easyui struts后台实现tree返回json数据详解编程语言

首先jsp页面有一ul用于展现tree

<ul id="trueULid"></ul>

加载tree

<script type="text/javascript"> 
$(function() { 
   $('#trueULid').tree( { 
	 url : 'admin/HhTestTree.do' 
   }); 
}); 
</script>

配置action

<action name="HhTestTree" method="testTree" 
	class="org.bkgd.ehome.jeeplugin.message.web.action.ActionHhMessageTypeQuery"> 
	<result type="json"> 
		<param name="root">testTreeNodes</param> 
	</result> 
</action>

需要封装对象tree

public class TestTreeNode implements Serializable { 
	/** 
	 *  
	 */ 
	private static final long serialVersionUID = 1L; 
	private String id; 
	private String text; 
	private String state = "open"; 
	private boolean checked; 
 
	public TestTreeNode(String id, String text, String state, boolean checked) { 
		this.id = id; 
		this.text = text; 
		this.state = state; 
		this.checked = checked; 
	} 
	public String getId() { 
		return id; 
	} 
 
	public void setId(String id) { 
		this.id = id; 
	} 
 
	public String getText() { 
		return text; 
	} 
 
	public boolean isChecked() { 
		return checked; 
	} 
 
	public void setChecked(boolean checked) { 
		this.checked = checked; 
	} 
 
	public void setText(String text) { 
		this.text = text; 
	} 
 
	public String getState() { 
		return state; 
	} 
 
	public void setState(String state) { 
		this.state = state; 
	} 
}

表结构如图

首先查询所有parentid为NONE的数据(测试数组件的ID为null)然后同时判断该节点下是否有子节点，
如果有则状态是关闭状态
当继续展开树的时候 会将该ID值传入，然后查询该节点的子节点。

action方法实现

private List<TestTreeNode> testTreeNodes = new ArrayList<TestTreeNode>(); 
private String id;// 树组件使用的ID 
 
public String testTree() { 
	try { 
		List<Map<String,Object>> list = aloneIMP.getTreeNodes(id).search().getResultList(); 
		for(Map<String,Object> m:list){ 
			//判断是否有子节点 
			List<Map<String,Object>> isHasChildren = aloneIMP.getTreeChildren(null).addUserWhere(" and parentid ='"+(String)m.get("ID")+"'").search().getResultList(); 
			if(isHasChildren.size()==0){ 
				testTreeNodes.add(new TestTreeNode((String)m.get("ID"),(String)m.get("NAME"),"open",false));	 
			}else{ 
				testTreeNodes.add(new TestTreeNode((String)m.get("ID"),(String)m.get("NAME"),"closed",false)); 
			} 
					 
		} 
	} catch (SQLException e) { 
		e.printStackTrace(); 
	} 
	return SUCCESS; 
}

此方法不具公共性，是自己的一些封装实现。主要是如何进行查询节点，

getTreeNodes()的实现方法为：

@Override 
public DataQuery getTreeNodes(String id) { 
	if(id==null){ 
		dbQuery = DataQuery 
		.init( 
				query, 
				"hh_message_type", 
				"ID,STATE,PARENTID,NAME,TITLE").addUserWhere(" and parentid = 'NONE'"); 
	}else{ 
		dbQuery = DataQuery 
		.init( 
				query, 
				"hh_message_type", 
				"ID,STATE,PARENTID,NAME,TITLE").addUserWhere(" and parentid = '"+id+"'"); 
	} 
	 
	return dbQuery; 
}

getTreeChildren()的实现方法为：

@Override 
	public DataQuery getTreeChildren(DataQuery query) { 
		DataQuery dbQuery = DataQuery 
			.init( 
					query, 
					"hh_message_type", 
					"ID,STATE,PARENTID,NAME,TITLE"); 
		return dbQuery; 
	}

实现效果图为：

修正版参见：EasyUI实现异步加载tree(整合Struts2)

项目源码下载：http://download.csdn.net/detail/blog.ytso.com/7852021