android–Volley JsonObjectRequest在GET请求中发送头文件

概述我试图从GET请求发送一些身份验证标头,我尝试使用VolleyJsonObjectRequest调用：Map<String,String>params=newHashMap<String,String>();params.put("token","fghjbvjhnjjk");activity.showDialog();JsonObjectRequestreq=newJs

我试图从GET请求发送一些身份验证标头,我尝试使用Volley JsonObjectRequest调用：

Map<String,String> params=new HashMap<String,String>();        params.put("token","fghjbvjhnjjk");        activity.showDialog();        JsonObjectRequest req = new JsonObjectRequest(Request.Method.GET,url,                new JsONObject(params), new Response.Listener<JsONObject>() {            @OverrIDe            public voID onResponse(JsONObject response) {                Log.d(tag, response.toString());                activity.hIDeDialog();                try {                    activity.onRequestServed(response, code);                } catch (JsONException e) {                    e.printstacktrace();                }            }        }, new Response.ErrorListener() {            @OverrIDe            public voID one rrorResponse(VolleyError error) {                VolleyLog.d(tag, "Error: " + error.getMessage());                Log.e(tag, "Site Info Error: " + error.getMessage());                Toast.makeText(activity.getApplicationContext(),                        error.getMessage(), Toast.LENGTH_SHORT).show();                activity.hIDeDialog();                try {                    activity.onRequestServed(null,code);                } catch (JsONException e) {                    e.printstacktrace();                }            }        });        req.setShouldCache(true);

但它显示：

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.hashCode()' on a null object reference        at com.androID.volley.Request.<init>(Request.java:136)        at com.androID.volley.toolBox.JsonRequest.<init>(JsonRequest.java:58)        at com.androID.volley.toolBox.JsonObjectRequest.<init>(JsonObjectRequest.java:47)

我在某处读到你可以通过制作一个hashmap来传递头文件,从而用该参数创建一个新的JsonObject.也许这将适用于POST请求.请帮忙..

解决方法:

嗯,事情很简单,非常精确.将标头传递给GET或POST请求,您需要覆盖JsonObjectRequest类中的getheaders方法.这是如何做到的：

JsonObjectRequest req = new JsonObjectRequest(Request.Method.GET,url,                null, new Response.Listener<JsONObject>() {            @OverrIDe            public voID onResponse(JsONObject response) {                Log.d(tag, response.toString());                activity.hIDeDialog();                try {                    activity.onRequestServed(response, code);                } catch (JsONException e) {                    e.printstacktrace();                }            }        }, new Response.ErrorListener() {            @OverrIDe            public voID one rrorResponse(VolleyError error) {                VolleyLog.d(tag, "Error: " + error.getMessage());                Log.e(tag, "Site Info Error: " + error.getMessage());                Toast.makeText(activity.getApplicationContext(),                        error.getMessage(), Toast.LENGTH_SHORT).show();                activity.hIDeDialog();                try {                    activity.onRequestServed(null,code);                } catch (JsONException e) {                    e.printstacktrace();                }            }        }) {            /**             * Passing some request headers             */            @OverrIDe            public Map<String, String> getheaders() throws AuthFailureError {                HashMap<String, String> headers = new HashMap<String, String>();                //headers.put("Content-Type", "application/Json");                headers.put("key", "Value");                return headers;            }        };

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