想在web3j实现 合约的abi.encode() 方法，下面是简单实例，如何组装结构体嵌套结构体列表的问题？ 目的：得到与 solidity端， abi.encode(struct detail)，同样的值。

import org.web3j.abi.DefaultFunctionEncoder;
import org.web3j.abi.datatypes.Address;
import org.web3j.abi.datatypes.Type;
import org.web3j.abi.datatypes.generated.Uint256;
import java.util.ArrayList;
import java.util.List;

/**
 * 结构A
 */
public class A {
    private String address;
    private Long tokenId;
}

/**
 * 结构体B
 */
public class B {
    private String owner;
    private List<A> aList;
    private Long data;
}

/**
 * abi.encode
 */
public class Encode() {

    public void main() {
        A a = new A();
        B b = new B();

        List<Type> typeList = new ArrayList<>();

        Type<Address> address = new Address(b.getOwner());
        typeList.add(address);

        /**
         * List<A>
         * 如何组装嵌套结构体？
         */
        List<List<Type>> structList = new ArrayList<>();
        for (B b : bList) {
            List<Type> bTtypeList = new ArrayList<>();
            bTtypeList.add(new Address(b.getAddress()));
            bTtypeList.add(new Uint256(b.getTokenId()));
            structList.add(bTtypeList);
        }
        typeList.add(structList); // error : java.util.ArrayList cannot be cast to org.web3j.abi.datatypes.Type

        Type<Uint> uint = new Uint256(b.getdata());
        typeList.add(uint);

        DefaultFunctionEncoder encoder = new DefaultFunctionEncoder();
        String abiStr = encoder.encodeParameters(typeList);
    }
}

执行到：typeList.add(structList); error : java.util.ArrayList cannot be cast to org.web3j.abi.datatypes.Type

求指点，感谢！