用jQuery ajax时，后台无法获取前台传来的json数组，急，急，急！！！

代码如下： 望高手指点或提供一个用jQuery ajax传json数组后台解析的例子，在此感谢不尽。

前台js：

$(function(){

$("#btnOk").click(function(){

$.post("link.do?operate=parse", "[ {name:'a', gender:'男'}, {name:'b', gender:'女'} ]");

})

});

后台：

StringBuffer jsondata = new StringBuffer();

System.out.println("json数组解析开始了！！！");

String line = null;

while ((line = request.getReader().readLine()) != null) {

jsondata.append(message);

}

System.out.println("接收到的json数据："+ jsondata.toString());

JSONArray array = new JSONArray(jsondata);

for(int i = 0; i < array.length(); i++) {

JSONObject json = (JSONObject) array.get(i);

System.out.println(json.getString("name")+ ","+ json.getString("gender"));

}

输出：

信息: Initialize action of type: com.json.struts.action.LinkAction

json数组解析开始了

接收到的json数据：

2010-3-2 21:27:22 org.apache.struts.chain.commands.AbstractExceptionHandler execute

警告: Unhandled exception

java.lang.NullPointerException

at java.io.StringReader.(StringReader.java:33)

at org.json.JSONTokener.(JSONTokener.java:66)

at org.json.JSONArray.(JSONArray.java:157)

at com.json.struts.action.LinkAction.parsejson(LinkAction.java:88)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

at java.lang.reflect.Method.invoke(Method.java:597)

at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:269)

at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:170)

at org.apache.struts.chain.commands.servlet.ExecuteAction.execute(ExecuteAction.java:58)

at org.apache.struts.chain.commands.AbstractExecuteAction.execute(AbstractExecuteAction.java:67)

at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)

at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)

at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:304)

at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)

at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)

at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)

at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)

at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)

at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)

at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)

at java.lang.Thread.run(Thread.java:619)