package be.nikiroo.utils.serial;
import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
-public abstract class CustomSerializer {
+import be.nikiroo.utils.streams.BufferedInputStream;
+import be.nikiroo.utils.streams.ReplaceInputStream;
+import be.nikiroo.utils.streams.ReplaceOutputStream;
- protected abstract String toString(Object value);
+/**
+ * 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;
- protected abstract Object fromString(String content) 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 builder if possible (if supported).
+ * 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 builder
+ * @param out
* the builder to append to
* @param value
* the object to encode
- * @return TRUE if success, FALSE if not (the content of the builder won't
- * be changed in case of failure)
+ *
+ * @throws IOException
+ * in case of I/O error
*/
- public boolean encode(StringBuilder builder, Object value) {
- int prev = builder.length();
- String customString = toString(value);
- builder.append("custom^").append(getType()).append("^");
- if (!SerialUtils.encode(builder, customString)) {
- builder.delete(prev, builder.length());
- return false;
- }
+ public void encode(OutputStream out, Object value) throws IOException {
+ ReplaceOutputStream replace = new ReplaceOutputStream(out, //
+ new String[] { "\\", "\n" }, //
+ new String[] { "\\\\", "\\n" });
- return true;
+ try {
+ SerialUtils.write(replace, "custom^");
+ SerialUtils.write(replace, getType());
+ SerialUtils.write(replace, "^");
+ toStream(replace, value);
+ } finally {
+ replace.close(false);
+ }
}
- public Object decode(String encodedValue) throws IOException {
- return fromString((String) SerialUtils.decode(contentOf(encodedValue)));
- }
+ /**
+ * 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" });
- public static boolean isCustom(String encodedValue) {
- int pos1 = encodedValue.indexOf('^');
- int pos2 = encodedValue.indexOf('^', pos1 + 1);
+ try {
+ return fromStream(replace);
+ } finally {
+ replace.close(false);
+ }
+ }
- return pos1 >= 0 && pos2 >= 0 && encodedValue.startsWith("custom^");
+ public static boolean isCustom(BufferedInputStream in) throws IOException {
+ return in.startsWith("custom^");
}
public static String typeOf(String encodedValue) {
return type;
}
-
- public static String contentOf(String encodedValue) {
- int pos1 = encodedValue.indexOf('^');
- int pos2 = encodedValue.indexOf('^', pos1 + 1);
- String encodedContent = encodedValue.substring(pos2 + 1);
-
- return encodedContent;
- }
}