首先jsp页面有一ul用于展现Tree

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加载Tree

<script type=text/java script>
	$('#mytree').tree({   
	    url:'treeLoad.action'
	}); 

  
	
    
     
     
      treeNodes 
      
     
   

  

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1.extends是json-default,表示返回json对象格式。

2.result中param的name为root,里面设置的值就是action中要返回的JSON对象

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需要封装对象Tree

public class TreeNode {
	private static final long serialVersionUID = 1L;
	private String id;   // 节点id
	private String text; // 显示的节点文本
	private String state = open; // 节点状态,'open'或者'closed',默认是'open'
	private boolean checked;       // 指明检查节点是否选中.

	public TreeNode() {}

	public TreeNode(String id, String text, String state, boolean checked) {
		this.id = id;
		this.text = text;
		this.state = state;
		this.checked = checked;
	}

	//...省略setXX() getXX()

}

首先查询所有parentid为空值的数据,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。

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action方法实现

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import com.home.util.ConnectionManager;

/**
 * 查询数据使用JDBC进行操作 
 *
 */
public class TreeAction {
	private List
  
    treeNodes = new ArrayList
   
    (); //返回的JSON数据 private String id; // 树组件使用的ID public String treeLoad() { Statement sta = null; ResultSet rs = null; try { Connection conn = ConnectionManager.getConnection(); sta = conn.createStatement(); String sql = ; if (id == null) { //如果id为null则是根节点 sql = select * from easyui_tree where parentid = ''; } else { //查询下面的子节点 sql = select * from easyui_tree where parentid = + id; } rs = sta.executeQuery(sql); while (rs.next()) { String id = rs.getString(id); String name = rs.getString(name); TreeNode node = new TreeNode(); node.setId(id); node.setText(name); node.setChecked(false); //判断是否有子节点，如果有则closed否则open if(isChildrenNode(id)){ node.setState(closed); }else{ node.setState(open); } treeNodes.add(node); } // 关闭所有资源 ConnectionManager.closeAll(rs, sta, conn); } catch (SQLException e) { e.printStackTrace(); } return success; } /** * 判断是否有子节点 * * @return */ public boolean isChildrenNode(String id) { Boolean flag = false; Statement sta = null; ResultSet rs = null; try { Connection conn = ConnectionManager.getConnection(); sta = conn.createStatement(); String sql = select * from easyui_tree where parentid = + id; rs = sta.executeQuery(sql); while (rs.next()) { flag = true; } // 关闭所有资源 ConnectionManager.closeAll(rs, sta, conn); } catch (SQLException e) { e.printStackTrace(); } return flag; } public List
    
      getTreeNodes() { return treeNodes; } public void setTreeNodes(List
     
       treeNodes) { this.treeNodes = treeNodes; } public String getId() { return id; } public void setId(String id) { this.id = id; } }