rk_svnadmin/src/main/java/com/rekoe/tree/service/AbstractTreeNodeService.java

package com.rekoe.tree.service;

import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.commons.lang3.StringEscapeUtils;

import com.rekoe.tree.entity.Tree;
import com.rekoe.tree.entity.TreeNode;

/**
 * 抽象树节点服务层
 * 
 */
public abstract class AbstractTreeNodeService implements TreeNodeService {

	public StringBuffer getHTML(Tree tree, Map<String, Object> parameters) {
		StringBuffer html = new StringBuffer();
		List<TreeNode> nodes = getTreeNodes(tree, parameters);
		if (nodes == null || nodes.size() == 0) {
			return null;
		}
		html.append("<ul>");
		for (int i = 0; nodes != null && i < nodes.size(); i++) {
			TreeNode treeNode = nodes.get(i);
			html.append("<li");
			if (this.isLeaf(tree, treeNode)) {// 叶子
				if (i == nodes.size() - 1) {// last
					this.prepareAttribute(html, "class", "last");
				}
			} else {// 父节点
				if (i == nodes.size() - 1) {// last
					this.prepareAttribute(html, "class", "closed lastclosed");
				} else {
					this.prepareAttribute(html, "class", "closed");
				}
				this.prepareAttribute(html, TreeService.TREE_PARENTID_VAR, tree.getId());
			}

			Map<String, Object> allParam = new HashMap<String, Object>();
			if (parameters != null) {
				allParam.putAll(parameters);
			}
			Map<String, String> treeNodeParameters = treeNode.getParameters();
			if (treeNodeParameters != null) {
				allParam.putAll(treeNodeParameters);
			}
			allParam.remove(TreeService.TREE_ID_VAR);
			allParam.remove(TreeService.TREE_PARENTID_VAR);
			prepareParameters(html, allParam);

			if (treeNode.getUrl() != null) {
				this.prepareAttribute(html, "url", treeNode.getUrl());
			}
			Map<String, String> attributes = treeNode.getAttributes();
			if (attributes != null) {
				Iterator<String> attributeKeys = treeNode.getAttributes().keySet().iterator();
				while (attributeKeys.hasNext()) {
					String att = attributeKeys.next();
					prepareAttribute(html, att, treeNode.getAttributes().get(att));
				}
			}
			html.append(" >");
			if (this.isLeaf(tree, treeNode)) {
				html.append("<span class='file'>");
			} else {
				if (i == nodes.size() - 1) {// last folder
					html.append("<div class='hit closed-hit lastclosed-hit' onclick='$att(this);'></div>");
				} else {
					html.append("<div class='hit closed-hit' onclick='$att(this);'></div>");
				}
				html.append("<span class='folder' onclick='$att(this);'>");
			}
			html.append("<a href='javascript:void(0);' onclick='$atc(this)'>");
			html.append(StringEscapeUtils.escapeHtml4(treeNode.getText()));
			html.append("</a>");
			html.append("</span>");
			html.append("</li>");

		}
		html.append("</ul>");
		return html;
	}

	/**
	 * 获取子节点
	 * 
	 * @param parent
	 *            树
	 * @param parameters
	 *            参数
	 * @return 子节点
	 */
	protected abstract List<TreeNode> getTreeNodes(Tree parent, Map<String, Object> parameters);

	/**
	 * 处理参数
	 * 
	 * @param handlers
	 *            html
	 * @param params
	 *            参数
	 */
	protected void prepareParameters(StringBuffer handlers, Map<String, Object> params) {
		if (params == null)
			return;

		StringBuffer result = new StringBuffer();
		Iterator<String> iterKeys = params.keySet().iterator();
		int count = 0;
		while (iterKeys.hasNext()) {
			if (count > 0)
				result.append("&amp;");
			count++;

			String key = iterKeys.next();
			Object value = params.get(key);
			if (value != null) {
				if (value instanceof String) {
					result.append(key).append("=").append(value.toString());
				} else if (value instanceof String[]) {
					String[] arrs = (String[]) value;
					for (String string : arrs) {
						if (string == null) {
							result.append(key).append("=");
						} else {
							result.append(key).append("=").append(string);
						}
					}
				} else {
					throw new RuntimeException("Not support parameter: " + key + "=" + value);// TODO
				}
			} else {
				result.append(key).append("=");
			}

		}
		if (result.length() > 0) {
			this.prepareAttribute(handlers, "param", result.toString());
		}
	}

	/**
	 * Prepares an attribute if the value is not null, appending it to the the
	 * given StringBuffer.
	 * 
	 * @param handlers
	 *            The StringBuffer that output will be appended to.
	 * @param name
	 *            属性名称
	 * @param value
	 *            属性值
	 */
	protected void prepareAttribute(StringBuffer handlers, String name, Object value) {
		if (value != null) {
			handlers.append(" ");
			handlers.append(name);
			handlers.append("=\"");
			handlers.append(value);
			handlers.append("\"");
		}
	}

	/**
	 * @param tree
	 *            树
	 * @param treeNode
	 *            节点
	 * @return 是否是叶子节点
	 */
	protected boolean isLeaf(Tree tree, TreeNode treeNode) {
		return treeNode.isLeaf() || tree.isLeaf();
	}
}