树节点类：
-
package
cn.com.tree;
-
-
public
class
Node {
-
private
Integer id;
-
private
Integer parentId;
-
private
String name;
-
private
String link;
-
-
public
Integer getId() {
-
return
id;
-
}
-
public
void
setId(Integer id) {
-
this
.id = id;
-
}
-
public
Integer getParentId() {
-
return
parentId;
-
}
-
public
void
setParentId(Integer parentId) {
-
this
.parentId = parentId;
-
}
-
public
String getName() {
-
return
name;
-
}
-
public
void
setName(String name) {
-
this
.name = name;
-
}
-
public
String getLink() {
-
return
link;
-
}
-
public
void
setLink(String link) {
-
this
.link = link;
-
}
-
}
输出树形菜单类：
-
package
cn.com.tree;
-
-
import
java.util.ArrayList;
-
import
java.util.List;
-
-
public
class
Tree {
-
private
StringBuffer html =
new
StringBuffer();
-
private
List<Node> nodes;
-
-
public
Tree(List<Node> nodes){
-
this
.nodes = nodes;
-
}
-
-
public
String buildTree(){
-
html.append(
“<ul>”
);
-
for
(Node node : nodes) {
-
Integer id = node.getId();
-
if
(node.getParentId() ==
null
) {
-
html.append(
“\r\n<li id='”
+ id +
“‘>”
+ node.getName()+
“</li>”
);
-
build(node);
-
}
-
}
-
html.append(
“\r\n</ul>”
);
-
return
html.toString();
-
}
-
-
private
void
build(Node node){
-
List<Node> children = getChildren(node);
-
if
(!children.isEmpty()) {
-
html.append(
“\r\n<ul>”
);
-
for
(Node child : children) {
-
Integer id = child.getId();
-
html.append(
“\r\n<li id='”
+ id +
“‘>”
+ child.getName()+
“</li>”
);
-
build(child);
-
}
-
html.append(
“\r\n</ul>”
);
-
}
-
}
-
-
private
List<Node> getChildren(Node node){
-
List<Node> children =
new
ArrayList<Node>();
-
Integer id = node.getId();
-
for
(Node child : nodes) {
-
if
(id.equals(child.getParentId())) {
-
children.add(child);
-
}
-
}
-
return
children;
-
}
-
}
测试
类：
-
package
zzj.test;
-
-
import
java.util.ArrayList;
-
import
java.util.List;
-
-
import
cn.com.tree.Node;
-
import
cn.com.tree.Tree;
-
-
-
public
class
Test {
-
-
/**
-
* @param args
-
*/
-
public
static
void
main(String[] args) {
-
List<Node> nodes =
new
ArrayList<Node>();
-
-
Node node1 =
new
Node();
-
node1.setId(
1
);
-
node1.setName(
“node1”
);
-
node1.setParentId(
null
);
-
node1.setLink(
null
);
-
nodes.add(node1);
-
-
Node node11 =
new
Node();
-
node11.setId(
11
);
-
node11.setName(
“node11”
);
-
node11.setParentId(
1
);
-
node11.setLink(
null
);
-
nodes.add(node11);
-
-
Node node111 =
new
Node();
-
node111.setId(
111
);
-
node111.setName(
“node111”
);
-
node111.setParentId(
11
);
-
node111.setLink(
null
);
-
nodes.add(node111);
-
-
Node node12 =
new
Node();
-
node12.setId(
12
);
-
node12.setName(
“node12”
);
-
node12.setParentId(
1
);
-
node12.setLink(
null
);
-
nodes.add(node12);
-
-
Node node2 =
new
Node();
-
node2.setId(
2
);
-
node2.setName(
“node2”
);
-
node2.setParentId(
null
);
-
node2.setLink(
null
);
-
nodes.add(node2);
-
-
Node node21 =
new
Node();
-
node21.setId(
21
);
-
node21.setName(
“node21”
);
-
node21.setParentId(
2
);
-
node21.setLink(
null
);
-
nodes.add(node21);
-
-
Node node3 =
new
Node();
-
node3.setId(
3
);
-
node3.setName(
“node3”
);
-
node3.setParentId(
null
);
-
node3.setLink(
null
);
-
nodes.add(node3);
-
-
Tree tree =
new
Tree(nodes);
-
System.out.println(tree.buildTree());
-
}
-
}
输出：
-
<ul>
-
<li id=’1′>node1</li>
-
<ul>
-
<li id=’11’>node11</li>
-
<ul>
-
<li id=’111′>node111</li>
-
</ul>
-
<li id=’12’>node12</li>
-
</ul>
-
<li id=’2′>node2</li>
-
<ul>
-
<li id=’21’>node21</li>
-
</ul>
-
<li id=’3′>node3</li>
-
</ul>
浏览器效果：
