Volley﹕ [37470] NetworkDispatcher.run: Unhandled exception java.lang.NullPointerException

<pre name="code" class="java">{first_name=null, fb_id=XXXX, email=null, name=Yuan, link=null, last_name=null, gender=null, device_id=""}

 

E/Volley﹕ [37470] NetworkDispatcher.run<span style="color:#ffffcc;">:<span style="background-color: rgb(204, 102, 0);"> Unhandled exception java.lang.NullPointerException
    java.lang.NullPointerException</span></span>
            at libcore.net.UriCodec.encode(UriCodec.java:132)
            at java.net.URLEncoder.encode(URLEncoder.java:57)
            at android.volley.Request.encodeParameters(Request.java:406)
            at android.volley.Request.getBody(Request.java:392)
            at android.volley.toolbox.HurlStack.addBodyIfExists(HurlStack.java:223)
            at android.volley.toolbox.HurlStack.setConnectionParametersForRequest(HurlStack.java:210)
            at android.volley.toolbox.HurlStack.performRequest(HurlStack.java:106)
            at android.volley.toolbox.BasicNetwork.performRequest(BasicNetwork.java:82)
            at android.volley.NetworkDispatcher.run(NetworkDispatcher.java:105)

Volley post请求不能将数据中的null 转换成" " ,所以我们在使用过程中需要将null转换

 protected Map<String, String> getParams(){
            Map<String, String> params = new HashMap<String, String>();
            params.put("key1", value1);
            params.put("key2",value2);
            params.put("key3",value3);
            return <span style="color:#ff0000;">checkParams</span>(params);
        }; <span style="color:#ff0000;">
 
 
     </span>   private Map<String, String> <span style="color:#ff0000;">checkParams</span>(Map<String, String> map){               
            Iterator<Entry<String, String>> it = map.entrySet().iterator();
            while (it.hasNext()) {
                Map.Entry<String, String> pairs = (Map.Entry<String, String>)it.next();
                if(pairs.getValue()==null){
                    map.put(pairs.getKey(), "");
                } 
            } 
            return map;             
        } <span style="color:#ff0000;">
</span>