Properties
open class Properties : Hashtable<Any!, Any!>
Known Direct Subclasses
| Provider |
This class represents a "provider" for the Java Security API, where a provider implements some or all parts of Java Security.
|
|
Known Indirect Subclasses
|
The Properties class represents a persistent set of properties. The Properties can be saved to a stream or loaded from a stream. Each key and its corresponding value in the property list is a string.
A property list can contain another property list as its "defaults"; this second property list is searched if the property key is not found in the original property list.
Because Properties inherits from Hashtable, the put and putAll methods can be applied to a Properties object. Their use is strongly discouraged as they allow the caller to insert entries whose keys or values are not Strings. The setProperty method should be used instead. If the store or save method is called on a "compromised" Properties object that contains a non-String key or value, the call will fail. Similarly, the call to the propertyNames or list method will fail if it is called on a "compromised" Properties object that contains a non-String key.
The iterators returned by the iterator method of this class's "collection views" (that is, entrySet(), keySet(), and values()) may not fail-fast (unlike the Hashtable implementation). These iterators are guaranteed to traverse elements as they existed upon construction exactly once, and may (but are not guaranteed to) reflect any modifications subsequent to construction.
The load(Reader) / store(Writer, String) methods load and store properties from and to a character based stream in a simple line-oriented format specified below. The load(InputStream) / store(OutputStream, String) methods work the same way as the load(Reader)/store(Writer, String) pair, except the input/output stream is encoded in ISO 8859-1 character encoding. Characters that cannot be directly represented in this encoding can be written using Unicode escapes as defined in section {@jls 3.3} of The Java Language Specification; only a single 'u' character is allowed in an escape sequence.
The loadFromXML(java.io.InputStream) and storeToXML(java.io.OutputStream,java.lang.String,java.lang.String) methods load and store properties in a simple XML format. By default the UTF-8 character encoding is used, however a specific encoding may be specified if required. Implementations are required to support UTF-8 and UTF-16 and may support other encodings. An XML properties document has the following DOCTYPE declaration:
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
Note that the system URI (http://java.sun.com/dtd/properties.dtd) is
not accessed when exporting or importing properties; it merely serves as a string to uniquely identify the DTD, which is:
<?xml version="1.0" encoding="UTF-8"?>
<!-- DTD for properties -->
<!ELEMENT properties ( comment?, entry* ) >
<!ATTLIST properties version CDATA #FIXED "1.0">
<!ELEMENT comment (#PCDATA) >
<!ELEMENT entry (#PCDATA) >
<!ATTLIST entry key CDATA #REQUIRED>
This class is thread-safe: multiple threads can share a single Properties object without the need for external synchronization.
Summary
| Public constructors |
|
Creates an empty property list with no default values.
|
|
Creates an empty property list with no default values, and with an initial size accommodating the specified number of elements without the need to dynamically resize.
|
|
Creates an empty property list with the specified defaults.
|
| Public methods |
| open Unit |
|
| open Any |
|
| open Any? |
|
| open Any! |
|
| open Any? |
|
| open Boolean |
|
| open Boolean |
|
| open Boolean |
|
| open Enumeration<Any!>! |
|
| open Boolean |
|
| open Unit |
|
| open Any? |
|
| open Any! |
|
| open String! |
Searches for the property with the specified key in this property list.
|
| open String! |
Searches for the property with the specified key in this property list.
|
| open Int |
|
| open Boolean |
|
| open Enumeration<Any!>! |
|
| open Unit |
Prints this property list out to the specified output stream.
|
| open Unit |
Prints this property list out to the specified output stream.
|
| open Unit |
Reads a property list (key and element pairs) from the input character stream in a simple line-oriented format.
|
| open Unit |
Reads a property list (key and element pairs) from the input byte stream.
|
| open Unit |
Loads all of the properties represented by the XML document on the specified input stream into this properties table.
|
| open Any? |
|
| open Enumeration<*>! |
Returns an enumeration of all the keys in this property list, including distinct keys in the default property list if a key of the same name has not already been found from the main properties list.
|
| open Any? |
|
| open Unit |
|
| open Any? |
|
| open Any? |
|
| open Boolean |
|
| open Boolean |
|
| open Any? |
|
| open Unit |
|
| open Unit |
Calls the store(OutputStream out, String comments) method and suppresses IOExceptions that were thrown.
|
| open Any! |
Calls the Hashtable method put.
|
| open Unit |
Writes this property list (key and element pairs) in this Properties table to the output character stream in a format suitable for using the load(Reader) method.
|
| open Unit |
Writes this property list (key and element pairs) in this Properties table to the output stream in a format suitable for loading into a Properties table using the load(InputStream) method.
|
| open Unit |
Emits an XML document representing all of the properties contained in this table.
|
| open Unit |
Emits an XML document representing all of the properties contained in this table, using the specified encoding.
|
| open Unit |
Emits an XML document representing all of the properties contained in this table, using the specified encoding.
|
| open MutableSet<String!>! |
Returns an unmodifiable set of keys from this property list where the key and its corresponding value are strings, including distinct keys in the default property list if a key of the same name has not already been found from the main properties list.
|
| open String |
|
| Protected methods |
| open Unit |
|
Public constructors
Properties
Properties()
Creates an empty property list with no default values.
Properties
Properties(initialCapacity: Int)
Creates an empty property list with no default values, and with an initial size accommodating the specified number of elements without the need to dynamically resize.
| Parameters |
initialCapacity |
Int: the Properties will be sized to accommodate this many elements |
| Exceptions |
java.lang.IllegalArgumentException |
if the initial capacity is less than zero. |
Properties
Properties(defaults: Properties!)
Creates an empty property list with the specified defaults.
Public methods
clear
open fun clear(): Unit
| Exceptions |
java.lang.UnsupportedOperationException |
if the clear operation is not supported by this map |
clone
open fun clone(): Any
| Return |
Any |
a clone of the hashtable |
| Exceptions |
java.lang.CloneNotSupportedException |
if the object's class does not support the Cloneable interface. Subclasses that override the clone method can also throw this exception to indicate that an instance cannot be cloned. |
compute
open fun compute(
key: Any!,
remappingFunction: BiFunction<in Any!, in Any?, *>
): Any?
| Parameters |
key |
Any!: key with which the specified value is to be associated |
remappingFunction |
BiFunction<in Any!, in Any?, *>: the remapping function to compute a value |
| Return |
Any? |
the new value associated with the specified key, or null if none |
| Exceptions |
java.lang.NullPointerException |
if the specified key is null and this map does not support null keys, or the remappingFunction is null |
java.lang.UnsupportedOperationException |
if the put operation is not supported by this map (optional) |
java.lang.ClassCastException |
if the class of the specified key or value prevents it from being stored in this map (optional) |
java.lang.IllegalArgumentException |
if some property of the specified key or value prevents it from being stored in this map (optional) |
java.util.ConcurrentModificationException |
if it is detected that the remapping function modified this map |
computeIfAbsent
open fun computeIfAbsent(
key: Any!,
mappingFunction: Function<in Any!, *>
): Any!
| Parameters |
key |
Any!: key with which the specified value is to be associated |
mappingFunction |
Function<in Any!, *>: the mapping function to compute a value |
| Return |
Any! |
the current (existing or computed) value associated with the specified key, or null if the computed value is null |
| Exceptions |
java.lang.NullPointerException |
if the specified key is null and this map does not support null keys, or the mappingFunction is null |
java.lang.UnsupportedOperationException |
if the put operation is not supported by this map (optional) |
java.lang.ClassCastException |
if the class of the specified key or value prevents it from being stored in this map (optional) |
java.lang.IllegalArgumentException |
if some property of the specified key or value prevents it from being stored in this map (optional) |
java.util.ConcurrentModificationException |
if it is detected that the mapping function modified this map |
computeIfPresent
open fun computeIfPresent(
key: Any!,
remappingFunction: BiFunction<in Any!, in Any, *>
): Any?
| Parameters |
key |
Any!: key with which the specified value is to be associated |
remappingFunction |
BiFunction<in Any!, in Any, *>: the remapping function to compute a value |
| Return |
Any? |
the new value associated with the specified key, or null if none |
| Exceptions |
java.lang.NullPointerException |
if the specified key is null and this map does not support null keys, or the remappingFunction is null |
java.lang.UnsupportedOperationException |
if the put operation is not supported by this map (optional) |
java.lang.ClassCastException |
if the class of the specified key or value prevents it from being stored in this map (optional) |
java.lang.IllegalArgumentException |
if some property of the specified key or value prevents it from being stored in this map (optional) |
java.util.ConcurrentModificationException |
if it is detected that the remapping function modified this map |
contains
open fun contains(value: Any!): Boolean
| Parameters |
value |
Any!: a value to search for |
| Return |
Boolean |
true if and only if some key maps to the value argument in this hashtable as determined by the equals method; false otherwise. |
| Exceptions |
java.lang.NullPointerException |
if the value is null |
containsKey
open fun containsKey(key: Any!): Boolean
| Parameters |
key |
Any!: possible key |
| Return |
Boolean |
true if and only if the specified object is a key in this hashtable, as determined by the equals method; false otherwise. |
| Exceptions |
java.lang.ClassCastException |
if the key is of an inappropriate type for this map (optional) |
java.lang.NullPointerException |
if the key is null |
containsValue
open fun containsValue(value: Any!): Boolean
| Parameters |
value |
Any!: value whose presence in this hashtable is to be tested |
| Return |
Boolean |
true if this map maps one or more keys to the specified value |
| Exceptions |
java.lang.ClassCastException |
if the value is of an inappropriate type for this map (optional) |
java.lang.NullPointerException |
if the value is null |
equals
open fun equals(other: Any?): Boolean
| Parameters |
obj |
the reference object with which to compare. |
o |
object to be compared for equality with this hashtable |
| Return |
Boolean |
true if the specified Object is equal to this Map |
forEach
open fun forEach(action: BiConsumer<in Any!, in Any!>): Unit
| Parameters |
action |
BiConsumer<in Any!, in Any!>: The action to be performed for each entry |
| Exceptions |
java.lang.NullPointerException |
if the specified action is null |
java.util.ConcurrentModificationException |
if an entry is found to be removed during iteration |
get
open fun get(key: Any!): Any?
| Parameters |
key |
Any!: the key whose associated value is to be returned |
| Return |
Any? |
the value to which the specified key is mapped, or null if this map contains no mapping for the key |
| Exceptions |
java.lang.NullPointerException |
if the specified key is null |
java.lang.ClassCastException |
if the key is of an inappropriate type for this map (optional) |
getOrDefault
open fun getOrDefault(
key: Any!,
defaultValue: Any!
): Any!
| Parameters |
key |
Any!: the key whose associated value is to be returned |
defaultValue |
Any!: the default mapping of the key |
| Return |
Any! |
the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key |
| Exceptions |
java.lang.ClassCastException |
if the key is of an inappropriate type for this map (optional) |
java.lang.NullPointerException |
if the specified key is null and this map does not permit null keys (optional) |
getProperty
open fun getProperty(key: String!): String!
Searches for the property with the specified key in this property list. If the key is not found in this property list, the default property list, and its defaults, recursively, are then checked. The method returns null if the property is not found.
| Parameters |
key |
String!: the property key. |
| Return |
String! |
the value in this property list with the specified key value. |
getProperty
open fun getProperty(
key: String!,
defaultValue: String!
): String!
Searches for the property with the specified key in this property list. If the key is not found in this property list, the default property list, and its defaults, recursively, are then checked. The method returns the default value argument if the property is not found.
| Parameters |
key |
String!: the hashtable key. |
defaultValue |
String!: a default value. |
| Return |
String! |
the value in this property list with the specified key value. |
hashCode
open fun hashCode(): Int
| Return |
Int |
the hash code value for this map |
isEmpty
open fun isEmpty(): Boolean
| Return |
Boolean |
true if this hashtable maps no keys to values; false otherwise. |
list
open fun list(out: PrintStream!): Unit
Prints this property list out to the specified output stream. This method is useful for debugging.
| Exceptions |
java.lang.ClassCastException |
if any key in this property list is not a string. |
list
open fun list(out: PrintWriter!): Unit
Prints this property list out to the specified output stream. This method is useful for debugging.
| Exceptions |
java.lang.ClassCastException |
if any key in this property list is not a string. |
load
open fun load(reader: Reader!): Unit
Reads a property list (key and element pairs) from the input character stream in a simple line-oriented format.
Properties are processed in terms of lines. There are two kinds of line, natural lines and logical lines. A natural line is defined as a line of characters that is terminated either by a set of line terminator characters (\n or \r or \r\n) or by the end of the stream. A natural line may be either a blank line, a comment line, or hold all or some of a key-element pair. A logical line holds all the data of a key-element pair, which may be spread out across several adjacent natural lines by escaping the line terminator sequence with a backslash character \. Note that a comment line cannot be extended in this manner; every natural line that is a comment must have its own comment indicator, as described below. Lines are read from input until the end of the stream is reached.
A natural line that contains only white space characters is considered blank and is ignored. A comment line has an ASCII '#' or '!' as its first non-white space character; comment lines are also ignored and do not encode key-element information. In addition to line terminators, this format considers the characters space (' ', '\u005Cu0020'), tab ('\t', '\u005Cu0009'), and form feed ('\f', '\u005Cu000C') to be white space.
If a logical line is spread across several natural lines, the backslash escaping the line terminator sequence, the line terminator sequence, and any white space at the start of the following line have no affect on the key or element values. The remainder of the discussion of key and element parsing (when loading) will assume all the characters constituting the key and element appear on a single natural line after line continuation characters have been removed. Note that it is not sufficient to only examine the character preceding a line terminator sequence to decide if the line terminator is escaped; there must be an odd number of contiguous backslashes for the line terminator to be escaped. Since the input is processed from left to right, a non-zero even number of 2n contiguous backslashes before a line terminator (or elsewhere) encodes n backslashes after escape processing.
The key contains all of the characters in the line starting with the first non-white space character and up to, but not including, the first unescaped '=', ':', or white space character other than a line terminator. All of these key termination characters may be included in the key by escaping them with a preceding backslash character; for example,
\:\=
would be the two-character key ":=". Line terminator characters can be included using \r and \n escape sequences. Any white space after the key is skipped; if the first non-white space character after the key is '=' or ':', then it is ignored and any white space characters after it are also skipped. All remaining characters on the line become part of the associated element string; if there are no remaining characters, the element is the empty string "". Once the raw character sequences constituting the key and element are identified, escape processing is performed as described above.
As an example, each of the following three lines specifies the key "Truth" and the associated element value "Beauty":
Truth = Beauty
Truth:Beauty
Truth :Beauty
As another example, the following three lines specify a single property:
fruits apple, banana, pear, \
cantaloupe, watermelon, \
kiwi, mango
The key is
"fruits" and the associated element is:
"apple, banana, pear, cantaloupe, watermelon, kiwi, mango"
Note that a space appears before each
\ so that a space will appear after each comma in the final result; the
\, line terminator, and leading white space on the continuation line are merely discarded and are
not replaced by one or more other characters.
As a third example, the line:
cheeses
specifies that the key is
"cheeses" and the associated element is the empty string
"".
Characters in keys and elements can be represented in escape sequences similar to those used for character and string literals (see sections {@jls 3.3} and {@jls 3.10.6} of The Java Language Specification). The differences from the character escape sequences and Unicode escapes used for characters and strings are:
- Octal escapes are not recognized.
- The character sequence
\b does not represent a backspace character.
- The method does not treat a backslash character,
\, before a non-valid escape character as an error; the backslash is silently dropped. For example, in a Java string the sequence "\z" would cause a compile time error. In contrast, this method silently drops the backslash. Therefore, this method treats the two character sequence "\b" as equivalent to the single character 'b'.
- Escapes are not necessary for single and double quotes; however, by the rule above, single and double quote characters preceded by a backslash still yield single and double quote characters, respectively.
- Only a single 'u' character is allowed in a Unicode escape sequence.
The specified stream remains open after this method returns.
| Parameters |
reader |
Reader!: the input character stream. |
| Exceptions |
java.io.IOException |
if an error occurred when reading from the input stream. |
java.lang.IllegalArgumentException |
if a malformed Unicode escape appears in the input. |
java.lang.NullPointerException |
if reader is null. |
load
open fun load(inStream: InputStream!): Unit
Reads a property list (key and element pairs) from the input byte stream. The input stream is in a simple line-oriented format as specified in load(Reader) and is assumed to use the ISO 8859-1 character encoding; that is each byte is one Latin1 character. Characters not in Latin1, and certain special characters, are represented in keys and elements using Unicode escapes as defined in section {@jls 3.3} of The Java Language Specification.
The specified stream remains open after this method returns.
| Exceptions |
java.io.IOException |
if an error occurred when reading from the input stream. |
java.lang.IllegalArgumentException |
if the input stream contains a malformed Unicode escape sequence. |
java.lang.NullPointerException |
if inStream is null. |
loadFromXML
open fun loadFromXML(in: InputStream!): Unit
Loads all of the properties represented by the XML document on the specified input stream into this properties table.
The XML document must have the following DOCTYPE declaration:
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
Furthermore, the document must satisfy the properties DTD described above.
An implementation is required to read XML documents that use the "UTF-8" or "UTF-16" encoding. An implementation may support additional encodings.
The specified stream is closed after this method returns.
| Parameters |
in |
InputStream!: the input stream from which to read the XML document. |
| Exceptions |
java.io.IOException |
if reading from the specified input stream results in an IOException. |
java.io.UnsupportedEncodingException |
if the document's encoding declaration can be read and it specifies an encoding that is not supported |
java.util.InvalidPropertiesFormatException |
Data on input stream does not constitute a valid XML document with the mandated document type. |
java.lang.NullPointerException |
if in is null. |
merge
open fun merge(
key: Any!,
value: Any,
remappingFunction: BiFunction<in Any, in Any, *>
): Any?
| Parameters |
key |
Any!: key with which the resulting value is to be associated |
value |
Any: the non-null value to be merged with the existing value associated with the key or, if no existing value or a null value is associated with the key, to be associated with the key |
remappingFunction |
BiFunction<in Any, in Any, *>: the remapping function to recompute a value if present |
| Return |
Any? |
the new value associated with the specified key, or null if no value is associated with the key |
| Exceptions |
java.lang.UnsupportedOperationException |
if the put operation is not supported by this map (optional) |
java.lang.ClassCastException |
if the class of the specified key or value prevents it from being stored in this map (optional) |
java.lang.IllegalArgumentException |
if some property of the specified key or value prevents it from being stored in this map (optional) |
java.lang.NullPointerException |
if the specified key is null and this map does not support null keys or the value or remappingFunction is null |
java.util.ConcurrentModificationException |
if it is detected that the remapping function modified this map |
propertyNames
open fun propertyNames(): Enumeration<*>!
Returns an enumeration of all the keys in this property list, including distinct keys in the default property list if a key of the same name has not already been found from the main properties list.
| Return |
Enumeration<*>! |
an enumeration of all the keys in this property list, including the keys in the default property list. |
| Exceptions |
java.lang.ClassCastException |
if any key in this property list is not a string. |
put
open fun put(
key: Any!,
value: Any!
): Any?
| Parameters |
key |
Any!: the hashtable key |
value |
Any!: the value |
| Return |
Any? |
the previous value of the specified key in this hashtable, or null if it did not have one |
| Exceptions |
java.lang.NullPointerException |
if the key or value is null |
java.lang.UnsupportedOperationException |
if the put operation is not supported by this map |
java.lang.ClassCastException |
if the class of the specified key or value prevents it from being stored in this map |
java.lang.IllegalArgumentException |
if some property of the specified key or value prevents it from being stored in this map |
putAll
open fun putAll(from: Map<*, *>): Unit
| Parameters |
m |
mappings to be stored in this map |
t |
mappings to be stored in this map |
| Exceptions |
java.lang.UnsupportedOperationException |
if the putAll operation is not supported by this map |
java.lang.ClassCastException |
if the class of a key or value in the specified map prevents it from being stored in this map |
java.lang.NullPointerException |
if the specified map is null |
java.lang.IllegalArgumentException |
if some property of a key or value in the specified map prevents it from being stored in this map |
putIfAbsent
open fun putIfAbsent(
key: Any!,
value: Any!
): Any?
| Parameters |
key |
Any!: key with which the specified value is to be associated |
value |
Any!: value to be associated with the specified key |
| Return |
Any? |
the previous value associated with the specified key, or null if there was no mapping for the key. (A null return can also indicate that the map previously associated null with the key, if the implementation supports null values.) |
| Exceptions |
java.lang.UnsupportedOperationException |
if the put operation is not supported by this map (optional) |
java.lang.ClassCastException |
if the key or value is of an inappropriate type for this map (optional) |
java.lang.NullPointerException |
if the specified key or value is null, and this map does not permit null keys or values (optional) |
java.lang.IllegalArgumentException |
if some property of the specified key or value prevents it from being stored in this map (optional) |
remove
open fun remove(key: Any!): Any?
| Parameters |
key |
Any!: the key that needs to be removed |
| Return |
Any? |
the value to which the key had been mapped in this hashtable, or null if the key did not have a mapping |
| Exceptions |
java.lang.NullPointerException |
if the key is null |
java.lang.UnsupportedOperationException |
if the remove operation is not supported by this map |
java.lang.ClassCastException |
if the key is of an inappropriate type for this map (optional) |
remove
open fun remove(
key: Any!,
value: Any!
): Boolean
| Parameters |
key |
Any!: key with which the specified value is associated |
value |
Any!: value expected to be associated with the specified key |
| Return |
Boolean |
true if the value was removed |
| Exceptions |
java.lang.UnsupportedOperationException |
if the remove operation is not supported by this map (optional) |
java.lang.ClassCastException |
if the key or value is of an inappropriate type for this map (optional) |
java.lang.NullPointerException |
if the specified key or value is null, and this map does not permit null keys or values (optional) |
replace
open fun replace(
key: Any!,
oldValue: Any!,
newValue: Any!
): Boolean
| Parameters |
key |
Any!: key with which the specified value is associated |
oldValue |
Any!: value expected to be associated with the specified key |
newValue |
Any!: value to be associated with the specified key |
| Return |
Boolean |
true if the value was replaced |
| Exceptions |
java.lang.UnsupportedOperationException |
if the put operation is not supported by this map (optional) |
java.lang.ClassCastException |
if the class of a specified key or value prevents it from being stored in this map |
java.lang.NullPointerException |
if oldValue is null and this map does not permit null values (optional) |
java.lang.IllegalArgumentException |
if some property of a specified key or value prevents it from being stored in this map |
replace
open fun replace(
key: Any!,
value: Any!
): Any?
| Parameters |
key |
Any!: key with which the specified value is associated |
value |
Any!: value to be associated with the specified key |
| Return |
Any? |
the previous value associated with the specified key, or null if there was no mapping for the key. (A null return can also indicate that the map previously associated null with the key, if the implementation supports null values.) |
| Exceptions |
java.lang.UnsupportedOperationException |
if the put operation is not supported by this map (optional) |
java.lang.ClassCastException |
if the class of the specified key or value prevents it from being stored in this map (optional) |
java.lang.NullPointerException |
if the specified key or value is null, and this map does not permit null keys or values |
java.lang.IllegalArgumentException |
if some property of the specified key or value prevents it from being stored in this map |
replaceAll
open fun replaceAll(function: BiFunction<in Any!, in Any!, *>): Unit
| Parameters |
function |
BiFunction<in Any!, in Any!, *>: the function to apply to each entry |
| Exceptions |
java.lang.UnsupportedOperationException |
if the set operation is not supported by this map's entry set iterator. |
java.lang.ClassCastException |
if a replacement value is of an inappropriate type for this map (optional) |
java.lang.NullPointerException |
if function or a replacement value is null, and this map does not permit null keys or values (optional) |
java.lang.IllegalArgumentException |
if some property of a replacement value prevents it from being stored in this map (optional) |
java.util.ConcurrentModificationException |
if an entry is found to be removed during iteration |
save
open fun save(
out: OutputStream!,
: String!
): Unit
Deprecated: This method does not throw an IOException if an I/O error occurs while saving the property list. The preferred way to save a properties list is via the store(OutputStream out, String comments) method or the storeToXML(OutputStream os, String comment) method.
Calls the store(OutputStream out, String comments) method and suppresses IOExceptions that were thrown.
| Parameters |
out |
OutputStream!: an output stream. |
comments |
String!: a description of the property list. |
| Exceptions |
java.lang.ClassCastException |
if this Properties object contains any keys or values that are not Strings. |
setProperty
open fun setProperty(
key: String!,
value: String!
): Any!
Calls the Hashtable method put. Provided for parallelism with the getProperty method. Enforces use of strings for property keys and values. The value returned is the result of the Hashtable call to put.
| Parameters |
key |
String!: the key to be placed into this property list. |
value |
String!: the value corresponding to key. |
| Return |
Any! |
the previous value of the specified key in this property list, or null if it did not have one. |
store
open fun store(
writer: Writer!,
: String!
): Unit
Writes this property list (key and element pairs) in this Properties table to the output character stream in a format suitable for using the load(Reader) method.
Properties from the defaults table of this Properties table (if any) are not written out by this method.
If the comments argument is not null, then an ASCII comments can serve as an identifying comment. Any one of a line feed ('\n'), a carriage return ('\r'), or a carriage return followed immediately by a line feed in comments is replaced by a line separator generated by the Writer and if the next character in comments is not character ! then an ASCII
Next, a comment line is always written, consisting of an ASCII toString method of Date for the current time), and a line separator as generated by the Writer.
Then every entry in this Properties table is written out, one per line. For each entry the key string is written, then an ASCII =, then the associated element string. For the key, all space characters are written with a preceding \ character. For the element, leading space characters, but not embedded or trailing space characters, are written with a preceding \ character. The key and element characters !, =, and : are written with a preceding backslash to ensure that they are properly loaded.
After the entries have been written, the output stream is flushed. The output stream remains open after this method returns.
| Parameters |
writer |
Writer!: an output character stream writer. |
comments |
String!: a description of the property list. |
| Exceptions |
java.io.IOException |
if writing this property list to the specified output stream throws an IOException. |
java.lang.ClassCastException |
if this Properties object contains any keys or values that are not Strings. |
java.lang.NullPointerException |
if writer is null. |
store
open fun store(
out: OutputStream!,
: String!
): Unit
Writes this property list (key and element pairs) in this Properties table to the output stream in a format suitable for loading into a Properties table using the load(InputStream) method.
Properties from the defaults table of this Properties table (if any) are not written out by this method.
This method outputs the comments, properties keys and values in the same format as specified in store(Writer), with the following differences:
- The stream is written using the ISO 8859-1 character encoding.
- Characters not in Latin-1 in the comments are written as
\u005Cuxxxx for their appropriate unicode hexadecimal value xxxx.
- Characters less than
\u005Cu0020 and characters greater than \u005Cu007E in property keys or values are written as \u005Cuxxxx for the appropriate hexadecimal value xxxx.
After the entries have been written, the output stream is flushed. The output stream remains open after this method returns.
| Parameters |
out |
OutputStream!: an output stream. |
comments |
String!: a description of the property list. |
| Exceptions |
java.io.IOException |
if writing this property list to the specified output stream throws an IOException. |
java.lang.ClassCastException |
if this Properties object contains any keys or values that are not Strings. |
java.lang.NullPointerException |
if out is null. |
storeToXML
open fun storeToXML(
os: OutputStream!,
: String!
): Unit
Emits an XML document representing all of the properties contained in this table.
An invocation of this method of the form props.storeToXML(os, comment) behaves in exactly the same way as the invocation props.storeToXML(os, comment, "UTF-8");.
| Parameters |
os |
OutputStream!: the output stream on which to emit the XML document. |
comment |
String!: a description of the property list, or null if no comment is desired. |
| Exceptions |
java.io.IOException |
if writing to the specified output stream results in an IOException. |
java.lang.NullPointerException |
if os is null. |
java.lang.ClassCastException |
if this Properties object contains any keys or values that are not Strings. |
storeToXML
open fun storeToXML(
os: OutputStream!,
: String!,
encoding: String!
): Unit
Emits an XML document representing all of the properties contained in this table, using the specified encoding.
The XML document will have the following DOCTYPE declaration:
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
If the specified comment is null then no comment will be stored in the document.
An implementation is required to support writing of XML documents that use the "UTF-8" or "UTF-16" encoding. An implementation may support additional encodings.
The specified stream remains open after this method returns.
This method behaves the same as storeToXML(java.io.OutputStream,java.lang.String,java.nio.charset.Charset) except that it will look up the charset using the given encoding name.
| Parameters |
os |
OutputStream!: the output stream on which to emit the XML document. |
comment |
String!: a description of the property list, or null if no comment is desired. |
encoding |
String!: the name of a supported character encoding |
| Exceptions |
java.io.IOException |
if writing to the specified output stream results in an IOException. |
java.io.UnsupportedEncodingException |
if the encoding is not supported by the implementation. |
java.lang.NullPointerException |
if os is null, or if encoding is null. |
java.lang.ClassCastException |
if this Properties object contains any keys or values that are not Strings. |
storeToXML
open fun storeToXML(
os: OutputStream!,
: String!,
charset: Charset!
): Unit
Emits an XML document representing all of the properties contained in this table, using the specified encoding.
The XML document will have the following DOCTYPE declaration:
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
If the specified comment is null then no comment will be stored in the document.
An implementation is required to support writing of XML documents that use the "UTF-8" or "UTF-16" encoding. An implementation may support additional encodings.
Unmappable characters for the specified charset will be encoded as numeric character references.
The specified stream remains open after this method returns.
| Parameters |
os |
OutputStream!: the output stream on which to emit the XML document. |
comment |
String!: a description of the property list, or null if no comment is desired. |
charset |
Charset!: the charset |
| Exceptions |
java.io.IOException |
if writing to the specified output stream results in an IOException. |
java.lang.NullPointerException |
if os or charset is null. |
java.lang.ClassCastException |
if this Properties object contains any keys or values that are not Strings. |
stringPropertyNames
open fun stringPropertyNames(): MutableSet<String!>!
Returns an unmodifiable set of keys from this property list where the key and its corresponding value are strings, including distinct keys in the default property list if a key of the same name has not already been found from the main properties list. Properties whose key or value is not of type String are omitted.
The returned set is not backed by this Properties object. Changes to this Properties object are not reflected in the returned set.
| Return |
MutableSet<String!>! |
an unmodifiable set of keys in this property list where the key and its corresponding value are strings, including the keys in the default property list. |
toString
open fun toString(): String
| Return |
String |
a string representation of this hashtable |
Protected methods
rehash
protected open fun rehash(): Unit
Properties
defaults
protected var defaults: Properties!
A property list that contains default values for any keys not found in this property list.
size
open val size: Int
| Return |
Int |
the number of keys in this hashtable. |
