+package be.nikiroo.utils.serial;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.NotSerializableException;
+import java.io.OutputStream;
+import java.lang.reflect.Array;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.UnknownFormatConversionException;
+
+import be.nikiroo.utils.IOUtils;
+import be.nikiroo.utils.Image;
+import be.nikiroo.utils.StringUtils;
+import be.nikiroo.utils.streams.Base64InputStream;
+import be.nikiroo.utils.streams.Base64OutputStream;
+import be.nikiroo.utils.streams.BufferedInputStream;
+import be.nikiroo.utils.streams.NextableInputStream;
+import be.nikiroo.utils.streams.NextableInputStreamStep;
+
+/**
+ * Small class to help with serialisation.
+ * <p>
+ * Note that we do not support inner classes (but we do support nested classes)
+ * and all objects require an empty constructor to be deserialised.
+ * <p>
+ * It is possible to add support to custom types (both the encoder and the
+ * decoder will require the custom classes) -- see {@link CustomSerializer}.
+ * <p>
+ * Default supported types are:
+ * <ul>
+ * <li>NULL (as a null value)</li>
+ * <li>String</li>
+ * <li>Boolean</li>
+ * <li>Byte</li>
+ * <li>Character</li>
+ * <li>Short</li>
+ * <li>Long</li>
+ * <li>Float</li>
+ * <li>Double</li>
+ * <li>Integer</li>
+ * <li>Enum (any enum whose name and value is known by the caller)</li>
+ * <li>java.awt.image.BufferedImage (as a {@link CustomSerializer})</li>
+ * <li>An array of the above (as a {@link CustomSerializer})</li>
+ * <li>URL</li>
+ * </ul>
+ *
+ * @author niki
+ */
+public class SerialUtils {
+ private static Map<String, CustomSerializer> customTypes;
+
+ static {
+ customTypes = new HashMap<String, CustomSerializer>();
+
+ // Array types:
+ customTypes.put("[]", new CustomSerializer() {
+ @Override
+ protected void toStream(OutputStream out, Object value)
+ throws IOException {
+
+ String type = value.getClass().getCanonicalName();
+ type = type.substring(0, type.length() - 2); // remove the []
+
+ write(out, type);
+ try {
+ for (int i = 0; true; i++) {
+ Object item = Array.get(value, i);
+
+ // encode it normally if direct value
+ write(out, "\r");
+ if (!SerialUtils.encode(out, item)) {
+ try {
+ write(out, "B64:");
+ OutputStream out64 = new Base64OutputStream(
+ out, true);
+ new Exporter(out64).append(item);
+ out64.flush();
+ } catch (NotSerializableException e) {
+ throw new UnknownFormatConversionException(e
+ .getMessage());
+ }
+ }
+ }
+ } catch (ArrayIndexOutOfBoundsException e) {
+ // Done.
+ }
+ }
+
+ @Override
+ protected Object fromStream(InputStream in) throws IOException {
+ NextableInputStream stream = new NextableInputStream(in,
+ new NextableInputStreamStep('\r'));
+
+ try {
+ List<Object> list = new ArrayList<Object>();
+ stream.next();
+ String type = IOUtils.readSmallStream(stream);
+
+ while (stream.next()) {
+ Object value = new Importer().read(stream).getValue();
+ list.add(value);
+ }
+
+ Object array = Array.newInstance(
+ SerialUtils.getClass(type), list.size());
+ for (int i = 0; i < list.size(); i++) {
+ Array.set(array, i, list.get(i));
+ }
+
+ return array;
+ } catch (Exception e) {
+ if (e instanceof IOException) {
+ throw (IOException) e;
+ }
+ throw new IOException(e.getMessage());
+ }
+ }
+
+ @Override
+ protected String getType() {
+ return "[]";
+ }
+ });
+
+ // URL:
+ customTypes.put("java.net.URL", new CustomSerializer() {
+ @Override
+ protected void toStream(OutputStream out, Object value)
+ throws IOException {
+ String val = "";
+ if (value != null) {
+ val = ((URL) value).toString();
+ }
+
+ out.write(StringUtils.getBytes(val));
+ }
+
+ @Override
+ protected Object fromStream(InputStream in) throws IOException {
+ String val = IOUtils.readSmallStream(in);
+ if (!val.isEmpty()) {
+ return new URL(val);
+ }
+
+ return null;
+ }
+
+ @Override
+ protected String getType() {
+ return "java.net.URL";
+ }
+ });
+
+ // Images (this is currently the only supported image type by default)
+ customTypes.put("be.nikiroo.utils.Image", new CustomSerializer() {
+ @Override
+ protected void toStream(OutputStream out, Object value)
+ throws IOException {
+ Image img = (Image) value;
+ OutputStream encoded = new Base64OutputStream(out, true);
+ try {
+ InputStream in = img.newInputStream();
+ try {
+ IOUtils.write(in, encoded);
+ } finally {
+ in.close();
+ }
+ } finally {
+ encoded.flush();
+ // Cannot close!
+ }
+ }
+
+ @Override
+ protected String getType() {
+ return "be.nikiroo.utils.Image";
+ }
+
+ @Override
+ protected Object fromStream(InputStream in) throws IOException {
+ try {
+ // Cannot close it!
+ InputStream decoded = new Base64InputStream(in, false);
+ return new Image(decoded);
+ } catch (IOException e) {
+ throw new UnknownFormatConversionException(e.getMessage());
+ }
+ }
+ });
+ }
+
+ /**
+ * Create an empty object of the given type.
+ *
+ * @param type
+ * the object type (its class name)
+ *
+ * @return the new object
+ *
+ * @throws ClassNotFoundException
+ * if the class cannot be found
+ * @throws NoSuchMethodException
+ * if the given class is not compatible with this code
+ */
+ public static Object createObject(String type)
+ throws ClassNotFoundException, NoSuchMethodException {
+
+ String desc = null;
+ try {
+ Class<?> clazz = getClass(type);
+ String className = clazz.getName();
+ List<Object> args = new ArrayList<Object>();
+ List<Class<?>> classes = new ArrayList<Class<?>>();
+ Constructor<?> ctor = null;
+ if (className.contains("$")) {
+ for (String parentName = className.substring(0,
+ className.lastIndexOf('$'));; parentName = parentName
+ .substring(0, parentName.lastIndexOf('$'))) {
+ Object parent = createObject(parentName);
+ args.add(parent);
+ classes.add(parent.getClass());
+
+ if (!parentName.contains("$")) {
+ break;
+ }
+ }
+
+ // Better error description in case there is no empty
+ // constructor:
+ desc = "";
+ String end = "";
+ for (Class<?> parent = clazz; parent != null
+ && !parent.equals(Object.class); parent = parent
+ .getSuperclass()) {
+ if (!desc.isEmpty()) {
+ desc += " [:";
+ end += "]";
+ }
+ desc += parent;
+ }
+ desc += end;
+ //
+
+ try {
+ ctor = clazz.getDeclaredConstructor(classes
+ .toArray(new Class[] {}));
+ } catch (NoSuchMethodException nsme) {
+ // TODO: it seems we do not always need a parameter for each
+ // level, so we currently try "ALL" levels or "FIRST" level
+ // only -> we should check the actual rule and use it
+ ctor = clazz.getDeclaredConstructor(classes.get(0));
+ Object firstParent = args.get(0);
+ args.clear();
+ args.add(firstParent);
+ }
+ desc = null;
+ } else {
+ ctor = clazz.getDeclaredConstructor();
+ }
+
+ ctor.setAccessible(true);
+ return ctor.newInstance(args.toArray());
+ } catch (ClassNotFoundException e) {
+ throw e;
+ } catch (NoSuchMethodException e) {
+ if (desc != null) {
+ throw new NoSuchMethodException("Empty constructor not found: "
+ + desc);
+ }
+ throw e;
+ } catch (Exception e) {
+ throw new NoSuchMethodException("Cannot instantiate: " + type);
+ }
+ }
+
+ /**
+ * Insert a custom serialiser that will take precedence over the default one
+ * or the target class.
+ *
+ * @param serializer
+ * the custom serialiser
+ */
+ static public void addCustomSerializer(CustomSerializer serializer) {
+ customTypes.put(serializer.getType(), serializer);
+ }
+
+ /**
+ * Serialise the given object into this {@link OutputStream}.
+ * <p>
+ * <b>Important: </b>If the operation fails (with a
+ * {@link NotSerializableException}), the {@link StringBuilder} will be
+ * corrupted (will contain bad, most probably not importable data).
+ *
+ * @param out
+ * the output {@link OutputStream} to serialise to
+ * @param o
+ * the object to serialise
+ * @param map
+ * the map of already serialised objects (if the given object or
+ * one of its descendant is already present in it, only an ID
+ * will be serialised)
+ *
+ * @throws NotSerializableException
+ * if the object cannot be serialised (in this case, the
+ * {@link StringBuilder} can contain bad, most probably not
+ * importable data)
+ * @throws IOException
+ * in case of I/O errors
+ */
+ static void append(OutputStream out, Object o, Map<Integer, Object> map)
+ throws NotSerializableException, IOException {
+
+ Field[] fields = new Field[] {};
+ String type = "";
+ String id = "NULL";
+
+ if (o != null) {
+ int hash = System.identityHashCode(o);
+ fields = o.getClass().getDeclaredFields();
+ type = o.getClass().getCanonicalName();
+ if (type == null) {
+ // Anonymous inner classes support
+ type = o.getClass().getName();
+ }
+ id = Integer.toString(hash);
+ if (map.containsKey(hash)) {
+ fields = new Field[] {};
+ } else {
+ map.put(hash, o);
+ }
+ }
+
+ write(out, "{\nREF ");
+ write(out, type);
+ write(out, "@");
+ write(out, id);
+ write(out, ":");
+
+ if (!encode(out, o)) { // check if direct value
+ try {
+ for (Field field : fields) {
+ field.setAccessible(true);
+
+ if (field.getName().startsWith("this$")
+ || field.isSynthetic()
+ || (field.getModifiers() & Modifier.STATIC) == Modifier.STATIC) {
+ // Do not keep this links of nested classes
+ // Do not keep synthetic fields
+ // Do not keep final fields
+ continue;
+ }
+
+ write(out, "\n^");
+ write(out, field.getName());
+ write(out, ":");
+
+ Object value = field.get(o);
+
+ if (!encode(out, value)) {
+ write(out, "\n");
+ append(out, value, map);
+ }
+ }
+ } catch (IllegalArgumentException e) {
+ e.printStackTrace(); // should not happen (see
+ // setAccessible)
+ } catch (IllegalAccessException e) {
+ e.printStackTrace(); // should not happen (see
+ // setAccessible)
+ }
+
+ write(out, "\n}");
+ }
+ }
+
+ /**
+ * Encode the object into the given {@link OutputStream} if possible and if
+ * supported.
+ * <p>
+ * A supported object in this context means an object we can directly
+ * encode, like an Integer or a String. Custom objects and arrays are also
+ * considered supported, but <b>compound objects are not supported here</b>.
+ * <p>
+ * For compound objects, you should use {@link Exporter}.
+ *
+ * @param out
+ * the {@link OutputStream} to append to
+ * @param value
+ * the object to encode (can be NULL, which will be encoded)
+ *
+ * @return TRUE if success, FALSE if not (the content of the
+ * {@link OutputStream} won't be changed in case of failure)
+ *
+ * @throws IOException
+ * in case of I/O error
+ */
+ static boolean encode(OutputStream out, Object value) throws IOException {
+ if (value == null) {
+ write(out, "NULL");
+ } else if (value.getClass().getSimpleName().endsWith("[]")) {
+ // Simple name does support [] suffix and do not return NULL for
+ // inner anonymous classes
+ customTypes.get("[]").encode(out, value);
+ } else if (customTypes.containsKey(value.getClass().getCanonicalName())) {
+ customTypes.get(value.getClass().getCanonicalName())//
+ .encode(out, value);
+ } else if (value instanceof String) {
+ encodeString(out, (String) value);
+ } else if (value instanceof Boolean) {
+ write(out, value);
+ } else if (value instanceof Byte) {
+ write(out, "b");
+ write(out, value);
+ } else if (value instanceof Character) {
+ write(out, "c");
+ encodeString(out, "" + value);
+ } else if (value instanceof Short) {
+ write(out, "s");
+ write(out, value);
+ } else if (value instanceof Integer) {
+ write(out, "i");
+ write(out, value);
+ } else if (value instanceof Long) {
+ write(out, "l");
+ write(out, value);
+ } else if (value instanceof Float) {
+ write(out, "f");
+ write(out, value);
+ } else if (value instanceof Double) {
+ write(out, "d");
+ write(out, value);
+ } else if (value instanceof Enum) {
+ write(out, "E:");
+ String type = value.getClass().getCanonicalName();
+ write(out, type);
+ write(out, ".");
+ write(out, ((Enum<?>) value).name());
+ write(out, ";");
+ } else {
+ return false;
+ }
+
+ return true;
+ }
+
+ static boolean isDirectValue(BufferedInputStream encodedValue)
+ throws IOException {
+ if (CustomSerializer.isCustom(encodedValue)) {
+ return false;
+ }
+
+ for (String fullValue : new String[] { "NULL", "null", "true", "false" }) {
+ if (encodedValue.is(fullValue)) {
+ return true;
+ }
+ }
+
+ for (String prefix : new String[] { "c\"", "\"", "b", "s", "i", "l",
+ "f", "d", "E:" }) {
+ if (encodedValue.startsWith(prefix)) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ /**
+ * Decode the data into an equivalent supported source object.
+ * <p>
+ * A supported object in this context means an object we can directly
+ * encode, like an Integer or a String (see
+ * {@link SerialUtils#decode(String)}.
+ * <p>
+ * Custom objects and arrays are also considered supported here, but
+ * <b>compound objects are not</b>.
+ * <p>
+ * For compound objects, you should use {@link Importer}.
+ *
+ * @param encodedValue
+ * the encoded data, cannot be NULL
+ *
+ * @return the object (can be NULL for NULL encoded values)
+ *
+ * @throws IOException
+ * if the content cannot be converted
+ */
+ static Object decode(BufferedInputStream encodedValue) throws IOException {
+ if (CustomSerializer.isCustom(encodedValue)) {
+ // custom^TYPE^ENCODED_VALUE
+ NextableInputStream content = new NextableInputStream(encodedValue,
+ new NextableInputStreamStep('^'));
+ try {
+ content.next();
+ @SuppressWarnings("unused")
+ String custom = IOUtils.readSmallStream(content);
+ content.next();
+ String type = IOUtils.readSmallStream(content);
+ content.nextAll();
+ if (customTypes.containsKey(type)) {
+ return customTypes.get(type).decode(content);
+ }
+ content.end();
+ throw new IOException("Unknown custom type: " + type);
+ } finally {
+ content.close(false);
+ encodedValue.end();
+ }
+ }
+
+ String encodedString = IOUtils.readSmallStream(encodedValue);
+ return decode(encodedString);
+ }
+
+ /**
+ * Decode the data into an equivalent supported source object.
+ * <p>
+ * A supported object in this context means an object we can directly
+ * encode, like an Integer or a String.
+ * <p>
+ * For custom objects and arrays, you should use
+ * {@link SerialUtils#decode(InputStream)} or directly {@link Importer}.
+ * <p>
+ * For compound objects, you should use {@link Importer}.
+ *
+ * @param encodedValue
+ * the encoded data, cannot be NULL
+ *
+ * @return the object (can be NULL for NULL encoded values)
+ *
+ * @throws IOException
+ * if the content cannot be converted
+ */
+ static Object decode(String encodedValue) throws IOException {
+ try {
+ String cut = "";
+ if (encodedValue.length() > 1) {
+ cut = encodedValue.substring(1);
+ }
+
+ if (encodedValue.equals("NULL") || encodedValue.equals("null")) {
+ return null;
+ } else if (encodedValue.startsWith("\"")) {
+ return decodeString(encodedValue);
+ } else if (encodedValue.equals("true")) {
+ return true;
+ } else if (encodedValue.equals("false")) {
+ return false;
+ } else if (encodedValue.startsWith("b")) {
+ return Byte.parseByte(cut);
+ } else if (encodedValue.startsWith("c")) {
+ return decodeString(cut).charAt(0);
+ } else if (encodedValue.startsWith("s")) {
+ return Short.parseShort(cut);
+ } else if (encodedValue.startsWith("l")) {
+ return Long.parseLong(cut);
+ } else if (encodedValue.startsWith("f")) {
+ return Float.parseFloat(cut);
+ } else if (encodedValue.startsWith("d")) {
+ return Double.parseDouble(cut);
+ } else if (encodedValue.startsWith("i")) {
+ return Integer.parseInt(cut);
+ } else if (encodedValue.startsWith("E:")) {
+ cut = cut.substring(1);
+ return decodeEnum(cut);
+ } else {
+ throw new IOException("Unrecognized value: " + encodedValue);
+ }
+ } catch (Exception e) {
+ if (e instanceof IOException) {
+ throw (IOException) e;
+ }
+ throw new IOException(e.getMessage(), e);
+ }
+ }
+
+ /**
+ * Write the given {@link String} into the given {@link OutputStream} in
+ * UTF-8.
+ *
+ * @param out
+ * the {@link OutputStream}
+ * @param data
+ * the data to write, cannot be NULL
+ *
+ * @throws IOException
+ * in case of I/O error
+ */
+ static void write(OutputStream out, Object data) throws IOException {
+ out.write(StringUtils.getBytes(data.toString()));
+ }
+
+ /**
+ * Return the corresponding class or throw an {@link Exception} if it
+ * cannot.
+ *
+ * @param type
+ * the class name to look for
+ *
+ * @return the class (will never be NULL)
+ *
+ * @throws ClassNotFoundException
+ * if the class cannot be found
+ * @throws NoSuchMethodException
+ * if the class cannot be created (usually because it or its
+ * enclosing class doesn't have an empty constructor)
+ */
+ static private Class<?> getClass(String type)
+ throws ClassNotFoundException, NoSuchMethodException {
+ Class<?> clazz = null;
+ try {
+ clazz = Class.forName(type);
+ } catch (ClassNotFoundException e) {
+ int pos = type.length();
+ pos = type.lastIndexOf(".", pos);
+ if (pos >= 0) {
+ String parentType = type.substring(0, pos);
+ String nestedType = type.substring(pos + 1);
+ Class<?> javaParent = null;
+ try {
+ javaParent = getClass(parentType);
+ parentType = javaParent.getName();
+ clazz = Class.forName(parentType + "$" + nestedType);
+ } catch (Exception ee) {
+ }
+
+ if (javaParent == null) {
+ throw new NoSuchMethodException(
+ "Class not found: "
+ + type
+ + " (the enclosing class cannot be created: maybe it doesn't have an empty constructor?)");
+ }
+ }
+ }
+
+ if (clazz == null) {
+ throw new ClassNotFoundException("Class not found: " + type);
+ }
+
+ return clazz;
+ }
+
+ @SuppressWarnings({ "unchecked", "rawtypes" })
+ static private Enum<?> decodeEnum(String escaped) {
+ // escaped: be.xxx.EnumType.VALUE;
+ int pos = escaped.lastIndexOf(".");
+ String type = escaped.substring(0, pos);
+ String name = escaped.substring(pos + 1, escaped.length() - 1);
+
+ try {
+ return Enum.valueOf((Class<Enum>) getClass(type), name);
+ } catch (Exception e) {
+ throw new UnknownFormatConversionException("Unknown enum: <" + type
+ + "> " + name);
+ }
+ }
+
+ // aa bb -> "aa\tbb"
+ static void encodeString(OutputStream out, String raw) throws IOException {
+ // TODO: not. efficient.
+ out.write('\"');
+ for (char car : raw.toCharArray()) {
+ encodeString(out, car);
+ }
+ out.write('\"');
+ }
+
+ // for encoding string, NOT to encode a char by itself!
+ static void encodeString(OutputStream out, char raw) throws IOException {
+ switch (raw) {
+ case '\\':
+ out.write('\\');
+ out.write('\\');
+ break;
+ case '\r':
+ out.write('\\');
+ out.write('r');
+ break;
+ case '\n':
+ out.write('\\');
+ out.write('n');
+ break;
+ case '"':
+ out.write('\\');
+ out.write('\"');
+ break;
+ default:
+ out.write(raw);
+ break;
+ }
+ }
+
+ // "aa\tbb" -> aa bb
+ static String decodeString(String escaped) {
+ StringBuilder builder = new StringBuilder();
+
+ boolean escaping = false;
+ for (char car : escaped.toCharArray()) {
+ if (!escaping) {
+ if (car == '\\') {
+ escaping = true;
+ } else {
+ builder.append(car);
+ }
+ } else {
+ switch (car) {
+ case '\\':
+ builder.append('\\');
+ break;
+ case 'r':
+ builder.append('\r');
+ break;
+ case 'n':
+ builder.append('\n');
+ break;
+ case '"':
+ builder.append('"');
+ break;
+ }
+ escaping = false;
+ }
+ }
+
+ return builder.substring(1, builder.length() - 1);
+ }
+}