java 结果集中list中根据每一个币种进行金额求和怎么写

Posted 2023-05-16

参考技术A 代码写好了，币种和金额作为Money类的属性存储到List中，再将List中重复币种的金额相加，如下（注意在Eclipse或者MyEclispse里面运行时，添加相关的包）：
public class Money

private String type; //币种
private int value; //金额
//初始化币种和金额
public Money(String type,int value)
this.type=type;
this.value=value;

//这个构造器仅仅用于获得一个Money类去调用isSameType()方法，注意这个类只能在本类中使用
Money()
//获取相同类型的币种并且将它们的金额总和放在一个list中
public List isSameType(List<Money> list)
List l = new ArrayList<Money>();
if(list!=null)
for (int i = 0; i < list.size(); i++)
int sumMoney=list.get(i).value;
for(int j = i+1;j<list.size();j++)
if(list.get(i).type.equals(list.get(j).type))
sumMoney=sumMoney+list.get(j).value;
list.remove(list.get(j));
j=j-1;//删除一个元素以后还原指针位置


Money m =new Money(list.get(i).type,sumMoney);
l.add(m);


return l;

public String toString()
return "币种类型："+ this.type+"\t金额总和："+this.value;

public static void main(String[] args)
//初始化
List<Money> list = new ArrayList<Money>();
Money m1 = new Money("dollar",6);
Money m2 = new Money("renmbi",8);
Money m3 = new Money("dollar",7);
Money m4 = new Money("dollar",9);
Money m5 = new Money("lubu",4);
Money m6 = new Money("renmbi",10);
Money m7 = new Money("lubu",3);
Money m8 = new Money("taidao",15);
list.add(m1);//注意这里加入两次m1
list.add(m1);
list.add(m2);
list.add(m3);
list.add(m4);
list.add(m5);
list.add(m6);
list.add(m7);
list.add(m8);
Money m = new Money();
//求和
List l = m.isSameType(list);
for (int i = 0; i < l.size(); i++)
System.out.println(l.get(i));

java比较两个集合中重复的元素并去除

有些代码经常用，却总是忘记，比如说集合去重复。。
今天在博客上记录一下吧
最近做项目的时候需要在汇率集合中将币种表里面无效的币种所出现的汇率去掉
//查询出所有汇率

List<ExchangeRate> exchangeRate = userManagementService.getExchangeRate(id);

//查询出被禁用的币种

List<Currency> unableCurrent = t_currencyDao.getCurrencyUnenable();

//将汇率中含有被禁用的币种去除掉

for (int i=0;i<exchangeRate.size();i++){
            ExchangeRate exchangeRate = exchangeRate.get(i);
            for (int j=0;j<unableCurrent.size();j++){
                Currency currency = unableCurrent.get(j);
                if (exchangeRate.getGoalCurrencyID().equals(currency.getCurrencyID()) || exchangeRate.getSourceCurrencyID().equals(currency.getCurrencyID())){
                    exchangeRate.remove(i);
                }
            }
        }