add ByteUtil.getUnsignedShort

git-svn-id: https://svn.code.sf.net/p/jackcess/code/jackcess/trunk@301 f203690c-595d-4dc9-a70b-905162fa7fd2

2 files changed, 35 insertions, 6 deletions

diff --git a/src/java/com/healthmarketscience/jackcess/ByteUtil.java b/src/java/com/healthmarketscience/jackcess/ByteUtil.java
index 876187a..d27a432 100644
--- a/src/java/com/healthmarketscience/jackcess/ByteUtil.java
+++ b/src/java/com/healthmarketscience/jackcess/ByteUtil.java
@@ -147,9 +147,9 @@ public final class ByteUtil {
   }
 
   /**
-   * Read a 3 byte int from a buffer
+   * Read an unsigned byte from a buffer
    * @param buffer Buffer containing the bytes
-   * @return The int
+   * @return The unsigned byte as an int
    */
   public static int getUnsignedByte(ByteBuffer buffer) {
     int pos = buffer.position();
@@ -159,14 +159,36 @@ public final class ByteUtil {
   }
 
   /**
-   * Read a 3 byte int from a buffer
+   * Read an unsigned byte from a buffer
    * @param buffer Buffer containing the bytes
    * @param offset Offset at which to read the byte
-   * @return The int
+   * @return The unsigned byte as an int
    */
   public static int getUnsignedByte(ByteBuffer buffer, int offset) {  
     return asUnsignedByte(buffer.get(offset));
   }
+  
+  /**
+   * Read an unsigned short from a buffer
+   * @param buffer Buffer containing the short
+   * @return The unsigned short as an int
+   */
+  public static int getUnsignedShort(ByteBuffer buffer) {
+    int pos = buffer.position();
+    int rtn = getUnsignedShort(buffer, pos);
+    buffer.position(pos + 2);
+    return rtn;
+  }
+
+  /**
+   * Read an unsigned short from a buffer
+   * @param buffer Buffer containing the short
+   * @param offset Offset at which to read the short
+   * @return The unsigned short as an int
+   */
+  public static int getUnsignedShort(ByteBuffer buffer, int offset) {  
+    return asUnsignedShort(buffer.getShort(offset));
+  }
 
   
   /**
@@ -388,4 +410,11 @@ public final class ByteUtil {
     return b & 0xFF;
   }
   
+  /**
+   * @return the short value converted to an unsigned int value
+   */
+  public static int asUnsignedShort(short s) { 
+    return s & 0xFFFF;
+  }
+  
 }
diff --git a/src/java/com/healthmarketscience/jackcess/Table.java b/src/java/com/healthmarketscience/jackcess/Table.java
index 650bce5..11397fa 100644
--- a/src/java/com/healthmarketscience/jackcess/Table.java
+++ b/src/java/com/healthmarketscience/jackcess/Table.java
@@ -1070,7 +1070,7 @@ public class Table
    * 2) bytes encoded using the {@link JetFormat#CHARSET}
    */
   private String readName(ByteBuffer buffer) {
-    short nameLength = buffer.getShort();
+    int nameLength = ByteUtil.getUnsignedShort(buffer);
     byte[] nameBytes = new byte[nameLength];
     buffer.get(nameBytes);
     return Column.decodeUncompressedText(nameBytes, getFormat());
@@ -1081,7 +1081,7 @@ public class Table
    * expected name format is the same as that for {@link #readName}.
    */
   private void skipName(ByteBuffer buffer) {
-    short nameLength = buffer.getShort();
+    int nameLength = ByteUtil.getUnsignedShort(buffer);
     buffer.position(buffer.position() + nameLength);
   }