java - 在 android volley、php、xampp mysql 中将响应转换为 JSON ARRAY 或 OBJECT

Question

我正在做一个 android 项目，登录 API 在 postman 中正常工作，但对于 JSON 格式，它显示意外的“S”。我的同事告诉我要转换LoginRequest.java中的Response必须更改为JSONArray或JSONObject

这里有PHP、Android JAVA代码

    <?php

include("Connection.php");

if(isset($_POST["email"]) && isset($_POST["password"]))
{

   $email=$_POST["email"];

   $password=$_POST["password"];

   $result = mysqli_query($conn, "select * from user_master where email='$email' && password='$password'");

    if(mysqli_num_rows($result) > 0)
    {   
        echo "Success";
        exit;
    }           
    else
    {   
        echo "INVALID";
        exit;
    }
}


?>

LoginRequest.java

    package com.talentakeaways.ttpms;

import com.android.volley.AuthFailureError;
import com.android.volley.Response;
import com.android.volley.toolbox.StringRequest;

import java.util.HashMap;
import java.util.Map;

/**
 * Created by chand on 15-03-2018.
 */

public class LoginRequest extends StringRequest {
    private static final String url = "http://10.26.16.22:80/ttpms/login.php";
    private Map<String, String> parameters;

    LoginRequest(String username, String password, Response.Listener<String> listener, Response.ErrorListener errorListener) {
        super(Method.POST, url, listener, errorListener);
        parameters = new HashMap<>();
        parameters.put("username", username);
        parameters.put("password", password);
    }

    @Override
    protected Map<String, String> getParams() throws AuthFailureError {
        return parameters;
    }
}

Ttpm_Login.java

    package com.talentakeaways.ttpms;

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.android.volley.NetworkError;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.ServerError;
import com.android.volley.TimeoutError;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.Volley;

import org.json.JSONException;
import org.json.JSONObject;

import info.androidhive.androidsplashscreentimer.R;


public class Ttpm_Login extends AppCompatActivity {
    //declaration of edit text, button and string values
    EditText tenantname, passWord;
    Button bt_login;
    String userName, password;


    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_ttpm_login);
        setTitle("Login"); //set title of the activity
        initialize();
        final RequestQueue requestQueue = Volley.newRequestQueue(Ttpm_Login.this);
        //onClickListener method for button
        bt_login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //assigning String variables to the text in edit texts
                userName = tenantname.getText().toString();
                password = passWord.getText().toString();
                //Validating the String values
                if (validateUsername(userName) && validatePassword(password)) {

                    //Start ProgressDialog
                    final ProgressDialog progressDialog = new ProgressDialog(Ttpm_Login.this);
                    progressDialog.setTitle("Please Wait");
                    progressDialog.setMessage("Logging You In");
                    progressDialog.setCancelable(false);
                    progressDialog.show();

                    //Login Request from class LoginRequest
                    LoginRequest loginRequest = new LoginRequest(userName, password, new Response.Listener<String>() {
                        @Override
                        public void onResponse(String response) {
                            Log.i("Login Response", response);
                            progressDialog.dismiss();
                            try {
                                JSONObject jsonObject = new JSONObject(response);
                                //If Success then start Dashboard Activity
                                if (jsonObject.getBoolean("Success")) {

                                    Intent loginSuccess = new Intent(getApplicationContext(), Ttpm_Dashboard.class);
                                    startActivity(loginSuccess);
                                    finish();
                                }

                                //else Invalid
                                else {
                                    if (jsonObject.getString("status").equals("INVALID"))
                                        Toast.makeText(getApplicationContext(), "User Not Found", Toast.LENGTH_SHORT).show();
                                    else {
                                        Toast.makeText(getApplicationContext(), "Passwords Don't Match", Toast.LENGTH_SHORT).show();
                                    }
                                }
                            } catch (JSONException e) {
                                e.printStackTrace();
                                Log.getStackTraceString(e);
                                Toast.makeText(Ttpm_Login.this, "Bad Response from the Server", Toast.LENGTH_SHORT).show();
                            }
                        }
                    }, new Response.ErrorListener() {
                        @Override
                        public void onErrorResponse(VolleyError error) {
                            progressDialog.dismiss();
                            if (error instanceof ServerError) {
                                Toast.makeText(Ttpm_Login.this, "Server Error", Toast.LENGTH_SHORT).show();
                            } else if (error instanceof TimeoutError) {
                                Toast.makeText(Ttpm_Login.this, "Connection Timed Out", Toast.LENGTH_SHORT).show();
                            } else if (error instanceof NetworkError) {
                                Toast.makeText(Ttpm_Login.this, "Bad Network Connection", Toast.LENGTH_SHORT).show();
                            }
                        }
                    });
                    requestQueue.add(loginRequest);
                }
            }
        });
    }

    private void initialize() {
        tenantname = findViewById(R.id.tenantname);
        passWord = findViewById(R.id.password);
        bt_login = findViewById(R.id.login);
    }

    private boolean validateUsername(String string) {
        //Validating the entered USERNAME
        if (string.equals("")) {
            tenantname.setError("Enter a Username");
            return false;
        } else if (string.length() > 50) {
            tenantname.setError("Maximum 50 Characters");
            return false;
        } else if (string.length() < 6) {
            tenantname.setError("Minimum 6 Characters");
            return false;
        }
        tenantname.setEnabled(false);
        return true;
    }

    private boolean validatePassword(String string) {
        //Validating the entered PASSWORD
        if (string.equals("")) {
            passWord.setError("Enter Your Password");
            return false;
        } else if (string.length() > 32) {
            passWord.setError("Maximum 32 Characters");
            return false;
        }
//        else if (string.length() < 8) {
//            passWord.setError("Minimum 8 Characters");
//            return false;
//        }
//
        passWord.setEnabled(false);
        return true;
    }

}

这是我执行登录时的 logcat /image/94CGd.png

请帮忙。提前致谢

Answer 1

例如如果查看 JSON 结构，将会是这样的:

{

“结果”:[ { “用户登录”:“xyz”， “用户登录密码”:123456 }]}

首先，将 JSON 对象转换为 JSONArray 对象，如下所示:

    JSONArray jsonarr_1 = (JSONArray) jobj.get(“results”); 
 for(int i=0;i<jsonarr_1.size();i++)
{
  JSONObject jsonobj_1 = (JSONObject)jsonarr_1.get(i);
  System.out.println(“Elements under results array”);
  System.out.println(“\nuser_login: ” +jsonobj_1.get(“user_login”));
  System.out.println(“user_login_password: ” +jsonobj_1.get(“user_login_password”));
}

并将参数发送到服务器:

 protected Map<String, String> getParams() {

          /** Pass the parameters to according to the API.*/
            Map<String, String> params = new HashMap<String, String>();
            params.put("user_login", edt_email.getText().toString().trim());
            params.put("user_login_password", edt_password.getText().toString().trim());
            return params;
        }
    };
    /** Adding request to request queue*/
    AppController.getInstance().addToRequestQueue(jsonObjReq, cancel_login_api);
}