我已注册然后我正在尝试登录，但“值＆lt; br的java.lang.String类型无法转换为JSONObject”这个错误显示我不知道该怎么做，请帮助我。< / p>
这是我的Java代码：
package com.example.kamran.ebloodbank;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.app.AlertDialog;
import com.android.volley.AuthFailureError;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.Volley;
import com.android.volley.RequestQueue;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.Request;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.HashMap;
import java.util.Map;
public class LogIn extends AppCompatActivity {
Button btnLogin;
EditText userName;
EditText password;
RequestQueue requestQueue;
String logInUrl = "https://wwwkamranalitk.000webhostapp.com/donor_login.php";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_log_in);
userName = (EditText) findViewById(R.id.userName);
password = (EditText) findViewById(R.id.password);
btnLogin = (Button) findViewById(R.id.logInButton);
requestQueue = Volley.newRequestQueue(getApplicationContext());
btnLogin.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
StringRequest request = new StringRequest(Request.Method.POST, logInUrl, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
try {
JSONObject jsonResponse = new JSONObject(response);
boolean success = jsonResponse.getBoolean("success");
if(success){
Intent intent = new Intent(LogIn.this, AfterLoginMain.class);
startActivity(intent);
finish();
}else{
AlertDialog.Builder builder = new AlertDialog.Builder(LogIn.this);
builder.setMessage("Login Failed")
.setNegativeButton("Retry", null)
.create()
.show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
}){
@Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String,String> parameters = new HashMap<String, String>();
parameters.put("username", userName.getText().toString());
parameters.put("password", password.getText().toString());
return parameters;
}
};
RequestQueue queue = Volley.newRequestQueue(LogIn.this);
queue.add(request);
}
});
}
}
这是我的PHP代码：
<?php
$con = mysqli_connect("localhost", "id1023450_admin", "admin", "id1023450_bloodbank");
$username = $_POST['username'];
$password = $_POST['password'];
$statement = mysqli_prepare($con, "SELECT * FROM blood WHERE username = ? AND password = ?");
mysqli_stmt_bind_param($statement, "ss", $username, $password);
mysqli_stmt_execute($statement);
mysqli_stmt_store_result($statement);
mysqli_stmt_bind_result($statement, $name, $bloodgroup, $contactnumber, $emailaddress, $area, $disease, $username, $password);
$response = array();
$response["success"] = false;
while(mysqli_stmt_fetch($statement)){
$response["success"] = true;
$response["name"] = $name;
$response["bloodgroup"] = $bloodgroup;
$response["contactnumber"] = $contactnumber;
$response["emailaddress"] = $emailaddress;
$responce["area"] = $area;
$response["disease"] = $disease;
$response["username"] = $username;
$response["password"] = $password;
}
echo json_encode($response);
?>
这是Logcat：
04-04 03:28:53.112 5357-5357/com.example.kamran.ebloodbank W/System.err: org.json.JSONException: Value <br of type java.lang.String cannot be converted to JSONObject
04-04 03:28:53.113 5357-5357/com.example.kamran.ebloodbank W/System.err: at org.json.JSON.typeMismatch(JSON.java:111)
04-04 03:28:53.113 5357-5357/com.example.kamran.ebloodbank W/System.err: at org.json.JSONObject.<init>(JSONObject.java:160)
04-04 03:28:53.113 5357-5357/com.example.kamran.ebloodbank W/System.err: at org.json.JSONObject.<init>(JSONObject.java:173)
04-04 03:28:53.113 5357-5357/com.example.kamran.ebloodbank W/System.err: at com.example.kamran.ebloodbank.LogIn$1$1.onResponse(LogIn.java:48)
04-04 03:28:53.113 5357-5357/com.example.kamran.ebloodbank W/System.err: at com.example.kamran.ebloodbank.LogIn$1$1.onResponse(LogIn.java:43)
04-04 03:28:53.113 5357-5357/com.example.kamran.ebloodbank W/System.err: at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:60)
04-04 03:28:53.113 5357-5357/com.example.kamran.ebloodbank W/System.err: at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:30)
04-04 03:28:53.114 5357-5357/com.example.kamran.ebloodbank W/System.err: at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:99)
04-04 03:28:53.114 5357-5357/com.example.kamran.ebloodbank W/System.err: at android.os.Handler.handleCallback(Handler.java:739)
04-04 03:28:53.114 5357-5357/com.example.kamran.ebloodbank W/System.err: at android.os.Handler.dispatchMessage(Handler.java:95)
04-04 03:28:53.114 5357-5357/com.example.kamran.ebloodbank W/System.err: at android.os.Looper.loop(Looper.java:135)
04-04 03:28:53.114 5357-5357/com.example.kamran.ebloodbank W/System.err: at android.app.ActivityThread.main(ActivityThread.java:5254)
04-04 03:28:53.114 5357-5357/com.example.kamran.ebloodbank W/System.err: at java.lang.reflect.Method.invoke(Native Method)
04-04 03:28:53.114 5357-5357/com.example.kamran.ebloodbank W/System.err: at java.lang.reflect.Method.invoke(Method.java:372)
04-04 03:28:53.114 5357-5357/com.example.kamran.ebloodbank W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
04-04 03:28:53.114 5357-5357/com.example.kamran.ebloodbank W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
这是我的JSON回复：
{ “成功”：是的， “name”：null， “bloodgroup”：null， “contactnumber”：null， “emailaddress”：null， “疾病”：null， “用户名”：“kamran”， “密码”：“abc123” }