struts2 标签 for循环的实现

78 阅读 0 评论 52 点赞

我是靠谱客的博主单纯蜡烛，最近开发中收集的这篇文章主要介绍struts2 标签 for循环的实现，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

Java代码

<s:bean name= "org.apache.struts2.util.Counter" id= "counter" >
  <s:param name="first" value= "1" />
  <s:param name="last" value= "10" />
  <s:iterator>
    counter:<s:property value="current-1" />
  </s:iterator>
</s:bean>

其中first属性指定循环起始值，last指定循环终止值，其它相关属性可以查看org.apache.struts2.util.Counter类源码。在下面迭代器中输入循环的当前值，即：current-1

Counter类源码

/*
* $Id: Counter.java 471756 2006-11-06 15:01:43Z husted $
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*  http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.struts2.util;

import java.io.Serializable;


/**
* A bean that can be used to keep track of a counter.
* <p/>
* Since it is an Iterator it can be used by the iterator tag
*
*/
public class Counter implements java.util.Iterator, Serializable {

    private static final long serialVersionUID = 2796965884308060179L;

    boolean wrap = false ;

    // Attributes —————————————————-
    long first = 1 ;
    long current = first;
    long interval = 1 ;
    long last = - 1 ;


    public void setAdd( long addition) {
        current += addition;
    }

    public void setCurrent( long current) {
        this .current = current;
    }

    public long getCurrent() {
        return current;
    }

    public void setFirst( long first) {
        this .first = first;
        current = first;
    }

    public long getFirst() {
        return first;
    }

    public void setInterval( long interval) {
        this .interval = interval;
    }

    public long getInterval() {
        return interval;
    }

    public void setLast( long last) {
        this .last = last;
    }

    public long getLast() {
        return last;
    }

    // Public ——————————————————–
    public long getNext() {
        long next = current;
        current += interval;

        if (wrap && (current > last)) {
            current -= ((1 + last) - first);
        }

        return next;
    }

    public long getPrevious() {
        current -= interval;

        if (wrap && (current < first)) {
            current += (last - first + 1 );
        }

        return current;
    }

    public void setWrap( boolean wrap) {
        this .wrap = wrap;
    }

    public boolean isWrap() {
        return wrap;
    }

    public boolean hasNext() {
        return ((last == - 1 ) || wrap) ? true : (current <= last);
    }

    public Object next() {
        return new Long(getNext());
    }

    public void remove() {
        // Do nothing
    }
}