Develop Reference

Encode and decode string with special chars in client-server application

I'm developing my client-server application (server is like a servlet and client is an Android app). I have some difficulties sending information between two entities when the message has special chars (ie: 'è' or others)
On client side I use this code to send the message that can contain special chars:
public static String effettuaPOSTServer (String parameters) {
try {
byte [] parametersBytes = parameters.getBytes("UTF-8");
URL url = new URL("http://" + IP_SERVER + ":" + PORT + PATH_SERVLET);
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.setConnectTimeout(10000);
connection.setRequestMethod("POST");
connection.setRequestProperty("Content_Type", "application/x-www-form-urlencoded; charset=utf-8");
connection.setRequestProperty ("Content-Length", String.valueOf (parametersBytes.length));
connection.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(connection.getOutputStream());
wr.write(parametersBytes);
wr.flush();
wr.close();
BufferedReader br = new BufferedReader (new InputStreamReader(connection.getInputStream(), "UTF-8"));
StringBuilder sb = new StringBuilder ();
String s;
while ((s = br.readLine ()) != null) {
sb.append (s);
sb.append ("\n");
}
return sb.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (ProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
on server side I use this code to send the response (also the response can contain special chars like 'è' and others) (I'm in servlet doPost context so I work with HttpServletRequest request and HttpServletResponse response):
PrintWriter pw = response.getWriter();
...
String content = ...; //the string is formatted in JSON format
pw.println (content);
but on both sides I'm unable to receive and manage the correct strings where I have special chars.
I'm trying a lot of solutions on web about encoding/decoding etc. but without successful result.
How can I fix my problem? Thank you!
EDIT:
for example, immagine my request from client as follow (I report the request in GET format to show simply the case):
http://MY_URL:PORT/MY_PATH?parameter1=value1&parameter2=value2&parameter3=èqualcosaacaso
but on server I receive:
parameter1=value1
parameter2=value2
parameter3=Äqualcosaacaso

Reading rest service of content type application/vnd.oracle.adf.resourceitem+json

I have a webservice whose content type is application/vnd.oracle.adf.resourceitem+json.
The HttpEntity of the reponse obtained by hitting this service is looks like this
ResponseEntityProxy{[Content-Type: application/vnd.oracle.adf.resourceitem+json,Content-Length: 3,Chunked: false]}
When I try to convert this HttpEntity into String it gives me a blank String {}.
Below are the ways I tried to convert the HttpEntity to String
1.
String strResponse = EntityUtils.toString(response.getEntity());
2.
String strResponse = "";
String inputLine;
BufferedReader br = new BufferedReader(new InputStreamReader(entity.getContent()));
try {
while ((inputLine = br.readLine()) != null) {
System.out.println(inputLine);
strResponse += inputLine;
}
br.close();
} catch (IOException e) {
e.printStackTrace();
}
3.
response.getEntity().writeTo(new FileOutputStream(new File("C:\\Users\\harshita.sethi\\Documents\\Chabot\\post.txt")));
All returns String -> {}.
Can anyone tell me what am I doing wrong?
Is this because of the content type?

The above code is still giving the same response with empty JSON object. So I modified and wrote the below code. This one seems to run perfectly fine.
URL url = new URL(urlString);
HttpsURLConnection con = (HttpsURLConnection) url.openConnection();
con.setDoOutput(true);
con.setRequestMethod("POST");
con.addRequestProperty("Authorization", getAuthToken());
con.addRequestProperty("Content-Type", "application/vnd.oracle.adf.resourceitem+json;charset=utf-8");
String input = String.format("{\"%s\":\"%s\",\"%s\":\"%s\"}", field, value, field2, value2);
System.out.println(input);
OutputStream outputStream = con.getOutputStream();
outputStream.write(input.getBytes());
outputStream.flush();
con.connect();
System.out.println(con.getResponseCode());
// Uncompressing gzip content encoding
GZIPInputStream gzip = new GZIPInputStream(con.getInputStream());
StringBuffer szBuffer = new StringBuffer();
byte tByte[] = new byte[1024];
while (true) {
int iLength = gzip.read(tByte, 0, 1024);
if (iLength < 0) {
break;
}
szBuffer.append(new String(tByte, 0, iLength));
}
con.disconnect();
returnString = szBuffer.toString();
Authentication method
private String getAuthToken() {
String name = user;
String pwd = this.password;
String authString = name + ":" + pwd;
byte[] authEncBytes = Base64.getEncoder().encode(authString.getBytes());
System.out.println(new String(authEncBytes));
return "Basic " + new String(authEncBytes);
}
In case anybody faces the same issue. Let me share the challenged I faced and how I rectified those.
The above code works for all content-types/methods. Can be used for any type (GET, POST, PUT,DELETE).
For my requirement I had a POST webservice with
Content-Encoding →gzip
Content-Type →application/vnd.oracle.adf.resourceitem+json
Challenges : I was able to get the correct response code but I was getting junk characters as my response string.
Solution : This was because the output was compressed in gzip format which needed to be uncompressed.
The code of uncompressing the gzip content encoding is also mentioned above.
Hope it helps future users.

POST params empty, what am I doing wrong? HttpURLConnection / Android / Java

The code below shows a method, downloadUrl(), that takes a String, "myurl," its parameter. There are only two possible urls that I ever send to it, and the behavior of the method is different for each.
when myurl = URL1, it uses a GET request and everything works fine.
when myurl = URL2, however, it uses a POST request, and the response from the php page indicates that the post parameters sent with the request were empty. You can see the line where I set the POST params, so I don't understand why it's sending no params?!
Thanks for any help!
-Adam.
private String downloadUrl(String myurl) throws IOException {
InputStream is = null;
String response = "";
try {
URL urlObject = new URL(myurl);
HttpURLConnection conn = (HttpURLConnection) urlObject.openConnection();
// find out if there's a way to incorporate these timeouts into the progress bar
// and what they mean for shitty network situations
conn.setReadTimeout(10000 /* milliseconds */);
conn.setConnectTimeout(15000 /* milliseconds */);
conn.setDoInput(true);
// INSERTED QUICK CHECK TO SEE WHICH URL WE ARE LOADING FROM
// it's important because one is GET, and one is POST
if (myurl.equals(url2)){
Log.i(TAG, "dlurl() in async recognizes we are doing pre-call");
conn.setRequestMethod("POST");
conn.setDoOutput(true);
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(os, "UTF-8"));
String postParams = "?phone=" + phone;
writer.write(postParams);
Log.i(TAG, "we're adding " + postParams + "to " + urlObject);
writer.flush();
writer.close();
os.close();
}
else {
conn.setRequestMethod("GET");
conn.connect();
}
// Starts the query
int responseCode = conn.getResponseCode();
Log.i(TAG, "from " + myurl + ", The response code from SERVER is: " + responseCode);
is = conn.getInputStream();
// Convert the InputStream into a string
// i guess we look up how to do this
if (responseCode == HttpsURLConnection.HTTP_OK) {
String line;
BufferedReader br = new BufferedReader(new InputStreamReader(is));
while ((line = br.readLine()) != null) {
response += line;
}
} else {
response = "from downloadUrl, php page response was not OK: " + responseCode;
}
// it's good to close these things?
is.close();
conn.disconnect();
Log.i(TAG, "response is " + response);
return response;
// Makes sure that the InputStream is closed after the app is
// finished using it.
} finally {
if (is != null) {
is.close();
}
}
}

try with following code block to send parameters of the POST request.
Map<String,String> params = new LinkedHashMap<>();
params.put("phone", "phone");
StringBuilder postPraamString = new StringBuilder();
for (Map.Entry<String,Object> param : params.entrySet()) {
if (postPraamString.length() != 0) postPraamString.append('&');
postPraamString.append(URLEncoder.encode(param.getKey(), "UTF-8"));
postPraamString.append('=');
postPraamString.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8"));
}
byte[] postDataBytes = postData.toString().getBytes("UTF-8");
writer.write(postDataBytes);

So I figured out the root of the problem...
In the line:
String postParams = "?phone=" + phone;
The problem was that leading question mark. The question mark should only be used in GET requests.

Not able to execute URL with json value in JAVA API springs

I am tiring to execute some of my project URLs through JAVA APIs. But some of them contain JSON values. Its not accepting the JSON I am providing.
If I hit same URL through browser it executes. I am not getting what is going wrong. Are the " " specified not accepted ?
URL = http://admin.biin.net:8289/project.do?cmd=AddProject&mode=default&projectFieldValueJSON={"fieldIds":[{"id":1360,"value":"project SS33"},{"id":1362,"value":"12/03/2015"},{"id":1363,"value":"12/31/2015"}],"state":1}&jsessionid=AE5B03C9791D1019DCD7BBF0E34CCFEE
The Code is as follows
String requestString = "http://admin.biin.net:8289 /project.do?cmd=AddProject&mode=default&projectJSON={"fieldIds":[{"id":1360,"value":"project SS33"},{"id":1362,"value":"12/03/2015"},{"id":1363,"value":"12/31/2015"}],"state":1}&jsessionid=AE5B03C9791D1019DCD7BBF0E34CCFEE"
URL url = new URL(requestString);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setDoOutput(true);
conn.connect();
InputStream in = conn.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
StringBuffer responseString = new StringBuffer();
String line = null;
while ((line = reader.readLine()) != null) {
responseString.append(line);
}
Error :
java.io.IOException: Server returned HTTP response code: 505 for URL: http://admin.biin.net:8289/project.do?cmd=AddProject&mode=default&projectJSON={"fieldIds":[{"id":1360,"value":"project SS33"},{"id":1362,"value":"12/03/2015"},{"id":1363,"value":"12/31/2015"}],"state":1}&jsessionid=AE5B03C9791D1019DCD7BBF0E34CCFEE
If I remove the JSON the URL executes.

Don't pass json in QueryString. Since you are using HTTP POST. You should send the sensitive data in the HTTP body. Like this
String str = "some string goes here";
byte[] outputInBytes = str.getBytes("UTF-8");
OutputStream os = conn.getOutputStream();
os.write( outputInBytes );
os.close();
For your current problem. Encode the json value before passing it in url.
Try this:
try {
String s = "http://admin.biin.net:8289/project.do?cmd=AddProject&mode=default&projectFieldValueJSON="
+ URLEncoder.encode("{\"fieldIds\":[{\"id\":1360,\"value\":\"project SS33\"},{\"id\":1362,\"value\":\"12/03/2015\"},{\"id\":1363,\"value\":\"12/31/2015\"}],\"state\":1}", "UTF-8")
+ "&jsessionid=AE5B03C9791D1019DCD7BBF0E34CCFEE";
System.out.println(s);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
Result: http://admin.biin.net:8289/project.do?cmd=AddProject&mode=default&projectFieldValueJSON=%7B%22fieldIds%22%3A%5B%7B%22id%22%3A1360%2C%22value%22%3A%22project+SS33%22%7D%2C%7B%22id%22%3A1362%2C%22value%22%3A%2212%2F03%2F2015%22%7D%2C%7B%22id%22%3A1363%2C%22value%22%3A%2212%2F31%2F2015%22%7D%5D%2C%22state%22%3A1%7D&jsessionid=AE5B03C9791D1019DCD7BBF0E34CCFEE

Send information from PHP to Java

I want to send some information from PHP to Java. Why? Because I have a database on my server, and I get information from my database using PHP scripts.
Now I want to send that information to my client in Java. How can I do that?
I send information from Java to PHP by POST, and it works well, but I don't know how can I do the reverse.
Can you help me?
I saw this code, from a GET connection in Java... is it correct?
public String HttpClientTutorial(){
String url = "http://testes.neoscopio.com/myrepo/send.php";
InputStream content = null;
try {
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = httpclient.execute(new HttpGet(url));
content = response.getEntity().getContent();
} catch (Exception e) {
Log.e("[GET REQUEST]", "Network exception", e);
}
String response = content.toString();
return response;
}
P.S: I'm an android developer, not a Java developer...

From exampledepot: Sending POST request (Modified to get the output of your send.php.)
try {
// Construct data
String data = URLEncoder.encode("key1", "UTF-8") + "=" + URLEncoder.encode("value1", "UTF-8");
data += "&" + URLEncoder.encode("key2", "UTF-8") + "=" + URLEncoder.encode("value2", "UTF-8");
// Send data
URL url = new URL("http://testes.neoscopio.com/myrepo/send.php");
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
wr.write(data);
wr.flush();
// Get the response
BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line;
while ((line = rd.readLine()) != null) {
// Process line...
}
wr.close();
rd.close();
} catch (Exception e) {
}
P.S. This should work fine on Android. :)
(I usually import static java.net.URLEncoder.encode but that's a matter of taste.)