我正在尝试使用GWT开发基于Web客户端的在线游戏。
游戏机制现在工作得非常好，我真的想继续我的开发计划中的下一步，但现在我坚持使用我为客户端存储数据而创建的简单编码/解码功能变成一个字符串。
我采取的步骤并不复杂。在运行时，我的服务器创建游戏对象的“ImageStates”，以便在我的客户端上的Canvas上绘制。每个ImageState都包含许多图层，其中包含必须在特定时间等处绘制的内容的详细信息。
我尝试了ObjectInput / OutputStream，结合了GZip-Compression和ByteInputStreams，但是我找不到前两个的GWT实现，所以我不得不考虑另一个解决方案并遇到了gwt-lzma。
我的目标是将这些细节编码为单个字符串，在服务器上压缩它，将压缩的数据发送到客户端，在那里解压缩并解码，以便客户端“读取”它。为此，我创建了一个编码和解码功能：
编码器：
public static String encodeImageStateContainer(HashMap<String,HashMap<Long,ImageState>> imageStateContainer){
StringBuilder mainStringBuilder = new StringBuilder();
Iterator<Entry<String,HashMap<Long,ImageState>>> imageStateContainerIterator = imageStateContainer.entrySet().iterator();
while(imageStateContainerIterator.hasNext()){
Entry<String,HashMap<Long,ImageState>> tempImageStateManagerMetadata = imageStateContainerIterator.next();
HashMap<Long,ImageState> tempImageStateManager = tempImageStateManagerMetadata.getValue();
if(tempImageStateManager.size() > 0){
if(mainStringBuilder.length() > 0){
mainStringBuilder.append('}'); //Divisor between Image State Managers
}
mainStringBuilder.append(tempImageStateManagerMetadata.getKey());
mainStringBuilder.append('|'); //Divisor between Name and following Data
StringBuilder subOneStringBuilder = new StringBuilder();
Iterator<Entry<Long,ImageState>> tempImageStateManagerIterator = tempImageStateManager.entrySet().iterator();
while(tempImageStateManagerIterator.hasNext()){
Entry<Long,ImageState> tempImageStateMetaData = tempImageStateManagerIterator.next();
if(subOneStringBuilder.length() > 0){
subOneStringBuilder.append(')'); //Divisor between Image Objects
}
subOneStringBuilder.append(tempImageStateMetaData.getKey());
subOneStringBuilder.append('-'); //Divisor between Object Id and Image State Data
StringBuilder subTwoStringBuilder = new StringBuilder();
ImageState tempImageState = tempImageStateMetaData.getValue();
subOneStringBuilder.append(tempImageState.getFirstFrameId()); //1. => First Frame Id
subOneStringBuilder.append(';'); //Divisor between Image State data types
subOneStringBuilder.append(tempImageState.getFramesPerLayer()); //2. => Total Frame Count
subOneStringBuilder.append(';');
subOneStringBuilder.append(tempImageState.getMinumimScaleFactor()); //3. => Minimum Scale Factor
subOneStringBuilder.append(';');
ImageStateLayer[] tempImageStateLayers = tempImageState.getImageStateLayers();
for(int layerId = 0; layerId < tempImageStateLayers.length; ++layerId){
if(subTwoStringBuilder.length() > 0){
subTwoStringBuilder.append('/'); //Divisor between Image State Layers
}
//Frame Arrays
String[] imageNativePath = tempImageStateLayers[layerId].getImageNativePath();
short[] offsetX = tempImageStateLayers[layerId].getOffsetX();
short[] offsetY = tempImageStateLayers[layerId].getOffsetY();
short[] orientation = tempImageStateLayers[layerId].getOrientation();
//Finalization Arrays
byte[] imagePathChange = tempImageStateLayers[layerId].getImagePathChange();
byte[] offsetXChange = tempImageStateLayers[layerId].getOffsetXChange();
byte[] offsetYChange = tempImageStateLayers[layerId].getOffsetYChange();
byte[] orientationChange = tempImageStateLayers[layerId].getOrientationChange();
//Image Path Data
StringBuilder subThreeStrignBuilder = new StringBuilder();
for(int imagePathId = 0; imagePathId < imageNativePath.length; ++imagePathId){
if(subThreeStrignBuilder.length() > 0){
subThreeStrignBuilder.append('#'); //Divisor between Frame Data Sets
}
subThreeStrignBuilder.append(imageNativePath[imagePathId]);
subThreeStrignBuilder.append(','); //Divisor between Frame Data Set Data
subThreeStrignBuilder.append(imagePathChange[imagePathId]);
}
subTwoStringBuilder.append(subThreeStrignBuilder.toString());
subTwoStringBuilder.append('['); //Divisor between Frame Data Types
//OffsetX Data
subThreeStrignBuilder = new StringBuilder();
for(int offsetXId = 0; offsetXId < offsetX.length; ++offsetXId){
if(subThreeStrignBuilder.length() > 0){
subThreeStrignBuilder.append('#'); //Divisor between Frame Data Sets
}
subThreeStrignBuilder.append(offsetX[offsetXId]);
subThreeStrignBuilder.append(','); //Divisor between Frame Data Set Data
subThreeStrignBuilder.append(offsetXChange[offsetXId]);
}
subTwoStringBuilder.append(subThreeStrignBuilder.toString());
subTwoStringBuilder.append('['); //Divisor between Frame Data Types
//OffsetY Data
subThreeStrignBuilder = new StringBuilder();
for(int offsetYId = 0; offsetYId < offsetY.length; ++offsetYId){
if(subThreeStrignBuilder.length() > 0){
subThreeStrignBuilder.append('#'); //Divisor between Frame Data Sets
}
subThreeStrignBuilder.append(offsetY[offsetYId]);
subThreeStrignBuilder.append(','); //Divisor between Frame Data Set Data
subThreeStrignBuilder.append(offsetYChange[offsetYId]);
}
subTwoStringBuilder.append(subThreeStrignBuilder.toString());
subTwoStringBuilder.append('['); //Divisor between Frame Data Types
//Orientation Data
subThreeStrignBuilder = new StringBuilder();
for(int orientationId = 0; orientationId < orientation.length; ++orientationId){
if(subThreeStrignBuilder.length() > 0){
subThreeStrignBuilder.append('#'); //Divisor between Frame Data Sets
}
subThreeStrignBuilder.append(orientation[orientationId]);
subThreeStrignBuilder.append(','); //Divisor between Frame Data Set Data
subThreeStrignBuilder.append(orientationChange[orientationId]);
}
subTwoStringBuilder.append(subThreeStrignBuilder.toString());
}
subOneStringBuilder.append(subTwoStringBuilder.toString());
}
mainStringBuilder.append(subOneStringBuilder.toString());
}
}
return mainStringBuilder.toString();
}
解码器：
public static HashMap<String,HashMap<Long,ImageState>> decodeImageStateContainer(String data){
String[] imageStateManagerArray = data.split("\\}");
HashMap<String,HashMap<Long,ImageState>> imageStateManagerContainer = new HashMap<String,HashMap<Long,ImageState>>(imageStateManagerArray.length);
for(int managerId = 0; managerId < imageStateManagerArray.length; ++managerId){
String[] tempImageStateData = imageStateManagerArray[managerId].split("\\|");
HashMap<Long,ImageState> tempImageStateManager = new HashMap<Long,ImageState>();
imageStateManagerContainer.put(tempImageStateData[0], tempImageStateManager);
String[] tempImageStateManagerObjects = tempImageStateData[1].split("\\)");
for(int objectId = 0; objectId < tempImageStateManagerObjects.length; ++objectId){
String[] tempImageObjectData = tempImageStateManagerObjects[objectId].split("\\-");
long imageObjectId = Long.parseLong(tempImageObjectData[0]);
String[] imageStateMetaData = tempImageObjectData[1].split("\\;");
ImageState tempImageState = new ImageState(Integer.parseInt(imageStateMetaData[1]), Integer.parseInt(imageStateMetaData[0]), Integer.parseInt(imageStateMetaData[2]));
tempImageStateManager.put(imageObjectId, tempImageState);
String[] tempImageStateLayerMetaData = imageStateMetaData[3].split("\\/");
ImageStateLayer[] tempImageStateLayers = new ImageStateLayer[tempImageStateLayerMetaData.length];
for(int layerId = 0; layerId < tempImageStateLayerMetaData.length; ++layerId){
String[] layerElements = tempImageStateLayerMetaData[layerId].split("\\[");
String[] imageNativePathDetails = layerElements[0].split("\\#");
String[] offsetXDetails = layerElements[1].split("\\#");
String[] offsetYDetails = layerElements[2].split("\\#");
**String[] orientationDetails = layerElements[3].split("\\#");**
//Image Path Data
String[] imageNativePaths = new String[imageNativePathDetails.length];
byte[] imagePathChange = new byte[imageNativePathDetails.length];
for(int id = 0; id < imageNativePathDetails.length; ++id){
String[] imagePathDetailElements = imageNativePathDetails[id].split("\\,");
imageNativePaths[id] = imagePathDetailElements[0];
imagePathChange[id] = Byte.parseByte(imagePathDetailElements[1]);
}
//OffsetX Data
short[] offsetX = new short[offsetXDetails.length];
byte[] offsetXChange = new byte[offsetXDetails.length];
for(int id = 0; id < offsetXDetails.length; ++id){
String[] offsetXDetailElements = offsetXDetails[id].split("\\,");
offsetX[id] = Short.parseShort(offsetXDetailElements[0]);
offsetXChange[id] = Byte.parseByte(offsetXDetailElements[1]);
}
//OffsetY Data
short[] offsetY = new short[offsetYDetails.length];
byte[] offsetYChange = new byte[offsetYDetails.length];
for(int id = 0; id < offsetYDetails.length; ++id){
String[] offsetYDetailElements = offsetYDetails[id].split("\\,");
offsetY[id] = Short.parseShort(offsetYDetailElements[0]);
offsetYChange[id] = Byte.parseByte(offsetYDetailElements[1]);
}
//Orientation Data
short[] orientation = new short[orientationDetails.length];
byte[] orientationChange = new byte[orientationDetails.length];
for(int id = 0; id < orientationDetails.length; ++id){
String[] orientationDetailElements = orientationDetails[id].split("\\,");
orientation[id] = Short.parseShort(orientationDetailElements[0]);
orientationChange[id] = Byte.parseByte(orientationDetailElements[1]);
}
//Create the Layer and Add it to the Array
tempImageStateLayers[layerId] = new ImageStateLayer(imageNativePaths,new short[][]{offsetX,offsetY,orientation}, new byte[][]{imagePathChange,offsetXChange,offsetYChange,orientationChange});
}
//Connect the Reference to the layers with the Image State
tempImageState.setImageStateLayers(tempImageStateLayers);
}
}
return imageStateManagerContainer;
}
现在我的问题：如果我在服务器上对其进行编码并在之后直接解码它需要大约三个编码周期，直到我在解码器中的这个特定位置得到IndexOutofBoundsException，最后一行是错误似乎在哪一行根据stacktrace：
for(int layerId = 0; layerId < tempImageStateLayerMetaData.length; ++layerId){
String[] layerElements = tempImageStateLayerMetaData[layerId].split("\\[");
String[] imageNativePathDetails = layerElements[0].split("\\#");
String[] offsetXDetails = layerElements[1].split("\\#");
String[] offsetYDetails = layerElements[2].split("\\#");
String[] orientationDetails = layerElements[3].split("\\#");
我不会说我是专家，但在测试编码器后我可以肯定地说它生成的字符串总是有效的，我得到这个错误的字符串也是完整的。我的解码功能一定有问题，但我不知道它是什么。
正如我所说，前三个周期被正确编码和解码，并且要编码的数据没有显着变化。编码字符串无法导致String数组小于4个元素。基本上，就我理解我的代码而言，这个错误是不存在的。
我认为这可能是某种内存分配问题阻止字符串被正确分割，但这只是一个无能的程序员的想法。
非常感谢任何帮助！
答案 0 :(得分：2)
我找到了解决问题的方法：
编码时，我在字符串中打印数字类型。在选择我的Seperator符号时，我没有采用负值，因此在考虑数字之前会产生一个' - '，当我试图用' - '分割时，这导致我的字符串不受控制地分裂。我用另一个角色替换了减号，现在一切正常！