import java.util.*;
import java.text.*;
import java.util.stream.*;
import java.util.function.*;
public class Test{
public static void main(String[] args){
Map<String, Object> hash1 = new HashMap<String, Object>();
hash1.put("CN", 5.3);
hash1.put("EU", 50);
hash1.put("US", 30);
Map<String, Object> hash2 = new HashMap<String, Object>();
hash2.put("CN", 6.5);
hash2.put("EU", 51.2);
hash2.put("DE", 35);
Map<String, Object> hash3 = new HashMap<String, Object>();
hash3.put("EU", 12.2);
hash3.put("DE", 311);
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
list.add(hash1);
list.add(hash2);
list.add(hash3);
sop("input :");
sop(list);
sop("mergeKeyNumberValue output: ");
sop(mergeKeyNumberValue(list, Double.class));
Map<String, Object> a = new HashMap<String, Object>();
a.put("id", 1);
a.put("name", "name1");
a.put("val", 3);
//a.put("cnt", 30);
Map<String, Object> b = new HashMap<String, Object>();
b.put("id", 2);
b.put("name", "name2");
b.put("val", 4);
b.put("cnt", 40);
Map<String, Object> c = new HashMap<String, Object>();
c.put("id", 3);
c.put("name", "name3");
c.put("val", 5);
c.put("cnt", 50);
List<Map<String, Object>> list1 = new ArrayList<Map<String, Object>>();
list1.add(a);
list1.add(b);
list1.add(c);
Map<String, Object> a2 = new HashMap<String, Object>();
a2.put("id", 1);
a2.put("name", "name21");
a2.put("val", 7);
a2.put("cnt", 70);
Map<String, Object> b2 = new HashMap<String, Object>();
b2.put("id", 2);
b2.put("name", "name22");
b2.put("val", 8);
//b2.put("cnt", 80);
Map<String, Object> d2 = new HashMap<String, Object>();
d2.put("id", 4);
d2.put("name", "name24");
d2.put("val", 9);
d2.put("cnt", 90);
List<Map<String, Object>> list2 = new ArrayList<Map<String, Object>>();
list2.add(a2);
list2.add(b2);
list2.add(d2);
Map<String, Object> a3 = new HashMap<String, Object>();
a3.put("id", 1);
a3.put("name", "name21");
a3.put("val", 8);
a3.put("cnt", 33);
Map<String, Object> b3 = new HashMap<String, Object>();
b3.put("id", 2);
b3.put("name", "name22");
b3.put("val", 66);
//b3.put("cnt", 80);
Map<String, Object> e3 = new HashMap<String, Object>();
e3.put("id", 7);
e3.put("name", "name24");
e3.put("val", 8);
e3.put("cnt", 75);
List<Map<String, Object>> list3 = new ArrayList<Map<String, Object>>();
list3.add(a3);
list3.add(b3);
list3.add(e3);
String idField = "id";
String[] addValues = new String[]{"val", "cnt"};
List<List<Map<String, Object>>> ll = new ArrayList<List<Map<String, Object>>>();
ll.add(list1);
ll.add(list2);
ll.add(list3);
sop("input: ");
sop(ll);
sop("mergeListMap output: ");
sop(mergeListMap(ll, idField, addValues, Integer.class));
}
/*
* @param: [{EU=50, CN=5.3, US=30}, {EU=51.2, DE=35, CN=6.5}, {EU=12.2, DE=311}]
* @param: Double.class
* @return: {EU=113.4, DE=346.0, CN=11.8, US=30}
*/
private static Map<String, Object> mergeKeyNumberValue(List<Map<String, Object>> list, Class<? extends Number> clazz){
BinaryOperator<Object> mergeFunction = null;
mergeFunction = (v1, v2) -> addTwoNumberValue(v1, v2, clazz);
Map<String, Object> ret = list.stream()
.map(Map::entrySet)
.flatMap(Set::stream)
.collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue, mergeFunction));
return ret;
}
/*
* @param: [[{val=3, name=name1, id=1}, {val=4, name=name2, cnt=40, id=2}, {val=5, name=name3, cnt=50, id=3}], [{val=7, name=name21, cnt=70, id=1}, {val=8, name=name22, id=2}, {val=9, name=name24, cnt=90, id=4}], [{val=8, name=name21, cnt=33, id=1}, {val=66, name=name22, id=2}, {val=8, name=name24, cnt=75, id=7}]]
* @param: "id"
* @param: ["val","cnt"]
* @param: Integer.class
* @return: [{cnt=103, val=18, name=name1, id=1}, {val=78, name=name2, cnt=40, id=2}, {val=5, name=name3, cnt=50, id=3}, {val=9, name=name24, cnt=90, id=4}, {val=8, name=name24, cnt=75, id=7}]
*/
private static List<Map<String, Object>> mergeListMap(List<List<Map<String, Object>>> list, String idField, String[] addFields, Class<? extends Number> clazz){
List<Map<Object, Map<String, Object>>> lm = new ArrayList<Map<Object, Map<String, Object>>>();
for(List<Map<String, Object>> tl : list){
lm.add(tl.stream().collect(Collectors.toMap(m1 -> m1.get(idField), v -> v, (v1, v2) -> v1)));
}
final BinaryOperator<Object> mergeFunction = (v1, v2) -> addTwoNumberValue(v1, v2, clazz);
Map<Object, Map<String, Object>> ret = lm.stream()
.map(Map::entrySet)
.flatMap(Set::stream)
.collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue,
(v1t, v2t) -> {
Map<String, Object> v3 = new HashMap<String, Object>((Map<String, Object>) v1t);
for(String addField : addFields){
try{
v3.merge(addField, ((Map<String, Object>) v2t).get(addField), mergeFunction);
}catch(Exception e){}
}
return v3;
}));
List<Map<String, Object>> retList = new ArrayList<Map<String, Object>>(ret.values());
return retList;
}
private static <T extends Number> Number getNumberValue(Object obj, Class<? extends Number> clazz){
if(obj==null)return null;
if (clazz == Integer.class) {
return clazz.cast(Integer.parseInt(String.valueOf(obj)));
} else if (clazz == Double.class) {
return clazz.cast(Double.parseDouble(String.valueOf(obj)));
} else if (clazz == Float.class) {
return clazz.cast(Float.parseFloat(String.valueOf(obj)));
} else if (clazz == Long.class) {
return clazz.cast(Long.parseLong(String.valueOf(obj)));
}
return null;
}
private static <T extends Number> Number addTwoNumberValue(Object obj1, Object obj2, Class<? extends Number> clazz){
if(obj1==null)return null;
if (clazz == Integer.class) {
return clazz.cast(Integer.parseInt(String.valueOf(obj1)) + Integer.parseInt(String.valueOf(obj2)));
} else if (clazz == Double.class) {
return clazz.cast(Double.parseDouble(String.valueOf(obj1)) + Double.parseDouble(String.valueOf(obj2)));
} else if (clazz == Float.class) {
return clazz.cast(Float.parseFloat(String.valueOf(obj1)) + Float.parseFloat(String.valueOf(obj2)));
} else if (clazz == Long.class) {
return clazz.cast(Long.parseLong(String.valueOf(obj1)) + Long.parseLong(String.valueOf(obj2)));
}
return null;
}
public static void sop(Object obj){
System.out.println(obj.toString());
}
}