Contract

All Implemented Interfaces:
```
public interface Contract

                    
```
Defines a mechanism for implementing contracts, which perform transaction verification.
All participants run this code for every input and output state for every transaction they see on the network. All contracts must verify and accept the associated transaction for it to be finalized and persisted to the ledger. Failure of any contract constraint aborts the transaction, resulting in the transaction not being finalized.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description

Field Summary

Fields
Modifier and Type	Field	Description

Constructor Summary

Constructors
Constructor	Description

Enum Constant Summary

Enum Constants
Enum Constant	Description

Method Summary

Modifier and Type	Method	Description
`boolean`	`isVisible(@NotNull() ContractState state, @NotNull() VisibilityChecker checker)`	Determines whether the specified state is visible to a node observing, or recording the associated transaction.
`abstract void`	`verify(@NotNull() UtxoLedgerTransaction transaction)`	Verifies the specified transaction associated with the current contract.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
- Method Detail
  - isVisible
```
@Suspendable() boolean isVisible(@NotNull() ContractState state, @NotNull() VisibilityChecker checker)
```
    Determines whether the specified state is visible to a node observing, or recording the associated transaction.
    The default implementation determines that a state should be visible to its participants.
    
    Parameters:
    
    state - The ContractState for which to determine visibility.
    
    checker - Provides a mechanism to determine visibility of the specified ContractState.
  - verify
```
 abstract void verify(@NotNull() UtxoLedgerTransaction transaction)
```
    Verifies the specified transaction associated with the current contract.
    
    Parameters:
    
    transaction - The transaction to verify.