我想从本地主机读取JSON文件但发生错误。我不知道出了什么问题。
JSONParser：
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
UpdateFromSite：
public class UpdateFromSite extends Activity {
ListView list;
TextView name;
TextView description;
TextView price;
Button Btngetdata;
ArrayList<HashMap<String, String>> newItemlist = new ArrayList<HashMap<String, String>>();
//URL to get JSON Array
private static String url = "http://localhost/json/newItem.json";
//JSON Node Names
private static final String TAG_ITEM = "NewItem";
private static final String TAG_NAME = "name";
private static final String TAG_DESCRIPTION = "description";
private static final String TAG_PRICE = "price";
JSONArray NewItem = null;
@Override
protected void onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(R.layout.updateapp);
newItemlist = new ArrayList<HashMap<String, String>>();
Btngetdata = (Button)findViewById(R.id.getdata);
Btngetdata.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//check internet connection
Boolean isInternetPresent = false;
ConnectionDetector cd;
cd = new ConnectionDetector(getApplicationContext());
isInternetPresent = cd.isConnectingToInternet();
if (isInternetPresent) {
new JSONParse().execute(); }
else {
Toast.makeText(getApplicationContext(),"You don't have internet connection.",Toast.LENGTH_SHORT).show();
}
}
});
}
private class JSONParse extends AsyncTask<String, String, JSONObject> {
private ProgressDialog pDialog;
@Override
protected void onPreExecute() {
super.onPreExecute();
name = (TextView)findViewById(R.id.nameNewItem);
description = (TextView)findViewById(R.id.descriptionNewItem);
price = (TextView)findViewById(R.id.priceNewItem);
pDialog = new ProgressDialog(UpdateFromSite.this);
pDialog.setMessage("Getting Data ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected JSONObject doInBackground(String... args) {
try {
JSONParser jParser = new JSONParser();
// Getting JSON from URL
JSONObject json = jParser.getJSONFromUrl(url);
return json;
} catch (Exception ex){
Toast.makeText(getApplicationContext(),"network problem",Toast.LENGTH_SHORT).show();
return null;
}
}
@Override
protected void onPostExecute(JSONObject json) {
pDialog.dismiss();
try {
// Getting JSON Array from URL
NewItem = json.getJSONArray(TAG_ITEM);
for(int i = 0; i < NewItem.length(); i++){
JSONObject c = NewItem.getJSONObject(i);
// Storing JSON item in a Variable
String name = c.getString(TAG_NAME);
String description = c.getString(TAG_DESCRIPTION);
int price = c.getInt(TAG_PRICE);
// Adding value HashMap key => value
HashMap<String, String> map = new HashMap<String, String>();
map.put(TAG_NAME, name);
map.put(TAG_DESCRIPTION, description);
map.put(TAG_PRICE, Integer.toString(price));
newItemlist.add(map);
list=(ListView)findViewById(R.id.listupdate);
ListAdapter adapter = new SimpleAdapter(UpdateFromSite.this, newItemlist,
R.layout.updateapprow,
new String[] { TAG_NAME,TAG_DESCRIPTION, TAG_PRICE }, new int[] {
R.id.nameNewItem,R.id.descriptionNewItem, R.id.priceNewItem});
list.setAdapter(adapter);
}
}
catch (Exception e) {
Toast.makeText(getApplicationContext(),"network problem",Toast.LENGTH_SHORT).show();
}
}
}
}
错误：（logcat的）
12-12 20:43:26.292: WARN/System.err(1069): org.apache.http.conn.HttpHostConnectException: Connection to http://localhost refused
12-12 20:43:26.292: WARN/System.err(1069): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:178)
12-12 20:43:26.302: WARN/System.err(1069): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
12-12 20:43:26.302: WARN/System.err(1069): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
12-12 20:43:26.302: WARN/System.err(1069): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:359)
12-12 20:43:26.302: WARN/System.err(1069): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
12-12 20:43:26.302: WARN/System.err(1069): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
12-12 20:43:26.312: WARN/System.err(1069): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
12-12 20:43:26.312: WARN/System.err(1069): at com.example.easyshopping.JSONParser.getJSONFromUrl(JSONParser.java:31)
12-12 20:43:26.312: WARN/System.err(1069): at com.example.easyshopping.UpdateFromSite$JSONParse.doInBackground(UpdateFromSite.java:89)
12-12 20:43:26.312: WARN/System.err(1069): at com.example.easyshopping.UpdateFromSite$JSONParse.doInBackground(UpdateFromSite.java:65)
12-12 20:43:26.312: WARN/System.err(1069): at android.os.AsyncTask$2.call(AsyncTask.java:185)
12-12 20:43:26.312: WARN/System.err(1069): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
12-12 20:43:26.312: WARN/System.err(1069): at java.util.concurrent.FutureTask.run(FutureTask.java:138)
12-12 20:43:26.312: WARN/System.err(1069): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
12-12 20:43:26.332: WARN/System.err(1069): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
12-12 20:43:26.332: WARN/System.err(1069): at java.lang.Thread.run(Thread.java:1019)
12-12 20:43:26.345: WARN/System.err(1069): Caused by: java.net.ConnectException: /127.0.0.1:80 - Connection refused
12-12 20:43:26.352: WARN/System.err(1069): at org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:207)
12-12 20:43:26.352: WARN/System.err(1069): at org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:437)
12-12 20:43:26.352: WARN/System.err(1069): at java.net.Socket.connect(Socket.java:983)
12-12 20:43:26.352: WARN/System.err(1069): at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
12-12 20:43:26.352: WARN/System.err(1069): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:143)
12-12 20:43:26.352: WARN/System.err(1069): ... 15 more
12-12 20:43:26.364: ERROR/Buffer Error(1069): Error converting result java.lang.NullPointerException
12-12 20:43:26.364: ERROR/JSON Parser(1069): Error parsing data org.json.JSONException: End of input at character 0 of
12-12 20:43:26.502: WARN/InputManagerService(77): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@4089e480
myJsonFile：
{"NewItem:":[{"name":"Roast Ground Coffee","description":"Folgers Medium Classic Roast Ground Coffee 339 oz","price":8},{"name":"Seattle coffee","description":"Seattles Best Coffee Level 3 Whole Bean 12oz","price":10},{"name":"Medium Roast Bean Coffee","description":"Dunkin Donuts Original Blend Medium Roast Whole Bean Coffee 12 oz","price":6},{"name":"Espresso coffee","description":"Starbucks Dark Espresso Roast Whole Bean Coffee 12 oz","price":12},
{"name":"China Green Tea","description":"Tazo China Green Tips Tea 20 filterbags","price":8},{"name":"China Organic Green","description":"Uncle Lees Legends of China Organic Green Tea 100 Tea Bags","price":15},{"name":"Black Tea","description":"Tazo Earl Grey Black Tea 20 count","price":10},{"name":"Chai Spiced Black Tea","description":"Tazo Decaf Chai Spiced Black Tea Latte Concentrate 32 oz","price":5},
{"name":"Passion Tea","description":"Tazo Iced Passion Tea 6ct","price":11},{"name":"Peach Iced Tea","description":"Lipton Diet Peach Iced Tea Mix 2.9 oz","price":12}]}