I have a android application, where i extract data from the multiple urls and save then as arraylist of string. It works fine, but for fetching data from 13 urls, it takes close to 15-20 sec. Where as fetching the data from same set of urls take 3-4 sec in same app built using phonegap. Here is the code below.
#Override
protected String doInBackground(String... params) {
client = new DefaultHttpClient();
for(int i=0;i<url.size();i++)
{
get = new HttpGet(url.get(i));
try {
response = client.execute(get);
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
entity = response.getEntity();
InputStream is = null;
try {
is = entity.getContent();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
BufferedReader reader = new BufferedReader(
new InputStreamReader(is));
StringBuffer buffer = new StringBuffer();
String line = null;
do {
try {
line = reader.readLine();
} catch (IOException e) {
e.printStackTrace();
}
buffer.append(line);
} while (line != null);
String str = buffer.toString();
param.add(str);
}
return null;
}
Could anyone please suggest how i can speed this execution and reduce the extraction time.
You could try starting a separate thread for each iteration from the for loop.
Smth like this :
for(int i = 0; i < url.size(); i++){
//start thread that gets data from url and adds it to the list
}
Related
I'm participating in an online Android course and have (so far) gotten no response on their forum to this issue. I'm using Android Studio on Windows 8.1.
I have the following function to read a file and load an adapter:
private void loadItems() {
BufferedReader reader = null;
try {
FileInputStream fis = openFileInput(FILE_NAME);
reader = new BufferedReader(new InputStreamReader(fis));
String title = null;
String priority = null;
String status = null;
Date date = null;
while (null != (title = reader.readLine())) {
priority = reader.readLine();
status = reader.readLine();
date = ToDoItem.FORMAT.parse(reader.readLine());
mAdapter.add(new ToDoItem(title, Priority.valueOf(priority),
Status.valueOf(status), date));
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
} finally {
if (null != reader) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
My questions are:
I don't find the file named by the constant FILE_NAME anywhere on my hard drive. If the file doesn't exist shouldn't openFileInput() throw FileNotFoundException?
Why does InputStreamReader not throw an error?
Via the debugger, I've watched as The logic guarding entry into the WHILE construct happily allows a null value in the title variable to enter the loop. Am I missing something here?
Thanks in advance for any light anyone can shed!!
Markb
I am facing one problem in StringBuffer concatination for appending large characters of String from JSONArray.
My data is huge and it is coming in log after iteration of 205 indexes of Array properly
but when I am appending each row String in StringBuffer or StringBuilder from JSONArray, so it is taking on 4063 characters only not appending all characters present in JSON Array but iteration doesn't break and goes till complete 204 rows.
String outputFinal = null;
try {
StringBuilder cryptedString = new StringBuilder(1000000);
JSONObject object = new JSONObject(response);
JSONArray serverCustArr = object.getJSONArray("ServerData");
Log.d("TAG", "SurverCust Arr "+serverCustArr.length());
for (int i = 0; i < serverCustArr.length(); i++) {
String loclCryptStr = serverCustArr.getString(i);
Log.d("TAG", "Loop Count : "+i);
cryptedString.append(loclCryptStr);
}
Log.d("TAG", "Output :"+cryptedString.toString());
CryptLib _crypt = new CryptLib();
String key = this.preference.getEncryptionKey();
String iv = this.preference.getEncryptionIV();
outputFinal = _crypt.decrypt(cryptedString.toString(), key,iv); //decrypt
System.out.println("decrypted text=" + outputFinal);
} catch (Exception e) {
e.printStackTrace();
}
My JSONArray contacts 119797 characters in 205 and after iteration for appending in StringBuffer, I have to decrypt it with library that takes string for decryption. But StringBuffer is not having complete data of 119797 characters.
And Exception is because string is not complete, I am enclosing files on link below for reference and also using cross platform CryptLib uses AES 256 for encryption easily find on Github
3 Files With Original and Logged text
Dont use StringBuffer , instead use StringBuilder ..here's the detailed Explaination
http://stackoverflow.com/questions/11908665/max-size-for-string-buffer
Hope this helps. :)
EDIT
this is the code that i used to read whole string ...
public void parseLongString(String sourceFile, String path) {
String sourceString = "";
try {
BufferedReader br = new BufferedReader(new FileReader(sourceFile));
// use this for getting Keys Listing as Input
StringBuilder sb = new StringBuilder();
String line = br.readLine();
while (line != null) {
sb.append(line);
line = br.readLine();
}
br.close();
sourceString = sb.toString();
sourceString = sourceString.toUpperCase();
System.out.println(sourceString.length());
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
File file = new File(path);
FileWriter fileWriter = null;
BufferedWriter bufferFileWriter = null;
try {
fileWriter = new FileWriter(file, true);
bufferFileWriter = new BufferedWriter(fileWriter);
} catch (IOException e1) {
System.out.println(" IOException");
e1.printStackTrace();
}
try {
fileWriter.append(sourceString);
bufferFileWriter.close();
fileWriter.close();
} catch (IOException e) {
System.out.println("IOException");
e.printStackTrace();
}
}
and this is outPut file where i am just converting it to uppercase .
https://www.dropbox.com/s/yecq0wfeao672hu/RealTextCypher%20copy_replaced.txt?dl=0
hope this helps!
EDIT 2
If u are still looking for something ..you can also try STRINGWRITER
syntax would be
StringWriter writer = new StringWriter();
try {
IOUtils.copy(request.getInputStream(), writer, "UTF-8");
} catch (IOException e2) {
// TODO Auto-generated catch block
e2.printStackTrace();
}
String theString = writer.toString();
I am trying to check the status of a SHOUTcast stream using this URL:
http://85.17.167.136:8684/7.html
... which returns data like:
<HTML><meta http-equiv="Pragma" content="no-cache"></head><body>7,1,77,100,7,128,+44(0)7908 340 811 Follow Us #visionradiouk</body></html>
I know that the after the first comma returns 1 if the stream is up and running or returns 0 if the stream is down. My problem is getting the html of that page? I use this code, which works on other websites like Google etc.
TextView tView = (TextView) findViewById(R.id.textView1);
String htmlCode = "";
try {
URL url = new URL("http://85.17.167.136:8684/7.html");
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
String inputLine;
while ((inputLine = in.readLine())!= null)
htmlCode += inputLine;
System.out.println(htmlCode);
tView.setText(htmlCode);
in.close();
} catch (Exception e){
System.out.println("error");
}
}
Any ideas on what I am doing wrong?
Heres Pulsarman325's working solution, tidied up, with a little extra stuff i had to add to get it to work (try/catch and variable initialisations)
String url = "http://molestia.ponify.me:8062";
URL url2=null;
try
{
url2 = new URL(url + "/7.html");
}
catch (MalformedURLException e1)
{
e1.printStackTrace();
}
URLConnection con=null;
try
{
con = url2.openConnection();
}
catch (IOException e1)
{
e1.printStackTrace();
}
con.setRequestProperty("User-Agent", "Mozilla/5.0");
Reader r = null;
try
{
r = new InputStreamReader(con.getInputStream());
}
catch (IOException e)
{
e.printStackTrace();
}
StringBuilder buf = new StringBuilder();
int ch=0;
while (true)
{
try
{
ch = r.read();
}
catch (IOException e)
{
e.printStackTrace();
}
if (ch < 0)
break;
buf.append((char) ch);
}
String str = buf.toString();
String trackinfo = str.split(",")[6].split("</body>")[0];
Log.d("HTML", trackinfo);
I am looking to pull data from my websites JSON url and display only one object in the textview. I was able to parse the entire JSON array, but not the specific object.
Here's the JSON on the site:
{"id":3,"day":" an A","created_at":"2013-11-06T12:30:59.023Z","updated_at":"2013-11-06T12:30:59.023Z"}
As you can see, it's pretty simple, but basically all I want to pull is the
"day":" an A"
and display it in my textview as "an A". Until now, I've only been able to pull the entire array.
A reference to this or any solution would be greatly appreciated!
Thanks in advance!
MainActivity Class:
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.parseDay);
TextView textView1 = null;
try {
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try{
JSONObject json=new JSONObject("day");
try {
String day =json.getString("day");
textView1.setText(day);
} catch (JSONException e) {
e.printStackTrace();
}
}
//catch (JSONException e) {
// e.printStackTrace();
//}
catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
and My GetMethod:
public class GetMethod {
public String getInternetData() throws Exception {
BufferedReader in = null;
String data = null;
try {
HttpClient client = new DefaultHttpClient();
URI website = new URI("http://www.xelatechnologies.com/hfdays/show.json");
HttpGet request = new HttpGet();
request.setURI(website);
HttpResponse response = client.execute(request);
in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
StringBuffer sb = new StringBuffer("");
String l = "";
String nl = System.getProperty("line.separator");
while ((l = in.readLine()) !=null) {
sb.append(l + nl);
}
in.close();
data = sb.toString();
return data;
}
finally {
if (in !=null){
try{
in.close();
return data;
}catch (Exception e){
e.printStackTrace();
}
}
}
}
I'm extremely new to JSON parsing so I'm sure it is not right at all. But it's worth a try!
The JSON you posted is a JSONObject. In java you can put that object into an JSONObject like this (You can use any serialize/deserializer you would like, many exist, for this example try org.json):
String json = "{\"id\":3,\"day\":\" an A\",\"created_at\":\"2013-11-06T12:30:59.023Z\",\"updated_at\":\"2013-11-06T12:30:59.023Z\"}";
JSONObject jsonObject = new JSONObject(json);
Now you have created a json object. Next you want to set the text on the text view. The key to get your value in this case is "day". So now all you have to do is use the provided getString(String value) method on the json object.
final String DAY = "day";
String dayValue= "";
try {
value = jsonObject.getString(DAY);
} catch (JSONException e) {
e.printStackTrace();
}
TextView textView = findViewById(R.id.text_view);
textView.setText(dayValue);
{"id":3,"day":" an A","created_at":"2013-11-06T12:30:59.023Z","updated_at":"2013-11-06T12:30:59.023Z"}
As its starts from '{' so it is an Object not Array
JSONObject json=new JSONObject("YOUR_JSON_STRING");
try {
String days=json.getString("day");
textview.setText(days);
} catch (JSONException e) {
e.printStackTrace();
}
Edited:
TextView textView1;
String response;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.parseDay);
textView1 = (TextView)findViewById(R.id.your_textview_id);//First Initialise TextView
GetMethod method=new GetMethod();
response=method. getInternetData();// Then get the Json response
try{
JSONObject json=new JSONObject(response);
try {
String day =json.getString("day");
textView1.setText(day);
} catch (JSONException e) {
e.printStackTrace();
}
}
catch (JSONException e) {
e.printStackTrace();
}
catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
And dont forget to add Internet Permission in Manifest file
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
Try like this.
I was previously using HttpClient and BasicNameValuePairs, for some reason i have to shift to HttpUrlConnection.
Hence this code, to make a HttpPost request with certain parameters:
public class MConnections {
static String BaseURL = "http://www.xxxxxxxxx.com";
static String charset = "UTF-8";
private static String result;
private static StringBuilder sb;
private static List<String> cookies = new ArrayList<String>();
public static String PostData(String url, String sa[][]) {
HttpURLConnection connection = null;
try {
connection = (HttpURLConnection) new URL(BaseURL + url)
.openConnection();
} catch (MalformedURLException e1) {
} catch (IOException e1) {
}
cookies = connection.getHeaderFields().get("Set-Cookie");
try{
connection.setDoOutput(true); // Triggers POST.
connection.setRequestProperty("Accept-Charset", charset);
connection.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded;charset=" + charset);
}catch (Exception e) {
//Here i get Exception that "java.lang.IllegalStateException: Already connected"
}
OutputStream output = null;
String query = "";
int n = sa.length;
for (int i = 0; i < n; i++) {
try {
query = query + sa[i][0] + "="
+ URLEncoder.encode(sa[i][1], "UTF-8");
} catch (UnsupportedEncodingException e) {
}
}
try {
output = connection.getOutputStream();
output.write(query.getBytes(charset));
} catch (Exception e) {
//Here i get Exception that "android: java.net.protocolException: Does not support output"
} finally {
if (output != null)
try {
output.close();
} catch (IOException e) {
}
}
InputStream response = null;
try {
response = connection.getInputStream();
} catch (IOException e) {
//Here i get Exception that "java.io.IOException: BufferedInputStream is closed"
} finally {
//But i am closing it here
connection.disconnect();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
response, "iso-8859-1"), 8);
sb = new StringBuilder();
sb.append(reader.readLine());
String line = "0";
while ((line = reader.readLine()) != null) {
sb.append("\n" + line);
}
response.close();
result = sb.toString();
} catch (Exception e) {
}
return result;
}
}
But i get such Exceptions as commented in the code.
Actually i am calling MConnections.PostData() twice from my Activity using a AsyncTask. This might cause the Exception: Already Connected but i am using connection.disconnect. But why am i still getting that Exception?
Am i using it the wrong way?
Thank You
For the protocol exception, try adding the following before you call getOutputStream():
connection.setDoOutput(true);
Discovered this answer thanks to Brian Roach's answer here: https://stackoverflow.com/a/14026377/387781
Side note: I was having this issue on my HTC Thunderbolt running Gingerbread, but not on my Nexus 4 running Jelly Bean.