遍历Map的四种方式

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package com.test.basic.collection;import java.util.ArrayList;import java.util.HashMap;import java.util.Iterator;import java.util.List;import java.util.Map;import java.util.Map.Entry;import java.util.Set;/** * 遍历Map的四种方式 * @author wang.yanan * 2014.3.15 * */public class TraverasMap {public static void main(String[] args) {Map<String, Integer> tempMap = new HashMap<String, Integer>();tempMap.put("a", 1);tempMap.put("b", 2);tempMap.put("c", 3);/*方式一：EntrySet.Iterator*/System.out.println("方式一：EntrySet.Iterator-while");Iterator<Entry<String, Integer>> itEntry = tempMap.entrySet().iterator();while(itEntry.hasNext()) {Entry<String, Integer> entry = itEntry.next();System.out.println(entry.getKey() + ", " + entry.getValue());}/*方式二：EntrySet*/System.out.println("方式二：EntrySet-for");//Set<Map.Entry<String, Integer>> entrySet = tempMap.entrySet();//for(Map.Entry<String, Integer> entry : entrySet) {for(Map.Entry<String, Integer> entry : tempMap.entrySet()) {System.out.println(entry.getKey() + ", " + entry.getValue());}/*方式三：KeySet.Iterator*/System.out.println("方式三：KeySet.Interator-while");Iterator<String> itKey = tempMap.keySet().iterator();while(itKey.hasNext()) {String key = itKey.next();Integer value = tempMap.get(key);System.out.println(key + ", " + value);}/*方式四：KeySet*/System.out.println("方式四：KeySet-for");Set<String> keySet = tempMap.keySet();for(String key : keySet) {System.out.println(key + ", " + tempMap.get(key));}System.out.println("遍历：Map<String, List>");Map<String, List> tempMap2 = new HashMap<String, List>();List<Integer> list1 = new ArrayList<Integer>();List<Integer> list2 = new ArrayList<Integer>();List<Integer> list3 = new ArrayList<Integer>();list1.add(1);list1.add(2);list1.add(3);list2.add(1);list2.add(2);list2.add(3);list3.add(1);list3.add(2);list3.add(3);tempMap2.put("a", list1);tempMap2.put("b", list2);tempMap2.put("c", list3);for(Map.Entry<String, List> entry : tempMap2.entrySet()) {String key = entry.getKey();List<Integer> value = tempMap2.get(key);for(Integer i : value) {System.out.println(key + ", " + i);}}}}
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