提交数据url太长导致提交失败

使用了dojo开发。在datagrid过滤的时候。为了让过滤好处理，直接设置为完全二叉树的方式来存查询条件。但是在提交数据的时候，默认是get?url的方式。结果导致条件选择一两个,url会特别长。然后会报404错误。差点把前面的设计推掉，重来。项目就差一小部分了。时间上也来不及了。硬着头皮，看了一天的js源代码，我只能说，俺对js的世界无法理解啊。反复的试验了好久，硬是将rest的get请求，改为了post请求。代码如下：

 require(["dojo/_base/declare", "dojox/rpc/JsonRest", "dojox/data/JsonRestStore", "dojo/dom", "dojo/domReady!"],
         function (declare, rpcJsonRest,JsonRestStore, locale, dom) {
             return declare("mydata.JsonRestStore", [dojox.data.JsonRestStore], {//我的rest并不标准{Data:data,ErrorNo:1,ErrorInfo:errorinfo}这种形式。
                 _processResults: function (results, deferred) {
                     // index the results
                     if (results.ErrorNo > ) {
                         alert(results.ErrorInfo);
                         throw new Error(results.ErrorInfo || '');
                     }
                     var count = results.Data.TotalRowCount;
                     results = results.Data.Items;
                     // if we don't know the length, and it is partial result, we will guess that it is twice as big, that will work for most widgets
                     return { totalCount: deferred.fullLength || (deferred.request.count == count ? (deferred.request.start || ) + count *  : count), items: results };
                 },
                 _doQuery: function (args) {//重写了一个_doQuery
                     var query = typeof args.queryStr == 'string' ? args.queryStr : args.query;
                     //var myservice = this.service({}, args);
                     var myservice = this.service._getRequest({ operation: query.operation }, args)//从这里开始新的调用。
                     var xhrArgs = {
                         url: myservice.url,
                         handleAs: "json",
                         headers: {
                             Accept: "application/json,application/javascript",
                             Range: myservice.headers.Range
                         },
                         content: { filtercodtion: query.filtercodtion }
                     };
                     var deferred = dojo.xhrPost(xhrArgs); //rpcJsonRest.query(this.service, query, args);原来的调用。
                     var self = this;
                     if (this.loadReferencedSchema) {
                         deferred.addCallback(function (result) {
                             var contentType = deferred.ioArgs && deferred.ioArgs.xhr && deferred.ioArgs.xhr.getResponseHeader("Content-Type");
                             var schemaRef = contentType && contentType.match(/definedby\s*=\s*([^;]*)/);
                             if (contentType && !schemaRef) {
                                 schemaRef = deferred.ioArgs.xhr.getResponseHeader("Link");
                                 schemaRef = schemaRef && schemaRef.match(/<([^>]*)>;\s*rel="?definedby"?/);
                             }
                             schemaRef = schemaRef && schemaRef[];
                             if (schemaRef) {
                                 var serviceAndId = rpcJsonRest.getServiceAndId((self.target + schemaRef).replace(/^(.*\/)?(\w+:\/\/)|[^\/\.]+\/\.\.\/|^.*\/(\/)/, "$2$3"));
                                 var schemaDeferred = rpcJsonRest.byId(serviceAndId.service, serviceAndId.id);
                                 schemaDeferred.addCallbacks(function (newSchema) {
                                     lang.mixin(self.schema, newSchema);
                                     return result;
                                 }, function (error) {
                                     alert(error);
                                     console.error(error); // log it, but don't let it cause the main request to fail
                                     return result;
                                 });
                                 return schemaDeferred;
                             }
                             return undefined;//don't change anything, and deal with the stupid post-commit lint complaints
                         });
                     }
                     return deferred;
                 }
             });
         }
 );

解决问题的思路因为觉得太复杂[的确是复杂]，而不知道怎么入手。要改变方法。耗的时间太久了。