我有一个问题，我不知道如何分割条件和大小的名单。
现在，我可以根据大小拆分列表，但如何添加诸如值和之类的条件。
如果金额总和>100，则拆分到下一个新列表。如果金额之和小于100，则大小必须小于等于3。
输入示例：

[[Txn{txnId='T1', amt=81}], [Txn{txnId='T2', amt=5}], [Txn{txnId='T3', amt=12}], [Txn{txnId='T4', amt=28}], [Txn{txnId='T5', amt=78}], [Txn{txnId='T6', amt=8}], [Txn{txnId='T7', amt=7}], [Txn{txnId='T8', amt=65}]]

预期产量：

[
  [Txn{txnId='T1', amt=81}, Txn{txnId='T2', amt=5}],
  [Txn{txnId='T3', amt=12}, Txn{txnId='T4', amt=28}],
  [Txn{txnId='T5', amt=78}, Txn{txnId='T6', amt=8}, Txn{txnId='T7', amt=7}], 
  [Txn{txnId='T8', amt=65}]
]

我的输出错误：

[
  [Txn{txnId='T1', amt=81}, Txn{txnId='T2', amt=5}, Txn{txnId='T3', amt=12}],
  [Txn{txnId='T4', amt=28}, Txn{txnId='T5', amt=78}, Txn{txnId='T6', amt=8}], 
  [Txn{txnId='T7', amt=7}, Txn{txnId='T8', amt=65}]
]

我的代码：

import java.util.*;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.stream.Collectors;

public class TestStream {
    public class Transaction {
        String txnId;
        int amount;

        public Transaction(String txnId, int amount) {
            this.txnId = txnId;
            this.amount = amount;
        }

        @Override
        public String toString() {
            return "Txn{" +
                    "txnId='" + txnId + '\'' +
                    ", amt=" + amount +
                    '}';
        }
    }

    public static <T> Collection<List<T>> partitionBasedOnSize(List<T> inputList) {
        final AtomicInteger counter = new AtomicInteger(0);
        return inputList.stream()
                .collect(Collectors.groupingBy(s -> counter.getAndIncrement()/3))
                .values();
    }

    @Test
    public void test() {
        List<Transaction> transactionList = new ArrayList<>();
        Transaction txn1 = new Transaction("T1", 81);
        Transaction txn2 = new Transaction("T2", 5);
        Transaction txn3 = new Transaction("T3", 12);
        Transaction txn4 = new Transaction("T4", 28);
        Transaction txn5 = new Transaction("T5", 78);
        Transaction txn6 = new Transaction("T6", 8);
        Transaction txn7 = new Transaction("T7", 7);
        Transaction txn8 = new Transaction("T8", 65);

        transactionList.add(txn1);
        transactionList.add(txn2);
        transactionList.add(txn3);
        transactionList.add(txn4);
        transactionList.add(txn5);
        transactionList.add(txn6);
        transactionList.add(txn7);
        transactionList.add(txn8);

        System.out.println(partitionBasedOnSize(transactionList).toString() + "\n");
    }
}