在我的程序中有NetworkDispatcher.run错误我正在使用volley库。 我的程序部分是。我已经完成但没有任何工作请帮助我做我的程序。我通过许多网络内容搜索但没有任何帮助我。我正在做的是在Android中的登录验证程序。
if(!(usr.getText().toString().length()<11)&&!(pwd.getText().toString().length()<3)) {
susr = usr.getText().toString();
spwd = pwd.getText().toString();
String whois = susr.substring(0, Math.min(susr.length(), 2));
if (whois.equals("AG") || whois.equals("RT")) {
if (whois.equals("AG")) {
id = susr.substring(susr.length() - 9);
Toast.makeText(getApplicationContext(), id, Toast.LENGTH_LONG).show();
StringRequest stringRequest = new StringRequest(Request.Method.POST, agenturl,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
//Toast.makeText(getApplicationContext(),response,Toast.LENGTH_LONG).show();
if(response.equals("0")){
Toast.makeText(getApplicationContext(),"Login successful",Toast.LENGTH_LONG).show();
Intent intent=new Intent(getBaseContext(),Deals.class);
startActivity(intent);
}else{
Toast.makeText(getApplicationContext(),"username or password is incorrect",Toast.LENGTH_LONG).show();
}
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
//Toast.makeText(MainActivity.this,error.toString(), Toast.LENGTH_LONG).show();
if(error instanceof NoConnectionError) {
Toast.makeText(getApplicationContext(),"No internet Access, Check your internet connection.", Toast.LENGTH_LONG).show();
}
}
}){
@Override
protected Map<String,String> getParams(){
Map<String,String> params = new HashMap<String, String>();
params.put("id",id);
params.put("pwd",spwd);
return params;
}
};
requestQueue.add(stringRequest);
}
else if(whois.equals("RT")){
StringRequest stringRequest2 = new StringRequest(Request.Method.POST, retailerurl,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
//Toast.makeText(getApplicationContext(),"hf",Toast.LENGTH_LONG).show();
//Toast.makeText(getApplicationContext(),response,Toast.LENGTH_LONG).show();
if(response.equals("0")){
Toast.makeText(getApplicationContext(),"Login successful",Toast.LENGTH_LONG).show();
Intent intent=new Intent(getBaseContext(),Deals.class);
startActivity(intent);
}else{
Toast.makeText(getApplicationContext(),"username or password is incorrect",Toast.LENGTH_LONG).show();
}
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
//Toast.makeText(MainActivity.this,error.toString(), Toast.LENGTH_LONG).show();
if(error instanceof NoConnectionError) {
Toast.makeText(getApplicationContext(),"No internet Access, Check your internet connection.", Toast.LENGTH_LONG).show();
}
}
}){
@Override
protected Map<String,String> getParams(){
Map<String,String> params = new HashMap<String, String>();
params.put("id",id);
params.put("pwd",spwd);
return params;
}
};
requestQueue2.add(stringRequest2);
}
} else{
Toast.makeText(getApplicationContext(), "The user id or password is incorrect", Toast.LENGTH_LONG).show();
usr.setText("");
}
}else {
Toast.makeText(getApplicationContext(), "The user id or password is incorrect", Toast.LENGTH_LONG).show();
usr.setText("");
}
和错误日志cat是。
E/Volley: [197] NetworkDispatcher.run: Unhandled exception java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.length()' on a null object reference
java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.length()' on a null object reference
at libcore.net.UriCodec.encode(UriCodec.java:132)
at java.net.URLEncoder.encode(URLEncoder.java:57)
at com.android.volley.Request.encodeParameters(Request.java:484)
at com.android.volley.Request.getBody(Request.java:470)
at com.android.volley.toolbox.HurlStack.addBodyIfExists(HurlStack.java:253)
at com.android.volley.toolbox.HurlStack.setConnectionParametersForRequest(HurlStack.java:227)
at com.android.volley.toolbox.HurlStack.performRequest(HurlStack.java:107)
at com.android.volley.toolbox.BasicNetwork.performRequest(BasicNetwork.java:97)
at com.android.volley.NetworkDispatcher.run(NetworkDispatcher.java:114)
答案 0 :(得分：9)
错误是说你得到NullPointerException。
这意味着您在此代码中使用的变量在运行时为空。
答案 1 :(得分：2)
我明白了。
else if(whois.equals("RT")){之后我忘了放id = susr.substring(susr.length() - 9);
由于null值，主要发生 NetworkDispatcher.run错误 传入了凌空库的getParams（）方法。所以我们必须意识到 关于将值传递给getParams（）方法。
答案 2 :(得分：2)
此错误经常发生在服务器上发送数据 错误
尝试在此代码中放入硬编码值，以确保没有任何服务器 错误
public Map<String, String> getParams()
{
Map<String, String> params = new HashMap<String, String>();
params.put("rollno","1234");
params.put("password","abcd");
return params;
}
};
如果它正常工作，那么你应该调试以确保此参数获得值
params.put("id",id);
params.put("pwd",spwd);