Class Properties

protected Properties defaults

The property list that contains default values for any keys not in this property list.

public Properties()

Creates a new empty property list with no default values.

public Properties(Properties defaults)

Create a new empty property list with the specified default values.

Parameters:

defaults - a Properties object containing the default values

public String getProperty(String key)

Gets the property with the specified key in this property list. If the key is not found, the default property list is searched. If the property is not found in the default, null is returned.

Parameters:

key - The key for this property

Returns:

the value for the given key, or null if not found

Throws:

ClassCastException - if this property contains any key or value that isn't a string

See Also:

defaults, setProperty(String,String), getProperty(String,String)

public String getProperty(String key,
                          String defaultValue)

Gets the property with the specified key in this property list. If the key is not found, the default property list is searched. If the property is not found in the default, the specified defaultValue is returned.

Parameters:

key - The key for this property

defaultValue - A default value

Returns:

The value for the given key

Throws:

ClassCastException - if this property contains any key or value that isn't a string

See Also:

defaults, setProperty(String,String)

public void list(PrintStream out)

Prints the key/value pairs to the given print stream. This is mainly useful for debugging purposes.

Parameters:

out - the print stream, where the key/value pairs are written to

Throws:

ClassCastException - if this property contains a key or a value that isn't a string

See Also:

list(PrintWriter)

public void list(PrintWriter out)

Prints the key/value pairs to the given print writer. This is mainly useful for debugging purposes.

Parameters:

out - the print writer where the key/value pairs are written to

Throws:

ClassCastException - if this property contains a key or a value that isn't a string

Since:

1.1

See Also:

list(PrintStream)

public void load(InputStream inStream)
            throws IOException

Reads a property list from an input stream. The stream should have the following format:
An empty line or a line starting with # or ! is ignored. An backslash (\) at the end of the line makes the line continueing on the next line (but make sure there is no whitespace after the backslash). Otherwise, each line describes a key/value pair.
The chars up to the first whitespace, = or : are the key. You can include this caracters in the key, if you precede them with a backslash (\). The key is followed by optional whitespaces, optionally one = or :, and optionally some more whitespaces. The rest of the line is the resource belonging to the key.
Escape sequences \t, \n, \r, \\, \", \', \!, \#, \ (a space), and unicode characters with the \\uxxxx notation are detected, and converted to the corresponding single character.

# This is a comment
key     = value
k\:5      \ a string starting with space and ending with newline\n
# This is a multiline specification; note that the value contains
# no white space.
weekdays: Sunday,Monday,Tuesday,Wednesday,\\
Thursday,Friday,Saturday
# The safest way to include a space at the end of a value:
label   = Name:\\u0020

Parameters:

inStream - the input stream

Throws:

IOException - if an error occurred when reading the input

NullPointerException - if in is null

public void loadFromXML(InputStream in)
            throws IOException,
                   InvalidPropertiesFormatException

Decodes the contents of the supplied InputStream as an XML file, which represents a set of properties. The format of the XML file must match the DTD http://java.sun.com/dtd/properties.dtd.

Parameters:

in - the input stream from which to receive the XML data.

Throws:

IOException - if an I/O error occurs in reading the input data.

InvalidPropertiesFormatException - if the input data does not constitute an XML properties file.

NullPointerException - if in is null.

Since:

1.5

public Enumeration propertyNames()

Returns an enumeration of all keys in this property list, including the keys in the default property list.

Returns:

an Enumeration of all defined keys

public Object setProperty(String key,
                          String value)

Adds the given key/value pair to this properties. This calls the hashtable method put.

Parameters:

key - the key for this property

value - the value for this property

Returns:

The old value for the given key

Since:

1.2

See Also:

getProperty(String)

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

Writes the key/value pairs to the given output stream, in a format suitable for load.
If header is not null, this method writes a comment containing the header as first line to the stream. The next line (or first line if header is null) contains a comment with the current date. Afterwards the key/value pairs are written to the stream in the following format.
Each line has the form key = value. Newlines, Returns and tabs are written as \n,\t,\r resp. The characters \, !, #, = and : are preceeded by a backslash. Spaces are preceded with a backslash, if and only if they are at the beginning of the key. Characters that are not in the ascii range 33 to 127 are written in the \uxxxx Form.
Following the listing, the output stream is flushed but left open.

Parameters:

out - the output stream

header - the header written in the first line, may be null

Throws:

ClassCastException - if this property contains any key or value that isn't a string

IOException - if writing to the stream fails

NullPointerException - if out is null

Since:

1.2

public void storeToXML(OutputStream os,
                       String comment)
            throws IOException

Encodes the properties as an XML file using the UTF-8 encoding. The format of the XML file matches the DTD http://java.sun.com/dtd/properties.dtd.

Invoking this method provides the same behaviour as invoking storeToXML(os, comment, "UTF-8").

Parameters:

os - the stream to output to.

comment - a comment to include at the top of the XML file, or null if one is not required.

Throws:

IOException - if the serialization fails.

NullPointerException - if os is null.

Since:

1.5

public void storeToXML(OutputStream os,
                       String comment,
                       String encoding)
            throws IOException

Encodes the properties as an XML file using the supplied encoding. The format of the XML file matches the DTD http://java.sun.com/dtd/properties.dtd.

Parameters:

os - the stream to output to.

comment - a comment to include at the top of the XML file, or null if one is not required.

encoding - the encoding to use for the XML output.

Throws:

IOException - if the serialization fails.

NullPointerException - if os or encoding is null.

Since:

1.5

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

Deprecated. use store(OutputStream,String) instead

Calls store(OutputStream out, String header) and ignores the IOException that may be thrown.

Parameters:

out - the stream to write to

header - a description of the property list

Throws:

ClassCastException - if this property contains any key or value that are not strings