GWT Datastore Key and Text supersource for App Engine

Key.java

package com.google.appengine.api.datastore;

import java.io.Serializable;
import java.util.Iterator;
import java.util.LinkedList;

public final class Key implements Serializable, Comparable<Key> {
  static final long serialVersionUID = -448150158203091507L;

  private Key parentKey;
  private String kind;
  private long id;
  private String name;

  @SuppressWarnings("unused")
  private Key() {
    parentKey = null;
    kind = null;
    id = 0;
    name = null;
  }

  Key(String kind, String name) {
    this(kind, null, name);
  }

  Key(String kind, Key parentKey) {
    this(kind, parentKey, 0);
  }

  Key(String kind, Key parentKey, long id) {
    this(kind, parentKey, id, null);
  }

  Key(String kind, Key parentKey, String name) {
    this(kind, parentKey, 0, name);
  }

  Key(String kind, Key parentKey, long id, String name) {
    if (kind == null || kind.length() == 0) throw new IllegalArgumentException("No kind specified.");
    if (name != null) {
      if (name.length() == 0) throw new IllegalArgumentException("Name may not be empty.");
      if (id != 0) throw new IllegalArgumentException("Id and name may not both be specified at once.");
    }
    this.name = name;
    this.id = id;
    this.parentKey = parentKey;
    this.kind = kind;
  }

  public String getKind() {
    return kind;
  }

  public Key getParent() {
    return parentKey;
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;

    Key key = (Key) o;

    if (id != key.id) return false;
    if (!kind.equals(key.kind)) return false;
    if (name != null ? !name.equals(key.name) : key.name != null) return false;
    if (parentKey != null ? !parentKey.equals(key.parentKey) : key.parentKey != null) return false;

    return true;
  }

  @Override
  public int hashCode() {
    int result = parentKey != null ? parentKey.hashCode() : 0;
    result = 31 * result + kind.hashCode();
    result = 31 * result + (int) (id ^ (id >>> 32));
    result = 31 * result + (name != null ? name.hashCode() : 0);
    return result;
  }

  public String toString() {
    StringBuilder buffer = new StringBuilder();
    appendToString(buffer);
    return buffer.toString();
  }

  private void appendToString(StringBuilder buffer) {
    if (parentKey != null) {
      parentKey.appendToString(buffer);
      buffer.append("/");
    }
    buffer.append(kind);
    buffer.append("(");
    if (name != null)
      buffer.append('"').append(name).append('"');
    else
      buffer.append(id);
    buffer.append(")");
  }

  public long getId() {
    return id;
  }

  public String getName() {
    return name;
  }

  public Key getChild(String kind, long id) {
    return new Key(kind, this, id);
  }

  public Key getChild(String kind, String name) {
    return new Key(kind, this, name);
  }

  private static Iterator<Key> getPathIterator(Key key) {
    LinkedList<Key> stack = new LinkedList<Key>();
    do {
      stack.addFirst(key);
      key = key.getParent();
    } while (key != null);

    return stack.iterator();
  }

  public int compareTo(Key other) {
    if (this == other) return 0;
    Iterator<Key> thisPath = getPathIterator(this);
    Iterator<Key> otherPath = getPathIterator(other);
    while (thisPath.hasNext()) {
      Key thisKey = (Key) thisPath.next();
      if (otherPath.hasNext()) {
        Key otherKey = (Key) otherPath.next();
        int result = compareToInternal(thisKey, otherKey);
        if (result != 0) return result;
      } else {
        return 1;
      }
    }
    return otherPath.hasNext() ? -1 : 0;
  }

  private static int compareToInternal(Key thisKey, Key otherKey) {
    if (thisKey == otherKey) return 0;
    int result = thisKey.getKind().compareTo(otherKey.getKind());
    if (result != 0) return result;
    if (thisKey.getId() != 0) if (otherKey.getId() == 0)
      return -1;
    else
      return Long.valueOf(thisKey.getId()).compareTo(Long.valueOf(otherKey.getId()));
    if (otherKey.getId() != 0)
      return 1;
    else
      return thisKey.getName().compareTo(otherKey.getName());
  }
}

Key_CustomFieldSerializer.java

package com.google.gwt.user.client.rpc.core.com.google.appengine.api.datastore;

import com.google.appengine.api.datastore.Key;
import com.google.appengine.api.datastore.KeyFactory;
import com.google.gwt.user.client.rpc.CustomFieldSerializer;
import com.google.gwt.user.client.rpc.SerializationException;
import com.google.gwt.user.client.rpc.SerializationStreamReader;
import com.google.gwt.user.client.rpc.SerializationStreamWriter;

public class Key_CustomFieldSerializer extends CustomFieldSerializer<Key> {

  public static void deserialize(SerializationStreamReader streamReader, Key instance) {
  }

  public static Key instantiate(SerializationStreamReader streamReader) throws SerializationException {
    Key parent = (Key) streamReader.readObject();
    String kind = streamReader.readString();
    long id = streamReader.readLong();
    String name = streamReader.readString();

    if (name == null) {
      return KeyFactory.createKey(parent, kind, id);
    } else {
      return KeyFactory.createKey(parent, kind, name);
    }
  }

  public static void serialize(SerializationStreamWriter streamWriter, Key instance) throws SerializationException {
    streamWriter.writeObject(instance.getParent());
    streamWriter.writeString(instance.getKind());
    streamWriter.writeLong(instance.getId());
    streamWriter.writeString(instance.getName());
  }

  @Override
  public boolean hasCustomInstantiateInstance() {
    return true;
  }

  public Key instantiateInstance(SerializationStreamReader streamReader) throws SerializationException {
    return instantiate(streamReader);
  }

  @Override
  public void deserializeInstance(SerializationStreamReader streamReader, Key instance) throws SerializationException {
    deserialize(streamReader, instance);
  }

  @Override
  public void serializeInstance(SerializationStreamWriter streamWriter, Key instance) throws SerializationException {
    serialize(streamWriter, instance);
  }

}

KeyFactory.java

package com.google.appengine.api.datastore;

/**
 * GWT emulation class, with most of the methods from KeyFactory. Does not support the keyToString()/stringToKey()
 * methods.
 */
public class KeyFactory {
  public static final class Builder {
    public Builder addChild(String kind, String name) {
      current = KeyFactory.createKey(current, kind, name);
      return this;
    }

    public Builder addChild(String kind, long id) {
      current = KeyFactory.createKey(current, kind, id);
      return this;
    }

    public Key getKey() {
      return current;
    }

    private Key current;

    public Builder(String kind, String name) {
      current = KeyFactory.createKey(null, kind, name);
    }

    public Builder(String kind, long id) {
      current = KeyFactory.createKey(null, kind, id);
    }

    public Builder(Key key) {
      current = key;
    }
  }

  public static Key createKey(String kind, long id) {
    return createKey(null, kind, id);
  }

  public static Key createKey(Key parent, String kind, long id) {
    if (id == 0L)
      throw new IllegalArgumentException("id cannot be zero");
    else
      return new Key(kind, parent, id);
  }

  public static Key createKey(String kind, String name) {
    return createKey(null, kind, name);
  }

  public static Key createKey(Key parent, String kind, String name) {
    if (name == null || name.length() == 0)
      throw new IllegalArgumentException("name cannot be null or empty");
    else
      return new Key(kind, parent, name);
  }

  private KeyFactory() {
  }

}

project.gwt.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE module PUBLIC "-//Google Inc.//DTD Google Web Toolkit 2.7.0//EN"
  "http://gwtproject.org/doctype/2.7.0/gwt-module.dtd">
<module rename-to='WrightwayEconomy'>

    <!-- Add this to point to the super source directory -->
    <super-source path="gwtsupersource" />

    
</module>

Text.java

package com.google.appengine.api.datastore;

import java.io.Serializable;

/**
 * GWT emulation class.
 */
@SuppressWarnings("serial")
public class Text implements Serializable {
  private final String value;

  public Text(String value) {
    this.value = value;
  }

  public String getValue() {
    return value;
  }

  public int hashCode() {
    return value.hashCode();
  }

  public boolean equals(Object object) {
    if (object instanceof Text) {
      Text key = (Text) object;
      return value.equals(key.value);
    } else {
      return false;
    }
  }

  public String toString() {
    String text = value;
    if (text.length() > 70) text = text.substring(0, 70) + "...";

    return "<Text: " + text + ">";
  }
  
}

Text_CustomFieldSerializer.java

package com.google.gwt.user.client.rpc.core.com.google.appengine.api.datastore;

import com.google.appengine.api.datastore.Text;
import com.google.gwt.user.client.rpc.SerializationException;
import com.google.gwt.user.client.rpc.SerializationStreamReader;
import com.google.gwt.user.client.rpc.SerializationStreamWriter;

public class Text_CustomFieldSerializer {
  
  public static void deserialize(SerializationStreamReader streamReader, Text instance) throws SerializationException {
    // already handled in instantiate
  }

  public static Text instantiate(SerializationStreamReader streamReader) throws SerializationException {
    return new Text(streamReader.readString());
  }

  public static void serialize(SerializationStreamWriter streamWriter, Text instance) throws SerializationException {
    streamWriter.writeString(instance.getValue());
  }
  
}