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.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} 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 out
* the builder to append to
}
}
+ /**
+ * 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 {
- 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();
- }
+ return fromStream(replace);
} finally {
replace.close(false);
}
}
- public static boolean isCustom(String encodedValue) {
- int pos1 = encodedValue.indexOf('^');
- int pos2 = encodedValue.indexOf('^', pos1 + 1);
-
- 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;
- }
}
git://git.nikiroo.be / fanfix.git / blobdiff