I am reading the contents of buffered reader in the below method:
public static String readBuffer(Reader reader, int limit) throws IOException
{
StringBuilder sb = new StringBuilder();
for (int i = 0; i < limit; i++) {
int c = reader.read();
if (c == -1) {
return ((sb.length() > 0) ? sb.toString() : null);
}
if (((char) c == '\n') || ((char) c == '\r')) {
break;
}
sb.append((char) c);
}
return sb.toString();
}
I am invoking this method later to test -
URL url = new URL("http://www.oracle.com/");
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
StringBuffer sb = new StringBuffer();
String line=null;
while((line=readBuffer(in, 2048))!=null) {
sb.append(line);
}
System.out.println(sb.toString());
My question here is, I am returning the contents of bufferedreader into a string in my first method, and appending these String contents into a StringBuffer again in the second method, and reading out of it. Is this the right way? Any other way I can read the String contents that has contents from url?Please advise.
I hope this works -
public static String readFromURL(){
URL url = new URL("http://www.oracle.com/");
StringBuilder responseBuilder = new StringBuilder();
HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
httpCon.setDoOutput(true);
httpCon.setDoInput(true);
int resCode = httpCon.getResponseCode();
InputStream is = null;
if (resCode == 200) {
is = httpCon.getInputStream();
BufferedReader reader = new BufferedReader(
new InputStreamReader(is));
String response = null;
while (true) {
response = reader.readLine();
if (response == null)
break;
responseBuilder.append(response);
}
}
return responseBuilder.toString();
}
Related
How can I use try with resource to cover all corners when it comes to getInputStream and getErrorStream
HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
BufferedReader bufferedReader;
if(connection.getResponseCode() == 200) {
bufferedReader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
} else {
bufferedReader = new BufferedReader(new InputStreamReader(connection.getErrorStream()));
}
String line;
StringBuilder result = new StringBuilder();
while((line = bufferedReader.readLine()) != null) {result.append(line);}
bufferedReader.close();
if(connection.getResponseCode() != 200) {
throw new Gson().fromJson(result.toString(), FooException.class);
} else {
return new Gson().fromJson(result.toString(), Foo.class);
}
If I understand your question, then you might use a ternary operator ? : to construct your BufferedReader in a try-with-resources. Also, I'd save the responseCode to a local variable. Something like,
StringBuilder result = new StringBuilder();
int responseCode = connection.getResponseCode();
try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(
responseCode == 200 ? connection.getInputStream()
: connection.getErrorStream()))) {
String line;
while ((line = bufferedReader.readLine()) != null) {
result.append(line);
}
}
if (responseCode != 200) {
throw new Gson().fromJson(result.toString(), FooException.class);
} else {
return new Gson().fromJson(result.toString(), Foo.class);
}
private static String[] getUrlSource2(String site) throws IOException {
List<String> myList = new ArrayList<String>();
URL url = new URL(site);
HttpURLConnection conn = (HttpURLConnection) url.openConnection(); // Cast shouldn't fail
HttpURLConnection.setFollowRedirects(true);
conn.setRequestProperty("Accept-Encoding", "gzip, deflate");
String encoding = conn.getContentEncoding();
InputStream inStr = null;
if (encoding != null && encoding.equalsIgnoreCase("gzip")) {
inStr = new GZIPInputStream(conn.getInputStream());
} else {
inStr = conn.getInputStream();
}
BufferedReader in = new BufferedReader(new InputStreamReader(inStr,"UTF-8"));
String inputLine;
while ((inputLine = in.readLine()) != null)
myList.add(inputLine);
in.close();
String[] arr = myList.toArray(new String[myList.size()]);
return arr;
}
This is my getSource method, for some reason it just gives me part of the source code of a url page, I can't figure out why..
If yo could help, I would be deeply apreciatted.
For example if you run this:
public class Main {
public static void main(String[] args){
try {
String [] A =getUrlSource2("https://www.google.pt/");
for(int i=0;i<A.length;i++){
System.out.print(String.valueOf(i)+" ");
System.out.println(A[i]);
}
}catch(IOException e){
}
}
You will get 5 lines of source code when you should get about 300/400
So I made this piece of code:
options = getURL("http://florens.be/EnterRoomAlert/options.txt");
soundOptionStartPos = options.indexOf("sound") + 6;
soundOptionEndPos = options.indexOf("e", soundOptionStartPos) + 1;
soundOptionResult = options.substring(soundOptionStartPos, soundOptionEndPos);
And this is the getURL method:
public static String getURL(String urlToRead) throws Exception {
StringBuilder result = new StringBuilder();
URL url = new URL(urlToRead);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line;
while ((line = rd.readLine()) != null) {
result.append(line);
}
rd.close();
return result.toString();
}
This is the content off the file options.txt:
sound=false
mail=false
database=false
Everytime I run this code and print out soundOptionResult I get true.
here what's the problem
I have problem when I tried to get String from my StringBuilder
BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()), 128 * 1024);
StringBuilder dataResponseSB = new StringBuilder();
String line ;
while ((line = reader.readLine()) != null) {
dataResponseSB.append(line);
if (DataFactory.DEBUG_MODE) {
// all data here are complete
Log.i("===LoadDataActivity","line: "+line);
}
}
String rawdata = new String(dataResponseSB); // dataResponseSB.toString(); also not work
if (DataFactory.DEBUG_MODE) {
// data here are lost
Log.i("===LoadDataActivity","rawdata: "+rawdata);
}
(-) I receive a huge data from BufferedReader .readLine()
(-) I use Log to check and sure that I got about 5 line of 8000 Buffer Size per line and I am very sure that I have receive all data properly
(1) I append each line to StringBuilder Here
(-) after I append all the line to StringBuilder
(2) I try to convert it back to String
(-) Now, the problem, the when I check to new String here, the data have only 8192 (it should contain at least 30,000 or more)
What is the problem ? I am not sure it lost when it append to StringBuilder(1) or it lost when it convert back to String (2)
I add the code that I have tried below here ,, I have tried both UTF8 and without UTF8
HttpParams params = new BasicHttpParams();
HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
//params.setParameter(CoreProtocolPNames.PROTOCOL_VERSION, );
params.setParameter(CoreConnectionPNames.SOCKET_BUFFER_SIZE, 128 * 1024);
HttpClient client = new DefaultHttpClient(params);
// HttpClient client = new DefaultHttpClient(new BasicHttpParams());
HttpPost httppost = new HttpPost(DataFactory.REQUEST_API_URL + "?id=" + DataFactory.USER_ID );
// Depends on your web service
HttpConnectionParams.setConnectionTimeout(client.getParams(), 10000); //Timeout Limit
HttpConnectionParams.setSocketBufferSize(client.getParams(), 128 * 1024);
HttpResponse response = client.execute(httppost);
//response.setParams(client.getParams().setParameter(CoreConnectionPNames.SOCKET_BUFFER_SIZE, 128 * 1024));
//String rawdata = IOUtils.toString(response.getEntity().getContent(), "UTF-8");
// String rawdata = EntityUtils.toString(response.getEntity());
String rawdata = getResponseBody(response.getEntity());
//Scanner s = new Scanner(response.getEntity().getContent()).useDelimiter("\\A");
//String rawdata = s.hasNext() ? s.next() : "";
/*
//BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
// ===================
BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()), 128 * 1024);
StringBuilder dataResponseSB = new StringBuilder();
String line ;
while ((line = reader.readLine()) != null) {
dataResponseSB.append(line);
if (DataFactory.DEBUG_MODE) {
Log.i("===LoadDataActivity","line: "+line);
}
}
dataResponseSB.trimToSize();
String rawdata = new String(dataResponseSB);
/*
InputStreamReader reader = new InputStreamReader(response.getEntity().getContent());
StringBuffer sb = new StringBuffer();
int c;
while ((c = reader.read()) != -1) {
sb.append((char)c);
if (DataFactory.DEBUG_MODE) {
//Log.i("===LoadDataActivity","line: "+line);
}
}
*/
I'm pretty sure this is the problem:
Log.i("===LoadDataActivity","rawdata: "+rawdata);
You're assuming that a log entry can include all of your data - I believe each log entry is limited to 8192 characters.
I suggest you log rawdata.length() and you'll see that it's actually got all of the data - it's just logging it that's failing.
try this,,
public String getResponseBody(final HttpEntity entity) throws IOException, ParseException {
if (entity == null) {
throw new IllegalArgumentException("HTTP entity may not be null");
}
InputStream instream = entity.getContent();
if (instream == null) {
return "";
}
if (entity.getContentLength() > Integer.MAX_VALUE) {
throw new IllegalArgumentException(
"HTTP entity too large to be buffered in memory");
}
StringBuilder buffer = new StringBuilder();
BufferedReader reader = new BufferedReader(new InputStreamReader(instream, HTTP.UTF_8));
String line = null;
try {
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
} finally {
instream.close();
reader.close();
}
System.out.println("GEN END : " + Calendar.getInstance().getTimeInMillis());
return buffer.toString();
}
// Try this way,hope this will help you to solve your problem...
StringBuilder buffer = new StringBuilder();
BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), HTTP.UTF_8));
String line = null;
try {
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
} finally {
instream.close();
reader.close();
}
System.out.println("Buffer : " + buffer.toString());
I'm trying to get a json string from a url and my method is returning a null string value when I use this line of code:
String jsonStr = getJsonStringFromURL(url);
Here is the method I'm using:
public static String getJsonStringFromURL(String url) {
InputStream is = null;
String result = "";
JSONObject jsonObject = null;
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
}
catch (Exception e) {
return null;
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "utf-8"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
}
catch(Exception e) {
return null;
}
return result;
}
I have a url variable used where when I copy and paste the url into a browser it does return and display a json string. Any suggestions or help would be greatly appreciated.
The thing is you assigning value to the result when BufferReader is closed. Thats why you getting the null value.
Instead of assigning result = sb.toString(); outside of the BufferReader assign it before closing it.
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "utf-8"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
result = sb.toString();
System.out.println(result);// It will print you the value
is.close();
Hope it helps.