diff options
author | Brian Jones <cbj@gnu.org> | 2003-02-01 02:10:07 +0000 |
---|---|---|
committer | Brian Jones <cbj@gnu.org> | 2003-02-01 02:10:07 +0000 |
commit | a286d8e992bbc0a6180638df2bfb55e433642b78 (patch) | |
tree | 6c7ff3ab361b5543e219d49f537b2ecb38de6eb7 /external/jaxp/source/javax/xml/parsers/ClassStuff.java | |
parent | a1314139baa4e9cd89051573d3bb5a5b556f3b32 (diff) | |
download | classpath-a286d8e992bbc0a6180638df2bfb55e433642b78.tar.gz |
Initial revision
Diffstat (limited to 'external/jaxp/source/javax/xml/parsers/ClassStuff.java')
-rw-r--r-- | external/jaxp/source/javax/xml/parsers/ClassStuff.java | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/external/jaxp/source/javax/xml/parsers/ClassStuff.java b/external/jaxp/source/javax/xml/parsers/ClassStuff.java new file mode 100644 index 000000000..038863748 --- /dev/null +++ b/external/jaxp/source/javax/xml/parsers/ClassStuff.java @@ -0,0 +1,158 @@ +/* + * $Id: ClassStuff.java,v 1.1 2003-02-01 02:10:26 cbj Exp $ + * Copyright (C) 2001 David Brownell + * + * This file is part of GNU JAXP, a library. + * + * GNU JAXP is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * GNU JAXP 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 for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * As a special exception, if you link this library with other files to + * produce an executable, this library does not by itself cause the + * resulting executable to be covered by the GNU General Public License. + * This exception does not however invalidate any other reasons why the + * executable file might be covered by the GNU General Public License. + */ + +package javax.xml.parsers; + +import java.io.BufferedReader; +import java.io.File; +import java.io.FileInputStream; +import java.io.InputStream; +import java.io.InputStreamReader; +import java.lang.reflect.Method; +import java.util.Properties; + + +// $Id: ClassStuff.java,v 1.1 2003-02-01 02:10:26 cbj Exp $ + +/** + * Package-private utility methods for sharing + * magic related to class loading. + * NOTE: This is cloned in javax.xml.transform, + * where a different exception is thrown (bleech). + * Keep changes to the two copies in sync. + * + * @author David Brownell + * @version $Id: ClassStuff.java,v 1.1 2003-02-01 02:10:26 cbj Exp $ + */ +final class ClassStuff +{ + private ClassStuff () { } + + /** + * Get the default factory using the four-stage defaulting + * mechanism defined by JAXP. + */ + static Object + createFactory (String label, String defaultClass) + throws FactoryConfigurationError + { + String name = null; + ClassLoader loader = null; + + // figure out which class loader to use. + // source compiles on jdk 1.1, but works with jdk 1.2+ security + try { + Method m = null; + + // Can we use JDK 1.2 APIs? Preferred: security policies apply. + m = Thread.class.getMethod ("getContextClassLoader", null); + loader = (ClassLoader) m.invoke (Thread.currentThread(), null); + } catch (NoSuchMethodException e) { + // Assume that we are running JDK 1.1; use current ClassLoader + loader = ClassStuff.class.getClassLoader(); + } catch (NoSuchMethodError e) { + // evidently IE does this (one of its bugs) + loader = ClassStuff.class.getClassLoader(); + } catch (Throwable e) { + // "should not happen" + throw new UnknownError (e.getMessage()); + } + + // 1. Check System Property + // ... normally fails in applet environments + try { name = System.getProperty (label); + } catch (SecurityException e) { /* IGNORE */ } + + // 2. Check in $JAVA_HOME/lib/jaxp.properties + try { + if (name == null) { + String javaHome; + File file; + + javaHome = System.getProperty ("java.home"); + file = new File (new File (javaHome, "lib"), "jaxp.properties"); + if (file.exists() == true) { + FileInputStream in = new FileInputStream (file); + Properties props = new Properties(); + + props.load (in); + name = props.getProperty (label); + in.close (); + } + } + } catch (Exception e) { /* IGNORE */ } + + // 3. Check Services API + if (name == null) { + try { + String service = "META-INF/services/" + label; + InputStream in; + BufferedReader reader; + + if (loader == null) + in = ClassLoader.getSystemResourceAsStream (service); + else + in = loader.getResourceAsStream (service); + if (in != null) { + reader = new BufferedReader ( + new InputStreamReader (in, "UTF8")); + name = reader.readLine(); + in.close (); + } + } catch (Exception e2) { /* IGNORE */ } + } + + // 4. Distro-specific fallback + if (name == null) + name = defaultClass; + + // Instantiate! + try { + Class klass; + + if (loader == null) + klass = Class.forName (name); + else + klass = loader.loadClass (name); + return klass.newInstance (); + + } catch (ClassNotFoundException e) { + throw new FactoryConfigurationError (e, + "Factory class " + name + + " not found"); + } catch (IllegalAccessException e) { + throw new FactoryConfigurationError (e, + "Factory class " + name + + " found but cannot be loaded"); + } catch (InstantiationException e) { + throw new FactoryConfigurationError (e, + "Factory class " + name + + " loaded but cannot be instantiated" + + " ((no default constructor?)"); + } + } +} |