如何将json代码放入我的应用程序

时间：2016-12-19 07:22:41

标签： java android json listview

我正在进行JSON解析，在我的TypeMenu java文件中我收到来自服务器和放大器的响应当我点击列表视图中的项目时，我应该在列表视图中的下一个活动中获得相关项目。该listview项目也来自服务器。

这里我想从所选项目中获取项目，但我在下一个活动中获取所有项目来自SubMenu.java。就像我选择披萨所以在下一个活动中我应该得到与披萨相关的项目这里是我的TypeMenu.java文件。

package com.example.zeba.broccoli;

  import android.app.ProgressDialog;
  import android.content.Intent;
  import android.os.AsyncTask;
  import android.os.Bundle;
  import android.support.v7.app.AppCompatActivity;
  import android.support.v7.widget.Toolbar;
  import android.util.Log;
  import android.view.MenuItem;
  import android.view.View;
  import android.widget.AdapterView;
  import android.widget.ListAdapter;
  import android.widget.ListView;
  import android.widget.SimpleAdapter;
  import android.widget.TextView;
  import android.widget.Toast;

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

  import java.util.ArrayList;
  import java.util.HashMap;



 public class TypeMenu extends AppCompatActivity {

 private String TAG = TypeMenu.class.getSimpleName();
 String bid;

private ProgressDialog pDialog;
private ListView lv;
private static final String TAG_BID = "bid";

// URL to get contacts JSON
private static String url = "http://cloud.granddubai.com/brtemp/index.php";

ArrayList<HashMap<String, String>> contactList;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_type_menu);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);




    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    contactList = new ArrayList<>();

    lv = (ListView) findViewById(R.id.list);

    new GetContacts().execute();


    // on seleting single product
    // launching Edit Product Screen
    lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

            // getting values from selected ListItem

            HashMap<String, String> selected = contactList.get(position);
            String keyId = new ArrayList<>(selected.keySet()).get(0);
            String type_items  = selected.get(keyId);
            Intent in = new Intent(getApplicationContext(), SubMenu.class);
           //  sending pid to next activity
            in.putExtra(TAG_BID ,type_items );
            startActivityForResult(in, 100);
            Toast.makeText(getApplicationContext(),"Toast" +type_items ,Toast.LENGTH_LONG).show();
        }
    });













}

/**
 * Async task class to get json by making HTTP call
 */
private class GetContacts extends AsyncTask<Void, Void, Void> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        // Showing progress dialog
        pDialog = new ProgressDialog(TypeMenu.this);
        pDialog.setMessage("Please wait...");
        pDialog.setCancelable(false);
        pDialog.show();
       // Toast.makeText(getApplicationContext(),"Toast",Toast.LENGTH_LONG).show();

    }

    @Override
    protected Void doInBackground(Void... arg0) {
        HttpHandler sh = new HttpHandler();

        // Making a request to url and getting response
     String jsonStr = sh.makeServiceCall(url);

        Log.e(TAG, "Response from url: " + jsonStr);





        if (jsonStr != null) {
            try {
                JSONArray jsonArry = new JSONArray(jsonStr);

                for (int i = 0; i < jsonArry.length(); i++)
                {

                    JSONObject c = jsonArry.getJSONObject(i);
                    String id = c.getString("id");
                    String type = c.getString("type");
                    HashMap<String, String> contact = new HashMap<>();

                   contact.put("id", id);
                    contact.put("type", type);
                    contactList.add(contact);


                }
            } catch (final JSONException e) {
                Log.e(TAG, "Json parsing error: " + e.getMessage());
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(getApplicationContext(),
                                "Json parsing error: " + e.getMessage(),
                                Toast.LENGTH_LONG)
                                .show();
                    }
                });

            }
        } else {
            Log.e(TAG, "Couldn't get json from server.");
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    Toast.makeText(getApplicationContext(),
                            "Couldn't get json from server. Check LogCat for possible errors!",
                            Toast.LENGTH_LONG)
                            .show();
                }
            });

        }

           return null;
       }



        @Override
             protected void onPostExecute(Void result) {
              super.onPostExecute(result);
            // Dismiss the progress dialog
            if (pDialog.isShowing())
                pDialog.dismiss();
            /**
             * Updating parsed JSON data into ListView
             * */
               ListAdapter adapter = new SimpleAdapter(
                    TypeMenu.this, contactList,
                    R.layout.list_item, new String[]{ "type","id"},
                    new int[]{
                    R.id.type,R.id.id});

            lv.setAdapter(adapter);
        }

}
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                onBackPressed();
                return true;
            default:
                return super.onOptionsItemSelected(item);
            }
          }
          }

这是我的SubMenu.java文件：

    package com.example.zeba.broccoli;

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;

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

import java.util.ArrayList;
import java.util.HashMap;



public class SubMenu  extends AppCompatActivity {

    private String TAG = SubMenu.class.getSimpleName();
    String type_items ;

    private ProgressDialog pDialog;
    private ListView lv;
    private static final String TAG_BID = "bid";

    // URL to get contacts JSON
    private static String url = "http://cloud.granddubai.com/broccoli/menu_typeitem.php";

    ArrayList<HashMap<String, String>> contactList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_type_menu);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);


        Intent i = getIntent();

        // getting product id (pid) from intent
        type_items = i.getStringExtra(TAG_BID);
        Toast.makeText(getApplicationContext(),"Toast 12" + type_items ,Toast.LENGTH_LONG).show();

        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        contactList = new ArrayList<>();

        lv = (ListView) findViewById(R.id.list);

        new GetContacts().execute();


        // on seleting single product
        // launching Edit Product Screen
        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                pDialog = new ProgressDialog(SubMenu.this);
                pDialog.setMessage("Loading book details.");
                pDialog.setIndeterminate(false);
                pDialog.setCancelable(true);
                pDialog.show();
                // getting values from selected ListItem

                HashMap<String, String> selected = contactList.get(position);
                String keyId = new ArrayList<>(selected.keySet()).get(0);
                String type_items = selected.get(keyId);
                //Intent in = new Intent(getApplicationContext(), SubMenu.class);
                // sending pid to next activity
                // in.putExtra(TAG_BID ,text);
                //startActivityForResult(in, 100);
                Toast.makeText(getApplicationContext(),"Toast" + type_items,Toast.LENGTH_LONG).show();
            }
        });













    }

    /**
     * Async task class to get json by making HTTP call
     */
    private class GetContacts extends AsyncTask<Void, Void, Void> {

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            // Showing progress dialog
            pDialog = new ProgressDialog(SubMenu.this);
            pDialog.setMessage("Please wait...");
            pDialog.setCancelable(false);
            pDialog.show();
            // Toast.makeText(getApplicationContext(),"Toast",Toast.LENGTH_LONG).show();

        }

        @Override
        protected Void doInBackground(Void... arg0) {
            HttpHandler sh = new HttpHandler();

            // Making a request to url and getting response
            String jsonStr = sh.makeServiceCall(url);

            Log.e(TAG, "Response from url: " + jsonStr);





            if (jsonStr != null) {
                try {
                    JSONArray jsonArry = new JSONArray(jsonStr);

                    for (int i = 0; i < jsonArry.length(); i++)
                    {

                        JSONObject c = jsonArry.getJSONObject(i);
                        String id = c.getString("id");
                        String name = c.getString("name");
                        HashMap<String, String> contact = new HashMap<>();

                        contact.put("id", id);
                        contact.put("name", name);
                        contactList.add(contact);


                    }
                } catch (final JSONException e) {
                    Log.e(TAG, "Json parsing error: " + e.getMessage());
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            Toast.makeText(getApplicationContext(),
                                    "Json parsing error: " + e.getMessage(),
                                    Toast.LENGTH_LONG)
                                    .show();
                        }
                    });

                }
            } else {
                Log.e(TAG, "Couldn't get json from server.");
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(getApplicationContext(),
                                "Couldn't get json from server. Check LogCat for possible errors!",
                                Toast.LENGTH_LONG)
                                .show();
                    }
                });

            }

            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            super.onPostExecute(result);
            // Dismiss the progress dialog
            if (pDialog.isShowing())
                pDialog.dismiss();
            /**
             * Updating parsed JSON data into ListView
             * */
            ListAdapter adapter = new SimpleAdapter(
                    SubMenu.this, contactList,
                    R.layout.list_item, new String[]{ "name","id"},
                    new int[]{
                            R.id.type});
            lv.setAdapter(adapter);
        }

    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                onBackPressed();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }
}

这是我的php文件.. 

<?php 
include ('config.php');

if (isset($_GET["mid"])) 
{
    $type_items = $_GET['mid'];

$sql = mysqli_query($conn,"SELECT * FROM main_menu_items WHERE type_items = '".$type_items."'");                                                          
$arr = array();
$i=0;
while($result = mysqli_fetch_array($sql))
{
$arr[$i]['id']= $result['id'];
$arr[$i]['name']= $result['name'];
$i++;
}
}
echo json_encode($arr);

?>

这里我没有得到任何东西只有null当我在浏览器上使用url并且如果我在设备上检查它时它会显示我这样的错误 ＆＃34; Json解析错误：类型org.json.JSONObject $ 1的值null无法转换为JsonArray＆＃34;

2 个答案:

答案 0 :(得分：1)

不要做这个愚蠢的事情

jsut添加Json Libray从http://www.java2s.com/Code/Jar/g/Downloadgson222jar.htm下载 或者

dependencies {
  compile 'com.google.code.gson:gson:2.6.2'
}

就这样做吧 电影是pojo类的回应

Gson gson = new GsonBuilder().create();
Movie movie = gson.fromJson(response, Movie.class);

更多详情 - https://guides.codepath.com/android/Leveraging-the-Gson-Library和https://stackoverflow.com/a/22754230/4741746以及https://stackoverflow.com/a/28392599/4741746

创建类似

的类 
public class Responce implements Serializable {

    @SerializedName("result")
    public ArrayList<Data>  result;

    public class Data implements Serializable {

    @SerializedName("name")
    public String  name;


    }
}

然后在响应中解析它（把这3行放在这行下面String jsonStr = sh.makeServiceCall（url）; this line）

Gson gson = new GsonBuilder().create();
Responce mResponce = gson.fromJson(jsonStr , Responce .class);
String mName =mResponce.result.name;

答案 1 :(得分：0)

将JsonArray替换为像这样的JSONObject 

    JSONObject jsonObj = new JSONObject(jsonStr);
    String id = jsonObj.getString("id");
    String name = jsonObj.getString("name");
    HashMap<String, String> contact = new HashMap<>();

    contact.put("id", id);
    contact.put("name", name);
    contactList.add(contact);
相关问题
最新问题