Need help on JTree

[Akhil Jain]

Hi guys,

I am really in a desperate need of getting this thing work.
I want to create a Jtree with object Details.
Something like, i can pass any object and that tree should be able to show all its details using java reflection.

can someone please help me out with this.
i have done some coding, but not bale to instantiate few objects inside an object and so on.

sample code is as follows, which can give you fair idea of what i am trying to do here. Need you support on this, otherwise i am gone.

 public class EventObjectPanel extends JPanel {
 
/**
 * JTree to be shown with actual object.
 */
private JTree objTree;
 
/**
 * JScrollPane reference, inside which an object tree is placed.
 */
private JScrollPane scrollPane;
 
/**
 * Create the panel.
 */
public EventObjectPanel() {
 
this.setLayout(new BorderLayout());
this.setMinimumSize(new Dimension(300, 100));
this.setBorder(EventViewerUtil.getBorder(EventViewerUtil
.getString("EventViewer.ObjectPanel.title"), EventViewerUtil
.getString("EventViewer.ObjectPanel.title.ImageIcon"), this));
this.setBackground(Color.WHITE);
}
 
/**
 * Creates an object tree, by inspecting every field of an object and making
 * it either an expandable node or a leaf node.
 * 
 * @param obj
 *            of which inspections has to be done.
 * @return scrollPane containing an object tree.
 */
public final JScrollPane createTree(final Object obj) {
 
DefaultMutableTreeNode root = getTree(obj);
objTree = new JTree(root);
 
DefaultMutableTreeNode lastLeaf = root.getLastLeaf();
TreePath path = new TreePath(lastLeaf.getPath());
objTree.setSelectionPath(path);
 
objTree.setCellRenderer(new ObjectViewCellRenderer());
 
// just to make a tree expanded by default.
int row = 0;
while (row < objTree.getRowCount()) {
objTree.expandRow(row);
row++;
}
scrollPane = new JScrollPane();
// scrollPane.setBorder(null); // temp fix, but need to
// resize-scrollpane
// when window is resized.
// scrollPane.setViewportView(objTree);
scrollPane.getViewport().setView(objTree);
return scrollPane;
}
 
/**
 * Creates tree by inspecting every field of object. If object's field is of
 * primitive type, it is added directly to the object's root node. whereas,
 * if it is of some user-defined type, then it is again inspected and added
 * as a expandable node to the tree with its child as its properties.
 * 
 * @param obj
 *            to be inspected.
 * @return node of a tree.
 */
private DefaultMutableTreeNode getTree(final Object obj) {
try {
if (obj != null) {
Class c = obj.getClass();
 sop("Class of an Object is: " + c.getSimpleName());
 
DefaultMutableTreeNode root = new DefaultMutableTreeNode(obj
.getClass().getSimpleName());
 
Field[] f = c.getDeclaredFields();
for (int j = 0; j < f.length; ++j) {
 sop(" -- Field Type " + "[" + j + "]: " +
 f[j].getType());
if (isPrimitive(f[j])) {
if (Modifier.isStatic(f[j].getModifiers())) {
continue;
}
String value = getValue(obj, f[j]);
if (!value.equalsIgnoreCase("")) {
root.add(new DefaultMutableTreeNode(f[j].getName()
+ "=" + getValue(obj, f[j])));
}
} else {
root.add(getTree(getObject(obj, f[j])));
}
}
return root;
}
} catch (Exception e) {
e.printStackTrace();
}
 
return null;
}
 
/**
 * It returns the reference of a user-defined object inside an object to be
 * inspected.
 * 
 * @param obj
 *            to be inspected.
 * @param field
 *            of an object.
 * 
 * @throws SecurityException
 * @throws NoSuchMethodException
 * @throws IllegalArgumentException
 * @throws IllegalAccessException
 * @throws InvocationTargetException
 * 
 * @return Object refrence of user defined object type.
 */
private Object getObject(final Object obj, final Field field) {
// TODO Auto-generated method stub
String fieldName = field.getName();
 sop(" --Object Field: " + fieldName);
 
// assuming that every member variable in a class will be encapsulted
// and will be exposed via getter and setter methods.
// TODO: any other solution to retrieve member variable's value.
 
String methodName = "get" + Character.toUpperCase(fieldName.charAt(0))
+ fieldName.substring(1);
 
Method mth = null;
try {
mth = obj.getClass().getMethod(methodName, (Class[]) null);
} catch (SecurityException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
return null;
}
 
// check whether the method name assumed exists or not.
if (mth == null) {
sop("no such method " + methodName + " exists for the field "
+ fieldName);
return null;
}
 
Object obj1 = null;
try {
obj1 = mth.invoke(obj, (Object[]) null);
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
 
return obj1;
}
 
/**
 * Retrieves the value of a field inside an object when it was serialized.
 * 
 * @param obj
 *            to be inspected.
 * @param field
 *            of an object.
 * 
 * @throws SecurityException
 *             is thrown, if Security Violation has occured, if Security
 *             Manager is turned on.
 * @throws NoSuchMethodException
 *             is thrown, if no getter method is defined for a memeber
 *             field.
 * @throws IllegalArgumentException
 *             is thrown, if method has been passed an illegal argument.
 * @throws IllegalAccessException
 *             is thrown, when an instance creation, setting or getting a
 *             field, or method invocation is attempted when the operating
 *             body does not have access to the definition of specified
 *             class, field, method or constructor.
 * @throws InvocationTargetException
 *             is a checked exception that wraps an exception thrown by an
 *             invoked method or constructor.
 * 
 * @return String representation of an object field.
 */
private String getValue(final Object obj, final Field field)
throws SecurityException, NoSuchMethodException,
IllegalArgumentException, IllegalAccessException,
InvocationTargetException {
Object obj1 = this.getObject(obj, field);
if (obj1 == null) {
return "";
}
return obj1.toString();
}
 
/**
 * Checks whether an object's field is of primitive type or not. primitive
 * type includes String, Float, Integer, Character etc.
 * 
 * 
 * @param field
 *            of an object.
 * @return true/false whether a field type is of premitive type or not.
 * @throws InstantiationException
 *             is thrown, when an application tries to create an instance of
 *             a class using the newInstance method in class Class, but the
 *             specified class object cannot be instantiated because it is
 *             an interface or is an abstract class.
 * 
 * @throws IllegalAccessException
 *             is thrown, when an instance creation, setting or getting a
 *             field, or method invocation is attempted when the operating
 *             body does not have access to the definition of specified
 *             class, field, method or constructor.
 * 
 * @throws InvocationTargetException 
 * @throws IllegalArgumentException 
 */
private boolean isPrimitive(final Field field)
throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
Class c = field.getType();
 sop(" -- Field Type Class: " + c.getSimpleName());
if (c.isPrimitive()) {
return true;
}
//Constructor[] theConstructors  = c.getDeclaredConstructors();
//Class[] classArray = theConstructors[0].getParameterTypes();
//
//theConstructors[0].setAccessible(true);
//

Object o = c.newInstance();
if (o instanceof java.lang.String || o instanceof Float
|| o instanceof Integer || o instanceof Character) {
return true;
}
 
return false;
}
 
private static void sop(final String msg) {
System.out.println(msg);
}
 
class ObjectViewCellRenderer extends JLabel implements TreeCellRenderer {
/**
 * 
 */
private static final long serialVersionUID = 1L;
 
/**
 * Constructs the cell renderer to draw evey pixel within its bounds.
 * 
 */
ObjectViewCellRenderer() {
// setOpaque(true);
}
 
/**
 * Creates a custom cell renderer to display tree node's value.
 * 
 * @param tree
 *            for which renderer is meant for.
 * @param value
 *            of an object.
 * @param selected
 *            node.
 * @param expanded
 *            node.
 * @param leaf
 *            node.
 * @param row
 *            of a tree.
 * @param hasFocus
 *            defines which node has current focus.
 * 
 * @return this the current node.
 */
public Component getTreeCellRendererComponent(final JTree tree,
final Object value, final boolean selected,
final boolean expanded, final boolean leaf, final int row,
final boolean hasFocus) {
StringBuffer text = new StringBuffer();
text.append("    ");
if (expanded) {
// TODO: place - icon
setIcon(EventViewerUtil.getImageIcon("search.gif"));
} else {
// TODO: place + icon
setIcon(EventViewerUtil.getImageIcon("config.gif"));
}
if (leaf) {
// TODO: place . icon
setIcon(EventViewerUtil.getImageIcon("desc.gif"));
}
 
text.append(value.toString());
setText(text.toString());
return this;
}
}
}
   

Guys, pleae help me out with this...i want this code to handle any damn object it is passed on to create tree....no matter contructors are protected, private or anything, object passed can contain n-level objects in them and i should be able to show each one of them properly in tree form something like when you debug an object at runtime and in debug window you come to see all its properties, as well as properties of all the objects which it holds.

Object which will be supplied to create Jtree, is a serialized object, whcih is persisted in a file, so basically i have to read that object from a file and show its state graph with all the fields, their names, their values and so on.

regards
Akhil