struts2 遍历Map的多种方法

struts2 遍历Map的多种方法

主要针对以下几种情况的Map:

 private Map strMap = new HashMap();

private Map perMap = new HashMap();

private Map strArryMap = new HashMap();

private Map> perLstMap = new HashMap>();

下面给出一个示例
1).ExpressMapAction.java

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

import com.expre.struts2.bean.Person;
import com.expre.struts2.bean.Phone;
import com.opensymphony.xwork2.ActionSupport;

public class ExpressMapAction extends ActionSupport {
    private static final long serialVersionUID = -4251480679223607716L;

    private Map strMap = new HashMap();

    private Map perMap = new HashMap();

    private Map strArryMap = new HashMap();

    private Map> perLstMap = new HashMap>();

 //get&set方法,这里都省略了

 @Override
 public String execute() throws Exception {

  // 值为字符串
  strMap.put("first", "zxx");
  strMap.put("second", "lsx");
  strMap.put("third", "wxh");

  // 值为javabean对象
  Person person = new Person("001", "zxx", 22);
  person.setPhone(new Phone("apple", 18957157189L));

  perMap.put("one", person);

  person = new Person("002", "lsx", 25);
  person.setPhone(new Phone("HTC", 18957157187L));
  perMap.put("two", person);

  // 数组处理
  strArryMap.put("arr1", new String[] { "1", "310000", "hz" });
  strArryMap.put("arr2", new String[] { "2", "310001", "xh" });
  strArryMap.put("arr3", new String[] { "3", "310002", "sc" });

  //list对象处理
  List list=new ArrayList();
  list.add(new Person("001", "zxx", 22));
  list.add(new Person("002", "lsx", 25));
  perLstMap.put("one", list);

  list=new ArrayList();
  list.add(new Person("003", "wlx", 26));
  list.add(new Person("004", "hzx", 28));
  perLstMap.put("two", list);

  return "result";
 }
}

2).strMap.jsp

     
       访问Map:"strMap"/>   
       访问Map中某个元素:   
        "strMap.first"/> |   
        "strMap['second']"/> |   
        "strMap[\'third\']"/>   
          
       访问Map中所有的key:"strMap.keys"/>   
       访问Map中所有的value:"strMap.values"/>   
       访问容器的大小：   
        "strMap.size()"/> |   
        "strMap.size"/>//这是map特别的地方   
           
          
        迭代循环取值,最简单   
         "strMap" id="entry">   
           "#entry"/>{   
            key: "key"/>    
          value:"value"/>}|   
              
             
            
        迭代循环取值   
         "strMap.keySet()" id="key">   
           "key"/>或"#key"/>:   
               if test="strMap[#key]!=null">    
                "strMap.get(#key)"/> |   
               if>   
              
             
            
          迭代循环取数组值   
         "strMap" id="entry">   
           "#entry"/>{   
           "value[0]"/>    
           "value[1]"/>  |   
           "value[2]"/>  }   
              
             
            
          迭代循环取对象值,最直接:   
              
           "perMap" id="entry">      
               
              "#entry"/>  {   
             ID："value.ID"/>    
             Name："value.name"/>    
             Age："value.age"/>  }|   
                
              
              
             
            
          迭代循环取对象的属性值   
        "perMap.keySet()" id="key">   
              "#key"/>:   
               "perMap.get(#key)">   
                   "ID"/>   
                   "name"/>   
                   "phone.name"/>   
               |   
             
             
            
          稍复杂的迭代   
           "perLstMap" id="entry">     
            "total" value="#entry.value.size"/>     
            "#entry.value" status="s">     
               if test="#s.first">   
                "#entry.key"/>:共${total}条   
               if>   {   
               "ID"/>  |   
               "name"/>   |   
               "age"/>   
                };