void putAllForCreate(Map m) { for (Iterator i = m.entrySet().iterator(); i.hasNext(); ) { Map.Entry e = (Map.Entry) i.next(); putForCreate(e.getKey(), e.getValue()); } }
void putAllForCreate(Map m) { for (Iterator i = m.entrySet().iterator(); i.hasNext(); ) { Map.Entry e = (Map.Entry) i.next(); System.out.println(e.getKey().toString()); System.out.println(e.getValue().toString()); } }
package learn;import java.util.Collection; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.Set;public class LearnMap1 { public Map creatMap() { Map m = new HashMap(); for (int i = 0; i < 10; i++) { m.put(new Integer(i), new Integer(i)); } return m; } public Set getMapKey(Map m) { return m.keySet(); } public Collection getMapValues(Map m) { return m.values(); } public void printKey(Set s) { for (Iterator it = s.iterator(); it.hasNext();) { int temp = ((Integer) it.next()).intValue(); System.out.println("key:" + temp); } } public void printValue(Collection c) { for (Iterator iter = c.iterator(); iter.hasNext();) { int values = ((Integer) iter.next()).intValue(); System.out.println("value:" + values); } } public void printAll(Map m) { for (Iterator i = m.entrySet().iterator(); i.hasNext();) { Map.Entry e = (Map.Entry) i.next(); System.out.println(e.getKey()+" "+e.getValue());; } } public static void main(String[] args) { LearnMap1 lm = new LearnMap1(); Map map = lm.creatMap(); Set key = lm.getMapKey(map); lm.printKey(key); Collection values = lm.getMapValues(map); lm.printValue(values); lm.printAll(map); } }
keySet可以得到key的一个set,
values可以得到value的一个collection
entrySet可以得到key=value的一个set
for (Iterator i = m.entrySet().iterator(); i.hasNext(); ) {
Map.Entry e = (Map.Entry) i.next();
putForCreate(e.getKey(), e.getValue());
}
}
for (Iterator i = m.entrySet().iterator(); i.hasNext(); ) {
Map.Entry e = (Map.Entry) i.next();
System.out.println(e.getKey().toString());
System.out.println(e.getValue().toString());
}
}
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;public class LearnMap1 { public Map creatMap() {
Map m = new HashMap();
for (int i = 0; i < 10; i++) {
m.put(new Integer(i), new Integer(i));
}
return m;
} public Set getMapKey(Map m) {
return m.keySet();
} public Collection getMapValues(Map m) {
return m.values();
} public void printKey(Set s) {
for (Iterator it = s.iterator(); it.hasNext();) {
int temp = ((Integer) it.next()).intValue();
System.out.println("key:" + temp);
}
} public void printValue(Collection c) {
for (Iterator iter = c.iterator(); iter.hasNext();) {
int values = ((Integer) iter.next()).intValue();
System.out.println("value:" + values);
}
} public void printAll(Map m) {
for (Iterator i = m.entrySet().iterator(); i.hasNext();) {
Map.Entry e = (Map.Entry) i.next();
System.out.println(e.getKey()+" "+e.getValue());;
}
} public static void main(String[] args) {
LearnMap1 lm = new LearnMap1();
Map map = lm.creatMap();
Set key = lm.getMapKey(map);
lm.printKey(key);
Collection values = lm.getMapValues(map);
lm.printValue(values);
lm.printAll(map);
}
}
Iterator it= coll.iterator();
while(it.hasNext()){
用it.next();取就OK了
}
建议好好熟悉类库!