io.neow3j.devpack.Contract Maven / Gradle / Ivy
package io.neow3j.devpack;
import io.neow3j.devpack.annotations.Instruction;
import io.neow3j.devpack.constants.CallFlags;
import io.neow3j.script.OpCode;
import static io.neow3j.script.InteropService.SYSTEM_CONTRACT_CALL;
import static io.neow3j.script.InteropService.SYSTEM_CONTRACT_GETCALLFLAGS;
/**
* Represents a Neo smart contract and provides several contract-related methods for use in smart contracts.
*/
public class Contract {
/**
* The contract's ID. Each contract is assigned an ID at deployment time and is fixed.
*/
public final int id;
/**
* The number of times the contract has been updated.
*/
public final int updateCounter;
/**
* The contract's hash in little-endian order.
*/
public final Hash160 hash;
/**
* The contract's NEF.
*/
public final ByteString nef;
/**
* The contract's manifest in JSON format.
*/
public final Manifest manifest;
private Contract() {
id = 0;
updateCounter = 0;
hash = new Hash160(new byte[0]);
nef = new ByteString("");
manifest = null;
}
/**
* Makes a call to the {@code method} of the contract with the {@code scriptHash} passing the {@code arguments}.
*
* Make sure to pass the script hash in little-endian format, e.g., when you hardcode the hash in your contract
* code as shown in the following example.
*
* {@code Hash160 scriptHash = new Hash160(hexToBytes("cf76e28bd0062c4a478ee35561011319f3cfa4d2"))}
*
* @param scriptHash the script hash of the contract to invoke in little-endian format.
* @param method the method to call.
* @param callFlags the {@link CallFlags} to use for the call.
* @param arguments the arguments to hand to the method. If the called method doesn't take any arguments pass an
* empty object array, i.e., {@code new Object[]{}}. Passing null will make the contract fail at
* runtime.
* @return the value returned by the contract method call.
*/
@Instruction(interopService = SYSTEM_CONTRACT_CALL)
public static native Object call(Hash160 scriptHash, String method, byte callFlags, Object[] arguments);
/**
* Gets the call flags with which the contract has been called. I.e., use this to know with which call flags your
* contract is being called.
*
* @return the call flags encoded in one byte.
*/
@Instruction(interopService = SYSTEM_CONTRACT_GETCALLFLAGS)
public static native byte getCallFlags();
/**
* Compares this contract to the given object. The comparison happens by reference only. I.e., if you retrieve
* the same contract twice, e.g., with
* {@link io.neow3j.devpack.contracts.ContractManagement#getContract(Hash160)}, then comparing the two will
* return false.
*
* @param other the object to compare with.
* @return true if this and {@code other} reference the same contract. False, otherwise.
*/
@Override
@Instruction(opcode = OpCode.EQUAL)
public native boolean equals(Object other);
/**
* Compares this and the given contract by value.
*
* @param contract another contract to compare this contract to.
* @return true if all fields of the two contracts are equal. False, otherwise.
*/
public boolean equals(Contract contract) {
if (this == contract) {
return true;
}
return id == contract.id &&
updateCounter == contract.updateCounter &&
hash.equals(contract.hash) &&
nef.equals(contract.nef) &&
manifest.equals(contract.manifest);
}
}