在做了所有这些准备之后，下面就是这种图形遍历的标准实现：
public static IObjectProfileNode profile (Object obj)
{
final IdentityHashMap visited = new IdentityHashMap ();
final ObjectProfileNode root = createProfileTree (obj, visited,
CLASS_METADATA_CACHE);
finishProfileTree (root);
return root;
}
private static ObjectProfileNode createProfileTree (Object obj,
IdentityHashMap visited,
Map metadataMap)
{
final ObjectProfileNode root = new ObjectProfileNode (null, obj, null);
final LinkedList queue = new LinkedList ();
queue.addFirst (root);
visited.put (obj, root);
final ClassAccessPrivilegedAction caAction =
new ClassAccessPrivilegedAction ();
final FieldAccessPrivilegedAction faAction =
new FieldAccessPrivilegedAction ();
while (! queue.isEmpty ())
{
final ObjectProfileNode node = (ObjectProfileNode) queue.removeFirst ();
obj = node.m_obj;
final Class objClass = obj.getClass ();
if (objClass.isArray ())
{
final int arrayLength = Array.getLength (obj);
final Class componentType = objClass.getComponentType ();
// Add shell pseudo-node:
final AbstractShellProfileNode shell =
new ArrayShellProfileNode (node, objClass, arrayLength);
shell.m_size = sizeofArrayShell (arrayLength, componentType);
node.m_shell = shell;
node.addFieldRef (shell);
if (! componentType.isPrimitive ())
{
// Traverse each array slot:
for (int i = 0; i {final Object ref = Array.get (obj, i);if (ref != null){ObjectProfileNode child =(ObjectProfileNode) visited.get (ref);if (child != null)++ child.m_refcount;else{child = new ObjectProfileNode (node, ref,new ArrayIndexLink (node.m_link, i));node.addFieldRef (child);queue.addLast (child);visited.put (ref, child);}}}}}else // the object is of a non-array type{final ClassMetadata metadata =getClassMetadata (objClass, metadataMap, caAction, faAction);final Field [] fields = metadata.m_refFields;// Add shell pseudo-node:final AbstractShellProfileNode shell =new ObjectShellProfileNode (node,metadata.m_primitiveFieldCount,metadata.m_refFields.length);shell.m_size = metadata.m_shellSize;node.m_shell = shell;node.addFieldRef (shell);// Traverse all non-null ref fields:for (int f = 0, fLimit = fields.length; f{final Field field = fields [f];final Object ref;try // to get the field value:{ref = field.get (obj);}catch (Exception e){throw new RuntimeException ("cannot get field [" +field.getName () + "] of class [" +field.getDeclaringClass ().getName () +"]: " + e.toString ());}if (ref != null){ObjectProfileNode child =(ObjectProfileNode) visited.get (ref);if (child != null)++ child.m_refcount;else{child = new ObjectProfileNode (node, ref,new ClassFieldLink (field));node.addFieldRef (child);queue.addLast (child);visited.put (ref, child);}}}}}return root;}private static void finishProfileTree (ObjectProfileNode node){final LinkedList queue = new LinkedList ();IObjectProfileNode lastFinished = null;while (node != null){// Note that an unfinished nonshell node has its child count// in m_size and m_children[0] is its shell node:if ((node.m_size == 1) || (lastFinished == node.m_children [1])){node.finish ();lastFinished = node;}else{queue.addFirst (node);for (int i = 1; i{final IObjectProfileNode child = node.m_children [i];queue.addFirst (child);}}if (queue.isEmpty ())return;elsenode = (ObjectProfileNode) queue.removeFirst ();}}该代码是上一篇Java Q&A, "Attack of the Clones."使用的"通过反射克隆"实现的远亲。如前所述，它缓存了反射元数据来提高性能，并且使用了一个标识散列映射来标记访问过的对象。profile()方法从宽度优先遍历中的具有IObjectProfileNode的生成树的原始对象图形开始，以合计和分配所有节点尺寸的快速后序遍历结束。profile()返回一个 IObjectProfileNode，即产生的生成树的根，它的尺寸就是整个图形的尺寸。当然， profile()的输出只有当我有一个很好的方法扩展它时才有用。为了这个目的，每个IObjectProfileNode 必须支持由节点访问者和节点过滤器一起进行的测试：interface IObjectProfileNode{interface INodeFilter{boolean accept (IObjectProfileNode node);} // End of nested interfaceinterface INodeVisitor{/*** Pre-order visit.*/void previsit (IObjectProfileNode node);/*** Post-order visit.*/void postvisit (IObjectProfileNode node);} // End of nested interfaceboolean traverse (INodeFilter filter, INodeVisitor visitor);...} // End of interface节点访问者只有当伴随的过滤器为null或者过滤器接收该节点时才对树节点进行操作。为了简便，节点的子节点只有当节点本身已经测试时才进行测试。前序遍历和后序遍历访问都支持。来自java.lang.Object处理程序的尺寸提供以及所有初级数据都集中放在一个伪码内，这个伪码附属于代表对象实例的每个"真实"节点。这种处理程序节点可通过IObjectProfileNode.shell()访问，也可在IObjectProfileNode.children()列表中显示出来：目的就是能够编写数据过滤器和访问者，使它们可在实例化的数据类型的同一起点上考虑初级数据。如何实现过滤器和访问者就是你的事了。作为一个起点，类ObjectProfileFilters (见本文的download)提供几种有用的堆栈过滤器，它们可帮助你在节点尺寸、与父节点的尺寸相关的节点尺寸、与根对象相关的节点尺寸等等的基础上剪除大对象树。ObjectProfilerVisitors类包含IObjectProfileNode.dump()使用的默认访问者，也包含能够为更高级的对象浏览创建XML转储的访问者。将配置文件转换为SwingTreeModel也是很容易的。为了便于理解，我们创建了一个上文提及的两个字符串排列对象的完整转储：public class Main{public static void main (String [] args){Object obj = new String [] {new String ("JavaWorld"),new String ("JavaWorld")};IObjectProfileNode profile = ObjectProfiler.profile (obj);System.out.println ("obj size = " + profile.size () + " bytes");System.out.println (profile.dump ());}} // End of class该代码结果如下：obj size = 106 bytes106 -: String[]58 (54.7%) -[0] : String34 (32.1%) -String#value : char[], refcount=234 (32.1%) -24 (22.6%) -24 (22.6%) -24 (22.6%) -[1] : String24 (22.6%) -实际上，如前所述，内部的字符排列(被java.lang.String#value访问) 可被两个字符串共享。即使ObjectProfiler.profile()将该排列的从属关系指向第一个发现的字符串，它还是通知说，该排列共享（如它的下一句代码refcount=2所示）。简单的sizeof()ObjectProfiler.profile()创建了一个节点图形，它的尺寸一般来说是原始对象图形的几倍。如果你只需要根对象尺寸，你可以使用更快更有效的方法ObjectProfile
