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how to create an http client for sending post request using java

i would like to implement an simple http client which can send http post request with some extra headers and string xml body content inside of the payload of the request using java language.
Can anyone recommend me how can I do it.
Thank you

You could use java.net.HttpURLConnection or third party libraries like Apache HttpClient. Here is a StackOverflow thread where you can find answer for loading an XML;
Write in body request with HttpClient
This example from MkYong has sample code for adding headers;
https://www.mkyong.com/java/apache-httpclient-examples/

maybe you can use it.HttpClient,that one of the apache's subproject.
this is a demo:
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;
import org.apache.log4j.Logger;
public class HttpXmlClient {
private static Logger log = Logger.getLogger(HttpXmlClient.class);
public static String post(String url, Map<String, String> params) {
DefaultHttpClient httpclient = new DefaultHttpClient();
String body = null;
log.info("create httppost:" + url);
HttpPost post = postForm(url, params);
body = invoke(httpclient, post);
httpclient.getConnectionManager().shutdown();
return body;
}
public static String get(String url) {
DefaultHttpClient httpclient = new DefaultHttpClient();
String body = null;
log.info("create httppost:" + url);
HttpGet get = new HttpGet(url);
body = invoke(httpclient, get);
httpclient.getConnectionManager().shutdown();
return body;
}
private static String invoke(DefaultHttpClient httpclient,
HttpUriRequest httpost) {
HttpResponse response = sendRequest(httpclient, httpost);
String body = paseResponse(response);
return body;
}
private static String paseResponse(HttpResponse response) {
log.info("get response from http server..");
HttpEntity entity = response.getEntity();
log.info("response status: " + response.getStatusLine());
String charset = EntityUtils.getContentCharSet(entity);
log.info(charset);
String body = null;
try {
body = EntityUtils.toString(entity);
log.info(body);
} catch (ParseException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return body;
}
private static HttpResponse sendRequest(DefaultHttpClient httpclient,
HttpUriRequest httpost) {
log.info("execute post...");
HttpResponse response = null;
try {
response = httpclient.execute(httpost);
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return response;
}
private static HttpPost postForm(String url, Map<String, String> params){
HttpPost httpost = new HttpPost(url);
List<NameValuePair> nvps = new ArrayList <NameValuePair>();
Set<String> keySet = params.keySet();
for(String key : keySet) {
nvps.add(new BasicNameValuePair(key, params.get(key)));
}
try {
log.info("set utf-8 form entity to httppost");
httpost.setEntity(new UrlEncodedFormEntity(nvps, HTTP.UTF_8));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return httpost;
}
}
and you can use it like that:
Map<String, String> params = new HashMap<String, String>();
params.put("name", name);
params.put("password", password);
String xml = HttpXmlClient.post(loginUrl, params);
log.info(xml);

Warning/Error meaning - GbaRequest - GbaRequest: Constructor Called 222 userAgent Apache-HttpClient/UNAVAILABLE

W/System.err(27207): [DEBUG] GbaRequest - GbaRequest: Constructor Called 222 userAgent Apache-HttpClient/UNAVAILABLE (java 1.4)
Thank you in advance for the assistance. I wasn't able to find a post regarding this error I received on my project.
I receive this error only sometimes, though I'm not sure why it comes up as it seems random when it occurs. I don't notice anything out of the ordinary in my data input.
My android application is attempting to make a connection to a remote server and push data into the PostgreSQL tables. Would anyone be able to refer me to the proper documentation for this error or explain its meaning. I appreciate the assistance.
Here is my code:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.CoreProtocolPNames;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
public class JSONParser
{
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
public JSONParser()
{
// Empty Constructor
}
public JSONObject getJSONFromUrl(String url)
{
try
{
DefaultHttpClient httpClient = new DefaultHttpClient();
httpClient.getParams().setParameter(CoreProtocolPNames.USER_AGENT, System.getProperty("http.agent"));
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
{
jObj = new JSONObject(json);
}
catch (JSONException e)
{
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
return jObj;
}
public JSONObject makeHttpRequest(String url, String method, List<NameValuePair> params)
{
try
{
if (method == "POST")
{
DefaultHttpClient httpClient = new DefaultHttpClient();
httpClient.getParams().setParameter(CoreProtocolPNames.USER_AGENT, System.getProperty("http.agent"));
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
else if (method == "GET")
{
DefaultHttpClient httpClient = new DefaultHttpClient();
httpClient.getParams().setParameter(CoreProtocolPNames.USER_AGENT, System.getProperty("http.agent"));
String paramString = URLEncodedUtils.format(params, "utf-8");
url += "?" + paramString;
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
}
catch (UnsupportedEncodingException e)
{
e.printStackTrace();
}
catch (ClientProtocolException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
catch (Exception 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 jObj;
}
}

That is not an error itself, Apache-HttpClient/UNAVAILABLE (java 1.4) is the default User Agent string for your Apache HttpClient.
This happens when you don't send the User Agent ("User-Agent:") via HTTP headers, then the phone GBA Service warn you about that.
If you want send the default system User Agent you can do
httpClient.getParams().setParameter(CoreProtocolPNames.USER_AGENT, System.getProperty("http.agent"));
this should be like
Dalvik/1.6.0 (Linux; U; Android 4.2.2; Galaxy Nexus Build/JDQ39)
or if you want sent a custom User Agent you can do
httpClient.getParams().setParameter(CoreProtocolPNames.USER_AGENT, "My user agent");
or you can set the header via setHeader method
requestOrPost.setHeader("User-Agent", USER_AGENT);

parsing json data in API url using jsonparser

I have a JSON data in this URL : http://api.pemiluapi.org/calonpresiden/api/caleg/jk?apiKey=56513c05217f73e6be82d5542368ae4f
when I try parsing using this jsonparser code :
package percobaan;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public String makeHttpRequest(String url, String method) {
return this.makeHttpRequest(url, method, null);
}
public JSONObject getJSONFromUrl(String url, List<NameValuePair> params) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
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 sBuilder = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sBuilder.append(line + "\n");
}
is.close();
json = sBuilder.toString();
} catch (Exception exception) {
exception.printStackTrace();
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
}
// return JSON String
return jObj;
}
// function get json from url
// by making HTTP POST or GET mehtod
public String makeHttpRequest(String url, String method,
List<NameValuePair> params) {
// Making HTTP request
try {
DefaultHttpClient httpClient = new DefaultHttpClient();
// check for request method
if (method == "POST") {
HttpPost httpPost = new HttpPost(url);
if (params != null) {
httpPost.setEntity(new UrlEncodedFormEntity(params));
}
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} else if (method == "GET") {
if (params != null) {
String paramString = URLEncodedUtils
.format(params, "utf-8");
url += "?" + paramString;
}
HttpGet httpGet = new HttpGet(url);
// DefaultHttpClient httpClient = new
// DefaultHttpClient(httpParameters);
HttpResponse httpResponse = httpClient.execute(httpGet);
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) {
}
// return JSON String
return json;
}
}
why the output just says :
{"data":[]}
this is my code :
package percobaan;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
/**
*
* #author nafian
*/
public class Coba {
public static void main(String[] args) {
ArrayList<HashMap<String, String>> daftar_d = new ArrayList<HashMap<String, String>>();
JSONParser jsonParser = new JSONParser();
String link_url = "http://api.pemiluapi.org/calonpresiden/api/caleg/jk?apiKey=56513c05217f73e6be82d5542368ae4f";
List<NameValuePair> params = new ArrayList<NameValuePair>();
String parsing = jsonParser.makeHttpRequest(link_url, "POST",
params);
System.out.print(parsing);
// try {
// JSONObject json = new JSONObject(parsing).getJSONObject("data").getJSONObject("results");
// JSONArray caleg = json.getJSONArray("caleg");
//
// for (int i = 0; i < caleg.length(); i++) {
// HashMap<String, String> map = new HashMap<String, String>();
// JSONObject ar = caleg.getJSONObject(i);
// String nama = ar.getString("nama");
// String calon = ar.getString("role");
//
// JSONArray riwayat = ar.getJSONArray("riwayat_pendidikan");
// for (int j = 0; j < riwayat.length(); j++) {
// JSONObject ringkasan = riwayat.getJSONObject(j);
// String ringkasan_p = ringkasan.getString("ringkasan");
// map.put("pendidikan_r", ringkasan_p);
// }
//
// map.put("nama", nama);
// map.put("calon", calon);
// daftar_d.add(map);
//
// }
// } catch (JSONException ex) {
// ex.printStackTrace();
// }
// for (int i = 0; i < daftar_d.size(); i++) {
//
// System.out.println(daftar_d.get(i).get("pendidikan_r").toString());
// }
}
}
Am I missing something?

I suggest you use JSON-SIMPLE, it will literally simplify your life.
https://code.google.com/p/json-simple/
Here is a small example for the given URL.
Please note that's I'm using Jersey for establishing the connection, but you can pretty much use anything you like instead.
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientHandlerException;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.UniformInterfaceException;
import com.sun.jersey.api.client.WebResource;
...
String callString = "http://api.pemiluapi.org/calonpresiden/api/caleg/jk?apiKey=56513c05217f73e6be82d5542368ae4f";
Client client = Client.create();
WebResource webResource = client.resource(callString);
ClientResponse clientResponse = webResource.accept("application/json").get(ClientResponse.class);
if (clientResponse.getStatus() != 200) {
throw new RuntimeException("Failed"+ clientResponse.toString());
}
JSONObject resObj = (JSONObject)new JSONParser().parse(clientResponse.getEntity(String.class));
JSONObject data_obj = (JSONObject) resObj.get("data");
JSONObject results_obj = (JSONObject) data_obj.get("results");
JSONArray caleg_array = (JSONArray) results_obj.get("caleg");

How do you encode a url string in java to not put + signs in spaces?

I have a JSONParser class that would enable me to make HTTPRequests. So here is the class
package com.thesis.menubook;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
// function get json from url
// by making HTTP POST or GET mehtod
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params) {
// Making HTTP request
try {
// check for request method
if(method == "POST"){
// request method is POST
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}else if(method == "GET"){
// request method is GET
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(params, "utf-8");
url += "?" + paramString;
HttpGet httpGet = new HttpGet(url);
Log.d("URL",url);
HttpResponse httpResponse = httpClient.execute(httpGet);
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());
Log.e("JSON Parser", "json string :" +json);
}
// return JSON String
return jObj;
}
}
I access it like this.
params.add(new BasicNameValuePair("category", "MAIN DISH"));
JSONObject json = jsonParser.makeHttpRequest("http://"+ipaddress+"/MenuBook/selectMenu.php", "GET", params);
I would like to keep the format of the parameter as such, MAIN DISH. but when I look into my LogCat it returns a url formed like this.
http://192.168.10.149:80/MenuBook/selectMenu.php?category=MAIN+DISH
which then causes my application to fail and force close since I have no category like MAIN+DISH
I would like my URL to be formed like this.
http://192.168.10.149:80/MenuBook/selectMenu.php?category='MAIN DISH'
which would then return the proper results. I searched around in the net and only found solutions to make white spaces + and %20 which would not return the proper result.
Any solutions you can suggest?

Your question embodies a contradiction in terms. URL-encoding (actually form-encoding) is already defined, and it is already defined to replace spaces with '+', not to quote the value elements concerned. The server-side software needs to understand that and behave accordingly. All the server-side software provided by Java, e.g. HttpServletRequest, already does that. If your code doesn't comply with the RFCs, fix it so it does.

I solved it by hardcoding it with 'MAIN+DISH'

Http Basic Authentication in Java using HttpClient?

I am trying to mimic the functionality of this curl command in Java:
curl --basic --user username:password -d "" http://ipaddress/test/login
I wrote the following using Commons HttpClient 3.0 but somehow ended up getting an 500 Internal Server Error from the server. Can someone tell me if I'm doing anything wrong?
public class HttpBasicAuth {
private static final String ENCODING = "UTF-8";
/**
* #param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
try {
HttpClient client = new HttpClient();
client.getState().setCredentials(
new AuthScope("ipaddress", 443, "realm"),
new UsernamePasswordCredentials("test1", "test1")
);
PostMethod post = new PostMethod(
"http://address/test/login");
post.setDoAuthentication( true );
try {
int status = client.executeMethod( post );
System.out.println(status + "\n" + post.getResponseBodyAsString());
} finally {
// release any connection resources used by the method
post.releaseConnection();
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
And I later tried a Commons HttpClient 4.0.1 but still the same error:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
public class HttpBasicAuth {
private static final String ENCODING = "UTF-8";
/**
* #param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
try {
DefaultHttpClient httpclient = new DefaultHttpClient();
httpclient.getCredentialsProvider().setCredentials(
new AuthScope(AuthScope.ANY_HOST, AuthScope.ANY_PORT),
new UsernamePasswordCredentials("test1", "test1"));
HttpPost httppost = new HttpPost("http://host:post/test/login");
System.out.println("executing request " + httppost.getRequestLine());
HttpResponse response;
response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
System.out.println("----------------------------------------");
System.out.println(response.getStatusLine());
if (entity != null) {
System.out.println("Response content length: " + entity.getContentLength());
}
if (entity != null) {
entity.consumeContent();
}
httpclient.getConnectionManager().shutdown();
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

Have you tried this (using HttpClient version 4):
String encoding = Base64.getEncoder().encodeToString((user + ":" + pwd).getBytes());
HttpPost httpPost = new HttpPost("http://host:post/test/login");
httpPost.setHeader(HttpHeaders.AUTHORIZATION, "Basic " + encoding);
System.out.println("executing request " + httpPost.getRequestLine());
HttpResponse response = httpClient.execute(httpPost);
HttpEntity entity = response.getEntity();

Ok so this one works. Just in case anybody wants it, here's the version that works for me :)
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Base64;
public class HttpBasicAuth {
public static void main(String[] args) {
try {
URL url = new URL ("http://ip:port/login");
String encoding = Base64.getEncoder().encodeToString(("test1:test1").getBytes(‌"UTF‌​-8"​));
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
connection.setRequestProperty ("Authorization", "Basic " + encoding);
InputStream content = (InputStream)connection.getInputStream();
BufferedReader in =
new BufferedReader (new InputStreamReader (content));
String line;
while ((line = in.readLine()) != null) {
System.out.println(line);
}
} catch(Exception e) {
e.printStackTrace();
}
}
}

This is the code from the accepted answer above, with some changes made regarding the Base64 encoding. The code below compiles.
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import org.apache.commons.codec.binary.Base64;
public class HttpBasicAuth {
public static void main(String[] args) {
try {
URL url = new URL ("http://ip:port/login");
Base64 b = new Base64();
String encoding = b.encodeAsString(new String("test1:test1").getBytes());
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
connection.setRequestProperty ("Authorization", "Basic " + encoding);
InputStream content = (InputStream)connection.getInputStream();
BufferedReader in =
new BufferedReader (new InputStreamReader (content));
String line;
while ((line = in.readLine()) != null) {
System.out.println(line);
}
}
catch(Exception e) {
e.printStackTrace();
}
}
}

A small update - hopefully useful for somebody - it works for me in my project:
I use the nice Public Domain class Base64.java from Robert Harder (Thanks Robert - Code availble here: Base64 - download and put it in your package).
and make a download of a file (image, doc, etc.) with authentication and write to local disk
Example:
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
public class HttpBasicAuth {
public static void downloadFileWithAuth(String urlStr, String user, String pass, String outFilePath) {
try {
// URL url = new URL ("http://ip:port/download_url");
URL url = new URL(urlStr);
String authStr = user + ":" + pass;
String authEncoded = Base64.encodeBytes(authStr.getBytes());
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setDoOutput(true);
connection.setRequestProperty("Authorization", "Basic " + authEncoded);
File file = new File(outFilePath);
InputStream in = (InputStream) connection.getInputStream();
OutputStream out = new BufferedOutputStream(new FileOutputStream(file));
for (int b; (b = in.read()) != -1;) {
out.write(b);
}
out.close();
in.close();
}
catch (Exception e) {
e.printStackTrace();
}
}
}

Here are a few points:
You could consider upgrading to HttpClient 4 (generally speaking, if you can, I don't think version 3 is still actively supported).
A 500 status code is a server error, so it might be useful to see what the server says (any clue in the response body you're printing?). Although it might be caused by your client, the server shouldn't fail this way (a 4xx error code would be more appropriate if the request is incorrect).
I think setDoAuthentication(true) is the default (not sure). What could be useful to try is pre-emptive authentication works better:
client.getParams().setAuthenticationPreemptive(true);
Otherwise, the main difference between curl -d "" and what you're doing in Java is that, in addition to Content-Length: 0, curl also sends Content-Type: application/x-www-form-urlencoded. Note that in terms of design, you should probably send an entity with your POST request anyway.

while using Header array
String auth = Base64.getEncoder().encodeToString(("test1:test1").getBytes());
Header[] headers = {
new BasicHeader(HTTP.CONTENT_TYPE, ContentType.APPLICATION_JSON.toString()),
new BasicHeader("Authorization", "Basic " +auth)
};

Thanks for all answers above, but for me, I can not find Base64Encoder class, so I sort out my way anyway.
public static void main(String[] args) {
try {
DefaultHttpClient Client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet("https://httpbin.org/basic-auth/user/passwd");
String encoding = DatatypeConverter.printBase64Binary("user:passwd".getBytes("UTF-8"));
httpGet.setHeader("Authorization", "Basic " + encoding);
HttpResponse response = Client.execute(httpGet);
System.out.println("response = " + response);
BufferedReader breader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
StringBuilder responseString = new StringBuilder();
String line = "";
while ((line = breader.readLine()) != null) {
responseString.append(line);
}
breader.close();
String repsonseStr = responseString.toString();
System.out.println("repsonseStr = " + repsonseStr);
} catch (IOException e) {
e.printStackTrace();
}
}
One more thing, I also tried
Base64.encodeBase64String("user:passwd".getBytes());
It does NOT work due to it return a string almost same with
DatatypeConverter.printBase64Binary()
but end with "\r\n", then server will return "bad request".
Also following code is working as well, actually I sort out this first, but for some reason, it does NOT work in some cloud environment (sae.sina.com.cn if you want to know, it is a chinese cloud service). so have to use the http header instead of HttpClient credentials.
public static void main(String[] args) {
try {
DefaultHttpClient Client = new DefaultHttpClient();
Client.getCredentialsProvider().setCredentials(
AuthScope.ANY,
new UsernamePasswordCredentials("user", "passwd")
);
HttpGet httpGet = new HttpGet("https://httpbin.org/basic-auth/user/passwd");
HttpResponse response = Client.execute(httpGet);
System.out.println("response = " + response);
BufferedReader breader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
StringBuilder responseString = new StringBuilder();
String line = "";
while ((line = breader.readLine()) != null) {
responseString.append(line);
}
breader.close();
String responseStr = responseString.toString();
System.out.println("responseStr = " + responseStr);
} catch (IOException e) {
e.printStackTrace();
}
}

An easy way to login with a HTTP POST without doing any Base64 specific calls is to use the HTTPClient BasicCredentialsProvider
import java.io.IOException;
import static java.lang.System.out;
import org.apache.http.HttpResponse;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.client.HttpClientBuilder;
//code
CredentialsProvider provider = new BasicCredentialsProvider();
UsernamePasswordCredentials credentials = new UsernamePasswordCredentials(user, password);
provider.setCredentials(AuthScope.ANY, credentials);
HttpClient client = HttpClientBuilder.create().setDefaultCredentialsProvider(provider).build();
HttpResponse response = client.execute(new HttpPost("http://address/test/login"));//Replace HttpPost with HttpGet if you need to perform a GET to login
int statusCode = response.getStatusLine().getStatusCode();
out.println("Response Code :"+ statusCode);

for HttpClient always use HttpRequestInterceptor
for example
httclient.addRequestInterceptor(new HttpRequestInterceptor() {
public void process(HttpRequest arg0, HttpContext context) throws HttpException, IOException {
AuthState state = (AuthState) context.getAttribute(ClientContext.TARGET_AUTH_STATE);
if (state.getAuthScheme() == null) {
BasicScheme scheme = new BasicScheme();
CredentialsProvider credentialsProvider = (CredentialsProvider) context.getAttribute(ClientContext.CREDS_PROVIDER);
Credentials credentials = credentialsProvider.getCredentials(AuthScope.ANY);
if (credentials == null) {
System.out.println("Credential >>" + credentials);
throw new HttpException();
}
state.setAuthScope(AuthScope.ANY);
state.setAuthScheme(scheme);
state.setCredentials(credentials);
}
}
}, 0);

HttpBasicAuth works for me with smaller changes
I use maven dependency
<dependency>
<groupId>net.iharder</groupId>
<artifactId>base64</artifactId>
<version>2.3.8</version>
</dependency>
Smaller change
String encoding = Base64.encodeBytes ((user + ":" + passwd).getBytes());