added InnerClassAttribute#remove method

1 files changed, 34 insertions, 0 deletions

diff --git a/src/main/javassist/bytecode/InnerClassesAttribute.java b/src/main/javassist/bytecode/InnerClassesAttribute.java
index 5dffd6ee..cf021791 100644
--- a/src/main/javassist/bytecode/InnerClassesAttribute.java
+++ b/src/main/javassist/bytecode/InnerClassesAttribute.java
@@ -198,6 +198,40 @@ public class InnerClassesAttribute extends AttributeInfo {
     }
 
     /**
+     * Removes the {@code nth} entry.  It does not eliminate
+     * constant pool items that the removed entry refers to.
+     * {@link ClassFile#compact()} should be executed to remove
+     * these unnecessary items. 
+     *
+     * @param nth       0, 1, 2, ...
+     * @return  the number of items after the removal.
+     * @see ClassFile#compact()
+     */
+    public int remove(int nth) {
+        byte[] data = get();
+        int len = data.length;
+        if (len < 10)
+            return 0;
+
+        int n = ByteArray.readU16bit(data, 0);
+        int nthPos = 2 + nth * 8;
+        if (n <= nth)
+            return n;
+
+        byte[] newData = new byte[len - 8];
+        ByteArray.write16bit(n - 1, newData, 0);
+        int i = 2, j = 2;
+        while (i < len)
+            if (i == nthPos)
+                i += 8;
+            else
+                newData[j++] = data[i++];
+
+        set(newData);
+        return n - 1;
+    }
+
+    /**
      * Makes a copy.  Class names are replaced according to the
      * given <code>Map</code> object.
      *