JAVA 对树形结构中图片的修改

package graphic;
import javax.swing.ImageIcon;
import javax.swing.JTree;
import java.awt.Component;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.DefaultMutableTreeNode;
/**
*
* @author bianzhiqi
* 具体方法的使用查看DefaultTreeCellRenderer的文档
*/
public class MyRenderer extends DefaultTreeCellRenderer{
private ImageIcon leafIcon;
private ImageIcon midIcon;

public MyRenderer(ImageIcon leafIcon,ImageIcon midIcon)
{
this.leafIcon=leafIcon;
this.midIcon=midIcon;
}

public Component getTreeCellRendererComponent(
JTree tree,
Object value,
boolean sel,
boolean expanded,
boolean leaf,
int row,
boolean hasFocus) {
super.getTreeCellRendererComponent(
tree, value, sel,
expanded, leaf, row,
hasFocus);
DefaultMutableTreeNode node=(DefaultMutableTreeNode)value;
if(leaf && leafIcon!=null) setIcon(leafIcon);
else if((isKeyword(node)||isSpecial(node)) && midIcon!=null) setIcon(midIcon);
else setIcon(null);
return this;
}

protected boolean isKeyword(DefaultMutableTreeNode node)
{
String value=node.toString();
if(value.equals("int") || value.equals("real")||value.equals("while")||
value.equals("write")||value.equals("if")||value.equals("else")||
value.equals("read") ||value.equals("else if")
)
return true;
else return false;
}
protected boolean isSpecial(DefaultMutableTreeNode node){
String value=node.toString();
if(value.equals("<")||value.equals("<>")||value.equals("=")||value.equals("=="))
return true;
else return false;
}
}