Java tutorial
/* * Copyright 2010 Google Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package com.google.web.bindery.autobean.gwt.client.impl; import com.google.web.bindery.autobean.shared.Splittable; import com.google.web.bindery.autobean.shared.impl.HasSplittable; import com.google.web.bindery.autobean.shared.impl.StringQuoter; import com.google.gwt.core.client.GwtScriptOnly; import com.google.gwt.core.client.JavaScriptObject; import com.google.gwt.core.client.JsonUtils; import java.util.ArrayList; import java.util.Collections; import java.util.List; /** * Implements the EntityCodex.Splittable interface using a raw JavaScriptObject. * <p> * A string value represented by a JsoSplittable can't use the string object * directly, since {@code String.prototype} is overridden, so instead a * temporary wrapper object is used to encapsulate the string data. */ @GwtScriptOnly public final class JsoSplittable extends JavaScriptObject implements Splittable, HasSplittable { private static boolean stringifyFastTested; private static boolean stringifyFastResult; public static native JsoSplittable create() /*-{ return {}; }-*/; public static Splittable create(boolean value) { return create0(value); } public static Splittable create(double value) { return create0(value); } public static Splittable create(String value) { return create0(value); } public static native JsoSplittable createIndexed() /*-{ return []; }-*/; public static native JsoSplittable nullValue() /*-{ return null; }-*/; private static native Splittable create0(boolean object) /*-{ return Boolean(object); }-*/; private static native Splittable create0(double object) /*-{ return Number(object); }-*/; private static native Splittable create0(String object) /*-{ return { __s : object }; }-*/; private static native boolean isUnwrappedString(JavaScriptObject obj) /*-{ return Object.prototype.toString.call(obj) == '[object String]'; }-*/; private static boolean stringifyFastSupported() { if (stringifyFastTested) { return stringifyFastResult; } stringifyFastTested = true; return stringifyFastResult = stringifyFastSupported0(); } /** * Test that the JSON api is available and that it does not add function * objects to the output. The test for function objects is for old versions of * Safari. */ private static native boolean stringifyFastSupported0() /*-{ return $wnd.JSON && $wnd.JSON.stringify && $wnd.JSON.stringify({ b : function() { } }) == '{}'; }-*/; protected JsoSplittable() { }; public native boolean asBoolean() /*-{ return this == true; }-*/; public native double asNumber() /*-{ return Number(this); }-*/; public void assign(Splittable parent, int index) { if (isString()) { assign0(parent, index, asString()); } else { assign0(parent, index, this); } } public void assign(Splittable parent, String index) { if (isString()) { assign0(parent, index, asString()); } else { assign0(parent, index, this); } } public native String asString() /*-{ return this.__s; }-*/; public Splittable deepCopy() { return StringQuoter.split(getPayload()); } public JsoSplittable get(int index) { return getRaw(index); } public JsoSplittable get(String key) { return getRaw(key); } public String getPayload() { if (isString()) { return JsonUtils.escapeValue(asString()); } if (stringifyFastSupported()) { return stringifyFast(); } return stringifySlow(); } public List<String> getPropertyKeys() { List<String> toReturn = new ArrayList<String>(); getPropertyKeys0(toReturn); return Collections.unmodifiableList(toReturn); } public native Object getReified(String key) /*-{ return this.__reified && this.__reified[':' + key]; }-*/; public Splittable getSplittable() { return this; } public native boolean isBoolean() /*-{ return Object.prototype.toString.call(this) == '[object Boolean]'; }-*/; public native boolean isFunction() /*-{ return Object.prototype.toString.call(this) == '[object Function]'; }-*/; public native boolean isIndexed() /*-{ return Object.prototype.toString.call(this) == '[object Array]'; }-*/; public boolean isKeyed() { return this != NULL && !isString() && !isIndexed() && !isFunction(); } public native boolean isNull(int index) /*-{ return this[index] == null; }-*/; public native boolean isNull(String key) /*-{ return this[key] == null; }-*/; public native boolean isNumber() /*-{ return Object.prototype.toString.call(this) == '[object Number]'; }-*/; public native boolean isReified(String key) /*-{ return !!(this.__reified && this.__reified.hasOwnProperty(':' + key)); }-*/; /** * Returns whether or not the current object is a string-carrier. */ public native boolean isString() /*-{ return this && this.__s != null; }-*/; public native boolean isUndefined(String key) /*-{ return this[key] === undefined; }-*/; public native void setReified(String key, Object object) /*-{ // Use a function object so native JSON.stringify will ignore (this.__reified || (this.__reified = function() { }))[':' + key] = object; }-*/; public native void setSize(int size) /*-{ this.length = size; }-*/; public native int size() /*-{ return this.length; }-*/; private native void assign0(Splittable parent, int index, Splittable value) /*-{ parent[index] = value; }-*/; private native void assign0(Splittable parent, int index, String value) /*-{ parent[index] = value; }-*/; private native void assign0(Splittable parent, String index, Splittable value) /*-{ parent[index] = value; }-*/; private native void assign0(Splittable parent, String index, String value) /*-{ parent[index] = value; }-*/; private native void getPropertyKeys0(List<String> list) /*-{ for (key in this) { if (this.hasOwnProperty(key)) { list.@java.util.List::add(Ljava/lang/Object;)(key); } } }-*/; private native JsoSplittable getRaw(int index) /*-{ _ = this[index]; if (_ == null) { return null; } if (@com.google.web.bindery.autobean.gwt.client.impl.JsoSplittable::isUnwrappedString(*)(_)) { return @com.google.web.bindery.autobean.gwt.client.impl.JsoSplittable::create(Ljava/lang/String;)(_); } return Object(_); }-*/; private native JsoSplittable getRaw(String index) /*-{ _ = this[index]; if (_ == null) { return null; } if (@com.google.web.bindery.autobean.gwt.client.impl.JsoSplittable::isUnwrappedString(*)(_)) { return @com.google.web.bindery.autobean.gwt.client.impl.JsoSplittable::create(Ljava/lang/String;)(_); } return Object(_); }-*/; /** * The test for {@code $H} removes the key in the emitted JSON, however making * a similar test for {@code __reified} causes the key to be emitted with an * explicit {@code null} value. */ private native String stringifyFast() /*-{ return $wnd.JSON.stringify(this, function(key, value) { if (key == "$H") { return; } return value; }); }-*/; private String stringifySlow() { StringBuilder sb = new StringBuilder(); stringifySlow(sb); return sb.toString(); } private void stringifySlow(StringBuilder sb) { if (this == NULL) { sb.append("null"); return; } if (isBoolean()) { sb.append(asBoolean()); return; } if (isNumber()) { sb.append(asNumber()); return; } if (isString()) { sb.append(JsonUtils.escapeValue(asString())); return; } if (isIndexed()) { sb.append("["); for (int i = 0, j = size(); i < j; i++) { if (i > 0) { sb.append(","); } get(i).stringifySlow(sb); } sb.append("]"); return; } sb.append("{"); boolean needsComma = false; for (String key : getPropertyKeys()) { if (needsComma) { sb.append(","); } else { needsComma = true; } JsoSplittable value = get(key); if (!value.isFunction()) { if ("$H".equals(key)) { // Ignore hashcode continue; } sb.append(JsonUtils.escapeValue(key)); sb.append(":"); value.stringifySlow(sb); } } sb.append("}"); } }