#57919 Start on support for writing to a new File (faster than OutputStream)

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1753486 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java

@@ -1291,7 +1291,6 @@ public final class HSSFWorkbook extends POIDocument implements org.apache.poi.ss
         super.close();
     }
 
-    //@Override // TODO Not yet on POIDocument
     /**
      * Write out this workbook to the currently open {@link File} via the
      *  writeable {@link POIFSFileSystem} it was opened as. 
@@ -1300,6 +1299,7 @@ public final class HSSFWorkbook extends POIDocument implements org.apache.poi.ss
      *   instead of a File, or if this is not the root document. For those cases, 
      *   you must use {@link #write(OutputStream)} to write to a brand new stream.
      */
+    //@Override // TODO Not yet on POIDocument
     public void write() throws IOException {
         // TODO Push much of this logic down to POIDocument, as will be common for most formats
         if (directory == null) {
@@ -1323,6 +1323,34 @@ public final class HSSFWorkbook extends POIDocument implements org.apache.poi.ss
         directory.getFileSystem().writeFilesystem();
     }
     
+    /**
+     * Method write - write out this workbook to a new {@link File}.  Constructs
+     * a new POI POIFSFileSystem, passes in the workbook binary representation  and
+     * writes it out. If the file exists, it will be replaced, otherwise a new one
+     * will be created.
+     * 
+     * Note that you cannot write to the currently open File using this method.
+     * If you opened your Workbook from a File, you <i>must</i> use the {@link #write()}
+     * method instead!
+     * 
+     * TODO Finish Implementing
+     * 
+     * @param newFile - the new File you wish to write the XLS to
+     *
+     * @exception IOException if anything can't be written.
+     * @see org.apache.poi.poifs.filesystem.POIFSFileSystem
+     */
+    //@Override // TODO Not yet on POIDocument
+    public void write(File newFile) throws IOException {
+        POIFSFileSystem fs = POIFSFileSystem.create(newFile);
+        try {
+            write(fs);
+            fs.writeFilesystem();
+        } finally {
+            fs.close();
+        }
+    }
+    
     /**
      * Method write - write out this workbook to an {@link OutputStream}.  Constructs
      * a new POI POIFSFileSystem, passes in the workbook binary representation  and
@@ -1339,11 +1367,18 @@ public final class HSSFWorkbook extends POIDocument implements org.apache.poi.ss
      * @see org.apache.poi.poifs.filesystem.POIFSFileSystem
      */
     @Override
-	public void write(OutputStream stream)
-            throws IOException
-    {
+	public void write(OutputStream stream) throws IOException {
         NPOIFSFileSystem fs = new NPOIFSFileSystem();
         try {
+            write(fs);
+            fs.writeFilesystem(stream);
+        } finally {
+            fs.close();
+        }
+    }
+    
+    /** Writes the workbook out to a brand new, empty POIFS */
+    private void write(NPOIFSFileSystem fs) throws IOException {
         // For tracking what we've written out, used if we're
         //  going to be preserving nodes
         List<String> excepts = new ArrayList<String>(1);
@@ -1370,10 +1405,6 @@ public final class HSSFWorkbook extends POIDocument implements org.apache.poi.ss
             // see Bugzilla 47920
             fs.getRoot().setStorageClsid(this.directory.getStorageClsid());
         }
-            fs.writeFilesystem(stream);
-        } finally {
-            fs.close();
-        }
     }
 
     /**

src/java/org/apache/poi/poifs/filesystem/POIFSFileSystem.java

@@ -20,6 +20,7 @@
 package org.apache.poi.poifs.filesystem;
 
 import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 
@@ -122,6 +123,27 @@ public class POIFSFileSystem
         return NPOIFSFileSystem.hasPOIFSHeader(header8Bytes);
     }
     
+    /**
+     * Creates a new {@link POIFSFileSystem} in a new {@link File}.
+     * Use {@link #POIFSFileSystem(File)} to open an existing File,
+     *  this should only be used to create a new empty filesystem.
+     *
+     * @param file The file to create and open
+     * @return The created and opened {@link POIFSFileSystem}
+     */
+    public static POIFSFileSystem create(File file) throws IOException {
+        // TODO Make this nicer!
+        // Create a new empty POIFS in the file
+        POIFSFileSystem tmp = new POIFSFileSystem();
+        FileOutputStream fout = new FileOutputStream(file);
+        tmp.writeFilesystem(fout);
+        fout.close();
+        tmp.close();
+        
+        // Open it up again backed by the file
+        return new POIFSFileSystem(file);
+    }
+
     /**
      * read in a file and write it back out again
      *