| /* |
| * Copyright 2006 Sun Microsystems, Inc. All Rights Reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Sun designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Sun in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| * CA 95054 USA or visit www.sun.com if you need additional information or |
| * have any questions. |
| */ |
| |
| package com.sun.xml.internal.dtdparser; |
| |
| import org.xml.sax.EntityResolver; |
| import org.xml.sax.InputSource; |
| |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.net.URL; |
| import java.net.URLConnection; |
| import java.util.Hashtable; |
| |
| /** |
| * This entity resolver class provides a number of utilities which can help |
| * managment of external parsed entities in XML. These are commonly used |
| * to hold markup declarations that are to be used as part of a Document |
| * Type Declaration (DTD), or to hold text marked up with XML. |
| * <p/> |
| * <P> Features include: <UL> |
| * <p/> |
| * <LI> Static factory methods are provided for constructing SAX InputSource |
| * objects from Files, URLs, or MIME objects. This eliminates a class of |
| * error-prone coding in applications. |
| * <p/> |
| * <LI> Character encodings for XML documents are correctly supported: <UL> |
| * <p/> |
| * <LI> The encodings defined in the RFCs for MIME content types |
| * (2046 for general MIME, and 2376 for XML in particular), are |
| * supported, handling <em>charset=...</em> attributes and accepting |
| * content types which are known to be safe for use with XML; |
| * <p/> |
| * <LI> The character encoding autodetection algorithm identified |
| * in the XML specification is used, and leverages all of |
| * the JDK 1.1 (and later) character encoding support. |
| * <p/> |
| * <LI> The use of MIME typing may optionally be disabled, forcing the |
| * use of autodetection, to support web servers which don't correctly |
| * report MIME types for XML. For example, they may report text that |
| * is encoded in EUC-JP as being US-ASCII text, leading to fatal |
| * errors during parsing. |
| * <p/> |
| * <LI> The InputSource objects returned by this class always |
| * have a <code>java.io.Reader</code> available as the "character |
| * stream" property. |
| * <p/> |
| * </UL> |
| * <p/> |
| * <LI> Catalog entries can map public identifiers to Java resources or |
| * to local URLs. These are used to reduce network dependencies and loads, |
| * and will often be used for external DTD components. For example, packages |
| * shipping DTD files as resources in JAR files can eliminate network traffic |
| * when accessing them, and sites may provide local caches of common DTDs. |
| * Note that no particular catalog syntax is supported by this class, only |
| * the notion of a set of entries. |
| * <p/> |
| * </UL> |
| * <p/> |
| * <P> Subclasses can perform tasks such as supporting new URI schemes for |
| * URIs which are not URLs, such as URNs (see RFC 2396) or for accessing |
| * MIME entities which are part of a <em>multipart/related</em> group |
| * (see RFC 2387). They may also be used to support particular catalog |
| * syntaxes, such as the <a href="http://www.oasis-open.org/html/a401.htm"> |
| * SGML/Open Catalog (SOCAT)</a> which supports the SGML notion of "Formal |
| * Public Identifiers (FPIs). |
| * |
| * @author David Brownell |
| * @author Janet Koenig |
| */ |
| public class Resolver implements EntityResolver { |
| private boolean ignoringMIME; |
| |
| // table mapping public IDs to (local) URIs |
| private Hashtable id2uri; |
| |
| // tables mapping public IDs to resources and classloaders |
| private Hashtable id2resource; |
| private Hashtable id2loader; |
| |
| // |
| // table of MIME content types (less attributes!) known |
| // to be mostly "OK" to use with XML MIME entities. the |
| // idea is to rule out obvious braindamage ("image/jpg") |
| // not the subtle stuff ("text/html") that might actually |
| // be (or become) safe. |
| // |
| private static final String types [] = { |
| "application/xml", |
| "text/xml", |
| "text/plain", |
| "text/html", // commonly mis-inferred |
| "application/x-netcdf", // this is often illegal XML |
| "content/unknown" |
| }; |
| |
| /** |
| * Constructs a resolver. |
| */ |
| public Resolver() { |
| } |
| |
| /** |
| * Returns an input source, using the MIME type information and URL |
| * scheme to statically determine the correct character encoding if |
| * possible and otherwise autodetecting it. MIME carefully specifies |
| * the character encoding defaults, and how attributes of the content |
| * type can change it. XML further specifies two mandatory encodings |
| * (UTF-8 and UTF-16), and includes an XML declaration which can be |
| * used to internally label most documents encoded using US-ASCII |
| * supersets (such as Shift_JIS, EUC-JP, ISO-2022-*, ISO-8859-*, and |
| * more). |
| * <p/> |
| * <P> This method can be used to access XML documents which do not |
| * have URIs (such as servlet input streams, or most JavaMail message |
| * entities) and to support access methods such as HTTP POST or PUT. |
| * (URLs normally return content using the GET method.) |
| * <p/> |
| * <P> <em> The caller should set the system ID in order for relative URIs |
| * found in this document to be interpreted correctly.</em> In some cases, |
| * a custom resolver will need to be used; for example, documents |
| * may be grouped in a single MIME "multipart/related" bundle, and |
| * relative URLs would refer to other documents in that bundle. |
| * |
| * @param contentType The MIME content type for the source for which |
| * an InputSource is desired, such as <em>text/xml;charset=utf-8</em>. |
| * @param stream The input byte stream for the input source. |
| * @param checkType If true, this verifies that the content type is known |
| * to support XML documents, such as <em>application/xml</em>. |
| * @param scheme Unless this is "file", unspecified MIME types |
| * default to US-ASCII. Files are always autodetected since most |
| * file systems discard character encoding information. |
| */ |
| public static InputSource createInputSource(String contentType, |
| InputStream stream, |
| boolean checkType, |
| String scheme) throws IOException { |
| InputSource retval; |
| String charset = null; |
| |
| if (contentType != null) { |
| int index; |
| |
| contentType = contentType.toLowerCase(); |
| index = contentType.indexOf(';'); |
| if (index != -1) { |
| String attributes; |
| |
| attributes = contentType.substring(index + 1); |
| contentType = contentType.substring(0, index); |
| |
| // use "charset=..." if it's available |
| index = attributes.indexOf("charset"); |
| if (index != -1) { |
| attributes = attributes.substring(index + 7); |
| // strip out subsequent attributes |
| if ((index = attributes.indexOf(';')) != -1) |
| attributes = attributes.substring(0, index); |
| // find start of value |
| if ((index = attributes.indexOf('=')) != -1) { |
| attributes = attributes.substring(index + 1); |
| // strip out rfc822 comments |
| if ((index = attributes.indexOf('(')) != -1) |
| attributes = attributes.substring(0, index); |
| // double quotes are optional |
| if ((index = attributes.indexOf('"')) != -1) { |
| attributes = attributes.substring(index + 1); |
| attributes = attributes.substring(0, |
| attributes.indexOf('"')); |
| } |
| charset = attributes.trim(); |
| // XXX "\;", "\)" etc were mishandled above |
| } |
| } |
| } |
| |
| // |
| // Check MIME type. |
| // |
| if (checkType) { |
| boolean isOK = false; |
| for (int i = 0; i < types.length; i++) |
| if (types[i].equals(contentType)) { |
| isOK = true; |
| break; |
| } |
| if (!isOK) |
| throw new IOException("Not XML: " + contentType); |
| } |
| |
| // |
| // "text/*" MIME types have hard-wired character set |
| // defaults, as specified in the RFCs. For XML, we |
| // ignore the system "file.encoding" property since |
| // autodetection is more correct. |
| // |
| if (charset == null) { |
| contentType = contentType.trim(); |
| if (contentType.startsWith("text/")) { |
| if (!"file".equalsIgnoreCase(scheme)) |
| charset = "US-ASCII"; |
| } |
| // "application/*" has no default |
| } |
| } |
| |
| retval = new InputSource(XmlReader.createReader(stream, charset)); |
| retval.setByteStream(stream); |
| retval.setEncoding(charset); |
| return retval; |
| } |
| |
| |
| /** |
| * Creates an input source from a given URI. |
| * |
| * @param uri the URI (system ID) for the entity |
| * @param checkType if true, the MIME content type for the entity |
| * is checked for document type and character set encoding. |
| */ |
| static public InputSource createInputSource(URL uri, boolean checkType) |
| throws IOException { |
| |
| URLConnection conn = uri.openConnection(); |
| InputSource retval; |
| |
| if (checkType) { |
| String contentType = conn.getContentType(); |
| retval = createInputSource(contentType, conn.getInputStream(), |
| false, uri.getProtocol()); |
| } else { |
| retval = new InputSource(XmlReader.createReader(conn.getInputStream())); |
| } |
| retval.setSystemId(conn.getURL().toString()); |
| return retval; |
| } |
| |
| |
| /** |
| * Creates an input source from a given file, autodetecting |
| * the character encoding. |
| */ |
| static public InputSource createInputSource(File file) |
| throws IOException { |
| InputSource retval; |
| String path; |
| |
| retval = new InputSource(XmlReader.createReader(new FileInputStream(file))); |
| |
| // On JDK 1.2 and later, simplify this: |
| // "path = file.toURL ().toString ()". |
| path = file.getAbsolutePath(); |
| if (File.separatorChar != '/') |
| path = path.replace(File.separatorChar, '/'); |
| if (!path.startsWith("/")) |
| path = "/" + path; |
| if (!path.endsWith("/") && file.isDirectory()) |
| path = path + "/"; |
| |
| retval.setSystemId("file:" + path); |
| return retval; |
| } |
| |
| |
| /** |
| * <b>SAX:</b> |
| * Resolve the given entity into an input source. If the name can't |
| * be mapped to a preferred form of the entity, the URI is used. To |
| * resolve the entity, first a local catalog mapping names to URIs is |
| * consulted. If no mapping is found there, a catalog mapping names |
| * to java resources is consulted. Finally, if neither mapping found |
| * a copy of the entity, the specified URI is used. |
| * <p/> |
| * <P> When a URI is used, <a href="#createInputSource"> |
| * createInputSource</a> is used to correctly deduce the character |
| * encoding used by this entity. No MIME type checking is done. |
| * |
| * @param name Used to find alternate copies of the entity, when |
| * this value is non-null; this is the XML "public ID". |
| * @param uri Used when no alternate copy of the entity is found; |
| * this is the XML "system ID", normally a URI. |
| */ |
| public InputSource resolveEntity(String name, String uri) |
| throws IOException { |
| InputSource retval; |
| String mappedURI = name2uri(name); |
| InputStream stream; |
| |
| // prefer explicit URI mappings, then bundled resources... |
| if (mappedURI == null && (stream = mapResource(name)) != null) { |
| uri = "java:resource:" + (String) id2resource.get(name); |
| retval = new InputSource(XmlReader.createReader(stream)); |
| |
| // ...and treat all URIs the same (as URLs for now). |
| } else { |
| URL url; |
| URLConnection conn; |
| |
| if (mappedURI != null) |
| uri = mappedURI; |
| else if (uri == null) |
| return null; |
| |
| url = new URL(uri); |
| conn = url.openConnection(); |
| uri = conn.getURL().toString(); |
| // System.out.println ("++ URI: " + url); |
| if (ignoringMIME) |
| retval = new InputSource(XmlReader.createReader(conn.getInputStream())); |
| else { |
| String contentType = conn.getContentType(); |
| retval = createInputSource(contentType, |
| conn.getInputStream(), |
| false, url.getProtocol()); |
| } |
| } |
| retval.setSystemId(uri); |
| retval.setPublicId(name); |
| return retval; |
| } |
| |
| |
| /** |
| * Returns true if this resolver is ignoring MIME types in the documents |
| * it returns, to work around bugs in how servers have reported the |
| * documents' MIME types. |
| */ |
| public boolean isIgnoringMIME() { |
| return ignoringMIME; |
| } |
| |
| /** |
| * Tells the resolver whether to ignore MIME types in the documents it |
| * retrieves. Many web servers incorrectly assign text documents a |
| * default character encoding, even when that is incorrect. For example, |
| * all HTTP text documents default to use ISO-8859-1 (used for Western |
| * European languages), and other MIME sources default text documents |
| * to use US-ASCII (a seven bit encoding). For XML documents which |
| * include text encoding declarations (as most should do), these server |
| * bugs can be worked around by ignoring the MIME type entirely. |
| */ |
| public void setIgnoringMIME(boolean value) { |
| ignoringMIME = value; |
| } |
| |
| |
| // maps the public ID to an alternate URI, if one is registered |
| private String name2uri(String publicId) { |
| if (publicId == null || id2uri == null) |
| return null; |
| return (String) id2uri.get(publicId); |
| } |
| |
| |
| /** |
| * Registers the given public ID as corresponding to a particular |
| * URI, typically a local copy. This URI will be used in preference |
| * to ones provided as system IDs in XML entity declarations. This |
| * mechanism would most typically be used for Document Type Definitions |
| * (DTDs), where the public IDs are formally managed and versioned. |
| * |
| * @param publicId The managed public ID being mapped |
| * @param uri The URI of the preferred copy of that entity |
| */ |
| public void registerCatalogEntry(String publicId, |
| String uri) { |
| if (id2uri == null) |
| id2uri = new Hashtable(17); |
| id2uri.put(publicId, uri); |
| } |
| |
| |
| // return the resource as a stream |
| private InputStream mapResource(String publicId) { |
| // System.out.println ("++ PUBLIC: " + publicId); |
| if (publicId == null || id2resource == null) |
| return null; |
| |
| String resourceName = (String) id2resource.get(publicId); |
| ClassLoader loader = null; |
| |
| if (resourceName == null) |
| return null; |
| // System.out.println ("++ Resource: " + resourceName); |
| |
| if (id2loader != null) |
| loader = (ClassLoader) id2loader.get(publicId); |
| // System.out.println ("++ Loader: " + loader); |
| if (loader == null) |
| return ClassLoader.getSystemResourceAsStream(resourceName); |
| return loader.getResourceAsStream(resourceName); |
| } |
| |
| /** |
| * Registers a given public ID as corresponding to a particular Java |
| * resource in a given class loader, typically distributed with a |
| * software package. This resource will be preferred over system IDs |
| * included in XML documents. This mechanism should most typically be |
| * used for Document Type Definitions (DTDs), where the public IDs are |
| * formally managed and versioned. |
| * <p/> |
| * <P> If a mapping to a URI has been provided, that mapping takes |
| * precedence over this one. |
| * |
| * @param publicId The managed public ID being mapped |
| * @param resourceName The name of the Java resource |
| * @param loader The class loader holding the resource, or null if |
| * it is a system resource. |
| */ |
| public void registerCatalogEntry(String publicId, |
| String resourceName, |
| ClassLoader loader) { |
| if (id2resource == null) |
| id2resource = new Hashtable(17); |
| id2resource.put(publicId, resourceName); |
| |
| if (loader != null) { |
| if (id2loader == null) |
| id2loader = new Hashtable(17); |
| id2loader.put(publicId, loader); |
| } |
| } |
| } |
