a human readable form.
void	list(PrintWriter writer) Lists the mappings in this Properties to the specified PrintWriter in a human readable form.
void	load(InputStream in) Loads properties from the specified InputStream.
Enumeration<?>	propertyNames() Answers all of the property names that this Properties contains.
void	save(OutputStream out, String comment) Deprecated. Does not throw an IOException, use store()
Object	setProperty(String name, String value) Maps the specified key to the specified value.
void	store(OutputStream out, String comment) Stores the mappings in this Properties to the specified OutputStream, putting the specified comment at the beginning.

Methods inherited from class java.util.Hashtable

clear, clone, contains, containsKey, containsValue, elements, entrySet, equals, get, hashCode, isEmpty, keys, keySet, put, putAll, rehash, remove, size, toString, values

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

defaults

protected Properties defaults

The default values for this Properties.

Constructor Detail

Properties

public Properties()

Constructs a new Properties object.

Properties

public Properties(Properties properties)

Constructs a new Properties object using the specified default properties.

Parameters:

properties - the default properties

Method Detail

getProperty

public String getProperty(String name)

Searches for the property with the specified name. If the property is not found, look in the default properties. If the property is not found in the default properties, answer null.

Parameters:

name - the name of the property to find

Returns:

the named property value

getProperty

public String getProperty(String name,
                          String defaultValue)

Searches for the property with the specified name. If the property is not found, look in the default properties. If the property is not found in the default properties, answer the specified default.

Parameters:

name - the name of the property to find

defaultValue - the default value

Returns:

the named property value

list

public void list(PrintStream out)

Lists the mappings in this Properties to the specified PrintStream in a human readable form.

Parameters:

out - the PrintStream

list

public void list(PrintWriter writer)

Lists the mappings in this Properties to the specified PrintWriter in a human readable form.

Parameters:

writer - the PrintWriter

load

public void load(InputStream in)
          throws IOException

Loads properties from the specified InputStream. The properties are of the form key=value, one property per line.

Parameters:

in - the input stream

Throws:

IOException - if I/O error occurs

propertyNames

public Enumeration<?> propertyNames()

Answers all of the property names that this Properties contains.

Returns:

an Enumeration containing the names of all properties

save

@Deprecated
public void save(OutputStream out,
                            String comment)

Deprecated. Does not throw an IOException, use store()

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() method.

Parameters:

out - the OutputStream

comment - the comment

Throws:

ClassCastException - when the key or value of a mapping is not a String

setProperty

public Object setProperty(String name,
                          String value)

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

store

public void store(OutputStream out,
                  String comment)
           throws IOException

Stores 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() method.

Parameters:

out - the OutputStream

comment - the comment

Throws:

ClassCastException - when the key or value of a mapping is not a String

IOException - if I/O error occurs