Develop Reference

How to send HTTPS Post request along with JSON object in java?

I want to send JSON Data to an application using HTTPS connection from java code. please guide me.
`import java.net.URL;
import java.io.*;
import javax.net.ssl.HttpsURLConnection;
public class JavaHttpsExample
{
public static void main(String[] args) throws Exception {
String httpsURL = "https://your.https.url.here/";
URL myUrl = new URL(httpsURL);
HttpsURLConnection conn = (HttpsURLConnection)myUrl.openConnection();
InputStream is = conn.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String inputLine;
while ((inputLine = br.readLine()) != null) {
System.out.println(inputLine);
}
br.close();
}
}`

Reading REST Request Output using HttpURLConnection

I am trying to do REST request on the StackExchange API on java and I have some problems to read the output. I made a small code example to see if I can read properly:
package Utils;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
public class RestClient
{
public static void main(String[] args)
{
try
{
URL url = new URL("https://api.stackexchange.com/2.2/questions?order=desc&sort=activity&site=stackoverflow");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
System.out.println(conn.getResponseCode());
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String output;
while ((output = reader.readLine()) != null)
{
System.out.println(output);
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
Below is a sample output from the website:
{"items":[{"tags":["c++","templates","covariant"],"owner":{"reputation":3,"user_id":7447292,"user_type":"registered","profile_image":"https://www.gravatar.com/avatar/8979f1b328b9b0f786dec8b4edd514bc?s=128&d=identicon&r=PG&f=1","display_name":"B.Oudot","link":"http://stackoverflow.com/users/7447292/b-oudot"}
However when I print the output of my java program, I get the status code 200 and then the rest is just bunch of non-ascii characters. I am new with REST and JSON. I would like to not use any 3rd party library if possible.
EDIT
I have put the output of my program as an image.

you need to use GZIPInputStream api, when the content encoding used gZip. it is also an inputstream.
i used gipinput stream to your response and i see output in json.
public static void main(String[] args){
try
{
URL url = new URL("https://api.stackexchange.com/2.2/questions?order=desc&sort=activity&site=stackoverflow");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
System.out.println(conn.getResponseCode());
GZIPInputStream gzis = new GZIPInputStream(conn.getInputStream());
InputStreamReader reader = new InputStreamReader(gzis);
BufferedReader in = new BufferedReader(reader);
String readed;
while ((readed = in.readLine()) != null) {
System.out.println(readed);
}
//BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String output;
while ((output = in.readLine()) != null)
{
System.out.println(output);
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
it worked for me.

Getting 403 error with java

When I pass the URL "http://echo.jsontest.com/key/value/one/two" to the code below it returns JSON data.
But when I pass "http://jsonplaceholder.typicode.com/comments?postId=1" instead, I get 403 forbidden error.
I'm not sure what's going on. Any advice?
package automation_Demo_First;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import java.nio.charset.Charset;
import org.testng.annotations.Test;
public class JsonReader{
//http://jsonplaceholder.typicode.com/comments?postId=1
public String url ="http://echo.jsontest.com/key/value/one/two";
#Test
public void testJson() throws IOException{
String data = getDataByJavaIO(url);
System.out.println(data);
}
public String getDataByJavaIO(String url) throws IOException{
InputStream inputstream = null;
BufferedReader bufferreader = null;
try{
inputstream = new URL(url).openStream();
bufferreader = new BufferedReader(new InputStreamReader(inputstream, Charset.forName("UTF-8")));
return readData(bufferreader);
}catch(IOException e){
throw e;
}
finally{
closeResource(inputstream);
closeResource(bufferreader);
}
}
public String readData(Reader reader) throws IOException{
StringBuilder stringbuilder = new StringBuilder();
int cp;
while((cp=reader.read())!=-1){
stringbuilder.append((char)cp);
}
return stringbuilder.toString();
}
public void closeResource(AutoCloseable closable){
try{
if(closable!=null){
closable.close();
System.out.println("\n" +closable.getClass().getName() + "closed ..." );
}
}
catch(Exception e){
e.printStackTrace(System.err);
}
}
}

In your try block,
try {
inputstream = new URL(url).openStream();
bufferreader = new BufferedReader(new InputStreamReader(inputstream, Charset.forName("UTF-8")));
return readData(bufferreader);
}
change it to
try {
HttpURLConnection httpCon = (HttpURLConnection) new URL(url).openConnection();
httpCon.addRequestProperty("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.95 Safari/537.36");
inputstream = httpCon.getInputStream();
bufferreader = new BufferedReader(new InputStreamReader(inputstream, Charset.forName("UTF-8")));
return readData(bufferreader);
}
Source: https://stackoverflow.com/a/18889991/3903483

Use:
URLConnection hc = new URL(url).openConnection();
hc.setRequestProperty("User-Agent", "");
inputstream = hc.getInputStream();
Instead of:
inputstream = new URL(url).openStream();

How to Read from and Post to a Remote Server using Java

I am new to this type of problems. Here I want to make a request to a website API and get response in JSON format.
I then want to send this response directly to a a different remote URL.

See the below sample code
PostMethod post = new PostMethod("Your URL");
post.setRequestBody("your json data");
post.setRequestHeader("Content-type", "application/json;charset=utf-8");
// Get HTTP client
HttpClient httpclient = new HttpClient();
// Execute request
try
{
int result = httpclient.executeMethod(post);
s_log.info("Response status code: " + result);
s_log.info(post.getResponseBodyAsString());
}
catch (HttpException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
finally
{
post.releaseConnection();
}

Reading from and writing to a remote URL can be done using the standard Java API and is detailed in the official Java tutorials:
https://docs.oracle.com/javase/tutorial/networking/urls/readingWriting.html
Reading:
import java.net.*;
import java.io.*;
public class URLConnectionReader {
public static void main(String[] args) throws Exception {
URL oracle = new URL("http://www.oracle.com/");
URLConnection yc = oracle.openConnection();
BufferedReader in = new BufferedReader(new InputStreamReader(
yc.getInputStream()));
String inputLine;
while ((inputLine = in.readLine()) != null)
System.out.println(inputLine);
in.close();
}
}
Writing
import java.io.*;
import java.net.*;
public class Reverse {
public static void main(String[] args) throws Exception {
if (args.length != 2) {
System.err.println("Usage: java Reverse "
+ "http://<location of your servlet/script>"
+ " string_to_reverse");
System.exit(1);
}
String stringToReverse = URLEncoder.encode(args[1], "UTF-8");
URL url = new URL(args[0]);
URLConnection connection = url.openConnection();
connection.setDoOutput(true);
OutputStreamWriter out = new OutputStreamWriter(
connection.getOutputStream());
out.write("string=" + stringToReverse);
out.close();
BufferedReader in = new BufferedReader(
new InputStreamReader(
connection.getInputStream()));
String decodedString;
while ((decodedString = in.readLine()) != null) {
System.out.println(decodedString);
}
in.close();
}
}

C drive memory overloading by running swing

I'm making a management software in java for a book store. There is a database on my server. I get my database data by php code.which is also in my server.I use the code below to get data by running the php code.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
public class HttpUtility {
private static HttpURLConnection httpConn;
public static HttpURLConnection sendGetRequest(String requestURL)
throws IOException {
URL url = new URL(requestURL);
httpConn = (HttpURLConnection) url.openConnection();
httpConn.setUseCaches(false);
httpConn.setDoInput(true);
httpConn.setDoOutput(false);
return httpConn;
}
public static HttpURLConnection sendPostRequest(String requestURL,
Map<String, String> params) throws IOException {
URL url = new URL(requestURL);
httpConn = (HttpURLConnection) url.openConnection();
httpConn.setUseCaches(false);
httpConn.setDoInput(true);
StringBuffer requestParams = new StringBuffer();
if (params != null && params.size() > 0) {
httpConn.setDoOutput(true);
Iterator<String> paramIterator = params.keySet().iterator();
while (paramIterator.hasNext()) {
String key = paramIterator.next();
String value = params.get(key);
requestParams.append(URLEncoder.encode(key, "UTF-8"));
requestParams.append("=").append(
URLEncoder.encode(value, "UTF-8"));
requestParams.append("&");
}
OutputStreamWriter writer = new OutputStreamWriter(
httpConn.getOutputStream());
writer.write(requestParams.toString());
writer.flush();
}
return httpConn;
}
public static String readSingleLineRespone() throws IOException {
InputStream inputStream = null;
if (httpConn != null) {
inputStream = httpConn.getInputStream();
} else {
throw new IOException("Connection is not established.");
}
BufferedReader reader = new BufferedReader(new InputStreamReader(
inputStream));
String response = reader.readLine();
reader.close();
return response;
}
public static String[] readMultipleLinesRespone() throws IOException {
InputStream inputStream = null;
if (httpConn != null) {
inputStream = httpConn.getInputStream();
} else {
throw new IOException("Connection is not established.");
}
BufferedReader reader = new BufferedReader(new InputStreamReader(
inputStream));
List<String> response = new ArrayList<String>();
String line = "";
while ((line = reader.readLine()) != null) {
response.add(line);
}
reader.close();
return (String[]) response.toArray(new String[0]);
}
public static void disconnect() {
if (httpConn != null) {
httpConn.disconnect();
}
}
}
Now I'm facing a problem like the image link (don't have enough reputation for the upload)below.There are 3 image link.
before log in
After the log in and before the search query
Another link is in the comment.
After every request making my C:// drive is loosing 10 MB space and I don't know why(Very noob coder sorry.)
Can anyone help me.