java - Android JSON 解析 - 在错误的字符 0 处输入结束

Question

这是我第一次制作解析 JSON 数据的 Android 应用程序。但是，我遇到了有关 JSON 解析的错误。我尝试过用谷歌搜索这个问题，但大多数解决方案都不适合我。

这是我的代码:

MainActivity.java

package com.example.jsonparser;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.util.Log;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
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 MainActivity extends AppCompatActivity {

    private String TAG = MainActivity.class.getSimpleName();

    private ProgressDialog pDialog;
    private ListView lv;

    // URL to get contacts JSON
    private static String url = "http://pastebin.com/raw/79D93HR4";

    ArrayList<HashMap<String, String>> itemList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        itemList = new ArrayList<>();

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

        new GetItems().execute();
    }

    /**
     * Async task class to get json by making HTTP call
     */
    private class GetItems extends AsyncTask<Void, Void, Void> {
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            // Showing progress dialog
            pDialog = new ProgressDialog(MainActivity.this);
            pDialog.setMessage("Please wait...");
            pDialog.setCancelable(false);
            pDialog.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 {
                    //JSONObject jsonObj = new JSONObject(jsonStr);

                    // Getting JSON Array node
                    JSONArray items = new JSONArray("");

                    // looping through All Contacts
                    for (int i = 0; i < items.length(); i++) {
                        JSONObject c = items.getJSONObject(i);

                        String ItemCode = c.getString("ItemCode");
                        String ItemName = c.getString("ItemName");

                        // tmp hash map for single item
                        HashMap<String, String> item = new HashMap<>();

                        // adding each child node to HashMap key => value
                        item.put("ItemCode", ItemCode);
                        item.put("ItemName", ItemName);

                        // adding item to item list
                        itemList.add(item);
                    }

                } 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(
                    MainActivity.this, itemList,
                    R.layout.list_item, new String[]{"ItemCode", "ItemName"}, new int[]{R.id.ItemCode,
                    R.id.ItemName});

            lv.setAdapter(adapter);
        }

    }
}

HttpHandler.java

package com.example.jsonparser;

/**
 * Created by Me on 1/3/2017.
 */
import android.util.Log;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;

public class HttpHandler {

    private static final String TAG = HttpHandler.class.getSimpleName();

    public HttpHandler() {
    }

    public String makeServiceCall(String reqUrl) {
        String response = null;
        try {
            URL url = new URL(reqUrl);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            // read the response
            InputStream in = new BufferedInputStream(conn.getInputStream());
            response = convertStreamToString(in);
        } catch (MalformedURLException e) {
            Log.e(TAG, "MalformedURLException: " + e.getMessage());
        } catch (ProtocolException e) {
            Log.e(TAG, "ProtocolException: " + e.getMessage());
        } catch (IOException e) {
            Log.e(TAG, "IOException: " + e.getMessage());
        } catch (Exception e) {
            Log.e(TAG, "Exception: " + e.getMessage());
        }
        return response;
    }

    private String convertStreamToString(InputStream is) {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();

        String line;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line).append('\n');
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }
}

这是错误代码:

01-04 00:13:05.366 10069-10112/com.example.jsonparser E/MainActivity: Response from url: [{"ItemCode":"C0100001  ","ItemName":"UBNT CRM-P-CRM Point","LocationCode":null,"ViewBy":null,"SearchDate":null,"CutOffDate":"\/Date(-62135596800000)\/","CurrentDate":"\/Date(-62135596800000)\/"},{"ItemCode":"C0100002  ","ItemName":"UBNT ETH-SP-Ethernet Surge Protector","LocationCode":null,"ViewBy":null,"SearchDate":null,"CutOffDate":"\/Date(-62135596800000)\/","CurrentDate":"\/Date(-62135596800000)\/"}]
01-04 00:13:05.367 10069-10112/com.example.jsonparser E/MainActivity: Json parsing error: End of input at character 0 of 

我做错了什么？

Answer 1

JSONArray 需要一个 json 字符串。在 JSONArray 中传递您的 json 初始化

JSONArray items = new JSONArray(jsonStr );