All Downloads are FREE. Search and download functionalities are using the official Maven repository.

java.util.Properties Maven / Gradle / Ivy

Go to download

JVM AOT compiler currently generating JavaScript, C++, Haxe, with initial focus on Kotlin and games.

There is a newer version: 0.6.8
Show newest version
/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package java.util;

import java.io.*;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;

/**
 * A {@code Properties} object is a {@code Hashtable} where the keys and values
 * must be {@code String}s. Each property can have a default
 * {@code Properties} list which specifies the default
 * values to be used when a given key is not found in this {@code Properties}
 * instance.
 *
 * 

Character Encoding

*

Note that in some cases {@code 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 {@code loadFromXML}/{@code storeToXML} methods (which use UTF-8 by * default) or the {@code load}/{@code store} overloads that take * an {@code OutputStreamWriter} (so you can supply a UTF-8 instance) instead. * * @see Hashtable * @see System#getProperties */ public class Properties extends Hashtable { private static final long serialVersionUID = 4112578634029874840L; //private transient DocumentBuilder builder = null; private static final String PROP_DTD_NAME = "http://java.sun.com/dtd/properties.dtd"; private static final String PROP_DTD = "" + " " + " " + " " + " " + " "; /** * The default values for keys not found in this {@code Properties} * instance. */ protected Properties defaults; private static final int NONE = 0, SLASH = 1, UNICODE = 2, CONTINUE = 3, KEY_DONE = 4, IGNORE = 5; /** * Constructs a new {@code Properties} object. */ public Properties() { } /** * Constructs a new {@code Properties} object using the specified default * {@code Properties}. * * @param properties * the default {@code Properties}. */ public Properties(Properties properties) { defaults = properties; } private void dumpString(StringBuilder buffer, String string, boolean key) { int i = 0; if (!key && i < string.length() && string.charAt(i) == ' ') { buffer.append("\\ "); i++; } for (; i < string.length(); i++) { char ch = string.charAt(i); switch (ch) { case '\t': buffer.append("\\t"); break; case '\n': buffer.append("\\n"); break; case '\f': buffer.append("\\f"); break; case '\r': buffer.append("\\r"); break; default: if ("\\#!=:".indexOf(ch) >= 0 || (key && ch == ' ')) { buffer.append('\\'); } if (ch >= ' ' && ch <= '~') { buffer.append(ch); } else { String hex = Integer.toHexString(ch); buffer.append("\\u"); for (int j = 0; j < 4 - hex.length(); j++) { buffer.append("0"); } buffer.append(hex); } } } } /** * Searches for the property with the specified name. If the property is not * found, the default {@code Properties} are checked. If the property is not * found in the default {@code Properties}, {@code null} is returned. * * @param name * the name of the property to find. * @return the named property value, or {@code null} if it can't be found. */ public String getProperty(String name) { Object result = super.get(name); String property = result instanceof String ? (String) result : null; if (property == null && defaults != null) { property = defaults.getProperty(name); } return property; } /** * Searches for the property with the specified name. If the property is not * found, it looks in the default {@code Properties}. If the property is not * found in the default {@code Properties}, it returns the specified * default. * * @param name * the name of the property to find. * @param defaultValue * the default value. * @return the named property value. */ public String getProperty(String name, String defaultValue) { Object result = super.get(name); String property = result instanceof String ? (String) result : null; if (property == null && defaults != null) { property = defaults.getProperty(name); } if (property == null) { return defaultValue; } return property; } /** * Lists the mappings in this {@code Properties} to {@code out} in a human-readable form. * Note that values are truncated to 37 characters, so this method is rarely useful. */ public void list(PrintStream out) { listToAppendable(out); } /** * Lists the mappings in this {@code Properties} to {@code 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) { listToAppendable(out); } private void listToAppendable(Appendable out) { try { if (out == null) { throw new NullPointerException("out == null"); } StringBuilder sb = new StringBuilder(80); Enumeration keys = propertyNames(); while (keys.hasMoreElements()) { String key = (String) keys.nextElement(); sb.append(key); sb.append('='); String property = (String) super.get(key); Properties def = defaults; while (property == null) { property = (String) def.get(key); def = def.defaults; } if (property.length() > 40) { sb.append(property.substring(0, 37)); sb.append("..."); } else { sb.append(property); } sb.append(System.lineSeparator()); out.append(sb.toString()); sb.setLength(0); } } catch (IOException ex) { // Appendable.append throws IOException, but PrintStream and PrintWriter don't. throw new AssertionError(ex); } } /** * Loads properties from the specified {@code InputStream}, assumed to be ISO-8859-1. * See "Character Encoding". * * @param in the {@code InputStream} * @throws IOException */ public synchronized void load(InputStream in) throws IOException { if (in == null) { throw new NullPointerException("in == null"); } load(new InputStreamReader(in, "ISO-8859-1")); } /** * Loads properties from the specified {@code 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).
  • *
* * @param in the {@code Reader} * @throws IOException * @since 1.6 */ @SuppressWarnings("fallthrough") public synchronized void load(Reader in) throws IOException { if (in == null) { throw new NullPointerException("in == null"); } int mode = NONE, unicode = 0, count = 0; char nextChar, buf[] = new char[40]; int offset = 0, keyLength = -1, intVal; boolean firstChar = true; BufferedReader br = new BufferedReader(in); while (true) { intVal = br.read(); if (intVal == -1) { break; } nextChar = (char) intVal; if (offset == buf.length) { char[] newBuf = new char[buf.length * 2]; System.arraycopy(buf, 0, newBuf, 0, offset); buf = newBuf; } if (mode == UNICODE) { int digit = Character.digit(nextChar, 16); if (digit >= 0) { unicode = (unicode << 4) + digit; if (++count < 4) { continue; } } else if (count <= 4) { throw new IllegalArgumentException("Invalid Unicode sequence: illegal character"); } mode = NONE; buf[offset++] = (char) unicode; if (nextChar != '\n') { continue; } } if (mode == SLASH) { mode = NONE; switch (nextChar) { case '\r': mode = CONTINUE; // Look for a following \n continue; case '\n': mode = IGNORE; // Ignore whitespace on the next line continue; case 'b': nextChar = '\b'; break; case 'f': nextChar = '\f'; break; case 'n': nextChar = '\n'; break; case 'r': nextChar = '\r'; break; case 't': nextChar = '\t'; break; case 'u': mode = UNICODE; unicode = count = 0; continue; } } else { switch (nextChar) { case '#': case '!': if (firstChar) { while (true) { intVal = br.read(); if (intVal == -1) { break; } nextChar = (char) intVal; if (nextChar == '\r' || nextChar == '\n') { break; } } continue; } break; case '\n': if (mode == CONTINUE) { // Part of a \r\n sequence mode = IGNORE; // Ignore whitespace on the next line continue; } // fall into the next case case '\r': mode = NONE; firstChar = true; if (offset > 0 || (offset == 0 && keyLength == 0)) { if (keyLength == -1) { keyLength = offset; } String temp = new String(buf, 0, offset); put(temp.substring(0, keyLength), temp .substring(keyLength)); } keyLength = -1; offset = 0; continue; case '\\': if (mode == KEY_DONE) { keyLength = offset; } mode = SLASH; continue; case ':': case '=': if (keyLength == -1) { // if parsing the key mode = NONE; keyLength = offset; continue; } break; } if (Character.isWhitespace(nextChar)) { if (mode == CONTINUE) { mode = IGNORE; } // if key length == 0 or value length == 0 if (offset == 0 || offset == keyLength || mode == IGNORE) { continue; } if (keyLength == -1) { // if parsing the key mode = KEY_DONE; continue; } } if (mode == IGNORE || mode == CONTINUE) { mode = NONE; } } firstChar = false; if (mode == KEY_DONE) { keyLength = offset; mode = NONE; } buf[offset++] = nextChar; } if (mode == UNICODE && count <= 4) { throw new IllegalArgumentException("Invalid Unicode sequence: expected format \\uxxxx"); } if (keyLength == -1 && offset > 0) { keyLength = offset; } if (keyLength >= 0) { String temp = new String(buf, 0, offset); String key = temp.substring(0, keyLength); String value = temp.substring(keyLength); if (mode == SLASH) { value += "\u0000"; } put(key, value); } } /** * Returns all of the property names (keys) in this {@code Properties} object. */ public Enumeration propertyNames() { Hashtable selected = new Hashtable(); selectProperties(selected, false); return selected.keys(); } /** * Returns those property names (keys) in this {@code Properties} object for which * both key and value are strings. * * @return a set of keys in the property list * @since 1.6 */ public Set stringPropertyNames() { Hashtable stringProperties = new Hashtable(); selectProperties(stringProperties, true); return Collections.unmodifiableSet(stringProperties.keySet()); } private void selectProperties(Hashtable selectProperties, final boolean isStringOnly) { if (defaults != null) { defaults.selectProperties(selectProperties, isStringOnly); } Enumeration keys = keys(); while (keys.hasMoreElements()) { @SuppressWarnings("unchecked") K key = (K) keys.nextElement(); if (isStringOnly && !(key instanceof String)) { // Only select property with string key and value continue; } Object value = get(key); selectProperties.put(key, value); } } /** * Saves the mappings in this {@code Properties} to the specified {@code * OutputStream}, putting the specified comment at the beginning. The output * from this method is suitable for being read by the * {@link #load(InputStream)} method. * * @param out the {@code OutputStream} to write to. * @param comment the comment to add at the beginning. * @throws ClassCastException if the key or value of a mapping is not a * String. * @deprecated This method ignores any {@code IOException} thrown while * writing — use {@link #store} instead for better exception * handling. */ @Deprecated public void save(OutputStream out, String comment) { try { store(out, comment); } catch (IOException e) { } } /** * Maps the specified key to the specified value. If the key already exists, * the old value is replaced. The key and value cannot be {@code null}. * * @param name * the key. * @param value * the value. * @return the old value mapped to the key, or {@code null}. */ public Object setProperty(String name, String value) { return put(name, value); } /** * Stores properties to the specified {@code OutputStream}, using ISO-8859-1. * See "Character Encoding". * * @param out the {@code OutputStream} * @param comment an optional comment to be written, or null * @throws IOException * @throws ClassCastException if a key or value is not a string */ public synchronized void store(OutputStream out, String comment) throws IOException { store(new OutputStreamWriter(out, "ISO-8859-1"), comment); } /** * Stores the mappings in this {@code Properties} object to {@code out}, * putting the specified comment at the beginning. * * @param writer the {@code Writer} * @param comment an optional comment to be written, or null * @throws IOException * @throws ClassCastException if a key or value is not a string * @since 1.6 */ public synchronized void store(Writer writer, String comment) throws IOException { if (comment != null) { writer.write("#"); writer.write(comment); writer.write(System.lineSeparator()); } writer.write("#"); writer.write(new Date().toString()); writer.write(System.lineSeparator()); StringBuilder sb = new StringBuilder(200); for (Entry entry : entrySet()) { String key = (String) entry.getKey(); dumpString(sb, key, true); sb.append('='); dumpString(sb, (String) entry.getValue(), false); sb.append(System.lineSeparator()); writer.write(sb.toString()); sb.setLength(0); } writer.flush(); } /** * Loads the properties from an {@code 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. * * @param in the InputStream containing the XML document. * @throws IOException in case an error occurs during a read operation. * @throws InvalidPropertiesFormatException if the XML data is not a valid * properties file. */ native public synchronized void loadFromXML(InputStream in) throws IOException, InvalidPropertiesFormatException; //public synchronized void loadFromXML(InputStream in) throws IOException, // InvalidPropertiesFormatException { // if (in == null) { // throw new NullPointerException("in == null"); // } // // if (builder == null) { // DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); // // BEGIN android-removed: we still don't support validation. // // factory.setValidating(true); // // END android-removed // // try { // builder = factory.newDocumentBuilder(); // } catch (ParserConfigurationException e) { // throw new Error(e); // } // // builder.setErrorHandler(new ErrorHandler() { // public void warning(SAXParseException e) throws SAXException { // throw e; // } // // public void error(SAXParseException e) throws SAXException { // throw e; // } // // public void fatalError(SAXParseException e) throws SAXException { // throw e; // } // }); // // builder.setEntityResolver(new EntityResolver() { // public InputSource resolveEntity(String publicId, // String systemId) throws SAXException, IOException { // if (systemId.equals(PROP_DTD_NAME)) { // InputSource result = new InputSource(new StringReader( // PROP_DTD)); // result.setSystemId(PROP_DTD_NAME); // return result; // } // throw new SAXException("Invalid DOCTYPE declaration: " // + systemId); // } // }); // } // // try { // Document doc = builder.parse(in); // NodeList entries = doc.getElementsByTagName("entry"); // if (entries == null) { // return; // } // int entriesListLength = entries.getLength(); // // for (int i = 0; i < entriesListLength; i++) { // Element entry = (Element) entries.item(i); // String key = entry.getAttribute("key"); // String value = entry.getTextContent(); // // /* // * key != null & value != null but key or(and) value can be // * empty String // */ // put(key, value); // } // } catch (IOException e) { // throw e; // } catch (SAXException e) { // throw new InvalidPropertiesFormatException(e); // } //} /** * Writes all properties stored in this instance into the {@code * 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 {@code OutputStream} is not closed at the end. A * call to this method is the same as a call to {@code storeToXML(os, * comment, "UTF-8")}. * * @param os the {@code OutputStream} to write to. * @param comment the comment to add. If null, no comment is added. * @throws IOException if an error occurs during writing to the output. */ public void storeToXML(OutputStream os, String comment) throws IOException { storeToXML(os, comment, "UTF-8"); } /** * Writes all properties stored in this instance into the {@code * 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 * {@code encoding} defines which encoding should be used. The {@code * OutputStream} is not closed at the end. * * @param os the {@code OutputStream} to write to. * @param comment the comment to add. If null, no comment is added. * @param encoding the code identifying the encoding that should be used to * write into the {@code OutputStream}. * @throws IOException if an error occurs during writing to the output. */ public synchronized void storeToXML(OutputStream os, String comment, String encoding) throws IOException { if (os == null) { throw new NullPointerException("os == null"); } else if (encoding == null) { throw new NullPointerException("encoding == null"); } /* * We can write to XML file using encoding parameter but note that some * aliases for encodings are not supported by the XML parser. Thus we * have to know canonical name for encoding used to store data in XML * since the XML parser must recognize encoding name used to store data. */ String encodingCanonicalName; try { encodingCanonicalName = Charset.forName(encoding).name(); } catch (IllegalCharsetNameException e) { System.out.println("Warning: encoding name " + encoding + " is illegal, using UTF-8 as default encoding"); encodingCanonicalName = "UTF-8"; } catch (UnsupportedCharsetException e) { System.out.println("Warning: encoding " + encoding + " is not supported, using UTF-8 as default encoding"); encodingCanonicalName = "UTF-8"; } PrintStream printStream = new PrintStream(os, false, encodingCanonicalName); printStream.print(""); printStream.print(""); printStream.println(""); if (comment != null) { printStream.print(""); printStream.print(substitutePredefinedEntries(comment)); printStream.println(""); } for (Entry entry : entrySet()) { String keyValue = (String) entry.getKey(); String entryValue = (String) entry.getValue(); printStream.print(""); printStream.print(substitutePredefinedEntries(entryValue)); printStream.println(""); } printStream.println(""); printStream.flush(); } private String substitutePredefinedEntries(String s) { // substitution for predefined character entities to use them safely in XML. s = s.replaceAll("&", "&"); s = s.replaceAll("<", "<"); s = s.replaceAll(">", ">"); s = s.replaceAll("'", "'"); s = s.replaceAll("\"", """); return s; } }