package be.nikiroo.utils.serial;
-public abstract class CustomSerializer {
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import be.nikiroo.utils.IOUtils;
+import be.nikiroo.utils.streams.NextableInputStream;
+import be.nikiroo.utils.streams.NextableInputStreamStep;
+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);
+ /**
+ * 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();
- public void encode(StringBuilder builder, Object value) {
- String customString = toString(value);
- builder.append("custom:").append(getType()).append(":");
- SerialUtils.encode(builder, customString);
+ /**
+ * Encode the object into the given {@link OutputStream}.
+ *
+ * @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);
+ }
}
- public Object decode(String encodedValue) {
- return fromString((String) SerialUtils.decode(contentOf(encodedValue)));
+ /**
+ * Decode the value back into the supported object type.
+ *
+ * @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 {
+ NextableInputStream stream = new NextableInputStream(
+ replace.open(), new NextableInputStreamStep('^'));
+ try {
+ if (!stream.next()) {
+ throw new IOException(
+ "Cannot find the first custom^ element");
+ }
+
+ String custom = IOUtils.readSmallStream(stream);
+ if (!"custom".equals(custom)) {
+ throw new IOException(
+ "Cannot find the first custom^ element, it is: "
+ + custom + "^");
+ }
+
+ if (!stream.next()) {
+ throw new IOException("Cannot find the second custom^"
+ + getType() + " element");
+ }
+
+ String type = IOUtils.readSmallStream(stream);
+ if (!getType().equals(type)) {
+ throw new IOException("Cannot find the second custom^"
+ + getType() + " element, it is: custom^" + type
+ + "^");
+ }
+
+ if (!stream.nextAll()) {
+ throw new IOException("Cannot find the third custom^"
+ + getType() + "^value element");
+ }
+
+ return fromStream(stream);
+ } finally {
+ stream.close();
+ }
+ } finally {
+ replace.close(false);
+ }
}
public static boolean isCustom(String encodedValue) {
- int pos1 = encodedValue.indexOf(':');
- int pos2 = encodedValue.indexOf(':', pos1 + 1);
+ int pos1 = encodedValue.indexOf('^');
+ int pos2 = encodedValue.indexOf('^', pos1 + 1);
- return pos1 >= 0 && pos2 >= 0 && encodedValue.startsWith("custom:");
+ return pos1 >= 0 && pos2 >= 0 && encodedValue.startsWith("custom^");
}
public static String typeOf(String encodedValue) {
- int pos1 = encodedValue.indexOf(':');
- int pos2 = encodedValue.indexOf(':', pos1 + 1);
+ int pos1 = encodedValue.indexOf('^');
+ int pos2 = encodedValue.indexOf('^', pos1 + 1);
String type = encodedValue.substring(pos1 + 1, pos2);
return type;
}
public static String contentOf(String encodedValue) {
- int pos1 = encodedValue.indexOf(':');
- int pos2 = encodedValue.indexOf(':', pos1 + 1);
+ int pos1 = encodedValue.indexOf('^');
+ int pos2 = encodedValue.indexOf('^', pos1 + 1);
String encodedContent = encodedValue.substring(pos2 + 1);
return encodedContent;
git://git.nikiroo.be / nikiroo-utils.git / blobdiff