Map map = new HashMap();
for (Iterator it = list.iterator(); it.hasNext();) {
String s = (String) it.next();
if (!map.containsKey(s)) {
map.put(s, new Integer(1));
} else {
map.put(s, new Integer(((Integer)map.get(s)).intValue() + 1));
}
}

import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.HashMap;
import java.util.Map;

public class Xxx {

public static void main(String[] args) {
List list = Arrays.asList(new String[]{"a", "b", "a", "c", "b", "b"});
Map map = new HashMap();
for (Iterator it = list.iterator(); it.hasNext();) {
String s = (String) it.next();
if (!map.containsKey(s)) {
map.put(s, new Integer(1));
} else {
map.put(s, new Integer(((Integer)map.get(s)).intValue() + 1));
}
}
System.out.println(map);
}
}

LinkedMap histogram = new LinkedMap();

for (Object letter : list)
histogram.put(letter, !histogram.containsKey(letter) ? 1 : MapUtils.getIntValue(histogram, letter) + 1);

import java.util.Arrays;
import java.util.List;
import org.apache.commons.collections.MapUtils;
import org.apache.commons.collections.map.LinkedMap;

public class Solution437 {
public static void main(String[] args) {
List list = Arrays.asList(new String[]{"a", "b", "a", "c", "b", "b"});

LinkedMap histogram = new LinkedMap();

for (Object letter : list)
histogram.put(letter, !histogram.containsKey(letter) ? 1 : MapUtils.getIntValue(histogram, letter) + 1);

MapUtils.verbosePrint(System.out, "Histogram", histogram);
}
}