手机端靠山向前台传输数据的二进制压缩方法

手机端后台向前台传输数据的二进制压缩方法
后端取出数据后发给前端，原本我们使用json格式传输，每次传输将近1k左右，但是为了给用户省流量，我们采取先把json去掉每一个key，转换为二进制，然后gzip压缩，这样操作下来节省了70%的数据量，效果很好。

具体方法：
原有返回格式是这样

<StoresList><return>      {      "status": {      "request_status": "0",      "error_code": "BTMes0100002",      "error_msg": "success"      },      "bizobj": [      {      "STORE_ID": 1,      "STORE_NAME": "肯德基",      "STORE_PHONE": "4008-823823",      "STORE_ADDRESS": "文二路肯德基店",      "STORE_LAT": "30.33331",      "STORE_LONG": "120.22221",      "PHOTO_TYPE": 2,      "RESOLUTION_TYPE": 2,      "PHOTO_URL": "http://www.kendeji.com/a.jpg"      }, {      "STORE_ID": 2,      "STORE_NAME": "麦当劳",      "STORE_PHONE": "15233336666",      "STORE_ADDRESS": "文一路麦当劳店",      "STORE_LAT": "30.33332",      "STORE_LONG": "120.22222",      "PHOTO_TYPE": 2,      "RESOLUTION_TYPE": 2,      "PHOTO_URL": "http://www.maidanglao.com/a.jpg"      }  ],      "page_info": {      "cur_page": "1",      "page_size": "12",      "total_items": "3"      }      }    </return>  </StoresList>

我们约定每一个属性的长度，在一个xml文件中写成这样

<storeList id="status"><request_status>4</request_status><error_code>4</error_code><error_msg>40</error_msg></storeList><storeList id="page_info"><cur_page>4</cur_page><page_size>4</page_size><total_items>4</total_items></storeList><storeList id="bizobj"><STORE_ID>4</STORE_ID><STORE_NAME>50</STORE_NAME><STORE_PHONE>16</STORE_PHONE><STORE_ADDRESS>50</STORE_ADDRESS><STORE_LAT>12</STORE_LAT><STORE_LONG>12</STORE_LONG><PHOTO_TYPE>4</PHOTO_TYPE><RESOLUTION_TYPE>4</RESOLUTION_TYPE><PHOTO_URL>50</PHOTO_URL><CLASS_ID>4</CLASS_ID><STORE_URL>50</STORE_URL><distance>6</distance></storeList>

然后依次遍历每个storelist下的节点的ElementName以及ElementValue ，即可通过elementName得到json中的值，通过elementValue来给json中的值转换为byte[]，并且前补零。
最后把要拼装的jsonobject或者jsonarray的byte数组拼装成一个byte【】，然后对其gzip即可

public class BinaryUtil {/** * jsonobj转换为byte数组 * @param jsonObj * @param charset * @param xmlParameter * @return * @throws UnsupportedEncodingException * @throws DocumentException */public static byte[] convertJsonObj2ByteArray(JSONObject jsonObj, String charset,XmlParameter xmlParameter) throws UnsupportedEncodingException,DocumentException {List<Jsonvalue> list = new ArrayList<Jsonvalue>();List<XmlBean> xmllist = combineBizobj(xmlParameter);for (XmlBean bean : xmllist) {String name = jsonObj.getString(bean.getAttributeName());Integer value = bean.getAttributeValue();list.add(change2Jsonvalue(name, value, charset));}return combineList(list, charset);}/** * jsonarray转换为byte数组 * @param jsonArray * @param charset * @param xmlParameter * @return * @throws DocumentException * @throws UnsupportedEncodingException */public static byte[] convertJsonArray2ByteArray(JSONArray jsonArray,String charset, XmlParameter xmlParameter)throws DocumentException, UnsupportedEncodingException {if (jsonArray == null) {return null;}int arraySize = jsonArray.size();List<Jsonvalue> list = new ArrayList<Jsonvalue>();List<XmlBean> xmllist = combineBizobj(xmlParameter);for (int i = 0; i < arraySize; i++) {for (XmlBean bean : xmllist) {String name = jsonArray.getJSONObject(i).getString(bean.getAttributeName());Integer value = bean.getAttributeValue();list.add(change2Jsonvalue(name, value, charset));}}return combineList(list, charset);}/** * 合并多个byte数组，合并后的长度为多个子数组的和 * @param charset * @param firstByteArray * @param secondByteArray * @param objects * @return * @throws UnsupportedEncodingException */public static byte[] combineByteArray(String charset,byte[] firstByteArray,byte[] secondByteArray, Object... objects) throws UnsupportedEncodingException {if (firstByteArray == null) {return secondByteArray;} else if (secondByteArray == null) {return firstByteArray;} else {StringBuffer sb=new StringBuffer();sb.append(new String(firstByteArray));sb.append(new String(secondByteArray));if (objects != null) {int j = objects.length;for(int i=0;i<j;i++){sb.append(new String((byte[])objects[i]));}}return sb.toString().getBytes(charset);}}/** * 获得一个接口对应的所有的id * @param xmlParameter * @return * @throws DocumentException */public static List<String> getIds(XmlParameter xmlParameter)throws DocumentException {List<String> list = new ArrayList<String>();List<Element> elist = getElementList(xmlParameter);for (Element e : elist) {list.add(e.attributeValue("id"));}return list;}/** * gzip压缩数据 * @param data * @return * @throws IOException */public static byte[] gzipData(byte[] data) throws IOException {ByteArrayOutputStream bos = new ByteArrayOutputStream();GZIPOutputStream gzos = new GZIPOutputStream(bos);gzos.write(data);gzos.close();return bos.toByteArray();}/** * 获得接口名称对应的配置元素列表 * @param method * @return * @throws DocumentException */@SuppressWarnings("unchecked")private static List<Element> getElementList(XmlParameter xmlParameter)throws DocumentException {SAXReader saxReader = new SAXReader();Document document = saxReader.read(xmlParameter.getXmlPath());Element root = document.getRootElement();List<Element> elist = root.selectNodes(xmlParameter.getElementName());return elist;}private static byte[] combineList(List<Jsonvalue> list, String charset)throws UnsupportedEncodingException {StringBuffer result = new StringBuffer();for (int i = 0; i < list.size(); i++) {result.append(new String(list.get(i).getB()));}String f = result.toString();return f.getBytes(charset);}/** * 前补零 * @throws UnsupportedEncodingException  */private static byte[] fillZero(String charset,byte[] s, int bytesSize) throws UnsupportedEncodingException {byte[] zreo = new byte[1];zreo[0] = 0;while (s.length < bytesSize) {s = combineByteArray(charset,zreo, s);}return s;}private static Jsonvalue change2Jsonvalue(String value, Integer length,String charset) throws UnsupportedEncodingException {Jsonvalue jv = new Jsonvalue(fillZero(charset,value.getBytes(charset), length),length);return jv;}/** * 获得一个element对应的所有节点 *  * @param xmlParameter * @return * @throws DocumentException */@SuppressWarnings("unchecked")private static List<XmlBean> combineBizobj(XmlParameter xmlParameter)throws DocumentException {List<XmlBean> list = new ArrayList<XmlBean>();SAXReader saxReader = new SAXReader();Document document = saxReader.read(xmlParameter.getXmlPath());Element root = document.getRootElement();List<Element> elist = root.selectNodes(xmlParameter.getElementName());for (Element e : elist) {if (e.attribute("id").getValue().equalsIgnoreCase(xmlParameter.getElementId())) {List<Element> list1 = e.elements();for (Element ee : list1) {XmlBean xmlBean = new XmlBean(ee.getName(),Integer.parseInt(ee.getData().toString()));list.add(xmlBean);}}}return list;}}

压缩包见附件包含本身的jar以及依赖的jar

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