Question

我有两个用数据填充的课程。它们的结构相似，两个类都包含一个ArrayList，它与完全相同的结构与另一个类相同。数组列表。

ArrayLists名为t30，tB的结构为(BigDecimal, String)。查看new transactionB()和new Transaction30()的主要，它会变得更加清晰。

我想在这些ArrayLists之间执行＆＃34;事务＆＃34; ，因此，移动（或复制和删除）ArrayList中的值（t30） ArrayList（tB）

TransactionO：

public class TransactionO{
    public ArrayList<TransactionB>tBpost = new ArrayList<TransactionB>();
    public TransactionO(/*constructor as seen in main...*/){/*stuff*/} ^
                                            //                         |
    public void addBPost(TransactionB b) { //                          |
        this.tBpost.add(b);               //adding ---------------------
    }
}

Transaction00：

public class Transaction00 {
    public ArrayList<Transaction30>t30post = new ArrayList<Transaction30>();
    public Transaction00(/*constructor as shown below*/){/*stuff*/}    ^
                                               //                      |
    public void add30Post(Transaction30 t30) {//                       |
        this.t30post.add(t30);               //adding ------------------
    }
}

主要：

TransactionO tO = null;
Transaction00 t00 = null;
private static List<TransactionO> allTransactionsIn = new ArrayList<TransactionO>();
private static List<Transaction00> allTransactionsOut = new ArrayList<Transaction00>();
//reading from file, parsing data, and finally storing the data in the class obj
tO = new TransactionO(accountNumber,currency, paymentDate,currentAmount,transactionQty);
tB = new TransactionB(amount,reference); //(BigDecimal, String)
tO.addBPost(tB);
// ^adding the class TransactionB into arraylist "tB" into TransactionO

t00 = new Transaction00(accountNumberSend,clrNrSend);
t30 = new Transaction30(amountSend,referenceSend); //(BigDecimal, String)
t00.add30Post(t30);     
// ^adding the class Transaction30 into arraylist "t30" into Transaction00

//finally
allTransactionsIn.add(tO);
allTransactionsOut.add(t00);

摘要：在这些^ allTransaction*** ArrayLists中，有不同的类对象，但结构相同的ArrayLists (BigDecimal, String)。

arrayList allTransactionsOut的ASCII结构：

--------------------------------------------------------
| t00 (constructor-values) | t00.t30 (arrayList-values) | --------------copy
--------------------------------------------------------               |
Structurally different ^   |  Structurally same ^ (BigDecimal, String) |

arrayList allTransactionsIn的ASCII结构：

--------------------------------------------------------               |
| tO (constructor-values) | tO.tB (arrayList-values)    |  <------------
--------------------------------------------------------
Structurally different ^  |  Structurally same ^ (BigDecimal, String)

我如何将这些arrayList-values从一个列表转移到另一个列表？（不是constructor-values）

请不要犹豫，询问您是否需要进一步解释。感谢

Answer 1

尽管TransactionB和Transaction30碰巧都有BigDecimal和String类型的字段，但Java并不认为它们是相关的。< / p>

如果要将这两种类型存储在ArrayList中，那么您需要确保两种事务类型都从同一父级继承（扩展公共类型或实现公共接口）

e.g。

public abstract class ParentTransaction {
     protected BigDecimal value1
     protected String value2

     public ParentTransaction(BigDecimal value1, String value2) {
         this.value1 = value1;
         this.value2 = value2;
     }
}

public class TransactionB extends ParentTransaction {
   public TransactionB(BigDecimal amountSend, String referenceSend) {
       super(amountSend, referenceSend);
   }
   BigDecimal getAmountSend() {
       return value1;
   }
   String getReferenceSend() {
       return value2;
   }
}

public class Transaction30 extends ParentTransaction {
   public TransactionB(BigDecimal account, String reference) {
       super(account, reference);
   }
   BigDecimal getAccount() {
       return value1;
   }
   String getReference() {
       return value2;
   }
}

在两个部分不同的ArrayLists之间传输数据

1 个答案: