1 /* 2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package javax.activation; 27 28 import java.net.URL; 29 import java.net.URLConnection; 30 import java.io.InputStream; 31 import java.io.OutputStream; 32 import java.io.IOException; 33 34 /** 35 * The URLDataSource class provides an object that wraps a <code>URL</code> 36 * object in a DataSource interface. URLDataSource simplifies the handling 37 * of data described by URLs within the JavaBeans Activation Framework 38 * because this class can be used to create new DataHandlers. <i>NOTE: The 39 * DataHandler object creates a URLDataSource internally, 40 * when it is constructed with a URL.</i> 41 * 42 * @see javax.activation.DataSource 43 * @see javax.activation.DataHandler 44 * 45 * @since 1.6 46 */ 47 public class URLDataSource implements DataSource { 48 private URL url = null; 49 private URLConnection url_conn = null; 50 51 /** 52 * URLDataSource constructor. The URLDataSource class will 53 * not open a connection to the URL until a method requiring it 54 * to do so is called. 55 * 56 * @param url The URL to be encapsulated in this object. 57 */ 58 public URLDataSource(URL url) { 59 this.url = url; 60 } 61 62 /** 63 * Returns the value of the URL content-type header field. 64 * It calls the URL's <code>URLConnection.getContentType</code> method 65 * after retrieving a URLConnection object. 66 * <i>Note: this method attempts to call the <code>openConnection</code> 67 * method on the URL. If this method fails, or if a content type is not 68 * returned from the URLConnection, getContentType returns 69 * "application/octet-stream" as the content type.</i> 70 * 71 * @return the content type. 72 */ 73 public String getContentType() { 74 String type = null; 75 76 try { 77 if (url_conn == null) 78 url_conn = url.openConnection(); 79 } catch (IOException e) { } 80 81 if (url_conn != null) 82 type = url_conn.getContentType(); 83 84 if (type == null) 85 type = "application/octet-stream"; 86 87 return type; 88 } 89 90 /** 91 * Calls the <code>getFile</code> method on the URL used to 92 * instantiate the object. 93 * 94 * @return the result of calling the URL's getFile method. 95 */ 96 public String getName() { 97 return url.getFile(); 98 } 99 100 /** 101 * The getInputStream method from the URL. Calls the 102 * <code>openStream</code> method on the URL. 103 * 104 * @return the InputStream. 105 */ 106 public InputStream getInputStream() throws IOException { 107 return url.openStream(); 108 } 109 110 /** 111 * The getOutputStream method from the URL. First an attempt is 112 * made to get the URLConnection object for the URL. If that 113 * succeeds, the getOutputStream method on the URLConnection 114 * is returned. 115 * 116 * @return the OutputStream. 117 */ 118 public OutputStream getOutputStream() throws IOException { 119 // get the url connection if it is available 120 url_conn = url.openConnection(); 121 122 if (url_conn != null) { 123 url_conn.setDoOutput(true); 124 return url_conn.getOutputStream(); 125 } else 126 return null; 127 } 128 129 /** 130 * Return the URL used to create this DataSource. 131 * 132 * @return The URL. 133 */ 134 public URL getURL() { 135 return url; 136 } 137 }