把简单的键值对转换成复杂的结构对象

MapConverter.java

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class MapConverter{

	/**
	 * 把键值对转换成对象
	 * 
	 * <pre>
	 * 例如：
	 * student.id=001
	 * student.name=xiaoming
	 * student.works[0].id=001
	 * student.works[0].name=name1
	 * student.works[0].id=002
	 * student.works[0].name=name2
	 * 结果是{student:{id:'001',name:'xiaoming',works:[{id:'001',name:'name1'},{id:'002',name:'name2'}]}}
	 * </pre>
	 * 
	 * @param map
	 * @return
	 */
	public static Map<String, Object> mapToComplexMap(Map<String, String> params) {
		Map<String, Object> rtnMap = new HashMap<String, Object>();
		boolean nodeIsArray = false;
		String nodeName = "";
		Pattern p = Pattern.compile("\\[(.*)\\]$");
		int index = 0;
		Map<String, Object> tmpMap = null;
		List<Object> tmpList = null;
		for (Entry<String, String> entry : params.entrySet()) {
			tmpMap = rtnMap;
			String[] properties = entry.getKey().split("\\.");
			for (int i = 0; i < properties.length; i++) {
				nodeName = properties[i];
				Matcher m = p.matcher(nodeName);
				if (m.find()) {
					nodeIsArray = true;
					index = parseInt(m.group(1));
					nodeName = nodeName.substring(0, nodeName.length()
							- m.group().length());
				} else {
					nodeIsArray = false;
				}

				if (nodeIsArray) {// 该节点为数组结构
					if (!tmpMap.containsKey(nodeName)) {
						tmpList = new ArrayList<Object>();
						tmpMap.put(nodeName, tmpList);
					} else {
						tmpList = (List<Object>) tmpMap.get(nodeName);
					}
					for (int j = tmpList.size() - 1; j < index; j++) {
						if (i != properties.length - 1) {
							tmpList.add(new HashMap<String, Object>());
						} else {
							tmpList.add(null);
						}
					}

					if (i != properties.length - 1) {// 如果不是最后一个节点，tmpMap应该是指定index的那个map
						tmpMap = (Map<String, Object>) tmpList.get(index);
					}
				} else {// 该节点为普通节点
					if (i != properties.length - 1) {// 如果不是最后一个节点，tmpMap应该从原map中取出一个map
						if (!tmpMap.containsKey(nodeName)) {
							tmpMap.put(nodeName, new HashMap<String, Object>());
						} 
						tmpMap = (Map<String, Object>) tmpMap.get(nodeName);
					}
				}
			}
			if (nodeIsArray) {
				tmpList.set(index, entry.getValue());
			} else {
				tmpMap.put(nodeName, entry.getValue());
			}
		}
		return rtnMap;
	}

	private static int parseInt(String num) {
		if (num != null && !num.isEmpty()) {
			if (Pattern.matches("^\\d+$", num)) {
				return Integer.parseInt(num);
			}
		}
		return 0;
	}

	public static void main(String[] args) {
		Map<String,String> map = new HashMap<String,String>();
		map.put("student.id", "001");
		map.put("student.name", "xiaoming");
		map.put("student.work[0].name[]", "workname0");
		map.put("student.sex", "n");
		map.put("student.work[1].id", "workid1");
		map.put("student.work[0].id", "workid0");

		Map<String,Object> rtn = mapToComplexMap(map);
		//System.out.println(Json.toJson(rtn));
		
		System.out.println(rtn);
		
	}

}