How does the method determine the transaction type of 'approved' or 'transferred'?

[gedowangvs97]

“getTransactionById” How does the method determine the transaction type of 'approved' or 'transferred'? Or is there any way to tell the difference?
Demo TxId：
232a8da14f777c360ec398568ae828852a60d64507fb482b118c922b1cb8cdbe
42eb88afe779f8e639cc758f688b192f9f2988db69a6f0c87e3282347b3b7635

[ferdinand026]

@gedowangvs97 For Tronscan, 'approved' or 'transferred' is only a description of the contract method called in this transaction. For the method specified by TRC standard, Tronscan will translate it to more readable statement with more obvious key information, for example, for approve transaction.

About how to determine the transaction type of the transaction which get through "getTransactionById" API, "raw_data.contract[0].type is the transaction type. For the type of triggerSmartContract, the invocation method can be obtained through "raw_data. contract[0]. parameter. value. data" filed, and the first 4 bytes is the method, we need to decode the data, please refer to the guide.

[Aiden-777]

public static final String APPROVE_FUNC_ID_BY_KECCAK256 =
        Hex.toHexString(
                new Keccak.Digest256().digest("approve(address,uint256)".getBytes())
        ).substring(0, 8);

String data = Hex.toHexString(triggerSmartContract.getData().toByteArray());

if (!TronConstants.APPROVE_FUNC_ID_BY_KECCAK256 .equals(funcId)) {
    ...
}

[gedowangvs97]

How to get this fundId field？

if (!TronConstants.APPROVE_FUNC_ID_BY_KECCAK256 .equals(funcId)) {
...
}

[Aiden-777]

https://developers.tron.network/docs/parameter-encoding-and-decoding

String funcId = data.substring(0, 8);

[gedowangvs97]

approve TxId：
232a8da14f777c360ec398568ae828852a60d64507fb482b118c922b1cb8cdbe

String funcId = data.substring(0, 8);
// substring：095ea7b3

public static final String APPROVE_FUNC_ID_BY_KECCAK256 =
Hex.toHexString(
new Keccak.Digest256().digest("approve(address, uint256)".getBytes())
).substring(0, 8);
// 8b069f2a

Why are the above two values different?

[ferdinand026]

approve TxId： 232a8da14f777c360ec398568ae828852a60d64507fb482b118c922b1cb8cdbe

String funcId = data.substring(0, 8); // substring：095ea7b3

public static final String APPROVE_FUNC_ID_BY_KECCAK256 = Hex.toHexString( new Keccak.Digest256().digest("approve(address, uint256)".getBytes()) ).substring(0, 8); // 8b069f2a

Why are the above two values different?

There should be no any space in the function method. Remove all the spaces and it will be "approve(address,uint256)"

[Aiden-777]

approve TxId： 232a8da14f777c360ec398568ae828852a60d64507fb482b118c922b1cb8cdbe
String funcId = data.substring(0, 8); // substring：095ea7b3
public static final String APPROVE_FUNC_ID_BY_KECCAK256 = Hex.toHexString( new Keccak.Digest256().digest("approve(address, uint256)".getBytes()) ).substring(0, 8); // 8b069f2a
Why are the above two values different?

There should be no any space in the function method. Remove all the spaces and it will be "approve(address,uint256)"

Yes, I made a stupid mistake and have corrected it.