Java核心技术II-第6章-对象查看树-源代码

Java核心技术II-第6章-对象查看树-源代码，在博文的最后有运行效果图。

package javaee.vii.ch06;

import java.awt.EventQueue;
import javax.swing.JFrame;

/**
 * This program demonstrates how to use a custom tree model. It displays the fields of an object.
 * @author lcwell
 */
public class ObjectInspectorTest {
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable(){

            @Override
            public void run() {
                JFrame frame = new ObjectInspectorFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            }
            
        });
    }
}

package javaee.vii.ch06;

import java.awt.BorderLayout;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;

/**
 * This frame holds the object tree.
 * @author lcwell
 */
public class ObjectInspectorFrame extends JFrame {
    
    public ObjectInspectorFrame() {
        setTitle("ObjectInspectorTest");
        setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
        
        // we inspect this frame object
        Variable v = new Variable(getClass(), "this", this);
        ObjectTreeModel model = new ObjectTreeModel();
        model.setRoot(v);
        
        // construct and show tree
        tree = new JTree(model);
        add(new JScrollPane(tree), BorderLayout.CENTER);
    }
    
    private JTree tree;
    private static final int DEFAULT_WIDTH = 400;
    private static final int DEFAULT_HEIGHT = 300;
}

package javaee.vii.ch06;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.EventListener;
import javax.swing.event.EventListenerList;
import javax.swing.event.TreeModelEvent;
import javax.swing.event.TreeModelListener;
import javax.swing.tree.TreeModel;
import javax.swing.tree.TreePath;

/**
 * This tree model describes the tree structure of a Java object. Children are the objects.
 * @author lcwell
 */
public class ObjectTreeModel implements TreeModel{
    
    public ObjectTreeModel() {
        root = null;
    }
    
    /**
     * Sets the root to a given variable.
     * @param v the variable that is beging described this tree.
     */
    public void setRoot(Variable v) {
        Variable oldRoot = v;
        root = v;
        fireTreeStructureChanged(oldRoot);
    }

    @Override
    public Object getRoot() {
        return root;
    }

    @Override
    public Object getChild(Object parent, int index) {
        ArrayList<Field> fields = ((Variable) parent).getFields();
        Field f = (Field) fields.get(index);
        Object parentValue = ((Variable) parent).getValue();
        try {
            return new Variable(f.getType(), f.getName(), f.get(parentValue));
        } catch (IllegalAccessException e) {
            return null;
        }
    }

    @Override
    public int getChildCount(Object parent) {
        return ((Variable) parent).getFields().size();
    }

    @Override
    public boolean isLeaf(Object node) {
        return getChildCount(node) == 0;
    }

    @Override
    public void valueForPathChanged(TreePath path, Object newValue) {
        
    }

    @Override
    public int getIndexOfChild(Object parent, Object child) {
        int n = getChildCount(parent);
        for (int i = 0; i < n; i++) {
            if (getChild(parent, i).equals(child)) return i;
        }
        return -1;
    }

    @Override
    public void addTreeModelListener(TreeModelListener l) {
        listenerList.add(TreeModelListener.class, l);
    }

    @Override
    public void removeTreeModelListener(TreeModelListener l) {
        listenerList.remove(TreeModelListener.class, l);
    }
    
    protected void fireTreeStructureChanged(Object oldRoot) {
        TreeModelEvent event = new TreeModelEvent(this, new Object[]{oldRoot});
        EventListener[] listeners = listenerList.getListeners(TreeModelListener.class);
        for (int i = 0; i < listeners.length; i++) {
            ((TreeModelListener) listeners[i]).treeStructureChanged(event);
        }
    }
    
    private Variable root;
    private EventListenerList listenerList = new EventListenerList();
}

package javaee.vii.ch06;

import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.ArrayList;

/**
 * A variable with a type, name, and value.
 * @author lcwell
 */
public class Variable {
    
    /**
     * Construct a variable
     * @param aType the type
     * @param aName the name
     * @param aValue  the value
     */
    public Variable(Class<?> aType, String aName, Object aValue) {
        type = aType;
        name = aName;
        value = aValue;
        fields = new ArrayList<Field>();
        
        // find all fields if we have a class type except we don't expand strings and null values
        if (!type.isPrimitive() && !type.isArray() && !type.equals(String.class) && value != null) {
            // get fields from the class and all superclasses
            for (Class<?> c = value.getClass(); c != null; c = c.getSuperclass()) {
                Field[] fs = c.getDeclaredFields();
                AccessibleObject.setAccessible(fs, true);
                
                // get all nonstatic fields
                for (Field f : fs)
                    if ((f.getModifiers() & Modifier.STATIC) == 0) fields.add(f);
            }
        }
    }
    
    /**
     * Get the value of this variable.
     * @return an array list of varialbes describing the fields
     */
    public Object getValue() {
        return value;
    }
    
    /**
     * Gets all nonstatic fields of this variable
     * @return an array list of varialbes describing the fields
     */
    public ArrayList<Field> getFields() {
        return fields;
    }
    
    @Override
    public String toString() {
        String r = type + " " + name;
        if (type.isPrimitive()) r += "=" + value;
        else if (type.equals(String.class)) r += "=" + value;
        else if (value == null) r += "=null";
        return r;
    }
    
    private Class<?> type;
    private String name;
    private Object value;
    private ArrayList<Field> fields;
}

 运行效果：