added some methods to javassist.Bytecode and Descriptor.

git-svn-id: http://anonsvn.jboss.org/repos/javassist/trunk@225 30ef5769-5b8d-40dd-aea6-55b5d6557bb3

4 files changed, 54 insertions, 9 deletions

diff --git a/src/main/javassist/CtClassType.java b/src/main/javassist/CtClassType.java
index 46fb268a..92f73d3e 100644
--- a/src/main/javassist/CtClassType.java
+++ b/src/main/javassist/CtClassType.java
@@ -193,8 +193,9 @@ class CtClassType extends CtClass {
             fin = new BufferedInputStream(fin);
             classfile = new ClassFile(new DataInputStream(fin));
             if (!classfile.getName().equals(qualifiedName))
-                throw new RuntimeException(classfile.getName() + " in "
-                                + qualifiedName.replace('.', '/') + ".java");
+                throw new RuntimeException("cannot find " + qualifiedName + ": " 
+                        + classfile.getName() + " found in "
+                        + qualifiedName.replace('.', '/') + ".class");
 
             return classfile;
         }
diff --git a/src/main/javassist/bytecode/Bytecode.java b/src/main/javassist/bytecode/Bytecode.java
index 32f9d2b2..9fe0bb84 100644
--- a/src/main/javassist/bytecode/Bytecode.java
+++ b/src/main/javassist/bytecode/Bytecode.java
@@ -1297,9 +1297,29 @@ public class Bytecode extends ByteVector implements Cloneable, Opcode {
      * @param desc      the descriptor of the field type.
      */
     public void addPutstatic(CtClass c, String name, String desc) {
+        addPutstatic0(c, null, name, desc);
+    }
+
+    /**
+     * Appends PUTSTATIC.
+     *
+     * @param classname         the fully-qualified name of the target class.
+     * @param filedName         the field name.
+     * @param desc              the descriptor of the field type.
+     */
+    public void addPutstatic(String classname, String fieldName, String desc) {
+        // if classname is null, the target class is THIS.
+        addPutstatic0(null, classname, fieldName, desc);
+    }
+
+    private void addPutstatic0(CtClass target, String classname,
+                               String fieldName, String desc) {
         add(PUTSTATIC);
-        int ci = constPool.addClassInfo(c);
-        addIndex(constPool.addFieldrefInfo(ci, name, desc));
+
+        // target is null if it represents THIS.
+        int ci = classname == null ? constPool.addClassInfo(target)
+                                : constPool.addClassInfo(classname);
+        addIndex(constPool.addFieldrefInfo(ci, fieldName, desc));
         growStack(-Descriptor.dataSize(desc));
     }
 
diff --git a/src/main/javassist/bytecode/Descriptor.java b/src/main/javassist/bytecode/Descriptor.java
index b67e7a49..ef194b7f 100644
--- a/src/main/javassist/bytecode/Descriptor.java
+++ b/src/main/javassist/bytecode/Descriptor.java
@@ -621,11 +621,28 @@ public class Descriptor {
      * <p>If the descriptor represents a method type, this method returns
      * (the size of the returned value) - (the sum of the data sizes
      * of all the parameters).  For example, if the descriptor is
-     * "(I)D", then this method returns 1 (= 2 - 1).
+     * <code>"(I)D"</code>, then this method returns 1 (= 2 - 1).
      *
      * @param desc descriptor
      */
     public static int dataSize(String desc) {
+        return dataSize(desc, true);
+    }
+
+    /**
+     * Computes the data size of parameters.
+     * If one of the parameters is double type, the size of that parameter
+     * is 2 words.  For example, if the given descriptor is
+     *  <code>"(IJ)D"</code>, then this method returns 3.  The size of the
+     * return type is not computed.
+     * 
+     * @param desc      a method descriptor.
+     */
+    public static int paramSize(String desc) {
+        return -dataSize(desc, false);
+    }
+
+    private static int dataSize(String desc, boolean withRet) {
         int n = 0;
         char c = desc.charAt(0);
         if (c == '(') {
@@ -658,10 +675,11 @@ public class Descriptor {
             }
         }
 
-        if (c == 'J' || c == 'D')
-            n += 2;
-        else if (c != 'V')
-            ++n;
+        if (withRet)
+            if (c == 'J' || c == 'D')
+                n += 2;
+            else if (c != 'V')
+                ++n;
 
         return n;
     }
diff --git a/tutorial/tutorial.html b/tutorial/tutorial.html
index f3766d43..b1541770 100644
--- a/tutorial/tutorial.html
+++ b/tutorial/tutorial.html
@@ -184,6 +184,7 @@ for that purpose.  It stops pruning, write a class file, defrost it, and turn
 pruning on again (if it was initially on).
 </ul>
 
+
 <h4>Class search path</h4>
 
 <p>The default <code>ClassPool</code> returned
@@ -328,6 +329,11 @@ cc.detach();
 
 <p>You must not call any method on that
 <code>CtClass</code> object after <code>detach()</code> is called.
+However, you can call <code>get()</code> on <code>ClassPool</code>
+to make a new instance of <code>CtClass</code> representing
+the same class.  If you call <code>get()</code>, the <code>ClassPool</code>
+reads a class file again and newly creates a <code>CtClass</code>
+object, which is returned by <code>get()</code>.
 
 <p>
 Another idea is to occasionally replace a <code>ClassPool</code> with