sonar fix - reduce complexity by using constants

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1744006 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/src/java/org/apache/poi/poifs/storage/HeaderBlock.java b/src/java/org/apache/poi/poifs/storage/HeaderBlock.java
index 20613896bf20666e1c921b859bd9e065725623b0..aced76bbe276a332531ea4fe6b98f6d43d64d4ef 100644 (file)
--- a/src/java/org/apache/poi/poifs/storage/HeaderBlock.java
+++ b/src/java/org/apache/poi/poifs/storage/HeaderBlock.java
@@ -40,7 +40,37 @@ import org.apache.poi.util.ShortField;
  * The block containing the archive header
  */
 public final class HeaderBlock implements HeaderBlockConstants {
-       /**
+    private static final byte[] MAGIC_BIFF2 = {
+        0x09, 0x00, // sid=0x0009
+        0x04, 0x00, // size=0x0004
+        0x00, 0x00, // unused
+        0x70, 0x00  // 0x70 = multiple values
+    };
+
+    private static final byte[] MAGIC_BIFF3 = {
+        0x09, 0x02, // sid=0x0209
+        0x06, 0x00, // size=0x0006
+        0x00, 0x00, // unused
+        0x70, 0x00  // 0x70 = multiple values
+    };
+
+    private static final byte[] MAGIC_BIFF4a = {
+        0x09, 0x04, // sid=0x0409
+        0x06, 0x00, // size=0x0006
+        0x00, 0x00, // unused
+        0x70, 0x00  // 0x70 = multiple values
+    };
+
+    private static final byte[] MAGIC_BIFF4b = {
+        0x09, 0x04, // sid=0x0409
+        0x06, 0x00, // size=0x0006
+        0x00, 0x00, // unused
+        0x00, 0x01
+    };
+
+    private static final byte _default_value = ( byte ) 0xFF;
+
+    /**
         * What big block size the file uses. Most files
         *  use 512 bytes, but a few use 4096
         */
@@ -85,8 +115,6 @@ public final class HeaderBlock implements HeaderBlockConstants {
         */
        private final byte[] _data;
        
-   private static final byte _default_value = ( byte ) 0xFF;
-
        /**
         * create a new HeaderBlockReader from an InputStream
         *
@@ -96,7 +124,7 @@ public final class HeaderBlock implements HeaderBlockConstants {
         */
        public HeaderBlock(InputStream stream) throws IOException {
                // Grab the first 512 bytes
-          // (For 4096 sized blocks, the remaining 3584 bytes are zero)
+           // (For 4096 sized blocks, the remaining 3584 bytes are zero)
                // Then, process the contents
                this(readFirst512(stream));
                
@@ -113,58 +141,40 @@ public final class HeaderBlock implements HeaderBlockConstants {
        }
        
        private HeaderBlock(byte[] data) throws IOException {
-          this._data = data;
+          this._data = data.clone();
           
                // verify signature
                long signature = LittleEndian.getLong(_data, _signature_offset);
 
                if (signature != _signature) {
                        // Is it one of the usual suspects?
-                       byte[] OOXML_FILE_HEADER = POIFSConstants.OOXML_FILE_HEADER;
-                       if (_data[0] == OOXML_FILE_HEADER[0] &&
-                               _data[1] == OOXML_FILE_HEADER[1] &&
-                               _data[2] == OOXML_FILE_HEADER[2] &&
-                               _data[3] == OOXML_FILE_HEADER[3]) {
-                               throw new OfficeXmlFileException("The supplied data appears to be in the Office 2007+ XML. You are calling the part of POI that deals with OLE2 Office Documents. You need to call a different part of POI to process this data (eg XSSF instead of HSSF)");
+                       if (cmp(POIFSConstants.OOXML_FILE_HEADER, data)) {
+                               throw new OfficeXmlFileException("The supplied data appears to be in the Office 2007+ XML. "
+                               + "You are calling the part of POI that deals with OLE2 Office Documents. "
+                               + "You need to call a different part of POI to process this data (eg XSSF instead of HSSF)");
                        }
                        
-            byte[] RAW_XML_FILE_HEADER = POIFSConstants.RAW_XML_FILE_HEADER;
-            if (_data[0] == RAW_XML_FILE_HEADER[0] &&
-                _data[1] == RAW_XML_FILE_HEADER[1] &&
-                _data[2] == RAW_XML_FILE_HEADER[2] &&
-                _data[3] == RAW_XML_FILE_HEADER[3] &&
-                _data[4] == RAW_XML_FILE_HEADER[4]) {
-                throw new NotOLE2FileException("The supplied data appears to be a raw XML file. Formats such as Office 2003 XML are not supported");
+            if (cmp(POIFSConstants.RAW_XML_FILE_HEADER, data)) {
+                throw new NotOLE2FileException("The supplied data appears to be a raw XML file. "
+                    + "Formats such as Office 2003 XML are not supported");
             }
             
-            if (_data[0] == 0x09 && _data[1] == 0x00 && // sid=0x0009
-                _data[2] == 0x04 && _data[3] == 0x00 && // size=0x0004
-                _data[4] == 0x00 && _data[5] == 0x00 && // unused
-               (_data[6] == 0x10 || _data[6] == 0x20 || _data[6] == 0x40) &&
-                _data[7] == 0x00) {
-                // BIFF2 raw stream
-                throw new OldExcelFormatException("The supplied data appears to be in BIFF2 format. " +
-                        "HSSF only supports the BIFF8 format, try OldExcelExtractor");
+            // BIFF2 raw stream
+            if (cmp(MAGIC_BIFF2, data)) {
+                throw new OldExcelFormatException("The supplied data appears to be in BIFF2 format. "
+                    + "HSSF only supports the BIFF8 format, try OldExcelExtractor");
             }
-            if (_data[0] == 0x09 && _data[1] == 0x02 && // sid=0x0209
-                _data[2] == 0x06 && _data[3] == 0x00 && // size=0x0006
-                _data[4] == 0x00 && _data[5] == 0x00 && // unused
-               (_data[6] == 0x10 || _data[6] == 0x20 || _data[6] == 0x40) &&
-                _data[7] == 0x00) {
-                // BIFF3 raw stream
-                throw new OldExcelFormatException("The supplied data appears to be in BIFF3 format. " +
-                        "HSSF only supports the BIFF8 format, try OldExcelExtractor");
+            
+            // BIFF3 raw stream
+            if (cmp(MAGIC_BIFF3, data)) {
+                throw new OldExcelFormatException("The supplied data appears to be in BIFF3 format. "
+                    + "HSSF only supports the BIFF8 format, try OldExcelExtractor");
             }
-            if (_data[0] == 0x09 && _data[1] == 0x04 && // sid=0x0409
-                _data[2] == 0x06 && _data[3] == 0x00 && // size=0x0006
-                _data[4] == 0x00 && _data[5] == 0x00) { // unused
-                if (((_data[6] == 0x10 || _data[6] == 0x20 || _data[6] == 0x40) &&
-                      _data[7] == 0x00) ||
-                    (_data[6] == 0x00 && _data[7] == 0x01)) {
-                    // BIFF4 raw stream
-                    throw new OldExcelFormatException("The supplied data appears to be in BIFF4 format. " +
-                            "HSSF only supports the BIFF8 format, try OldExcelExtractor");
-                }
+            
+            // BIFF4 raw stream
+            if (cmp(MAGIC_BIFF4a, data) || cmp(MAGIC_BIFF4b, data)) {
+                throw new OldExcelFormatException("The supplied data appears to be in BIFF4 format. "
+                    + "HSSF only supports the BIFF8 format, try OldExcelExtractor");
             }
 
                        // Give a generic error if the OLE2 signature isn't found
@@ -185,7 +195,7 @@ public final class HeaderBlock implements HeaderBlockConstants {
                }
 
           // Setup the fields to read and write the counts and starts
-      _bat_count      = new IntegerField(_bat_count_offset, data).get();
+      _bat_count  = new IntegerField(_bat_count_offset, data).get();
       _property_start = new IntegerField(_property_start_offset,_data).get();
       _sbat_start = new IntegerField(_sbat_start_offset, _data).get();
       _sbat_count = new IntegerField(_sbat_block_count_offset, _data).get();
@@ -221,7 +231,7 @@ public final class HeaderBlock implements HeaderBlockConstants {
       new IntegerField(0x34, 0, _data);
       new IntegerField(0x38, 0x1000, _data);
       
-      // Initialise the variables
+      // Initialize the variables
       _bat_count = 0;
       _sbat_count = 0;
       _xbat_count = 0;
@@ -394,9 +404,7 @@ public final class HeaderBlock implements HeaderBlockConstants {
     * @exception IOException on problems writing to the specified
     *            stream
     */
-   void writeData(final OutputStream stream)
-       throws IOException
-   {
+   void writeData(final OutputStream stream) throws IOException {
       // Update the counts and start positions 
       new IntegerField(_bat_count_offset,      _bat_count, _data);
       new IntegerField(_property_start_offset, _property_start, _data);
@@ -413,4 +421,15 @@ public final class HeaderBlock implements HeaderBlockConstants {
          stream.write(0);
       }
    }
+   
+   private static boolean cmp(byte[] magic, byte[] data) {
+       int i=0;
+       for (byte m : magic) {
+           byte d = data[i++];
+           if (!(d == m || (m == 0x70 && (d == 0x10 || d == 0x20 || d == 0x40)))) {
+               return false;
+           }
+       }
+       return true;
+   }
 }