This program compiles successfully but when I try to run the program it gives me errors.
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.InputStreamReader;
import java.net.URL;
public class Main {
public static void main(String[] args)
throws Exception {
URL url = new URL("http://www.google.com");
BufferedReader reader = new BufferedReader
(new InputStreamReader(url.openStream()));
BufferedWriter writer = new BufferedWriter
(new FileWriter("data.html"));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
writer.write(line);
writer.newLine();
}
reader.close();
writer.close();
}
}
The following error occurs (I have attached the image):
Screenshot of errors
I am behind a proxy server. Does that make a problem in connecting to the internet? If so please post the solution that .. Thanks in advance.
You should do something similar:
1st of all put proxy information to system properties:
System.getProperties().put( "proxySet", "true" );
System.getProperties().put( "proxyHost", "proxy_hostname" );
System.getProperties().put( "proxyPort", "8080" ); // or other proxy port
And then you need to do authentication on proxy, using something similar:
URL url = new URL("http://www.google.com");
URLConnection con = url.openConnection();
String pass = "MY_USERNAME:MY_PASS";
String encodedPass = base64Encode( pass );
con.setRequestProperty( "Proxy-Authorization", encodedPass );
Good luck.
Yes. Proxy settings can protect a standalone app from connecting to internet. If you know the proxy try using
-Dhttp.proxyHost=yourProxy & -Dhttp.proxyPort=proxyPort
These are VM arguments. If you are running it command line then use it as
java -Dhttp.proxyHost=yourProxy & -Dhttp.proxyPort=proxyPort Main
Related
I am trying to make a program where a user can asks GPT-3 a question through its API.
I tried to get GPT-3's assistant to design code for me, however there were some errors because it uses outdated information from 2021. Below is my modified code after going through the documentation, but I still cant get it to work, it is generating a 'java.io.FileNotFoundException' error.
I believe the problem is with the formatting of the completion section of my URL, however I am not sure. If anyone could tell me what's wrong it would be greatly appreciated.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
public class ChatGPT{
public static void main(String[] args) throws IOException {
String prompt = "What country has the most moderate weather?";
String model = "text-curie-001";
String apiKey = /*My API key*/;
// Encode the prompt and construct the API request URL
String url = String.format(
"https://api.openai.com/v1/completions?model=%s&prompt=%s",
model,
URLEncoder.encode(prompt, "UTF-8")
);
// Create the request
HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
conn.setRequestMethod("GET");
conn.setRequestProperty("Authorization", "Bearer " + apiKey);
// Make the request and retrieve the response
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuilder responseBody = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
responseBody.append(line);
}
reader.close();
// Print the response
System.out.println(responseBody);
}
}
I know my API key is valid because changing the url to whats shown below outputs the appropriate information:
String url = String.format(
"https://api.openai.com/v1/models/%s",
model
);
the format "/v1/models/text-curie-001" outputs the details for the model 'text-curie-001'
the format "/v1/completions..." outputs a response based on the given prompt.
Hy
I try to connect a java program to an REST API.
With the same part of code I have a Java Exception in Java 6 and it works fine in Java 8.
It's the same environment :
trustore
machine
unix user
the code :
import java.io.DataInputStream;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
public class MainClass {
public static void main (String[] args){
String serviceUrl = "https://api.domain.com" + "/endpont/path";
try {
URL url = new URL(serviceUrl);
URLConnection connection = null;
try{
connection = url.openConnection();
connection.setRequestProperty("Accept", "application/json");
connection.setRequestProperty("Content-Type", "application/json");
String body = "";
String inputLine;
DataInputStream input = new DataInputStream (connection.getInputStream());
while (((inputLine = input.readLine()) != null)){
body += inputLine;
}
System.out.println(body);
} catch (IOException e) {
e.printStackTrace();
}
} catch (MalformedURLException e) {
e.printStackTrace();
}
}
}
the error in Java 6 : sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Somebody know how it's different ? Can I use some tricks to have the same result in Java 6 ?
The CN of the cert is a wildcard : "*.domain.com" . It can be the cause ?
I tried several api but there all used the sun SSL layer. Do you know an other to replace it ?
JRE has it's own keystore, where certificates can be stored. Maybe your JDK/JRE for Java 6 has different keys than Java 8.
I'm using OpenJDK 11 on Linux and I need to make sure all my web requests done with HttpURLConnection are properly closed and do not keep any file descriptors open.
Oracle's manual tells to use close on the InputStream and Android's manual tells to use disconnect on the HttpURLConnection object.
I also set Connection: close and http.keepAlive to false to avoid pooling of connections.
This seems to work with plain http requests but not encrypted https requests whose response is sent with non-chunked encoding. Only a GC seems to clean up the closed connections.
This example code:
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.stream.Stream;
public class Test {
private static int printFds() throws IOException {
int cnt = 0;
try (Stream<Path> paths = Files.list(new File("/proc/self/fd").toPath())) {
for (Path path : (Iterable<Path>)paths::iterator) {
System.out.println(path);
++cnt;
}
}
System.out.println();
return cnt;
}
public static void main(String[] args) throws IOException, InterruptedException {
System.setProperty("http.keepAlive", "false");
for (int i = 0; i < 10; i++) {
// Must be a https endpoint returning non-chunked response
HttpURLConnection conn = (HttpURLConnection) new URL("https://www.google.com/").openConnection();
conn.setRequestProperty("Connection", "close");
BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
while (in.readLine() != null) {
}
in.close();
conn.disconnect();
conn = null;
in = null;
}
Thread.sleep(1000);
int numBeforeGc = printFds();
System.gc();
Thread.sleep(1000);
int numAfterGc = printFds();
System.out.println(numBeforeGc == numAfterGc ? "No socket leaks" : "Sockets were leaked");
}
}
prints this output:
/proc/self/fd/0
/proc/self/fd/1
/proc/self/fd/2
/proc/self/fd/3
/proc/self/fd/4
/proc/self/fd/5
/proc/self/fd/9
/proc/self/fd/6
/proc/self/fd/7
/proc/self/fd/8
/proc/self/fd/10
/proc/self/fd/11
/proc/self/fd/12
/proc/self/fd/13
/proc/self/fd/14
/proc/self/fd/15
/proc/self/fd/16
/proc/self/fd/17
/proc/self/fd/18
/proc/self/fd/19
/proc/self/fd/0
/proc/self/fd/1
/proc/self/fd/2
/proc/self/fd/3
/proc/self/fd/4
/proc/self/fd/5
/proc/self/fd/9
/proc/self/fd/6
/proc/self/fd/7
/proc/self/fd/8
Sockets were leaked
Changing to a http URL makes the sockets close correctly as expected without GC:
/proc/self/fd/0
/proc/self/fd/1
/proc/self/fd/2
/proc/self/fd/3
/proc/self/fd/4
/proc/self/fd/5
/proc/self/fd/6
/proc/self/fd/0
/proc/self/fd/1
/proc/self/fd/2
/proc/self/fd/3
/proc/self/fd/4
/proc/self/fd/5
/proc/self/fd/6
No socket leak
Tested with both OpenJDK 11 and 12. Did I miss something or is this a bug?
Turns out to be a bug after all: https://bugs.openjdk.java.net/browse/JDK-8216326
shutdownInput is now replaced by close in the latest builds of JDK 11 and 13 (but not 12).
Ok so I wrote a piece of code testing ability of my java to connect to internet. It is supposed to fetch html from www.google.com and display the contents in a JFrame's JTextArea object.
Here's the code, so you can have clear picture:
import java.awt.Color;
import java.awt.Dimension;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import javax.swing.JFrame;
import javax.swing.JTextArea;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
public class JSoupFetchTest extends JFrame{
String userAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:37.0) Gecko/20100101 Firefox/37.0";
boolean jsoupcond = true;
String address = "http://www.google.com";
JTextArea text;
public JSoupFetchTest(){
text = new JTextArea();
text.setPreferredSize(new Dimension(500, 500));
text.setBackground(Color.BLACK);
text.setForeground(Color.WHITE);
text.setVisible(true);
text.setLineWrap(true);
this.add(text);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
this.pack();
gogo();
}
private void gogo() {
if(jsoupcond){
text.setText(text.getText() +"\nstart...");
try {
text.setText(text.getText() +"\nConnecting to " +address+ "...");
Document doc = Jsoup.connect(address).userAgent(userAgent).get();
text.setText(text.getText() +"\nConverting page document into text");
String s = doc.toString();
text.setText(text.getText() +"\nText: \n" +s);
System.out.println();
} catch (Exception e) {
text.setText(text.getText() +"\n" +e.toString());
e.printStackTrace();
}
text.setText(text.getText() +"\nEnd.");
}
String html = downloadHtml(address);
text.setText(text.getText() +"\nDownloading HTML...");
text.setText(text.getText() +"\nHTML:");
text.setText(text.getText() +"\n" +html);
}
private String downloadHtml(String path) {
text.setText(text.getText() +"\ndownloadHtml entry point...");
InputStream is = null;
try {
text.setText(text.getText() +"\ntry block entered...");
String result = "";
String line;
URL url = new URL(path);
text.setText(text.getText() +"\nabout to open url stream...");
is = url.openStream(); // throws an IOException
text.setText(text.getText() +"\nurl stream opened...");
BufferedReader br = new BufferedReader(new InputStreamReader(is));
text.setText(text.getText() +"\nstarting to read lines...");
while ((line = br.readLine()) != null) {
result += line;
}
text.setText(text.getText() +"\nreading lines finished...");
return result;
} catch (IOException ioe) {
ioe.printStackTrace();
} finally {
try {
if (is != null) is.close();
} catch (IOException ioe) { }
}
return "";
}
public static void main(String[] args) {
new JSoupFetchTest();
}
}
I should also add that:
1. My eclipse (cause that's what I'm using) can't connect to marketplace nor can't fetch updates.
2. Eclipse's web browser works fine.
3. My system's browser (Mozilla Firefox) connects fine
4. I exported JSoupFetchTest into a runnable jar and tried to run it from system's level, with no effect
5. I am running Windows 7 Professional MSDN version
6. I contacted eclipse support and they concluded it is not eclipse's fault and suggested that I'm behind a proxy.
7. I contacted my ISP to see if I indeed am and they said I am not.
8. I changed my JAVA's network settings so now it connects "directly". Before the setting was "use browser settings" and it didn't work either.
9. My eclipse's Window -> Preferences -> General -> Network Connections active provider is set to "Native", I also tried "Direct"
10. Method downloadHtml(String path) stops at "is = url.openStream();" and goes on forever...
The exception I get from JSoup is:
java.net.SocketTimeoutException: Read timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:150)
at java.net.SocketInputStream.read(SocketInputStream.java:121)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:246)
at java.io.BufferedInputStream.read1(BufferedInputStream.java:286)
at java.io.BufferedInputStream.read(BufferedInputStream.java:345)
at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:703)
at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:647)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1534)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1439)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480)
at org.jsoup.helper.HttpConnection$Response.execute(HttpConnection.java:453)
at org.jsoup.helper.HttpConnection$Response.execute(HttpConnection.java:434)
at org.jsoup.helper.HttpConnection.execute(HttpConnection.java:181)
at org.jsoup.helper.HttpConnection.get(HttpConnection.java:170)
at JSoupFetchTest.gogo(JSoupFetchTest.java:42)
at JSoupFetchTest.<init>(JSoupFetchTest.java:32)
at JSoupFetchTest.main(JSoupFetchTest.java:92)
I also tried to set JSoup.connect's timeout to infinity. Then it goes on forever.
Before you guys say that my question is a duplicate, or delegate me to other, external possible solutions to my problem, believe me - either the question is mine or I was there - I browse internet in search for solution for weeks now and I feel like pulling my hair out...
Please help if you can cause it prevents me from installing stuff in my eclipse and from developing anything else than stand alone apps...
You need a socket number after the URL -- "http:/www.google.com:80" works. JSoup likely uses defaults for that, but opening the URL as a stream in Java does not.
The following program works for me. So Java and JSoup are working. It has to be some sort of local configuration problem with your network. Check your firewall, routers, gateway, and Java permissions. Do a clean rebuild of your project. Etc. Comment out lines until it does work and then put the lines back one at a time until you find the problem. Etc.
package stuff;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import java.net.URLConnection;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
public class SocketTest
{
public static void main( String[] args ) throws Exception
{
URL url = new URL( "http://www.google.com" );
URLConnection sock = url.openConnection();
InputStream ins = sock.getInputStream();
BufferedReader reader = new BufferedReader( new InputStreamReader(ins, "UTF-8" ) );
for( String line; (line = reader.readLine()) != null; ) {
System.out.println( line );
}
ins.close();
Document doc = Jsoup.connect( "http://www.google.com" ).get();
System.out.println( doc.toString() );
String userAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:37.0) Gecko/20100101 Firefox/37.0";
Document doc2 = Jsoup.connect( "http://www.google.com" ).userAgent(userAgent).get();
System.out.println( doc2.toString() );
}
}
I made some research to solve my problem but sadly until now I couldn't. It's not such a big deal but I've stuck on it..
I need to make a search with some keywords in search engines such as google. I got two class here to do this:
package com.sh.st;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class EventSearch extends SearchScreen implements ActionListener {
public EventSearch(){
btsearch.addActionListener(this);
}
public void actionPerformed(ActionEvent e){
if(e.getSource()==btsearch){
String query=txtsearch.getText();
}
}
}
and
package com.sh.st;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
public class HttpRequest extends SearchScreen
{
URL url = new URL("google.com" + "?" + query).openConnection();
URLConnection connection = url.openConnection();
connection.setRequestProperty("Accept-Charset", "UTF-8"); //Possible Incompatibility
InputStream response = connection.getInputStream();
}
So, txtsearch comes from another class named SearchScreen and I attributed the value to one string named query. I need to pass query to HttpRequest class and to do this I just extend, I'm sure it's wrong but I saw someone else doing this; and this is the first problem, how may I do this?
the second and most important I'm receiving syntax error:
I didn't fully understand the meaning and utility of "connection.setRequestProperty("Accept-Charset", "UTF-8");"
'course reading I can understand that is regarding the caracters that probably will come up from my request but even though the syntax error is not clear for me
I made research in links such:
How to send HTTP request in java?
getting text from password field
http://www.xyzws.com/Javafaq/how-to-use-httpurlconnection-post-data-to-web-server/139
Using java.net.URLConnection to fire and handle HTTP requests
All of them have a good material but I can't fully understand everything on it and the part the I'm trying to follow is not working. Could anyone help me please?
Edit: [Topic Solved]
Try this code: (comments inlined)
// Fixed search URL; drop openConnection() at the end
URL url = new URL("http://google.com/search?q=" + query);
// Setup connection properties (this doesn't open the connection)
URLConnection connection = url.openConnection();
connection.setRequestProperty("Accept-Charset", "UTF-8");
// Actually, open the HTTP connection
connection.connect();
// Setup a reader
BufferedReader reader = new BufferedReader(
new InputStreamReader(connection.getInputStream()));
// Read line by line
String line = null;
while ((line = reader.readLine()) != null) {
System.out.println (line);
}
// Close connection
reader.close();