问题
I'm having a problem in Android Studio on how to request JSON Object.
My Logcat can only print String onResponse but not JSONObject value. I'm having a problem in line try{} inside AccessActivity.java
My code explanation as below.
I have these JSON Object output that I fetch from mysql database.
{
"access":"PA001",
"password":"123",
"fullname":"ARCADE",
"branch":"HQ",
"section":"MPR"
}
In my PHP code, this is how I fetch the data and encode it as JSON Object.
access.php
<?php
$conn = mysqli_connect("","","","");
if(
isset($_POST['access']) &&
isset($_POST['password'])
){
$access = $_POST['access'];
$password = $_POST['password'];
$sql = "SELECT * FROM table WHERE access = '$access' AND password = '$password' ";
$result = mysqli_query($conn, $sql);
if($result && mysqli_num_rows($result) > 0){
while($row = mysqli_fetch_array($result)){
$accessdb = $row['access'];
$passworddb = $row['password'];
$fullnamedb = $row['fullname'];
$branchdb = $row['branch'];
$sectiondb = $row['section'];
echo "success_access";
$response = array('access' => $accessdb, 'password' => $passworddb, 'fullname' => $fullnamedb, 'branch' => $branchdb, 'section' => $sectiondb);
echo json_encode($response);
}
mysqli_free_result($result);
} else {
echo "access_failed";
}
}
?>
But my problem occurs in Android Studio,
- I can't even print Log.e(TAG, "JSON Object =" + jsonObject);
- I can't intent JSON Object value into next activity.
Here's my code .
AccessActivity.java
public class AccessActivity extends AppCompatActivity{
final String TAG = this.getClass().getName();
EditText etAccess, etPassword;
Button bLogin;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
etAccess = (EditText)findViewById(R.id.etAccess);
etPassword = (EditText)findViewById(R.id.etPassword);
bLogin = (Button)findViewById(R.id.bLogin);
bLogin.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String url = "http://localhost/access.php";
StringRequest stringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
Log.e(TAG, "Response is = " + response);
if(response.equals("success_access")){
try {
JSONObject jsonObject = new JSONObject(response);
Log.e(TAG, "JSON Object is = " + jsonObject);
final String accessdb = jsonObject.getString("access");
final String passworddb = jsonObject.getString("password");
final String fullnamedb = jsonObject.getString("fullname");
final String branchdb = jsonObject.getString("branch");
final String sectiondb = jsonObject.getString("branch");
Intent intent = new Intent(AccessActivity.this, NextActivity.class);
intent.putExtra("access", accessdb);
intent.putExtra("password", passworddb);
intent.putExtra("fullname", fullnamedb);
intent.putExtra("branch", branchdb);
intent.putExtra("section", sectiondb);
AccessActivity.this.startActivity(intent);
} catch (JSONException e) {
e.printStackTrace();
}
} else{
Toast.makeText(getApplicationContext(), "Access Error", Toast.LENGTH_SHORT).show();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(getApplicationContext(), "Volley Error", Toast.LENGTH_SHORT).show();
}
}){
@Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String, String> params = new HashMap<>();
params.put("access", etAccess.getText().toString());
params.put("password", etPassword.getText().toString());
return params;
}
};
MySingleton.getInstance(getApplicationContext()).addToRequestQueue(stringRequest);
}
});
}
}
UPDATE :
my logcat display this
08-22 10:22:22.059 19801-19908/com.apps.test D/NetworkSecurityConfig: No Network Security Config specified, using platform default
08-22 10:22:22.064 19801-19801/com.apps.test E/my.com.apps.test.Activity: Response is = success_access{"access":"PA001","password":"123","fullname":"ARCADE","branch":"HQ","section":"HQ"}
08-22 10:22:22.112 19801-19825/com.apps.test D/EGL_emulation: eglMakeCurrent: 0xb3305060: ver 2 0 (tinfo 0xb3303200)
08-22 10:22:22.128 19801-19825/com.apps.test D/EGL_emulation: eglMakeCurrent: 0xb3305060: ver 2 0 (tinfo 0xb3303200)
08-22 10:22:22.134 19801-19825/com.apps.test D/EGL_emulation: eglMakeCurrent: 0xb3305060: ver 2 0 (tinfo 0xb3303200)
08-22 10:22:22.140 19801-19825/com.apps.test D/EGL_emulation: eglMakeCurrent: 0xb3305060: ver 2 0 (tinfo 0xb3303200)
08-22 10:22:23.697 19801-19825/com.apps.test D/EGL_emulation: eglMakeCurrent: 0xb3305060: ver 2 0 (tinfo 0xb3303200)
08-22 10:22:25.751 19801-19825/com.apps.test D/EGL_emulation: eglMakeCurrent: 0xb3305060: ver 2 0 (tinfo 0xb3303200)
08-22 10:22:25.780 19801-19825/com.apps.test D/EGL_emulation: eglMakeCurrent: 0xb3305060: ver 2 0 (tinfo 0xb3303200)
Appreciate if someone can help me to solve this problem. Thanks.
回答1:
Try this.
In the AccessActivity
Intent intent = new Intent(AccessActivity.this, NextActivity.class);
intent.putExtra("access", accessdb);
intent.putExtra("password", passworddb);
intent.putExtra("fullname", fullnamedb);
intent.putExtra("branch", branchdb);
intent.putExtra("section", sectiondb);
AccessActivity.this.startActivity(intent);
change
LoginActivity.this.startActivity(intent);
to
AccessActivity.this.startActivity(intent);
In the NextActivity
Intent intent = getIntent();
String access = intent.getStringExtra("access");
String password = intent.getStringExtra("password");
String fullname = intent.getStringExtra("fullname");
String branch = intent.getStringExtra("branch");
String section = intent.getStringExtra("section");
Edited
change
if(response.equals("success_access")){
}
to
if(response.contains("success_access")){
}
And according to your code.
You need to make sure that your current Activity is com.apps.test.AccessActivity or com.apps.test.AccessActivity.
Edited
change to
if (response.contains("success_access")) {
String res = response.substring(response.indexOf("{"));
try {
JSONObject jsonObject = new JSONObject(res);
final String accessdb = jsonObject.getString("access");
final String passworddb = jsonObject.getString("password");
final String fullnamedb = jsonObject.getString("fullname");
final String branchdb = jsonObject.getString("branch");
final String sectiondb = jsonObject.getString("branch");
Log.e("Tag", accessdb);
} catch (JSONException e) {
e.printStackTrace();
}
}
回答2:
Your requesting a JsonObject?
You seem to have a grasp on StringRequest, so ill keep it simple. Change your StringRequest to a JsonObjectRequest.
回答3:
Problem :
As you can see in your logcat the response that you get from the server is success_access{"access":"PA001","password":"123","fullname":"ARCADE","branch":"HQ","section":"HQ"}
First, this is not a valid JSON.
Also, that is the value of the response variable.
Now, your response.equals("success_access") will never return true, and hence the code control will never enter the if block.
Solution :
Ideally, there should be no extra string like success_access, insted your response should be a JSON object ALWAYS containing one specified field (the result feild for example). To show success, your JSON will look something like :
{
result : "success_access",
/* other parameters down here */
}
And in case of failure :
{
result : "access_failed"
}
And then your code should convert the respose string into a JSON (your server code should make sure that it returns a valid JSON always) check for the value of the result field and proceed further.
Quick Fix :
Change your code to :
....
Log.e(TAG, "Response is = " + response);
String result = response.replace("{.*}","");
String jsonString = response.replace(result, "");
if(result.equals("success_access")){
try {
JSONObject jsonObject = new JSONObject(jsonString);
....
来源：https://stackoverflow.com/questions/45807707/how-to-display-request-json-object-using-android-volley