package testMap;
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;
/**
* 循環遍歷Map集合
*
* @author Administrator
*
*/
public class CircleMap {
public static void main(String[] args) {
Map<Integer, String> tempMap = new HashMap<Integer, String>();
tempMap.put(1, "張三");
tempMap.put(2, "李四");
tempMap.put(3, "王五");
/**
* JDK1.4中 遍歷方法一 hashmap entrySet() 遍歷
*/
System.out.println("------------------------------------------------------");
System.out.println("");
System.out.println("方法一:");
Iterator it = tempMap.entrySet().iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry) it.next();
Object key = entry.getKey();
Object value = entry.getValue();
System.out.println("key = " + key + " value = " + value);
}
/**
* JDK1.5中,應用新特性For-Each循環
*/
System.out.println("");
System.out.println("方法二:");
for (Map.Entry<Integer, String> entry : tempMap.entrySet()) {
String key = entry.getKey().toString();
String value = entry.getValue().toString();
System.out.println("key = " + key + " value = " + value);
}
/**
* 遍歷方法三 hashmap keySet() 遍歷
*/
System.out.println("");
System.out.println("方法三:");
for (Iterator i = tempMap.keySet().iterator(); i.hasNext();) {
Object obj = i.next();
System.out.println(obj);// 循環輸出Key
System.out.println("key = " + obj + " value = " + tempMap.get(obj));
}
for (Iterator i = tempMap.values().iterator(); i.hasNext();) {
Object obj = i.next();
System.out.println(obj);// 循環輸出value
}
/**
* 遍歷方法四 treemap keySet()遍歷
*/
System.out.println("");
System.out.println("方法四");
for (Object o : tempMap.keySet()) {
System.out.println("key = " + o + " value = " + tempMap.get(o));
}
System.out
.println("------------------------------------------------------");
/**
* java如何遍歷Map <String, ArrayList> map = new HashMap
* <String,ArrayList>();
*/
/*
System.out
.println("java遍歷Map <String, ArrayList> map = new HashMap <String,ArrayList>();");
Map<String, ArrayList> map = new HashMap<String, ArrayList>();
Set<String> keys = map.keySet();
Iterator<String> iterator = keys.iterator();
while (iterator.hasNext()) {
String key = iterator.next();
ArrayList arrayList = map.get(key);
for (Object o : arrayList) {
System.out.println(o + "遍歷過程");
}
}
System.out.println("=======================================");
Map<String, List> mapList = new HashMap<String, List>();
for (Map.Entry entry : mapList.entrySet()) {
String key = entry.getKey().toString();
List<String> values = (List) entry.getValue();
for (String value : values) {
System.out.println(key + " --> " + value);
}
}
*/
}
}
Java遍歷Map集合方法
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