List相同字段合并问题

Question

List里有多对象，每对象有货名String和货量Double的字段，如货名相同货量就相加，结果在新CargoList里只有一个对象了四条数据IPE:1400,BNZ:1100,VAM:1000,CSS:1000

Answer 1

class Student{

private String store;

private int money;

private Date date;

private Integer status=0;

    public String getStore() {  
        return store;  
    }  
    public void setStore(String store) {  
        this.store = store;  
    }  
    public int getMoney() {  
        return money;  
    }  
    public void setMoney(int money) {  
        this.money = money;  
    }  
    public Date getDate() {  
        return date;  
    }  
    public void setDate(Date date) {  
        this.date = date;  
    }  
    public Student() {  
        super();  
    }  
    /*public Student(String store, int money, Date date,Integer status) { 
        super(); 
        this.store = store; 
        this.money = money; 
        this.date = date; 
        this.status=status; 
    }*/  

    @Override  
    public String toString() {  
        return "\nStudent [store=" + store + ", money=" + money + ", date="  
                + DateUtil.formatDate(date, "yyyy-MM-dd") + ", status=" + status + "]\n";  
    }  

    public Student(String store, int money, Date date) {  
        super();  
        this.store = store;  
        this.money = money;  
        this.date = date;  
    }  
    public Integer getStatus() {  
        return status;  
    }  
    public void setStatus(Integer status) {  
        this.status = status;  
    }  
}  

  @Test  

ublic void testList() throws Exception{

String format="yyyy-MM-dd";

Student student1=new Student("bb",12,DateUtil.formatString("2017-06-01", format));

Student student2=new Student("aa",13 ,DateUtil.formatString("2017-06-01", format));

Student student3=new Student("bb",12,DateUtil.formatString("2017-06-01", format));

Student student4=new Student("dd",14,DateUtil.formatString("2017-06-02", format));

Student student5=new Student("cc",15,DateUtil.formatString("2017-06-03", format));

Student student6=new Student("bb",16,DateUtil.formatString("2017-06-03", format));

Student student7=new Student("bb",17,DateUtil.formatString("2017-06-03", format));

Student student8=new Student("dd",18,DateUtil.formatString("2017-06-04", format));

Student student9=new Student("cc",19,DateUtil.formatString("2017-06-04", format));

Student student10=new Student("dd",20,DateUtil.formatString("2017-06-04", format));

Student student11=new Student("aa",22,DateUtil.formatString("2017-06-01", format));

List list=Lists.newArrayList();

list.add(student1);

list.add(student2);

list.add(student3);

list.add(student4);

list.add(student5);

list.add(student6);

list.add(student7);

list.add(student8);

list.add(student9);

list.add(student10);

list.add(student11);

System.out.println("合并前list： "+list);

for(int i=0;i<list.size();i++){

Student student=list.get(i);

if (!student.getStatus().equals(1)) {

String store=student.getStore();

Date date=student.getDate();

    for (int j = i+1; j < list.size(); j++) {  
        if (!list.get(j).getStatus().equals(1)) {  
            Student mergeStudent=list.get(j);  
            if (mergeStudent.getStore().equals(store) && DateUtils.isSameDay(date, mergeStudent.getDate())) {  
                student.setMoney(student.getMoney()+mergeStudent.getMoney());  

                mergeStudent.setStatus(1);  
            }  
        }  
    }  
}  

}

System.out.println();

System.out.println("合并后list： "+list);

效果如下：
合并前list： [

Student [store=bb, money=12, date=2017-06-01, status=0]

,

Student [store=aa, money=13, date=2017-06-01, status=0]

,

Student [store=bb, money=12, date=2017-06-01, status=0]

,

Student [store=dd, money=14, date=2017-06-02, status=0]

,

Student [store=cc, money=15, date=2017-06-03, status=0]

,

Student [store=bb, money=16, date=2017-06-03, status=0]

,

Student [store=bb, money=17, date=2017-06-03, status=0]

,

Student [store=dd, money=18, date=2017-06-04, status=0]

,

Student [store=cc, money=19, date=2017-06-04, status=0]

,

Student [store=dd, money=20, date=2017-06-04, status=0]

,

Student [store=aa, money=22, date=2017-06-01, status=0]

]

合并后list： [

Student [store=bb, money=24, date=2017-06-01, status=0]

,

Student [store=aa, money=35, date=2017-06-01, status=0]

,

Student [store=bb, money=12, date=2017-06-01, status=1]

,

Student [store=dd, money=14, date=2017-06-02, status=0]

,

Student [store=cc, money=15, date=2017-06-03, status=0]

,

Student [store=bb, money=33, date=2017-06-03, status=0]

,

Student [store=bb, money=17, date=2017-06-03, status=1]

,

Student [store=dd, money=38, date=2017-06-04, status=0]

,

Student [store=cc, money=19, date=2017-06-04, status=0]

,

Student [store=dd, money=20, date=2017-06-04, status=1]

,

Student [store=aa, money=22, date=2017-06-01, status=1]

]