（转）java List多种遍历方式

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public static void main(String[] args) { Map<String, Object> map = new LinkedHashMap<String, Object>(); map.put( "username" , "wangking" ); map.put( "password" , "12345" ); map.put( "email" , "12345@qq.com" ); map.put( "sex" , "男" ); //第一种 用for循环的方式 for (Map.Entry<String, Object> m :map.entrySet())  { System.out.println(m.getKey()+ "\t" +m.getValue()); } //利用迭代 （Iterator） Set set=map.entrySet(); Iterator iterator=set.iterator(); while (iterator.hasNext()){ Map.Entry<String, Object> enter=(Entry<String, Object>) iterator.next(); System.out.println(enter.getKey()+ "\t" +enter.getValue()); } //利用KeySet 迭代 Iterator it = map.keySet().iterator(); while (it.hasNext()){ String key;      String value;      key=it.next().toString();      value=(String) map.get(key);      System.out.println(key+ "--" +value);   } //利用EnterySet迭代 Iterator i=map.entrySet().iterator();      System.out.println( map.entrySet().size());   String key;      String value;   while (i.hasNext()){        Map.Entry entry = (Map.Entry)i.next();           key=entry.getKey().toString();           value=entry.getValue().toString();           System.out.println(key+ "====" +value);           }  System.out.println(getKeyByValue(map, "zhaokuo" )); } public static String getKeyByValue(Map map, Object value) { String keys= "" ; Iterator it = map.entrySet().iterator(); while (it.hasNext()) { Map.Entry entry = (Entry) it.next(); Object obj = entry.getValue(); if (obj != null && obj.equals(value)) { keys=(String) entry.getKey(); }    } return keys; }

　　2.

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Map<String,String> map= new HashMap<String,String>();      map.put( "1" , "hello" );      map.put( "2" , "name" );      map.put( "3" , "tom" );      for (String key:map.keySet()){          System.out.println( "value值为:" +map.get(key));      }

　　3.

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Map map= new HashMap();      map.put( "1" , "hello" );      map.put( "2" , "name" );      map.put( "3" , "tom" );      Object obj= new Object();      String wa;      obj=map.get( "1" );      wa=(String) map.get( "2" );      System.out.println(obj);      System.out.println(wa);

　　List<Map>遍历方法

List<Map<String,Object>> list = new ArrayList<Map<String, Object>>();
            Map<String,Object> map1 = new HashMap<String, Object>();
            List<String> list1 = new ArrayList<String>();
            List<String> list2 = new ArrayList<String>();
            List<String> list3 = new ArrayList<String>();
            List<String> list4 = new ArrayList<String>();
            list1.add("添加的Object-->a");
            list2.add("添加的Object-->b");
            list3.add("添加的Object-->c");
            list4.add("添加的Object-->d");
        map1.put(</span>"a"<span style="color: #000000;">,list1);
        map1.put(</span>"b"<span style="color: #000000;">,list2);
        list.add(map1);

        Map</span>&lt;String,Object&gt; map2 = <span style="color: #0000ff;">new</span> HashMap&lt;String, Object&gt;<span style="color: #000000;">();
        map2.put(</span>"c"<span style="color: #000000;">,list3);
        map2.put(</span>"d"<span style="color: #000000;">,list4);
        list.add(map2);

        </span><span style="color: #0000ff;">for</span> (Map&lt;String,Object&gt;<span style="color: #000000;"> map:list
             ) {
            </span><span style="color: #0000ff;">for</span><span style="color: #000000;"> (String s:map.keySet()
                 ) {
                System.out.print(</span>"key:"+s+"\t"<span style="color: #000000;">);
                System.out.println(</span>"value:"+<span style="color: #000000;">map.get(s));
            }
        }
        System.out.println(</span>"======================华丽的分割线============================="<span style="color: #000000;">);
        </span><span style="color: #0000ff;">for</span> (<span style="color: #0000ff;">int</span> i = 0; i &lt; list.size(); i++<span style="color: #000000;">) {
            Map</span>&lt;String, Object&gt; map =<span style="color: #000000;"> list.get(i);
            Iterator it </span>=<span style="color: #000000;"> map.keySet().iterator();
            </span><span style="color: #0000ff;">while</span><span style="color: #000000;"> (it.hasNext()) {
                String str </span>=<span style="color: #000000;"> (String) it.next();
                System.out.print(</span>"key:"+str+"\t"<span style="color: #000000;">);
                System.out.println(</span>"value:"+<span style="color: #000000;">map.get(str));
            }
        }
        System.out.println(</span>"========================华丽的分割线================================"<span style="color: #000000;">);

        </span><span style="color: #0000ff;">for</span> (Map&lt;String, Object&gt;<span style="color: #000000;"> map : list) {
            </span><span style="color: #0000ff;">for</span> (Map.Entry&lt;String, Object&gt;<span style="color: #000000;"> m : map.entrySet()) {
                System.out.print(</span>"key:"+m.getKey() + "    "<span style="color: #000000;">);
                System.out.println(</span>"value:"+<span style="color: #000000;">m.getValue());
            }
        }</span></pre>


     
     
     

下面这个是运行结果:

key:a   value:[添加的Object-->a]
key:b   value:[添加的Object-->b]
key:c   value:[添加的Object-->c]
key:d   value:[添加的Object-->d]
======================华丽的分割线=============================
key:a   value:[添加的Object-->a]
key:b   value:[添加的Object-->b]
key:c   value:[添加的Object-->c]
key:d   value:[添加的Object-->d]
========================华丽的分割线================================
key:a    value:[添加的Object-->a]
key:b    value:[添加的Object-->b]
key:c    value:[添加的Object-->c]
key:d    value:[添加的Object-->d]