Build JavaMail activation inline

app/src/main/java/javax/activation/URLDataSource.java

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+/*
+ * Copyright (c) 1997, 2019 Oracle and/or its affiliates. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Distribution License v. 1.0, which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+package javax.activation;
+
+import java.net.URL;
+import java.net.URLConnection;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.IOException;
+
+/**
+ * The URLDataSource class provides an object that wraps a <code>URL</code>
+ * object in a DataSource interface. URLDataSource simplifies the handling
+ * of data described by URLs within Jakarta Activation
+ * because this class can be used to create new DataHandlers. <i>NOTE: The
+ * DataHandler object creates a URLDataSource internally,
+ * when it is constructed with a URL.</i>
+ *
+ * @see javax.activation.DataSource
+ * @see javax.activation.DataHandler
+ */
+public class URLDataSource implements DataSource {
+    private URL url = null;
+    private URLConnection url_conn = null;
+
+    /**
+     * URLDataSource constructor. The URLDataSource class will
+     * not open a connection to the URL until a method requiring it
+     * to do so is called.
+     *
+     * @param url The URL to be encapsulated in this object.
+     */
+    public URLDataSource(URL url) {
+	this.url = url;
+    }
+
+    /**
+     * Returns the value of the URL content-type header field.
+     * It calls the URL's <code>URLConnection.getContentType</code> method
+     * after retrieving a URLConnection object.
+     * <i>Note: this method attempts to call the <code>openConnection</code>
+     * method on the URL. If this method fails, or if a content type is not
+     * returned from the URLConnection, getContentType returns
+     * "application/octet-stream" as the content type.</i>
+     *
+     * @return the content type.
+     */
+    public String getContentType() {
+	String type = null;
+
+	try {
+	    if (url_conn == null)
+		url_conn = url.openConnection();
+	} catch (IOException e) { }
+	
+	if (url_conn != null)
+	    type = url_conn.getContentType();
+
+	if (type == null)
+	    type = "application/octet-stream";
+	
+	return type;
+    }
+
+    /**
+     * Calls the <code>getFile</code> method on the URL used to
+     * instantiate the object.
+     *
+     * @return the result of calling the URL's getFile method.
+     */
+    public String getName() {
+	return url.getFile();
+    }
+
+    /**
+     * The getInputStream method from the URL. Calls the
+     * <code>openStream</code> method on the URL.
+     *
+     * @return the InputStream.
+     */
+    public InputStream getInputStream() throws IOException {
+	return url.openStream();
+    }
+
+    /**
+     * The getOutputStream method from the URL. First an attempt is
+     * made to get the URLConnection object for the URL. If that
+     * succeeds, the getOutputStream method on the URLConnection
+     * is returned.
+     *
+     * @return the OutputStream.
+     */
+    public OutputStream getOutputStream() throws IOException {
+	// get the url connection if it is available
+	url_conn = url.openConnection();
+	
+	if (url_conn != null) {
+	    url_conn.setDoOutput(true);
+	    return url_conn.getOutputStream();
+	} else
+	    return null;
+    }
+
+    /**
+     * Return the URL used to create this DataSource.
+     *
+     * @return The URL.
+     */
+    public URL getURL() {
+	return url;
+    }
+}