Java example source code file (Properties.java)
The Properties.java Java example source code/*
* Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.util;
import java.io.IOException;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Reader;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.io.BufferedWriter;
import java.security.AccessController;
import java.security.PrivilegedAction;
import sun.util.spi.XmlPropertiesProvider;
/**
* The {@code Properties} class represents a persistent set of
* properties. The {@code 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.
* <p>
* 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.
* <p>
* Because {@code Properties} inherits from {@code Hashtable}, the
* {@code put} and {@code putAll} methods can be applied to a
* {@code Properties} object. Their use is strongly discouraged as they
* allow the caller to insert entries whose keys or values are not
* {@code Strings}. The {@code setProperty} method should be used
* instead. If the {@code store} or {@code save} method is called
* on a "compromised" {@code Properties} object that contains a
* non-{@code String} key or value, the call will fail. Similarly,
* the call to the {@code propertyNames} or {@code list} method
* will fail if it is called on a "compromised" {@code Properties}
* object that contains a non-{@code String} key.
*
* <p>
* The {@link #load(java.io.Reader) load(Reader)} <tt>/
* {@link #store(java.io.Writer, java.lang.String) store(Writer, String)}
* methods load and store properties from and to a character based stream
* in a simple line-oriented format specified below.
*
* The {@link #load(java.io.InputStream) load(InputStream)} <tt>/
* {@link #store(java.io.OutputStream, java.lang.String) 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 3.3 of
* <cite>The Java™ Language Specification;
* only a single 'u' character is allowed in an escape
* sequence. The native2ascii tool can be used to convert property files to and
* from other character encodings.
*
* <p> The {@link #loadFromXML(InputStream)} and {@link
* #storeToXML(OutputStream, String, 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:
*
* <pre>
* <!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
* </pre>
* Note that the system URI (http://java.sun.com/dtd/properties.dtd) is
* <i>not accessed when exporting or importing properties; it merely
* serves as a string to uniquely identify the DTD, which is:
* <pre>
* <?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>
* </pre>
*
* <p>This class is thread-safe: multiple threads can share a single
* <tt>Properties object without the need for external synchronization.
*
* @see <a href="../../../technotes/tools/solaris/native2ascii.html">native2ascii tool for Solaris
* @see <a href="../../../technotes/tools/windows/native2ascii.html">native2ascii tool for Windows
*
* @author Arthur van Hoff
* @author Michael McCloskey
* @author Xueming Shen
* @since JDK1.0
*/
public
class Properties extends Hashtable<Object,Object> {
/**
* use serialVersionUID from JDK 1.1.X for interoperability
*/
private static final long serialVersionUID = 4112578634029874840L;
/**
* A property list that contains default values for any keys not
* found in this property list.
*
* @serial
*/
protected Properties defaults;
/**
* Creates an empty property list with no default values.
*/
public Properties() {
this(null);
}
/**
* Creates an empty property list with the specified defaults.
*
* @param defaults the defaults.
*/
public Properties(Properties defaults) {
this.defaults = defaults;
}
/**
* Calls the <tt>Hashtable method {@code put}. Provided for
* parallelism with the <tt>getProperty method. Enforces use of
* strings for property keys and values. The value returned is the
* result of the <tt>Hashtable call to {@code put}.
*
* @param key the key to be placed into this property list.
* @param value the value corresponding to <tt>key.
* @return the previous value of the specified key in this property
* list, or {@code null} if it did not have one.
* @see #getProperty
* @since 1.2
*/
public synchronized Object setProperty(String key, String value) {
return put(key, value);
}
/**
* Reads a property list (key and element pairs) from the input
* character stream in a simple line-oriented format.
* <p>
* Properties are processed in terms of lines. There are two
* kinds of line, <i>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 ({@code \n} or {@code \r} or {@code \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
* {@code \}. 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.
*
* <p>
* A natural line that contains only white space characters is
* considered blank and is ignored. A comment line has an ASCII
* {@code '#'} or {@code '!'} 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
* ({@code ' '}, {@code '\u005Cu0020'}), tab
* ({@code '\t'}, {@code '\u005Cu0009'}), and form feed
* ({@code '\f'}, {@code '\u005Cu000C'}) to be white
* space.
*
* <p>
* 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 <i>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 2<i>n contiguous backslashes
* before a line terminator (or elsewhere) encodes <i>n
* backslashes after escape processing.
*
* <p>
* 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 {@code '='},
* {@code ':'}, 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,<p>
*
* {@code \:\=}<p>
*
* would be the two-character key {@code ":="}. Line
* terminator characters can be included using {@code \r} and
* {@code \n} escape sequences. Any white space after the
* key is skipped; if the first non-white space character after
* the key is {@code '='} or {@code ':'}, 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
* {@code ""}. Once the raw character sequences
* constituting the key and element are identified, escape
* processing is performed as described above.
*
* <p>
* As an example, each of the following three lines specifies the key
* {@code "Truth"} and the associated element value
* {@code "Beauty"}:
* <pre>
* Truth = Beauty
* Truth:Beauty
* Truth :Beauty
* </pre>
* As another example, the following three lines specify a single
* property:
* <pre>
* fruits apple, banana, pear, \
* cantaloupe, watermelon, \
* kiwi, mango
* </pre>
* The key is {@code "fruits"} and the associated element is:
* <pre>"apple, banana, pear, cantaloupe, watermelon, kiwi, mango"
* Note that a space appears before each {@code \} so that a space
* will appear after each comma in the final result; the {@code \},
* line terminator, and leading white space on the continuation line are
* merely discarded and are <i>not replaced by one or more other
* characters.
* <p>
* As a third example, the line:
* <pre>cheeses
* </pre>
* specifies that the key is {@code "cheeses"} and the associated
* element is the empty string {@code ""}.
* <p>
* <a name="unicodeescapes">
* Characters in keys and elements can be represented in escape
* sequences similar to those used for character and string literals
* (see sections 3.3 and 3.10.6 of
* <cite>The Java™ Language Specification).
*
* The differences from the character escape sequences and Unicode
* escapes used for characters and strings are:
*
* <ul>
* <li> Octal escapes are not recognized.
*
* <li> The character sequence {@code \b} does not
* represent a backspace character.
*
* <li> The method does not treat a backslash character,
* {@code \}, before a non-valid escape character as an
* error; the backslash is silently dropped. For example, in a
* Java string the sequence {@code "\z"} would cause a
* compile time error. In contrast, this method silently drops
* the backslash. Therefore, this method treats the two character
* sequence {@code "\b"} as equivalent to the single
* character {@code 'b'}.
*
* <li> 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.
*
* <li> Only a single 'u' character is allowed in a Unicode escape
* sequence.
*
* </ul>
* <p>
* The specified stream remains open after this method returns.
*
* @param reader the input character stream.
* @throws IOException if an error occurred when reading from the
* input stream.
* @throws IllegalArgumentException if a malformed Unicode escape
* appears in the input.
* @since 1.6
*/
public synchronized void load(Reader reader) throws IOException {
load0(new LineReader(reader));
}
/**
* 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
* {@link #load(java.io.Reader) 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 3.3 of
* <cite>The Java™ Language Specification.
* <p>
* The specified stream remains open after this method returns.
*
* @param inStream the input stream.
* @exception IOException if an error occurred when reading from the
* input stream.
* @throws IllegalArgumentException if the input stream contains a
* malformed Unicode escape sequence.
* @since 1.2
*/
public synchronized void load(InputStream inStream) throws IOException {
load0(new LineReader(inStream));
}
private void load0 (LineReader lr) throws IOException {
char[] convtBuf = new char[1024];
int limit;
int keyLen;
int valueStart;
char c;
boolean hasSep;
boolean precedingBackslash;
while ((limit = lr.readLine()) >= 0) {
c = 0;
keyLen = 0;
valueStart = limit;
hasSep = false;
//System.out.println("line=<" + new String(lineBuf, 0, limit) + ">");
precedingBackslash = false;
while (keyLen < limit) {
c = lr.lineBuf[keyLen];
//need check if escaped.
if ((c == '=' || c == ':') && !precedingBackslash) {
valueStart = keyLen + 1;
hasSep = true;
break;
} else if ((c == ' ' || c == '\t' || c == '\f') && !precedingBackslash) {
valueStart = keyLen + 1;
break;
}
if (c == '\\') {
precedingBackslash = !precedingBackslash;
} else {
precedingBackslash = false;
}
keyLen++;
}
while (valueStart < limit) {
c = lr.lineBuf[valueStart];
if (c != ' ' && c != '\t' && c != '\f') {
if (!hasSep && (c == '=' || c == ':')) {
hasSep = true;
} else {
break;
}
}
valueStart++;
}
String key = loadConvert(lr.lineBuf, 0, keyLen, convtBuf);
String value = loadConvert(lr.lineBuf, valueStart, limit - valueStart, convtBuf);
put(key, value);
}
}
/* Read in a "logical line" from an InputStream/Reader, skip all comment
* and blank lines and filter out those leading whitespace characters
* (\u0020, \u0009 and \u000c) from the beginning of a "natural line".
* Method returns the char length of the "logical line" and stores
* the line in "lineBuf".
*/
class LineReader {
public LineReader(InputStream inStream) {
this.inStream = inStream;
inByteBuf = new byte[8192];
}
public LineReader(Reader reader) {
this.reader = reader;
inCharBuf = new char[8192];
}
byte[] inByteBuf;
char[] inCharBuf;
char[] lineBuf = new char[1024];
int inLimit = 0;
int inOff = 0;
InputStream inStream;
Reader reader;
int readLine() throws IOException {
int len = 0;
char c = 0;
boolean skipWhiteSpace = true;
boolean isCommentLine = false;
boolean isNewLine = true;
boolean appendedLineBegin = false;
boolean precedingBackslash = false;
boolean skipLF = false;
while (true) {
if (inOff >= inLimit) {
inLimit = (inStream==null)?reader.read(inCharBuf)
:inStream.read(inByteBuf);
inOff = 0;
if (inLimit <= 0) {
if (len == 0 || isCommentLine) {
return -1;
}
if (precedingBackslash) {
len--;
}
return len;
}
}
if (inStream != null) {
//The line below is equivalent to calling a
//ISO8859-1 decoder.
c = (char) (0xff & inByteBuf[inOff++]);
} else {
c = inCharBuf[inOff++];
}
if (skipLF) {
skipLF = false;
if (c == '\n') {
continue;
}
}
if (skipWhiteSpace) {
if (c == ' ' || c == '\t' || c == '\f') {
continue;
}
if (!appendedLineBegin && (c == '\r' || c == '\n')) {
continue;
}
skipWhiteSpace = false;
appendedLineBegin = false;
}
if (isNewLine) {
isNewLine = false;
if (c == '#' || c == '!') {
isCommentLine = true;
continue;
}
}
if (c != '\n' && c != '\r') {
lineBuf[len++] = c;
if (len == lineBuf.length) {
int newLength = lineBuf.length * 2;
if (newLength < 0) {
newLength = Integer.MAX_VALUE;
}
char[] buf = new char[newLength];
System.arraycopy(lineBuf, 0, buf, 0, lineBuf.length);
lineBuf = buf;
}
//flip the preceding backslash flag
if (c == '\\') {
precedingBackslash = !precedingBackslash;
} else {
precedingBackslash = false;
}
}
else {
// reached EOL
if (isCommentLine || len == 0) {
isCommentLine = false;
isNewLine = true;
skipWhiteSpace = true;
len = 0;
continue;
}
if (inOff >= inLimit) {
inLimit = (inStream==null)
?reader.read(inCharBuf)
:inStream.read(inByteBuf);
inOff = 0;
if (inLimit <= 0) {
if (precedingBackslash) {
len--;
}
return len;
}
}
if (precedingBackslash) {
len -= 1;
//skip the leading whitespace characters in following line
skipWhiteSpace = true;
appendedLineBegin = true;
precedingBackslash = false;
if (c == '\r') {
skipLF = true;
}
} else {
return len;
}
}
}
}
}
/*
* Converts encoded \uxxxx to unicode chars
* and changes special saved chars to their original forms
*/
private String loadConvert (char[] in, int off, int len, char[] convtBuf) {
if (convtBuf.length < len) {
int newLen = len * 2;
if (newLen < 0) {
newLen = Integer.MAX_VALUE;
}
convtBuf = new char[newLen];
}
char aChar;
char[] out = convtBuf;
int outLen = 0;
int end = off + len;
while (off < end) {
aChar = in[off++];
if (aChar == '\\') {
aChar = in[off++];
if(aChar == 'u') {
// Read the xxxx
int value=0;
for (int i=0; i<4; i++) {
aChar = in[off++];
switch (aChar) {
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
value = (value << 4) + aChar - '0';
break;
case 'a': case 'b': case 'c':
case 'd': case 'e': case 'f':
value = (value << 4) + 10 + aChar - 'a';
break;
case 'A': case 'B': case 'C':
case 'D': case 'E': case 'F':
value = (value << 4) + 10 + aChar - 'A';
break;
default:
throw new IllegalArgumentException(
"Malformed \\uxxxx encoding.");
}
}
out[outLen++] = (char)value;
} else {
if (aChar == 't') aChar = '\t';
else if (aChar == 'r') aChar = '\r';
else if (aChar == 'n') aChar = '\n';
else if (aChar == 'f') aChar = '\f';
out[outLen++] = aChar;
}
} else {
out[outLen++] = aChar;
}
}
return new String (out, 0, outLen);
}
/*
* Converts unicodes to encoded \uxxxx and escapes
* special characters with a preceding slash
*/
private String saveConvert(String theString,
boolean escapeSpace,
boolean escapeUnicode) {
int len = theString.length();
int bufLen = len * 2;
if (bufLen < 0) {
bufLen = Integer.MAX_VALUE;
}
StringBuffer outBuffer = new StringBuffer(bufLen);
for(int x=0; x<len; x++) {
char aChar = theString.charAt(x);
// Handle common case first, selecting largest block that
// avoids the specials below
if ((aChar > 61) && (aChar < 127)) {
if (aChar == '\\') {
outBuffer.append('\\'); outBuffer.append('\\');
continue;
}
outBuffer.append(aChar);
continue;
}
switch(aChar) {
case ' ':
if (x == 0 || escapeSpace)
outBuffer.append('\\');
outBuffer.append(' ');
break;
case '\t':outBuffer.append('\\'); outBuffer.append('t');
break;
case '\n':outBuffer.append('\\'); outBuffer.append('n');
break;
case '\r':outBuffer.append('\\'); outBuffer.append('r');
break;
case '\f':outBuffer.append('\\'); outBuffer.append('f');
break;
case '=': // Fall through
case ':': // Fall through
case '#': // Fall through
case '!':
outBuffer.append('\\'); outBuffer.append(aChar);
break;
default:
if (((aChar < 0x0020) || (aChar > 0x007e)) & escapeUnicode ) {
outBuffer.append('\\');
outBuffer.append('u');
outBuffer.append(toHex((aChar >> 12) & 0xF));
outBuffer.append(toHex((aChar >> 8) & 0xF));
outBuffer.append(toHex((aChar >> 4) & 0xF));
outBuffer.append(toHex( aChar & 0xF));
} else {
outBuffer.append(aChar);
}
}
}
return outBuffer.toString();
}
private static void writeComments(BufferedWriter bw, String comments)
throws IOException {
bw.write("#");
int len = comments.length();
int current = 0;
int last = 0;
char[] uu = new char[6];
uu[0] = '\\';
uu[1] = 'u';
while (current < len) {
char c = comments.charAt(current);
if (c > '\u00ff' || c == '\n' || c == '\r') {
if (last != current)
bw.write(comments.substring(last, current));
if (c > '\u00ff') {
uu[2] = toHex((c >> 12) & 0xf);
uu[3] = toHex((c >> 8) & 0xf);
uu[4] = toHex((c >> 4) & 0xf);
uu[5] = toHex( c & 0xf);
bw.write(new String(uu));
} else {
bw.newLine();
if (c == '\r' &&
current != len - 1 &&
comments.charAt(current + 1) == '\n') {
current++;
}
if (current == len - 1 ||
(comments.charAt(current + 1) != '#' &&
comments.charAt(current + 1) != '!'))
bw.write("#");
}
last = current + 1;
}
current++;
}
if (last != current)
bw.write(comments.substring(last, current));
bw.newLine();
}
/**
* Calls the {@code store(OutputStream out, String comments)} method
* and suppresses IOExceptions that were thrown.
*
* @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 {@code store(OutputStream out,
* String comments)} method or the
* {@code storeToXML(OutputStream os, String comment)} method.
*
* @param out an output stream.
* @param comments a description of the property list.
* @exception ClassCastException if this {@code Properties} object
* contains any keys or values that are not
* {@code Strings}.
*/
@Deprecated
public void save(OutputStream out, String comments) {
try {
store(out, comments);
} catch (IOException e) {
}
}
/**
* Writes this property list (key and element pairs) in this
* {@code Properties} table to the output character stream in a
* format suitable for using the {@link #load(java.io.Reader) load(Reader)}
* method.
* <p>
* Properties from the defaults table of this {@code Properties}
* table (if any) are <i>not written out by this method.
* <p>
* If the comments argument is not null, then an ASCII {@code #}
* character, the comments string, and a line separator are first written
* to the output stream. Thus, the {@code 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 {@code Writer}
* and if the next character in comments is not character {@code #} or
* character {@code !} then an ASCII {@code #} is written out
* after that line separator.
* <p>
* Next, a comment line is always written, consisting of an ASCII
* {@code #} character, the current date and time (as if produced
* by the {@code toString} method of {@code Date} for the
* current time), and a line separator as generated by the {@code Writer}.
* <p>
* Then every entry in this {@code Properties} table is
* written out, one per line. For each entry the key string is
* written, then an ASCII {@code =}, then the associated
* element string. For the key, all space characters are
* written with a preceding {@code \} character. For the
* element, leading space characters, but not embedded or trailing
* space characters, are written with a preceding {@code \}
* character. The key and element characters {@code #},
* {@code !}, {@code =}, and {@code :} are written
* with a preceding backslash to ensure that they are properly loaded.
* <p>
* After the entries have been written, the output stream is flushed.
* The output stream remains open after this method returns.
* <p>
*
* @param writer an output character stream writer.
* @param comments a description of the property list.
* @exception IOException if writing this property list to the specified
* output stream throws an <tt>IOException.
* @exception ClassCastException if this {@code Properties} object
* contains any keys or values that are not {@code Strings}.
* @exception NullPointerException if {@code writer} is null.
* @since 1.6
*/
public void store(Writer writer, String comments)
throws IOException
{
store0((writer instanceof BufferedWriter)?(BufferedWriter)writer
: new BufferedWriter(writer),
comments,
false);
}
/**
* Writes this property list (key and element pairs) in this
* {@code Properties} table to the output stream in a format suitable
* for loading into a {@code Properties} table using the
* {@link #load(InputStream) load(InputStream)} method.
* <p>
* Properties from the defaults table of this {@code Properties}
* table (if any) are <i>not written out by this method.
* <p>
* This method outputs the comments, properties keys and values in
* the same format as specified in
* {@link #store(java.io.Writer, java.lang.String) store(Writer)},
* with the following differences:
* <ul>
* <li>The stream is written using the ISO 8859-1 character encoding.
*
* <li>Characters not in Latin-1 in the comments are written as
* {@code \u005Cu}<i>xxxx for their appropriate unicode
* hexadecimal value <i>xxxx.
*
* <li>Characters less than {@code \u005Cu0020} and characters greater
* than {@code \u005Cu007E} in property keys or values are written
* as {@code \u005Cu}<i>xxxx for the appropriate hexadecimal
* value <i>xxxx.
* </ul>
* <p>
* After the entries have been written, the output stream is flushed.
* The output stream remains open after this method returns.
* <p>
* @param out an output stream.
* @param comments a description of the property list.
* @exception IOException if writing this property list to the specified
* output stream throws an <tt>IOException.
* @exception ClassCastException if this {@code Properties} object
* contains any keys or values that are not {@code Strings}.
* @exception NullPointerException if {@code out} is null.
* @since 1.2
*/
public void store(OutputStream out, String comments)
throws IOException
{
store0(new BufferedWriter(new OutputStreamWriter(out, "8859_1")),
comments,
true);
}
private void store0(BufferedWriter bw, String comments, boolean escUnicode)
throws IOException
{
if (comments != null) {
writeComments(bw, comments);
}
bw.write("#" + new Date().toString());
bw.newLine();
synchronized (this) {
for (Enumeration<?> e = keys(); e.hasMoreElements();) {
String key = (String)e.nextElement();
String val = (String)get(key);
key = saveConvert(key, true, escUnicode);
/* No need to escape embedded and trailing spaces for value, hence
* pass false to flag.
*/
val = saveConvert(val, false, escUnicode);
bw.write(key + "=" + val);
bw.newLine();
}
}
bw.flush();
}
/**
* Loads all of the properties represented by the XML document on the
* specified input stream into this properties table.
*
* <p>The XML document must have the following DOCTYPE declaration:
* <pre>
* <!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
* </pre>
* Furthermore, the document must satisfy the properties DTD described
* above.
*
* <p> An implementation is required to read XML documents that use the
* "{@code UTF-8}" or "{@code UTF-16}" encoding. An implementation may
* support additional encodings.
*
* <p>The specified stream is closed after this method returns.
*
* @param in the input stream from which to read the XML document.
* @throws IOException if reading from the specified input stream
* results in an <tt>IOException.
* @throws java.io.UnsupportedEncodingException if the document's encoding
* declaration can be read and it specifies an encoding that is not
* supported
* @throws InvalidPropertiesFormatException Data on input stream does not
* constitute a valid XML document with the mandated document type.
* @throws NullPointerException if {@code in} is null.
* @see #storeToXML(OutputStream, String, String)
* @see <a href="http://www.w3.org/TR/REC-xml/#charencoding">Character
* Encoding in Entities</a>
* @since 1.5
*/
public synchronized void loadFromXML(InputStream in)
throws IOException, InvalidPropertiesFormatException
{
XmlSupport.load(this, Objects.requireNonNull(in));
in.close();
}
/**
* Emits an XML document representing all of the properties contained
* in this table.
*
* <p> An invocation of this method of the form props.storeToXML(os,
* comment)</tt> behaves in exactly the same way as the invocation
* <tt>props.storeToXML(os, comment, "UTF-8");.
*
* @param os the output stream on which to emit the XML document.
* @param comment a description of the property list, or {@code null}
* if no comment is desired.
* @throws IOException if writing to the specified output stream
* results in an <tt>IOException.
* @throws NullPointerException if {@code os} is null.
* @throws ClassCastException if this {@code Properties} object
* contains any keys or values that are not
* {@code Strings}.
* @see #loadFromXML(InputStream)
* @since 1.5
*/
public void storeToXML(OutputStream os, String comment)
throws IOException
{
storeToXML(os, comment, "UTF-8");
}
/**
* Emits an XML document representing all of the properties contained
* in this table, using the specified encoding.
*
* <p>The XML document will have the following DOCTYPE declaration:
* <pre>
* <!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
* </pre>
*
* <p>If the specified comment is {@code null} then no comment
* will be stored in the document.
*
* <p> An implementation is required to support writing of XML documents
* that use the "{@code UTF-8}" or "{@code UTF-16}" encoding. An
* implementation may support additional encodings.
*
* <p>The specified stream remains open after this method returns.
*
* @param os the output stream on which to emit the XML document.
* @param comment a description of the property list, or {@code null}
* if no comment is desired.
* @param encoding the name of a supported
* <a href="../lang/package-summary.html#charenc">
* character encoding</a>
*
* @throws IOException if writing to the specified output stream
* results in an <tt>IOException.
* @throws java.io.UnsupportedEncodingException if the encoding is not
* supported by the implementation.
* @throws NullPointerException if {@code os} is {@code null},
* or if {@code encoding} is {@code null}.
* @throws ClassCastException if this {@code Properties} object
* contains any keys or values that are not
* {@code Strings}.
* @see #loadFromXML(InputStream)
* @see <a href="http://www.w3.org/TR/REC-xml/#charencoding">Character
* Encoding in Entities</a>
* @since 1.5
*/
public void storeToXML(OutputStream os, String comment, String encoding)
throws IOException
{
XmlSupport.save(this, Objects.requireNonNull(os), comment,
Objects.requireNonNull(encoding));
}
/**
* 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
* {@code null} if the property is not found.
*
* @param key the property key.
* @return the value in this property list with the specified key value.
* @see #setProperty
* @see #defaults
*/
public String getProperty(String key) {
Object oval = super.get(key);
String sval = (oval instanceof String) ? (String)oval : null;
return ((sval == null) && (defaults != null)) ? defaults.getProperty(key) : sval;
}
/**
* 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.
*
* @param key the hashtable key.
* @param defaultValue a default value.
*
* @return the value in this property list with the specified key value.
* @see #setProperty
* @see #defaults
*/
public String getProperty(String key, String defaultValue) {
String val = getProperty(key);
return (val == null) ? defaultValue : val;
}
/**
* 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 an enumeration of all the keys in this property list, including
* the keys in the default property list.
* @throws ClassCastException if any key in this property list
* is not a string.
* @see java.util.Enumeration
* @see java.util.Properties#defaults
* @see #stringPropertyNames
*/
public Enumeration<?> propertyNames() {
Hashtable<String,Object> h = new Hashtable<>();
enumerate(h);
return h.keys();
}
/**
* Returns a set of keys in 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 <tt>String are omitted.
* <p>
* The returned set is not backed by the <tt>Properties object.
* Changes to this <tt>Properties are not reflected in the set,
* or vice versa.
*
* @return a set of keys in this property list where
* the key and its corresponding value are strings,
* including the keys in the default property list.
* @see java.util.Properties#defaults
* @since 1.6
*/
public Set<String> stringPropertyNames() {
Hashtable<String, String> h = new Hashtable<>();
enumerateStringProperties(h);
return h.keySet();
}
/**
* Prints this property list out to the specified output stream.
* This method is useful for debugging.
*
* @param out an output stream.
* @throws ClassCastException if any key in this property list
* is not a string.
*/
public void list(PrintStream out) {
out.println("-- listing properties --");
Hashtable<String,Object> h = new Hashtable<>();
enumerate(h);
for (Enumeration<String> e = h.keys() ; e.hasMoreElements() ;) {
String key = e.nextElement();
String val = (String)h.get(key);
if (val.length() > 40) {
val = val.substring(0, 37) + "...";
}
out.println(key + "=" + val);
}
}
/**
* Prints this property list out to the specified output stream.
* This method is useful for debugging.
*
* @param out an output stream.
* @throws ClassCastException if any key in this property list
* is not a string.
* @since JDK1.1
*/
/*
* Rather than use an anonymous inner class to share common code, this
* method is duplicated in order to ensure that a non-1.1 compiler can
* compile this file.
*/
public void list(PrintWriter out) {
out.println("-- listing properties --");
Hashtable<String,Object> h = new Hashtable<>();
enumerate(h);
for (Enumeration<String> e = h.keys() ; e.hasMoreElements() ;) {
String key = e.nextElement();
String val = (String)h.get(key);
if (val.length() > 40) {
val = val.substring(0, 37) + "...";
}
out.println(key + "=" + val);
}
}
/**
* Enumerates all key/value pairs in the specified hashtable.
* @param h the hashtable
* @throws ClassCastException if any of the property keys
* is not of String type.
*/
private synchronized void enumerate(Hashtable<String,Object> h) {
if (defaults != null) {
defaults.enumerate(h);
}
for (Enumeration<?> e = keys() ; e.hasMoreElements() ;) {
String key = (String)e.nextElement();
h.put(key, get(key));
}
}
/**
* Enumerates all key/value pairs in the specified hashtable
* and omits the property if the key or value is not a string.
* @param h the hashtable
*/
private synchronized void enumerateStringProperties(Hashtable<String, String> h) {
if (defaults != null) {
defaults.enumerateStringProperties(h);
}
for (Enumeration<?> e = keys() ; e.hasMoreElements() ;) {
Object k = e.nextElement();
Object v = get(k);
if (k instanceof String && v instanceof String) {
h.put((String) k, (String) v);
}
}
}
/**
* Convert a nibble to a hex character
* @param nibble the nibble to convert.
*/
private static char toHex(int nibble) {
return hexDigit[(nibble & 0xF)];
}
/** A table of hex digits */
private static final char[] hexDigit = {
'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'
};
/**
* Supporting class for loading/storing properties in XML format.
*
* <p> The {@code load} and {@code store} methods defined here delegate to a
* system-wide {@code XmlPropertiesProvider}. On first invocation of either
* method then the system-wide provider is located as follows: </p>
*
* <ol>
* <li> If the system property {@code sun.util.spi.XmlPropertiesProvider}
* is defined then it is taken to be the full-qualified name of a concrete
* provider class. The class is loaded with the system class loader as the
* initiating loader. If it cannot be loaded or instantiated using a zero
* argument constructor then an unspecified error is thrown. </li>
*
* <li> If the system property is not defined then the service-provider
* loading facility defined by the {@link ServiceLoader} class is used to
* locate a provider with the system class loader as the initiating
* loader and {@code sun.util.spi.XmlPropertiesProvider} as the service
* type. If this process fails then an unspecified error is thrown. If
* there is more than one service provider installed then it is
* not specified as to which provider will be used. </li>
*
* <li> If the provider is not found by the above means then a system
* default provider will be instantiated and used. </li>
* </ol>
*/
private static class XmlSupport {
private static XmlPropertiesProvider loadProviderFromProperty(ClassLoader cl) {
String cn = System.getProperty("sun.util.spi.XmlPropertiesProvider");
if (cn == null)
return null;
try {
Class<?> c = Class.forName(cn, true, cl);
return (XmlPropertiesProvider)c.newInstance();
} catch (ClassNotFoundException |
IllegalAccessException |
InstantiationException x) {
throw new ServiceConfigurationError(null, x);
}
}
private static XmlPropertiesProvider loadProviderAsService(ClassLoader cl) {
Iterator<XmlPropertiesProvider> iterator =
ServiceLoader.load(XmlPropertiesProvider.class, cl).iterator();
return iterator.hasNext() ? iterator.next() : null;
}
private static XmlPropertiesProvider loadProvider() {
return AccessController.doPrivileged(
new PrivilegedAction<XmlPropertiesProvider>() {
public XmlPropertiesProvider run() {
ClassLoader cl = ClassLoader.getSystemClassLoader();
XmlPropertiesProvider provider = loadProviderFromProperty(cl);
if (provider != null)
return provider;
provider = loadProviderAsService(cl);
if (provider != null)
return provider;
return new jdk.internal.util.xml.BasicXmlPropertiesProvider();
}});
}
private static final XmlPropertiesProvider PROVIDER = loadProvider();
static void load(Properties props, InputStream in)
throws IOException, InvalidPropertiesFormatException
{
PROVIDER.load(props, in);
}
static void save(Properties props, OutputStream os, String comment,
String encoding)
throws IOException
{
PROVIDER.store(props, os, comment, encoding);
}
}
}
Other Java examples (source code examples)Here is a short list of links related to this Java Properties.java source code file: |
The search page
Other Java source code examples at this package level
Click here to learn more about this project
