Java List以key为键生成Map小🌰

[java]
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
* @Description:
* @Author: Jasonote
* @Date: 2017/12/20
**/
public class TestDemo {

public static void main(String[] args) {
List<ProcurementOrderInstockDTO> poiInstockData = new ArrayList<>();

ProcurementOrderInstockDTO procurementOrderItemDTO = new ProcurementOrderInstockDTO();
procurementOrderItemDTO.setId(1L);
procurementOrderItemDTO.setPoi(111L);
procurementOrderItemDTO.setWeight(88L);
poiInstockData.add(procurementOrderItemDTO);

ProcurementOrderInstockDTO procurementOrderItemDTO2 = new ProcurementOrderInstockDTO();
procurementOrderItemDTO2.setId(2L);
procurementOrderItemDTO2.setPoi(111L);
procurementOrderItemDTO2.setWeight(99L);
poiInstockData.add(procurementOrderItemDTO2);

Map<Long, List<ProcurementOrderInstockDTO>> instockDataListMap = new HashMap<>();
for (ProcurementOrderInstockDTO procurementOrderInstockDTO1 : poiInstockData) {
if (instockDataListMap.containsKey(procurementOrderInstockDTO1.getPoi())) {
instockDataListMap.get(procurementOrderInstockDTO1.getPoi()).add(procurementOrderInstockDTO1);
} else {
List<ProcurementOrderInstockDTO> instockDTOList = new ArrayList<>();
instockDTOList.add(procurementOrderInstockDTO1);
instockDataListMap.put(procurementOrderInstockDTO1.getPoi(), instockDTOList);
}
}

System.out.println("instockDataListMap = " + instockDataListMap);
}
}

class ProcurementOrderInstockDTO {
private Long id;
private Long poi;
private Long weight;

public Long getId() {
return id;
}

public void setId(Long id) {
this.id = id;
}

public Long getPoi() {
return poi;
}

public void setPoi(Long poi) {
this.poi = poi;
}

public Long getWeight() {
return weight;
}

public void setWeight(Long weight) {
this.weight = weight;
}
}

[/java]

Jason.wang

When you find your talent can't afford to be ambitious, be quiet and study !

You may also like...