collection; @SuppressWarnings("unchecked") public void setItems(Object items) { this.items = items; if(items instanceof Collection){ collection = (Collection) items; } if(items instanceof Map){ @SuppressWarnings("rawtypes") Map map = (Map) items; collection = map.entrySet(); } if(items.getClass().isArray()){//这个是最重要的，反射判断 this.collection = new ArrayList(); int length = Array.getLength(items); for(int i = 0; i < length; i++){ Object value = Array.get(items, i); collection.add(value); } } } @Override public void doTag() throws JspException, IOException { Iterator it = this.collection.iterator(); while(it.hasNext()){ Object value = it.next(); this.getJspContext().setAttribute(var, value); this.getJspBody().invoke(null); } } public void setVar(String var) { this.var = var; } }
下面是tld文件对这个标签的描述
Foreach com.bird.web.tag.example.ForeachTag scriptless var true true items true true
开发迭代标签 <% List list = new ArrayList(); list.add("aaa"); list.add("bbb"); list.add("ccc"); request.setAttribute("list",list); %>
${temp } <% Map map = new HashMap(); map.put("aaa","111"); map.put("bbb","222"); map.put("ccc","333"); request.setAttribute("map",map); %>
${temp } <% Integer[] i = {1,2,3,4,5,6,7}; request.setAttribute("array",i); %>
${num } <% int[] t = {9,10,11,12,13}; request.setAttribute("t",t); %>
${m }
