From cb03495d36fd0cb32e41469c0b34ca73f371baee Mon Sep 17 00:00:00 2001
From: Andreas Beeker <kiwiwings@apache.org>
Date: Sat, 8 Oct 2016 17:07:15 +0000
Subject: [PATCH] Bug 60226 - ClassLoader workaround for OSGI when processing
 OOXML files

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1763922 13f79535-47bb-0310-9956-ffa450edef68
---
 .../java/org/apache/poi/POIXMLTypeLoader.java | 42 +++++++++++---
 .../apache/poi/xslf/usermodel/XSLFTable.java  | 58 ++++++++++---------
 .../org/apache/poi/TestPOIXMLDocument.java    | 37 ++++++++++++
 3 files changed, 103 insertions(+), 34 deletions(-)

diff --git a/src/ooxml/java/org/apache/poi/POIXMLTypeLoader.java b/src/ooxml/java/org/apache/poi/POIXMLTypeLoader.java
index b703d73d8..eeed5f7c8 100644
--- a/src/ooxml/java/org/apache/poi/POIXMLTypeLoader.java
+++ b/src/ooxml/java/org/apache/poi/POIXMLTypeLoader.java
@@ -23,6 +23,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.Reader;
 import java.io.StringReader;
+import java.lang.ref.WeakReference;
 import java.net.URL;
 import java.util.Collections;
 import java.util.HashMap;
@@ -32,6 +33,7 @@ import javax.xml.stream.XMLStreamReader;
 
 import org.apache.poi.util.DocumentHelper;
 import org.apache.xmlbeans.SchemaType;
+import org.apache.xmlbeans.SchemaTypeLoader;
 import org.apache.xmlbeans.XmlBeans;
 import org.apache.xmlbeans.XmlException;
 import org.apache.xmlbeans.XmlObject;
@@ -46,6 +48,8 @@ import org.xml.sax.SAXException;
 @SuppressWarnings("deprecation")
 public class POIXMLTypeLoader {
 
+    private static ThreadLocal<ClassLoader> classLoader = new ThreadLocal<ClassLoader>();
+    
     public static final XmlOptions DEFAULT_XML_OPTIONS;
     static {
         DEFAULT_XML_OPTIONS = new XmlOptions();
@@ -80,8 +84,32 @@ public class POIXMLTypeLoader {
         return options == null ? DEFAULT_XML_OPTIONS : options;
     }
 
+    /**
+     * Sets the {@link ClassLoader} which is used, when XmlBeans are dynamically instantiated -
+     * opposed to being loaded by the factory class which is accompanied by each generated XmlBeans interface.
+     * <p>
+     * This is especially necessary in a context which doesn't guarantee that the current (thread) context
+     * cassloader has access to all XmlBeans schema definitions (*.xsb) - which is typically in OSGI the case.
+     * <p>
+     * The classloader will be only set for the current thread in a {@link ThreadLocal}. Although the
+     * ThreadLocal is implemented via a {@link WeakReference}, it's good style to {@code null} the classloader
+     * when the user code is finalized.
+     * 
+     * @param cl the classloader to be used when XmlBeans classes and definitions are looked up
+     */
+    public static void setClassLoader(ClassLoader cl) {
+        classLoader.set(cl);
+    }
+    
+    private static SchemaTypeLoader getTypeLoader() {
+        ClassLoader cl = classLoader.get();
+        return (cl == null)
+            ? XmlBeans.getContextTypeLoader()
+            : XmlBeans.typeLoaderForClassLoader(cl);
+    }
+    
     public static XmlObject newInstance(SchemaType type, XmlOptions options) {
-        return XmlBeans.getContextTypeLoader().newInstance(type, getXmlOptions(options));
+        return getTypeLoader().newInstance(type, getXmlOptions(options));
     }
 
     public static XmlObject parse(String xmlText, SchemaType type, XmlOptions options) throws XmlException {
@@ -113,34 +141,34 @@ public class POIXMLTypeLoader {
     public static XmlObject parse(InputStream jiois, SchemaType type, XmlOptions options) throws XmlException, IOException {
         try {
             Document doc = DocumentHelper.readDocument(jiois);
-            return XmlBeans.getContextTypeLoader().parse(doc.getDocumentElement(), type, getXmlOptions(options));
+            return getTypeLoader().parse(doc.getDocumentElement(), type, getXmlOptions(options));
         } catch (SAXException e) {
             throw new IOException("Unable to parse xml bean", e);
         }
     }
 
     public static XmlObject parse(XMLStreamReader xsr, SchemaType type, XmlOptions options) throws XmlException {
-        return XmlBeans.getContextTypeLoader().parse(xsr, type, getXmlOptions(options));
+        return getTypeLoader().parse(xsr, type, getXmlOptions(options));
     }
 
     public static XmlObject parse(Reader jior, SchemaType type, XmlOptions options) throws XmlException, IOException {
         try {
             Document doc = DocumentHelper.readDocument(new InputSource(jior));
-            return XmlBeans.getContextTypeLoader().parse(doc.getDocumentElement(), type, getXmlOptions(options));
+            return getTypeLoader().parse(doc.getDocumentElement(), type, getXmlOptions(options));
         } catch (SAXException e) {
             throw new XmlException("Unable to parse xml bean", e);
         }
     }
 
     public static XmlObject parse(Node node, SchemaType type, XmlOptions options) throws XmlException {
-        return XmlBeans.getContextTypeLoader().parse(node, type, getXmlOptions(options));
+        return getTypeLoader().parse(node, type, getXmlOptions(options));
     }
 
     public static XmlObject parse(XMLInputStream xis, SchemaType type, XmlOptions options) throws XmlException, XMLStreamException {
-        return XmlBeans.getContextTypeLoader().parse(xis, type, getXmlOptions(options));
+        return getTypeLoader().parse(xis, type, getXmlOptions(options));
     }
     
     public static XMLInputStream newValidatingXMLInputStream ( XMLInputStream xis, SchemaType type, XmlOptions options ) throws XmlException, XMLStreamException {
-        return XmlBeans.getContextTypeLoader().newValidatingXMLInputStream(xis, type, getXmlOptions(options));
+        return getTypeLoader().newValidatingXMLInputStream(xis, type, getXmlOptions(options));
     }
 }
diff --git a/src/ooxml/java/org/apache/poi/xslf/usermodel/XSLFTable.java b/src/ooxml/java/org/apache/poi/xslf/usermodel/XSLFTable.java
index 023c8f7b4..61ab6b44d 100644
--- a/src/ooxml/java/org/apache/poi/xslf/usermodel/XSLFTable.java
+++ b/src/ooxml/java/org/apache/poi/xslf/usermodel/XSLFTable.java
@@ -19,8 +19,6 @@
 
 package org.apache.poi.xslf.usermodel;
 
-import static org.apache.poi.POIXMLTypeLoader.DEFAULT_XML_OPTIONS;
-
 import java.awt.geom.Rectangle2D;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -29,7 +27,6 @@ import java.util.List;
 
 import javax.xml.namespace.QName;
 
-import org.apache.poi.POIXMLException;
 import org.apache.poi.sl.draw.DrawFactory;
 import org.apache.poi.sl.draw.DrawTableShape;
 import org.apache.poi.sl.draw.DrawTextShape;
@@ -37,7 +34,6 @@ import org.apache.poi.sl.usermodel.TableShape;
 import org.apache.poi.util.Internal;
 import org.apache.poi.util.Units;
 import org.apache.xmlbeans.XmlCursor;
-import org.apache.xmlbeans.XmlException;
 import org.apache.xmlbeans.XmlObject;
 import org.apache.xmlbeans.impl.values.XmlAnyTypeImpl;
 import org.openxmlformats.schemas.drawingml.x2006.main.CTGraphicalObjectData;
@@ -53,6 +49,7 @@ import org.openxmlformats.schemas.presentationml.x2006.main.CTGraphicalObjectFra
 public class XSLFTable extends XSLFGraphicFrame implements Iterable<XSLFTableRow>,
     TableShape<XSLFShape,XSLFTextParagraph> {
     /* package */ static final String TABLE_URI = "http://schemas.openxmlformats.org/drawingml/2006/table";
+    /* package */ static final String DRAWINGML_URI = "http://schemas.openxmlformats.org/drawingml/2006/main";
 
     private CTTable _table;
     private List<XSLFTableRow> _rows;
@@ -60,28 +57,30 @@ public class XSLFTable extends XSLFGraphicFrame implements Iterable<XSLFTableRow
     /*package*/ XSLFTable(CTGraphicalObjectFrame shape, XSLFSheet sheet){
         super(shape, sheet);
 
-        XmlObject[] rs = shape.getGraphic().getGraphicData()
-                .selectPath("declare namespace a='http://schemas.openxmlformats.org/drawingml/2006/main' ./a:tbl");
-        if (rs.length == 0) {
-            throw new IllegalStateException("a:tbl element was not found in\n " + shape.getGraphic().getGraphicData());
+        CTGraphicalObjectData god = shape.getGraphic().getGraphicData();
+        XmlCursor xc = god.newCursor();
+        if (!xc.toChild(DRAWINGML_URI, "tbl")) {
+            throw new IllegalStateException("a:tbl element was not found in\n " + god);
         }
 
+        XmlObject xo = xc.getObject();
         // Pesky XmlBeans bug - see Bugzilla #49934
         // it never happens when using the full ooxml-schemas jar but may happen with the abridged poi-ooxml-schemas
-        if(rs[0] instanceof XmlAnyTypeImpl){
-            try {
-                rs[0] = CTTable.Factory.parse(rs[0].toString(), DEFAULT_XML_OPTIONS);
-            }catch (XmlException e){
-                throw new POIXMLException(e);
-            }
+        if (xo instanceof XmlAnyTypeImpl){
+            String errStr =
+                "Schemas (*.xsb) for CTTable can't be loaded - usually this happens when OSGI " +
+                "loading is used and the thread context classloader has no reference to " +
+                "the xmlbeans classes - use POIXMLTypeLoader.setClassLoader() to set the loader, " +
+                "e.g. with CTTable.class.getClassLoader()"
+            ;
+            throw new IllegalStateException(errStr);
         }
+        _table = (CTTable)xo;
+        xc.dispose();
 
-        _table = (CTTable) rs[0];
-        CTTableRow[] trArray = _table.getTrArray();
-        _rows = new ArrayList<XSLFTableRow>(trArray.length);
-        for(CTTableRow row : trArray) {
-            XSLFTableRow xr = new XSLFTableRow(row, this);
-            _rows.add(xr);
+        _rows = new ArrayList<XSLFTableRow>(_table.sizeOfTrArray());
+        for(CTTableRow row : _table.getTrArray()) {
+            _rows.add(new XSLFTableRow(row, this));
         }
         updateRowColIndexes();
     }
@@ -171,13 +170,18 @@ public class XSLFTable extends XSLFGraphicFrame implements Iterable<XSLFTableRow
 
         frame.addNewXfrm();
         CTGraphicalObjectData gr = frame.addNewGraphic().addNewGraphicData();
-        XmlCursor cursor = gr.newCursor();
-        cursor.toNextToken();
-        cursor.beginElement(new QName("http://schemas.openxmlformats.org/drawingml/2006/main", "tbl"));
-        cursor.beginElement(new QName("http://schemas.openxmlformats.org/drawingml/2006/main", "tblPr"));
-        cursor.toNextToken();
-        cursor.beginElement(new QName("http://schemas.openxmlformats.org/drawingml/2006/main", "tblGrid"));
-        cursor.dispose();
+        XmlCursor grCur = gr.newCursor();
+        grCur.toNextToken();
+        grCur.beginElement(new QName(DRAWINGML_URI, "tbl"));
+        
+        CTTable tbl = CTTable.Factory.newInstance();
+        tbl.addNewTblPr();
+        tbl.addNewTblGrid();
+        XmlCursor tblCur = tbl.newCursor();
+        
+        tblCur.moveXmlContents(grCur);
+        tblCur.dispose();
+        grCur.dispose();
         gr.setUri(TABLE_URI);
         return frame;
     }
diff --git a/src/ooxml/testcases/org/apache/poi/TestPOIXMLDocument.java b/src/ooxml/testcases/org/apache/poi/TestPOIXMLDocument.java
index 16b28a450..77f59372d 100644
--- a/src/ooxml/testcases/org/apache/poi/TestPOIXMLDocument.java
+++ b/src/ooxml/testcases/org/apache/poi/TestPOIXMLDocument.java
@@ -27,6 +27,7 @@ import static org.junit.Assert.fail;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.lang.reflect.InvocationTargetException;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -41,6 +42,8 @@ import org.apache.poi.openxml4j.opc.PackageRelationshipTypes;
 import org.apache.poi.util.NullOutputStream;
 import org.apache.poi.util.PackageHelper;
 import org.apache.poi.util.TempFile;
+import org.apache.poi.xslf.usermodel.XMLSlideShow;
+import org.apache.poi.xslf.usermodel.XSLFShape;
 import org.junit.Test;
 
 /**
@@ -277,4 +280,38 @@ public final class TestPOIXMLDocument {
             open.close();
         }
     }
+    
+    @Test(expected=IllegalStateException.class)
+    public void testOSGIClassLoadingAsIs() throws IOException {
+        Thread thread = Thread.currentThread();
+        ClassLoader cl = thread.getContextClassLoader();
+        InputStream is = POIDataSamples.getSlideShowInstance().openResourceAsStream("table_test.pptx");
+        try {
+            thread.setContextClassLoader(cl.getParent());
+            XMLSlideShow ppt = new XMLSlideShow(is);
+            ppt.getSlides().get(0).getShapes();
+        } finally {
+            thread.setContextClassLoader(cl);
+            is.close();
+        }
+    }
+
+
+    @Test
+    public void testOSGIClassLoadingFixed() throws IOException {
+        Thread thread = Thread.currentThread();
+        ClassLoader cl = thread.getContextClassLoader();
+        InputStream is = POIDataSamples.getSlideShowInstance().openResourceAsStream("table_test.pptx");
+        try {
+            thread.setContextClassLoader(cl.getParent());
+            POIXMLTypeLoader.setClassLoader(cl);
+            XMLSlideShow ppt = new XMLSlideShow(is);
+            ppt.getSlides().get(0).getShapes();
+        } finally {
+            thread.setContextClassLoader(cl);
+            POIXMLTypeLoader.setClassLoader(null);
+            is.close();
+        }
+    }
+
 }