X-Git-Url: http://git.nikiroo.be/?p=fanfix.git;a=blobdiff_plain;f=src%2Fbe%2Fnikiroo%2Futils%2Fserial%2FCustomSerializer.java;fp=src%2Fbe%2Fnikiroo%2Futils%2Fserial%2FCustomSerializer.java;h=e58ccf2af5945eab2ba4b508bd9d04c9213c56f1;hp=0000000000000000000000000000000000000000;hb=d46b7b96f94e88a776bcd2dfd756549ffb300cc9;hpb=c9994f27667bc421bcd448d39e55774fddf5c431

diff --git a/src/be/nikiroo/utils/serial/CustomSerializer.java b/src/be/nikiroo/utils/serial/CustomSerializer.java
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+++ b/src/be/nikiroo/utils/serial/CustomSerializer.java
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+package be.nikiroo.utils.serial;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import be.nikiroo.utils.streams.BufferedInputStream;
+import be.nikiroo.utils.streams.ReplaceInputStream;
+import be.nikiroo.utils.streams.ReplaceOutputStream;
+
+/**
+ * A {@link CustomSerializer} supports and generates values in the form:
+ * <ul>
+ * <li><tt>custom^<i>TYPE</i>^<i>ENCODED_VALUE</i></tt></li>
+ * </ul>
+ * <p>
+ * In this scheme, the values are:
+ * <ul>
+ * <li><tt>custom</tt>: a fixed keyword</li>
+ * <li><tt>^</tt>: a fixed separator character (the
+ * <tt><i>ENCODED_VALUE</i></tt> can still use it inside its content, though</li>
+ * <li><tt><i>TYPE</i></tt>: the object type of this value</li>
+ * <li><tt><i>ENCODED_VALUE</i></tt>: the custom encoded value</li>
+ * </ul>
+ * <p>
+ * To create a new {@link CustomSerializer}, you are expected to implement the
+ * abstract methods of this class. The rest should be taken care of bythe
+ * system.
+ * 
+ * @author niki
+ */
+public abstract class CustomSerializer {
+	/**
+	 * Generate the custom <tt><i>ENCODED_VALUE</i></tt> from this
+	 * <tt>value</tt>.
+	 * <p>
+	 * The <tt>value</tt> will always be of the supported type.
+	 * 
+	 * @param out
+	 *            the {@link OutputStream} to write the value to
+	 * @param value
+	 *            the value to serialize
+	 * 
+	 * @throws IOException
+	 *             in case of I/O error
+	 */
+	protected abstract void toStream(OutputStream out, Object value)
+			throws IOException;
+
+	/**
+	 * Regenerate the value from the custom <tt><i>ENCODED_VALUE</i></tt>.
+	 * <p>
+	 * The value in the {@link InputStream} <tt>in</tt> will always be of the
+	 * supported type.
+	 * 
+	 * @param in
+	 *            the {@link InputStream} containing the
+	 *            <tt><i>ENCODED_VALUE</i></tt>
+	 * 
+	 * @return the regenerated object
+	 * 
+	 * @throws IOException
+	 *             in case of I/O error
+	 */
+	protected abstract Object fromStream(InputStream in) throws IOException;
+
+	/**
+	 * Return the supported type name.
+	 * <p>
+	 * It <b>must</b> be the name returned by {@link Object#getClass()
+	 * #getCanonicalName()}.
+	 * 
+	 * @return the supported class name
+	 */
+	protected abstract String getType();
+
+	/**
+	 * Encode the object into the given {@link OutputStream}, i.e., generate the
+	 * <tt><i>ENCODED_VALUE</i></tt> part.
+	 * <p>
+	 * Use whatever scheme you wish, the system shall ensure that the content is
+	 * correctly encoded and that you will receive the same content at decode
+	 * time.
+	 * 
+	 * @param out
+	 *            the builder to append to
+	 * @param value
+	 *            the object to encode
+	 * 
+	 * @throws IOException
+	 *             in case of I/O error
+	 */
+	public void encode(OutputStream out, Object value) throws IOException {
+		ReplaceOutputStream replace = new ReplaceOutputStream(out, //
+				new String[] { "\\", "\n" }, //
+				new String[] { "\\\\", "\\n" });
+
+		try {
+			SerialUtils.write(replace, "custom^");
+			SerialUtils.write(replace, getType());
+			SerialUtils.write(replace, "^");
+			toStream(replace, value);
+		} finally {
+			replace.close(false);
+		}
+	}
+
+	/**
+	 * Decode the value back into the supported object type.
+	 * <p>
+	 * We do <b>not</b> expect the full content here but only:
+	 * <ul>
+	 * <li>ENCODED_VALUE
+	 * <li>
+	 * </ul>
+	 * That is, we do not expect the "<tt>custom</tt>^<tt><i>TYPE</i></tt>^"
+	 * part.
+	 * 
+	 * @param in
+	 *            the encoded value
+	 * 
+	 * @return the object
+	 * 
+	 * @throws IOException
+	 *             in case of I/O error
+	 */
+	public Object decode(InputStream in) throws IOException {
+		ReplaceInputStream replace = new ReplaceInputStream(in, //
+				new String[] { "\\\\", "\\n" }, //
+				new String[] { "\\", "\n" });
+
+		try {
+			return fromStream(replace);
+		} finally {
+			replace.close(false);
+		}
+	}
+
+	public static boolean isCustom(BufferedInputStream in) throws IOException {
+		return in.startsWith("custom^");
+	}
+
+	public static String typeOf(String encodedValue) {
+		int pos1 = encodedValue.indexOf('^');
+		int pos2 = encodedValue.indexOf('^', pos1 + 1);
+		String type = encodedValue.substring(pos1 + 1, pos2);
+
+		return type;
+	}
+}