1 files changed, 182 insertions, 0 deletions

diff --git a/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/XMLStringEncoder.java b/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/XMLStringEncoder.java
new file mode 100644
index 0000000000..fd637ebfa9
--- /dev/null
+++ b/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/XMLStringEncoder.java
@@ -0,0 +1,182 @@
+/*******************************************************************************
+ * Copyright (c) 2005, 2007 Oracle. All rights reserved.
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0, which accompanies this distribution
+ * and is available at http://www.eclipse.org/legal/epl-v10.html.
+ * 
+ * Contributors:
+ *     Oracle - initial API and implementation
+ ******************************************************************************/
+package org.eclipse.jpt.utility.internal;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.io.StringReader;
+
+/**
+ * This encoder will replace any of a specified set of characters with an XML
+ * "character reference": '/' => "/"
+ */
+public final class XMLStringEncoder {
+
+	/** The set of characters to be converted into XML character references. */
+	private final char[] chars;
+
+	/** Cache the value of the highest character in the set above. */
+	private final char maxChar;
+
+
+	// ********** constructors/initialization **********
+
+	/**
+	 * Construct an encoder that converts the specified set of characters
+	 * into XML character references.
+	 */
+	public XMLStringEncoder(char[] chars) {
+		super();
+		if (chars == null) {
+			throw new NullPointerException();
+		}
+		// the ampersand must be included since it is the escape character
+		if (CollectionTools.contains(chars, '&')) {
+			this.chars = chars;
+		} else {
+			this.chars = CollectionTools.add(chars, '&');
+		}
+		this.maxChar = this.calculateMaxInvalidFileNameChar();
+	}
+
+	/**
+	 * Calculate the maximum value of the set of characters to be converted
+	 * into XML character references. This will be used to short-circuit the
+	 * search for a character in the set.
+	 * @see #charIsToBeEncoded(char)
+	 */
+	private char calculateMaxInvalidFileNameChar() {
+		char[] localChars = this.chars;
+		char max = 0;
+		for (int i = localChars.length; i-- > 0; ) {
+			char c = localChars[i];
+			if (max < c) {
+				max = c;
+			}
+		}
+		return max;
+	}
+
+
+	// ********** API **********
+
+	/**
+	 * Return the specified string with any characters in the set
+	 * replaced with XML character references.
+	 */
+	public String encode(String s) {
+		int len = s.length();
+		// allow for a few encoded characters
+		StringBuffer sb = new StringBuffer(len + 20);
+		for (int i = 0; i < len; i++) {
+			this.appendCharacterTo(s.charAt(i), sb);
+		}
+		return sb.toString();
+	}
+
+	/**
+	 * Return the specified string with any XML character references
+	 * replaced by the characters themselves.
+	 */
+	public String decode(String s) {
+		StringBuffer sb = new StringBuffer(s.length());
+		StringBuffer temp = new StringBuffer();	// performance tweak
+		this.decodeTo(new StringReader(s), sb, temp);
+		return sb.toString();
+	}
+
+
+	// ********** internal methods **********
+
+	/**
+	 * Append the specified character to the string buffer,
+	 * converting it to an XML character reference if necessary.
+	 */
+	private void appendCharacterTo(char c, StringBuffer sb) {
+		if (this.charIsToBeEncoded(c)) {
+			this.appendCharacterReferenceTo(c, sb);
+		} else {
+			sb.append(c);
+		}
+	}
+
+	/**
+	 * Return whether the specified character is one of the characters
+	 * to be converted to XML character references.
+	 */
+	private boolean charIsToBeEncoded(char c) {
+		return (c <= this.maxChar) && CollectionTools.contains(this.chars, c);
+	}
+
+	/**
+	 * Append the specified character's XML character reference to the
+	 * specified string buffer (e.g. '/' => "&#x2f;").
+	 */
+	private void appendCharacterReferenceTo(char c, StringBuffer sb) {
+		sb.append("&#x");
+		sb.append(Integer.toString(c, 16));
+		sb.append(';');
+	}
+
+	private void decodeTo(Reader reader, StringBuffer sb, StringBuffer temp) {
+		try {
+			this.decodeTo_(reader, sb, temp);
+		} catch (IOException ex) {
+			throw new RuntimeException(ex);
+		}
+	}
+
+	private void decodeTo_(Reader reader, StringBuffer sb, StringBuffer temp) throws IOException {
+		int c = reader.read();
+		while (c != -1) {
+			if (c == '&') {
+				this.decodeCharacterReferenceTo(reader, sb, temp);
+			} else {
+				sb.append((char) c);
+			}
+			c = reader.read();
+		}
+		reader.close();
+	}
+
+	private void decodeCharacterReferenceTo(Reader reader, StringBuffer sb, StringBuffer temp) throws IOException {
+		int c = reader.read();
+		this.checkChar(c, '#');
+		c = reader.read();
+		this.checkChar(c, 'x');
+
+		temp.setLength(0);
+		c = reader.read();
+		while (c != ';') {
+			this.checkEndOfStream(c);
+			temp.append((char) c);
+			c = reader.read();
+		}
+		String charValue = temp.toString();
+		if (charValue.length() == 0) {
+			throw new IllegalStateException("missing numeric string");
+		}
+		sb.append((char) Integer.parseInt(charValue, 16));
+	}
+
+	private void checkChar(int c, int expected) {
+		this.checkEndOfStream(c);
+		if (c != expected) {
+			throw new IllegalStateException("expected '" + (char) expected + "', but encountered '" + (char) c + "'");
+		}
+	}
+
+	private void checkEndOfStream(int c) {
+		if (c == -1) {
+			throw new IllegalStateException("unexpected end of string");
+		}
+	}
+
+}