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package sun.net.www;

import java.net.URL;
import java.util.*;

A class to represent an active connection to an object represented by a URL.
Author: James Gosling
/** * A class to represent an active connection to an object * represented by a URL. * @author James Gosling */
abstract public class URLConnection extends java.net.URLConnection {
The URL that it is connected to
/** The URL that it is connected to */
private String contentType; private int contentLength = -1; protected MessageHeader properties;
Create a URLConnection object. These should not be created directly: instead they should be created by protocol handers in response to URL.openConnection.
Params:
  • u – The URL that this connects to.
/** Create a URLConnection object. These should not be created directly: instead they should be created by protocol handers in response to URL.openConnection. @param u The URL that this connects to. */
public URLConnection (URL u) { super(u); properties = new MessageHeader(); }
Call this routine to get the property list for this object. Properties (like content-type) that have explicit getXX() methods associated with them should be accessed using those methods.
/** Call this routine to get the property list for this object. * Properties (like content-type) that have explicit getXX() methods * associated with them should be accessed using those methods. */
public MessageHeader getProperties() { return properties; }
Call this routine to set the property list for this object.
/** Call this routine to set the property list for this object. */
public void setProperties(MessageHeader properties) { this.properties = properties; } public void setRequestProperty(String key, String value) { if(connected) throw new IllegalAccessError("Already connected"); if (key == null) throw new NullPointerException ("key cannot be null"); properties.set(key, value); }
The following three methods addRequestProperty, getRequestProperty, and getRequestProperties were copied from the superclass implementation before it was changed by CR:6230836, to maintain backward compatibility.
/** * The following three methods addRequestProperty, getRequestProperty, * and getRequestProperties were copied from the superclass implementation * before it was changed by CR:6230836, to maintain backward compatibility. */
public void addRequestProperty(String key, String value) { if (connected) throw new IllegalStateException("Already connected"); if (key == null) throw new NullPointerException ("key is null"); } public String getRequestProperty(String key) { if (connected) throw new IllegalStateException("Already connected"); return null; } public Map<String,List<String>> getRequestProperties() { if (connected) throw new IllegalStateException("Already connected"); return Collections.emptyMap(); } public String getHeaderField(String name) { try { getInputStream(); } catch (Exception e) { return null; } return properties == null ? null : properties.findValue(name); }
Return the key for the nth header field. Returns null if there are fewer than n fields. This can be used to iterate through all the headers in the message.
/** * Return the key for the nth header field. Returns null if * there are fewer than n fields. This can be used to iterate * through all the headers in the message. */
public String getHeaderFieldKey(int n) { try { getInputStream(); } catch (Exception e) { return null; } MessageHeader props = properties; return props == null ? null : props.getKey(n); }
Return the value for the nth header field. Returns null if there are fewer than n fields. This can be used in conjunction with getHeaderFieldKey to iterate through all the headers in the message.
/** * Return the value for the nth header field. Returns null if * there are fewer than n fields. This can be used in conjunction * with getHeaderFieldKey to iterate through all the headers in the message. */
public String getHeaderField(int n) { try { getInputStream(); } catch (Exception e) { return null; } MessageHeader props = properties; return props == null ? null : props.getValue(n); }
Call this routine to get the content-type associated with this object.
/** Call this routine to get the content-type associated with this * object. */
public String getContentType() { if (contentType == null) contentType = getHeaderField("content-type"); if (contentType == null) { String ct = null; try { ct = guessContentTypeFromStream(getInputStream()); } catch(java.io.IOException e) { } String ce = properties.findValue("content-encoding"); if (ct == null) { ct = properties.findValue("content-type"); if (ct == null) if (url.getFile().endsWith("/")) ct = "text/html"; else ct = guessContentTypeFromName(url.getFile()); } /* * If the Mime header had a Content-encoding field and its value * was not one of the values that essentially indicate no * encoding, we force the content type to be unknown. This will * cause a save dialog to be presented to the user. It is not * ideal but is better than what we were previously doing, namely * bringing up an image tool for compressed tar files. */ if (ct == null || ce != null && !(ce.equalsIgnoreCase("7bit") || ce.equalsIgnoreCase("8bit") || ce.equalsIgnoreCase("binary"))) ct = "content/unknown"; setContentType(ct); } return contentType; }
Set the content type of this URL to a specific value.
Params:
  • type – The content type to use. One of the content_* static variables in this class should be used. eg. setType(URL.content_html);
/** * Set the content type of this URL to a specific value. * @param type The content type to use. One of the * content_* static variables in this * class should be used. * eg. setType(URL.content_html); */
public void setContentType(String type) { contentType = type; properties.set("content-type", type); }
Call this routine to get the content-length associated with this object.
/** Call this routine to get the content-length associated with this * object. */
public int getContentLength() { try { getInputStream(); } catch (Exception e) { return -1; } int l = contentLength; if (l < 0) { try { l = Integer.parseInt(properties.findValue("content-length")); setContentLength(l); } catch(Exception e) { } } return l; }
Call this routine to set the content-length associated with this object.
/** Call this routine to set the content-length associated with this * object. */
protected void setContentLength(int length) { contentLength = length; properties.set("content-length", String.valueOf(length)); }
Returns true if the data associated with this URL can be cached.
/** * Returns true if the data associated with this URL can be cached. */
public boolean canCache() { return url.getFile().indexOf('?') < 0 /* && url.postData == null REMIND */ ; }
Call this to close the connection and flush any remaining data. Overriders must remember to call super.close()
/** * Call this to close the connection and flush any remaining data. * Overriders must remember to call super.close() */
public void close() { url = null; } private static HashMap<String,Void> proxiedHosts = new HashMap<>(); public synchronized static void setProxiedHost(String host) { proxiedHosts.put(host.toLowerCase(), null); } public synchronized static boolean isProxiedHost(String host) { return proxiedHosts.containsKey(host.toLowerCase()); } }