82 lines
2.7 KiB
Java
82 lines
2.7 KiB
Java
package urlConnection;
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import java.io.*;
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import java.net.*;
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import java.nio.charset.*;
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import java.util.*;
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/**
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* This program connects to an URL and displays the response header data and the first 10 lines of
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* the requested data.
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*
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* Supply the URL and an optional username and password (for HTTP basic authentication) on the
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* command line.
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* @version 1.11 2007-06-26
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* @author Cay Horstmann
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*/
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public class URLConnectionTest
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{
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public static void main(String[] args)
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{
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try
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{
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String urlName;
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if (args.length > 0) urlName = args[0];
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else urlName = "http://horstmann.com";
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URL url = new URL(urlName);
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URLConnection connection = url.openConnection();
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// set username, password if specified on command line
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if (args.length > 2)
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{
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String username = args[1];
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String password = args[2];
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String input = username + ":" + password;
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Base64.Encoder encoder = Base64.getEncoder();
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String encoding = encoder.encodeToString(input.getBytes(StandardCharsets.UTF_8));
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connection.setRequestProperty("Authorization", "Basic " + encoding);
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}
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connection.connect();
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// print header fields
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Map<String, List<String>> headers = connection.getHeaderFields();
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for (Map.Entry<String, List<String>> entry : headers.entrySet())
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{
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String key = entry.getKey();
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for (String value : entry.getValue())
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System.out.println(key + ": " + value);
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}
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// print convenience functions
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System.out.println("----------");
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System.out.println("getContentType: " + connection.getContentType());
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System.out.println("getContentLength: " + connection.getContentLength());
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System.out.println("getContentEncoding: " + connection.getContentEncoding());
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System.out.println("getDate: " + connection.getDate());
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System.out.println("getExpiration: " + connection.getExpiration());
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System.out.println("getLastModifed: " + connection.getLastModified());
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System.out.println("----------");
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String encoding = connection.getContentEncoding();
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if (encoding == null) encoding = "UTF-8";
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try (Scanner in = new Scanner(connection.getInputStream(), encoding))
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{
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// print first ten lines of contents
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for (int n = 1; in.hasNextLine() && n <= 10; n++)
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System.out.println(in.nextLine());
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if (in.hasNextLine()) System.out.println(". . .");
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}
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}
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catch (IOException e)
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{
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e.printStackTrace();
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}
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}
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}
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