java知识点:dom4j 由map转字符串

map.toString()是这样子的~

{welcome-file-list={welcome-file=[index.html, {a=[{b=[{c=[c1c1c1c1c1c1, c2c2c2c2c2c2]}, b2b2b2b2]}, 22222, 33333]}, index.jsp, default.html, default.htm, default.jsp]}, display-name=ask-ssh, context-param={param-value=classpath:applicationContext.xml, param-name=contextConfigLocation}, filter-mapping={url-pattern=/*, filter-name=struts2}, listener={listener-class=org.springframework.web.context.ContextLoaderListener}, filter={filter-class=org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter, filter-name=struts2}}

观察发现,由map 套 list 套 map

思路:

1. 遍历map
2. 判断 value 是否是一个Map
3. 判断 value 是否是一个List
4. 判断List中是否有Map
5. 递归

需要注意的是:在每个循环开始和结尾都需要加上 sb.append("<" + key + ">"); sb.append("</" + key + ">");

而中间是否要放值,取决于你是Map?是List?是String? 只有String才放值

public static String map2Dom(Map<String, Object> map) {// iterator法,遍历mapIterator keyIterator = map.keySet().iterator();StringBuffer sb = new StringBuffer();while (keyIterator.hasNext()) {String key = (String) keyIterator.next();Object value = map.get(key);// 如果value是map则调用map2Domif ("java.util.HashMap".equals(value.getClass().getName())) {mapAppend(sb, key, value);} else {// 不是map,判断是否是listif ("java.util.ArrayList".equals(value.getClass().getName())) {for (Object tmpObject : (List) value) {// 如果是map,则调用map2Dom// 此时就变成一开始的样子了`~~if ("java.util.HashMap".equals(tmpObject.getClass().getName())) {mapAppend(sb, key, tmpObject);} else {// "java.lang.String"stringAppend(sb, key, tmpObject);}}} else {stringAppend(sb, key, value);}}}return sb.toString();}    private static void stringAppend(StringBuffer sb, String key,            Object tmpObject) {        sb.append("<" + key + ">");        sb.append(tmpObject);        sb.append("</" + key + ">");    }    private static void mapAppend(StringBuffer sb, String key, Object tmpObject) {        sb.append("<" + key + ">");        sb.append(map2Dom((Map<String, Object>) tmpObject));        sb.append("</" + key + ">");    }