dtree的应用

前几天在javaeye上看到有这样一个帖子（http://www.iteye.com/topic/245728），今天把我的解决代码贴在我的blog中。数据库是这样的记录
year，month，title
2004 3      第一条标题
2004 5      第二条标题
2005 6      第三条标题
2005 6      第四条标题
2002 6      第五条标题
要求在前台以年，月，日，树状展示，比如点击2004，然后出来下面所有的月，在点击月，出来下面所有的标题

这里算是做一个dtree的简单应用吧。

Java代码
package app;  
 
public class Title {  
    private int year;  
    private int month;  
    private String name;  
      
    public Title() {  
    }  
      
    public Title(int year, int month, String name) {  
        this.year = year;  
        this.month = month;  
        this.name = name;  
    }  
      
    public int getYear() {  
        return year;  
    }  
    public void setYear(int year) {  
        this.year = year;  
    }  
    public int getMonth() {  
        return month;  
    }  
    public void setMonth(int month) {  
        this.month = month;  
    }  
    public String getName() {  
        return name;  
    }  
    public void setName(String name) {  
        this.name = name;  
    }  
} 

package app;

public class Title {
private int year;
private int month;
private String name;

public Title() {
}

public Title(int year, int month, String name) {
this.year = year;
this.month = month;
this.name = name;
}

public int getYear() {
return year;
}
public void setYear(int year) {
this.year = year;
}
public int getMonth() {
return month;
}
public void setMonth(int month) {
this.month = month;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}


Java代码
package app;  
 
public class TreeDaoImpl {  
      
    public Title[] queryAllTitle() {  
        Title[] titles = new Title[5];  
        titles[0] = new Title(2004, 3, "第一条标题");  
        titles[1] = new Title(2004, 5, "第二条标题");  
        titles[2] = new Title(2005, 6, "第三条标题");  
        titles[3] = new Title(2005, 6, "第四条标题");  
        titles[4] = new Title(2002, 6, "第五条标题");  
          
        return titles;  
    }  
} 

package app;

public class TreeDaoImpl {

public Title[] queryAllTitle() {
Title[] titles = new Title[5];
titles[0] = new Title(2004, 3, "第一条标题");
titles[1] = new Title(2004, 5, "第二条标题");
titles[2] = new Title(2005, 6, "第三条标题");
titles[3] = new Title(2005, 6, "第四条标题");
titles[4] = new Title(2002, 6, "第五条标题");

return titles;
}
}

Java代码
package app;  
 
import java.util.*;  
 
public class Node {  
    private Object data;  
    private Node parent;  
    private List<Node> children;  
      
    public Node() {  
        children = new ArrayList<Node>();  
    }  
      
    public Node(Object data, Node parent) {  
        this.data = data;  
        this.parent = parent;  
        children = new ArrayList<Node>();  
    }  
      
    public boolean hasChildren() {  
        return children.size() != 0;  
    }  
      
    public boolean containChildData(Object data) {  
        return queryChildByData(data) != null;  
    }  
      
    public Node queryChildByData(Object data) {  
        Node r = null;  
        for(Node node : children) {  
            if(node.getData().equals(data)) {  
                r = node;  
                break;  
            }  
        }  
          
        return r;  
    }  
      
    public void addChild(Node node) {  
        children.add(node);  
    }  
      
    public Object getData() {  
        return data;  
    }  
 
    public void setData(Object data) {  
        this.data = data;  
    }  
 
    public Node getParent() {  
        return parent;  
    }  
 
    public void setParent(Node parent) {  
        this.parent = parent;  
    }  
 
    public List<Node> getChildren() {  
        return children;  
    }  
 
    public void setChildren(List<Node> children) {  
        this.children = children;  
    }  
} 

package app;

import java.util.*;

public class Node {
private Object data;
private Node parent;
private List<Node> children;

public Node() {
children = new ArrayList<Node>();
}

public Node(Object data, Node parent) {
this.data = data;
this.parent = parent;
children = new ArrayList<Node>();
}

public boolean hasChildren() {
return children.size() != 0;
}

public boolean containChildData(Object data) {
return queryChildByData(data) != null;
}

public Node queryChildByData(Object data) {
Node r = null;
for(Node node : children) {
if(node.getData().equals(data)) {
r = node;
break;
}
}

return r;
}

public void addChild(Node node) {
children.add(node);
}

public Object getData() {
return data;
}

public void setData(Object data) {
this.data = data;
}

public Node getParent() {
return parent;
}

public void setParent(Node parent) {
this.parent = parent;
}

public List<Node> getChildren() {
return children;
}

public void setChildren(List<Node> children) {
this.children = children;
}
}


Java代码
package app;  
 
public class MenuTreeBuilder {  
      
    public MenuTreeBuilder(TreeDaoImpl dao) {  
        this.dao = dao;  
        idx = 1;  
        buffer = new StringBuffer();  
    }  
      
    public void generateMenuTree(String rootName) {  
          
        root = new Node(rootName, null);  
          
        Title[] titles = dao.queryAllTitle();  
        for(int i = 0; titles != null && i < titles.length; i++) {  
              
            Node yearNode = null;  
            Node monthNode = null;  
            String year = String.valueOf(titles[i].getYear());  
            String month = String.valueOf(titles[i].getMonth());  
              
            if( !root.containChildData(year) ) {  
                yearNode = new Node(year, root);  
                root.addChild(yearNode);  
            } else {  
                yearNode = root.queryChildByData(year);  
            }  
              
            if( !yearNode.containChildData(month) ) {  
                monthNode = new Node(month, yearNode);  
                yearNode.addChild(monthNode);  
            } else {  
                monthNode = yearNode.queryChildByData(month);  
            }  
              
            monthNode.addChild(new Node(titles[i].getName(), monthNode));  
        }  
 
    }  
      
    public String generateJS() {  
          
        buffer.append("d = new dTree('d');\n");  
        buffer.append("d.add(" + idx + "," + "-1, '" + root.getData().toString() + "');\n");  
          
        privateGenerateJs(root);          
        return buffer.toString();  
    }  
      
    private void privateGenerateJs(Node parentNode) {  
        int rootIdx = idx;  
        for(int i = 0; i < parentNode.getChildren().size(); i++) {  
            Node node = parentNode.getChildren().get(i);  
            ++idx;  
            buffer.append("d.add(" + idx + "," + rootIdx + ", '" + node.getData().toString() + "');\n");  
              
            privateGenerateJs(node);  
        }  
    }  
          
    private TreeDaoImpl dao;  
    private Node root;  
    private int idx;  
    private StringBuffer buffer;  
} 

package app;

public class MenuTreeBuilder {

public MenuTreeBuilder(TreeDaoImpl dao) {
this.dao = dao;
idx = 1;
buffer = new StringBuffer();
}

public void generateMenuTree(String rootName) {

root = new Node(rootName, null);

Title[] titles = dao.queryAllTitle();
for(int i = 0; titles != null && i < titles.length; i++) {

Node yearNode = null;
Node monthNode = null;
String year = String.valueOf(titles[i].getYear());
String month = String.valueOf(titles[i].getMonth());

if( !root.containChildData(year) ) {
yearNode = new Node(year, root);
root.addChild(yearNode);
} else {
yearNode = root.queryChildByData(year);
}

if( !yearNode.containChildData(month) ) {
monthNode = new Node(month, yearNode);
yearNode.addChild(monthNode);
} else {
monthNode = yearNode.queryChildByData(month);
}

monthNode.addChild(new Node(titles[i].getName(), monthNode));
}

}

public String generateJS() {

buffer.append("d = new dTree('d');\n");
buffer.append("d.add(" + idx + "," + "-1, '" + root.getData().toString() + "');\n");

privateGenerateJs(root);
return buffer.toString();
}

private void privateGenerateJs(Node parentNode) {
int rootIdx = idx;
for(int i = 0; i < parentNode.getChildren().size(); i++) {
Node node = parentNode.getChildren().get(i);
++idx;
buffer.append("d.add(" + idx + "," + rootIdx + ", '" + node.getData().toString() + "');\n");

privateGenerateJs(node);
}
}

private TreeDaoImpl dao;
private Node root;
private int idx;
private StringBuffer buffer;
}


Java代码
package app;  
 
public class Test {  
      
    public static void main(String[] args) {  
        TreeDaoImpl dao = new TreeDaoImpl();  
        MenuTreeBuilder mtb = new MenuTreeBuilder(dao);  
        mtb.generateMenuTree("年份");  
        String s = mtb.generateJS();  
        System.out.println(s);  
    }  
} 

package app;

public class Test {

public static void main(String[] args) {
TreeDaoImpl dao = new TreeDaoImpl();
MenuTreeBuilder mtb = new MenuTreeBuilder(dao);
mtb.generateMenuTree("年份");
String s = mtb.generateJS();
System.out.println(s);
}
} 最后，把程序生成的JS替换使用dtree的例子中的部分JS即可。当然，实际应用可能不是这个样子，这里只是做个例子，这个程序可以根据自己的需要更改。程序控制台输出

d = new dTree('d');
d.add(1,-1, '年份');
d.add(2,1, '2004');
d.add(3,2, '3');
d.add(4,3, '第一条标题');
d.add(5,2, '5');
d.add(6,5, '第二条标题');
d.add(7,1, '2005');
d.add(8,7, '6');
d.add(9,8, '第三条标题');
d.add(10,8, '第四条标题');
d.add(11,1, '2002');
d.add(12,11, '6');
d.add(13,12, '第五条标题');