How to send HTTP request GET/POST in Java

[933]

In this article, we will show you two examples to make HTTP GET/POST request via following APIs

1. Standard HttpURLConnection.
   
   
2. Apache HttpClient library.
   

1. Java HttpURLConnection example
This example uses HttpURLConnection (http) and HttpsURLConnection (https) to

1. Send an HTTP GET request to Google.com to get the search result.
   
   
2. Send an HTTP POST request to Apple.com search form to check the product detail.
   

HttpURLConnectionExample.java

Code:

[code]package com.mkyong;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

import javax.net.ssl.HttpsURLConnection;

public class HttpURLConnectionExample {

private final String USER_AGENT = "Mozilla/5.0";

public static void main(String[] args) throws Exception {

HttpURLConnectionExample http = new HttpURLConnectionExample();

System.out.println("Testing 1 - Send Http GET request");
http.sendGet();

System.out.println("\nTesting 2 - Send Http POST request");
http.sendPost();

}

// HTTP GET request
private void sendGet() throws Exception {

String url = "http://www.google.com/search?q=mkyong";

URL obj = new URL(url);
HttpURLConnection con = (HttpURLConnection) obj.openConnection();

// optional default is GET
con.setRequestMethod("GET");

//add request header
con.setRequestProperty("User-Agent", USER_AGENT);

int responseCode = con.getResponseCode();
System.out.println("\nSending 'GET' request to URL : " + url);
System.out.println("Response Code : " + responseCode);

BufferedReader in = new BufferedReader(
       new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();

while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();

//print result
System.out.println(response.toString());

}

// HTTP POST request
private void sendPost() throws Exception {

String url = "https://selfsolve.apple.com/wcResults.do";
URL obj = new URL(url);
HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();

//add reuqest header
con.setRequestMethod("POST");
con.setRequestProperty("User-Agent", USER_AGENT);
con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");

String urlParameters = "sn=C02G8416DRJM&cn=&locale=&caller=&num=12345";

// Send post request
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(urlParameters);
wr.flush();
wr.close();

int responseCode = con.getResponseCode();
System.out.println("\nSending 'POST' request to URL : " + url);
System.out.println("Post parameters : " + urlParameters);
System.out.println("Response Code : " + responseCode);

BufferedReader in = new BufferedReader(
       new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();

while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();

//print result
System.out.println(response.toString());

}

}

[/code]
Copy

Code:

[color=#212529][size=medium][font=-apple-system, BlinkMacSystemFont,]Output[/font][/size][/color]
[code]Sending 'GET' request to URL : http://www.google.com/search?q=mkyong
Response Code : 200
Google search result...

Testing 2 - Send Http POST request

Sending 'POST' request to URL : https://selfsolve.apple.com/wcResults.do
Post parameters : sn=C02G8416DRJM&cn=&locale=&caller=&num=12345
Response Code : 200
Apple product detail...

[/code]

Copy

2. Apache HttpClient
This is the equivalent example, but using Apache 



HttpClientExample.java

Code:

[code]package com.mkyong;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
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.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

public class HttpClientExample {

private final String USER_AGENT = "Mozilla/5.0";

public static void main(String[] args) throws Exception {

HttpClientExample http = new HttpClientExample();

System.out.println("Testing 1 - Send Http GET request");
http.sendGet();

System.out.println("\nTesting 2 - Send Http POST request");
http.sendPost();

}

// HTTP GET request
private void sendGet() throws Exception {

String url = "http://www.google.com/search?q=developer";

HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet(url);

// add request header
request.addHeader("User-Agent", USER_AGENT);

HttpResponse response = client.execute(request);

System.out.println("\nSending 'GET' request to URL : " + url);
System.out.println("Response Code : " +
                      response.getStatusLine().getStatusCode());

BufferedReader rd = new BufferedReader(
                      new InputStreamReader(response.getEntity().getContent()));

StringBuffer result = new StringBuffer();
String line = "";
while ((line = rd.readLine()) != null) {
result.append(line);
}

System.out.println(result.toString());

}

// HTTP POST request
private void sendPost() throws Exception {

String url = "https://selfsolve.apple.com/wcResults.do";

HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(url);

// add header
post.setHeader("User-Agent", USER_AGENT);

List<NameValuePair> urlParameters = new ArrayList<NameValuePair>();
urlParameters.add(new BasicNameValuePair("sn", "C02G8416DRJM"));
urlParameters.add(new BasicNameValuePair("cn", ""));
urlParameters.add(new BasicNameValuePair("locale", ""));
urlParameters.add(new BasicNameValuePair("caller", ""));
urlParameters.add(new BasicNameValuePair("num", "12345"));

post.setEntity(new UrlEncodedFormEntity(urlParameters));

HttpResponse response = client.execute(post);
System.out.println("\nSending 'POST' request to URL : " + url);
System.out.println("Post parameters : " + post.getEntity());
System.out.println("Response Code : " +
                                   response.getStatusLine().getStatusCode());

BufferedReader rd = new BufferedReader(
                       new InputStreamReader(response.getEntity().getContent()));

StringBuffer result = new StringBuffer();
String line = "";
while ((line = rd.readLine()) != null) {
result.append(line);
}

System.out.println(result.toString());

}

}

[/code]

Thanks Everyone  for Rep+ and Like

  Fake Traffic to Earn Money
Pruned#4956 

[22]

Thanks and nice work fammm

[1]

Hi, I need to say that if you use spring, even this request can be simpler. Just user restTemplate or Open feign

[22]

thanks

[933]

In this article, we will show you two examples to make HTTP GET/POST request via following APIs

1. Standard HttpURLConnection.
   
   
2. Apache HttpClient library.
   

1. Java HttpURLConnection example
This example uses HttpURLConnection (http) and HttpsURLConnection (https) to

1. Send an HTTP GET request to Google.com to get the search result.
   
   
2. Send an HTTP POST request to Apple.com search form to check the product detail.
   

HttpURLConnectionExample.java

Code:

 

Code:

[code]package com.mkyong;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

import javax.net.ssl.HttpsURLConnection;

public class HttpURLConnectionExample {

private final String USER_AGENT = "Mozilla/5.0";

public static void main(String[] args) throws Exception {

HttpURLConnectionExample http = new HttpURLConnectionExample();

System.out.println("Testing 1 - Send Http GET request");
http.sendGet();

System.out.println("\nTesting 2 - Send Http POST request");
http.sendPost();

}

// HTTP GET request
private void sendGet() throws Exception {

String url = "http://www.google.com/search?q=mkyong";

URL obj = new URL(url);
HttpURLConnection con = (HttpURLConnection) obj.openConnection();

// optional default is GET
con.setRequestMethod("GET");

//add request header
con.setRequestProperty("User-Agent", USER_AGENT);

int responseCode = con.getResponseCode();
System.out.println("\nSending 'GET' request to URL : " + url);
System.out.println("Response Code : " + responseCode);

BufferedReader in = new BufferedReader(
       new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();

while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();

//print result
System.out.println(response.toString());

}

// HTTP POST request
private void sendPost() throws Exception {

String url = "https://selfsolve.apple.com/wcResults.do";
URL obj = new URL(url);
HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();

//add reuqest header
con.setRequestMethod("POST");
con.setRequestProperty("User-Agent", USER_AGENT);
con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");

String urlParameters = "sn=C02G8416DRJM&cn=&locale=&caller=&num=12345";

// Send post request
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(urlParameters);
wr.flush();
wr.close();

int responseCode = con.getResponseCode();
System.out.println("\nSending 'POST' request to URL : " + url);
System.out.println("Post parameters : " + urlParameters);
System.out.println("Response Code : " + responseCode);

BufferedReader in = new BufferedReader(
       new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();

while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();

//print result
System.out.println(response.toString());

}

}

Copy

Code:

[color=#212529][size=medium][font=-apple-system, BlinkMacSystemFont,]Output[/font][/size][/color]
[code]Sending 'GET' request to URL : http://www.google.com/search?q=mkyong
Response Code : 200
Google search result...

Testing 2 - Send Http POST request

Sending 'POST' request to URL : https://selfsolve.apple.com/wcResults.do
Post parameters : sn=C02G8416DRJM&cn=&locale=&caller=&num=12345
Response Code : 200
Apple product detail...

[/code]

Copy

2. Apache HttpClient
This is the equivalent example, but using Apache 



HttpClientExample.java

Code:

[code]package com.mkyong;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
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.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

public class HttpClientExample {

private final String USER_AGENT = "Mozilla/5.0";

public static void main(String[] args) throws Exception {

HttpClientExample http = new HttpClientExample();

System.out.println("Testing 1 - Send Http GET request");
http.sendGet();

System.out.println("\nTesting 2 - Send Http POST request");
http.sendPost();

}

// HTTP GET request
private void sendGet() throws Exception {

String url = "http://www.google.com/search?q=developer";

HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet(url);

// add request header
request.addHeader("User-Agent", USER_AGENT);

HttpResponse response = client.execute(request);

System.out.println("\nSending 'GET' request to URL : " + url);
System.out.println("Response Code : " +
                      response.getStatusLine().getStatusCode());

BufferedReader rd = new BufferedReader(
                      new InputStreamReader(response.getEntity().getContent()));

StringBuffer result = new StringBuffer();
String line = "";
while ((line = rd.readLine()) != null) {
result.append(line);
}

System.out.println(result.toString());

}

// HTTP POST request
private void sendPost() throws Exception {

String url = "https://selfsolve.apple.com/wcResults.do";

HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(url);

// add header
post.setHeader("User-Agent", USER_AGENT);

List<NameValuePair> urlParameters = new ArrayList<NameValuePair>();
urlParameters.add(new BasicNameValuePair("sn", "C02G8416DRJM"));
urlParameters.add(new BasicNameValuePair("cn", ""));
urlParameters.add(new BasicNameValuePair("locale", ""));
urlParameters.add(new BasicNameValuePair("caller", ""));
urlParameters.add(new BasicNameValuePair("num", "12345"));

post.setEntity(new UrlEncodedFormEntity(urlParameters));

HttpResponse response = client.execute(post);
System.out.println("\nSending 'POST' request to URL : " + url);
System.out.println("Post parameters : " + post.getEntity());
System.out.println("Response Code : " +
                                   response.getStatusLine().getStatusCode());

BufferedReader rd = new BufferedReader(
                       new InputStreamReader(response.getEntity().getContent()));

StringBuffer result = new StringBuffer();
String line = "";
while ((line = rd.readLine()) != null) {
result.append(line);
}

System.out.println(result.toString());

}

}

[/code]

Code:

 

[/quote]

Okay Pm me then

Thanks Everyone  for Rep+ and Like

  Fake Traffic to Earn Money
Pruned#4956 

[933]

This is a bump

Thanks Everyone  for Rep+ and Like

  Fake Traffic to Earn Money
Pruned#4956 

[933]

This is a bump

Thanks Everyone  for Rep+ and Like

  Fake Traffic to Earn Money
Pruned#4956 

[933]

This is a bump

Thanks Everyone  for Rep+ and Like

  Fake Traffic to Earn Money
Pruned#4956