Precompiled Contract Service Interface¶

Tags: “Precompiled Contracts” “Interface” “Precompiled” “Service”

The Java SDK provides Java API interfaces for blockchain application developers. By function, Java APIs can be divided into the following categories:

Client: Provides support for accessing the JSON-RPC interface for FISCO BCOS 3.x nodes, providing support for deploying and invoking contracts；
Precompiled: Provides calls to FISCO BCOS 3.x Precompiled contract(Precompiled Contracts)interfaces, including ‘SensusService’, ‘SystemConfigService’, ‘BFSService’, ‘KVTableService’, ‘TableCRUDService’, and ‘AuthManager’。

5. BFSService¶

5.1 mkdir¶

Creates a directory at the specified absolute path。

Parameters

-path: absolute path

Return value

RetCode: Create directory results。

5.2 list¶

View the information of the specified absolute path. If it is a directory file, the meta information of all sub-resources in the directory is returned. If it is another file, the meta information of the file is returned。(After the node version 3.1, the interface only returns up to 500)

Parameters

-absolutePath: absolute path

Return value

ListReturns a list of meta information for a file。

5.3 list¶

Note: This interface can only be used when the node version is greater than 3.1

View the information of the specified absolute path. If it is a directory file, the meta information of all sub-resources in the directory is returned. If it is another file, the meta information of the file is returned。If there are too many directory files to traverse (greater than 500), you can traverse them using offsets and limits。

Parameters

-absolutePath: absolute path -offset: offset -limit: limit value

Return value

Tuple2<BigInteger, List>: If the first value of tuple is negative, it means that there is an error in execution, and if it is positive, it means how many files remain to be returned (when traversing directory files)；The second value of tuple is a list of meta information of the returned file。

5.4 isExist¶

Note: This interface can only be used when the node version is greater than 3.1

Determine whether the file resource exists。

Parameters

-absolutePath: absolute path

Return value

-BFSInfo: If it exists, it will return the specific file meta information, if it does not exist, it will return null。

5.5 link¶

Create soft links to contracts under / apps / to facilitate contract management and version control。This method provides the same interface as before in order to adapt to the CNS function of the old node version。

After successful execution, a link file is created under / apps /. For example, if the contract name is hello and the version number is v1, the absolute path of the link file is / apps / hello / v1

Parameters

-name: contract name -version: contract version number -contractAddress: contract address -abi: Contract ABI

Return value

RetCode: execution result

5.6 link¶

Note: This interface can only be used when the node version is greater than 3.1

Create soft links to contracts under / apps / to facilitate contract management and version control。This interface allows users to create soft links at any path in the / apps directory

Parameters

-absolutePath: absolute path -contractAddress: contract address -abi: Contract ABI

Return value

RetCode: execution result

5.7 readlink¶

Obtain the address corresponding to the link file。This method provides the same interface as before in order to adapt to the CNS function of the old node version。

Parameters

-absolutePath: absolute path

Return value

-address: the address corresponding to the link file

6. ConsensusService¶

6.1 addSealer¶

Add the specified node as a consensus node。

Parameters

-nodeId: the ID of the node added as the consensus node -weight: Add the weight of the consensus node

Return value

RetCode: Consensus Node Add Result。

Note

In order to ensure that the new node does not affect the consensus, the node to be added as a consensus node must establish a P2P network connection with other nodes in the group, and the node block height must not be lower than the current maximum block -10, otherwise it cannot be added as a consensus node。

6.2 addObserver¶

Add the specified node as an observation node。

Parameters

nodeId: The ID of the node added as an observation node

Return value

RetCode: Watch Node Add Results。

6.3 removeNode¶

Move the specified node out of the group。

Parameters

nodeId: The node ID of the node removed from the group

Return value

RetCode: Execution result of node removed from group。

6.4 setWeight¶

Set the weight of a consensus node。

Parameters

nodeId: The node ID of the consensus node -weight: weight, not less than 1

Return value

RetCode: Execution Results。

7. SystemConfigService¶

7.1 setValueByKey¶

Sets the value of the specified system configuration item。

Parameters

key: Configuration item. Currently, ‘tx _ count _ limit’ and ‘consensus _ leader _ period’ are supported；
value: The value to which the system configuration item is set。

Return value

RetCode: System Configuration Item Setting Results。

8. KVTableService¶

8.1 createTable¶

Create User Table。

Parameters

tableName: Name of the created user table;
keyFieldName: Primary key name of the user table;
valueFields: The fields of the user table

Return value

RetCode: User Table Creation Results。

8.2 set¶

Write a record to the specified user table。

Parameters

tableName: Name of the table in which the record needs to be inserted;
key: The value to which the primary key is set;
fieldNameToValue: Mapping of each field to its corresponding value。

Return value

RetCode: Whether the record is inserted successfully。

8.3 get¶

Query specified records in the user table。

Parameters

tableName: Queried user table name。
key: the primary key value to be queried。

Return value

String: Query Results。

8.4 desc¶

Obtain the description information of the specified user table。

Parameters

tableName: Queried user table name。

Return value

Map<String, String>: Description of the user table. The mapping between ‘PrecompiledConstant.KEY _ NAME’ and the mapping between ‘PrecompiledConstant.FIELD _ NAME’ and all fields. The fields are separated by commas。

8.5 asyncSet¶

‘set ‘asynchronous interface, writes the specified record to the specified table, and calls the specified callback function after receiving the receipt of the node。

Parameters

tableName: Name of the table in which the record needs to be inserted;
key: The value to which the primary key is set;
fieldNameToValue: Mapping of each field to its corresponding value;
callback: callback function。

Return value

None

9. CNSService¶

Note: Starting with version 3.0.0-rc3, CNS is no longer supported。For the corresponding contract alias function, please refer to the BFS link function。

Migration Instructions: Due to the abandonment of the CNS interface, BFS contains the functions of the CNS and also provides the corresponding adaptation interface。You can change the original CNS service interface to the BFS interface. The interface corresponds to the following table:

Method Name	CNSService	BFSService
Create a mapping between a contract name and a contract address	insert(string name, string version, string address,string abi);	link(string name, string version, string address,string abi);
Get the address of the corresponding name and version	selectByNameAndVersion(string name,string version);	readlink(string path);
Traverse all versions of contract name	selectByName(string name);	list(string path);
Contract Address	0x1004	0x100e

10. AuthManager Rights Management Interface¶

Rights management interfaces include the following three interfaces:

Query interface without permission；
Governance Committee-specific interface: an interface that has the private key of the governance committee to initiate transactions in order to execute correctly；
Administrator-specific interface: an interface where transactions initiated by an administrator’s private key with administrative rights to the corresponding contract can be executed correctly。

10.1 Query interface without permission¶

getCommitteeInfo¶

At initialization, a governance committee is deployed whose address information is automatically generated or specified at build _ chain.sh。Initialize only one member, and the weight of the member is 1。

Parameters

None

Return value

CommitteeInfo: governance committee details

getProposalInfo¶

Get information about a specific proposal。

Parameters

-proposalID: ID number of the proposal

Return value

ProposalInfo: details of the proposal

getDeployAuthType¶

Get the permissions policy for the current global deployment

Parameters

None

Return value

-BigInteger: Policy type: 0 is no policy, 1 is whitelist mode, 2 is blacklist mode

checkDeployAuth¶

Check whether an account has deployment permissions

Parameters

-account: account address

Return value

-Boolean: Permission

checkMethodAuth¶

Check whether an account has the permission to call an interface of a contract

Parameters

-contractAddr: contract address -func: function selector for the interface, 4 bytes -account: account address

Return value

-Boolean: Permission

getAdmin¶

Get the administrator address for a specific contract

Parameters

-contractAddr: contract address

Return value

-account: account address

10.2 Special Interface for Account Number of Governance Committee¶

There must be an account in the Governance Committee’s Governors to call, and if there is only one Governance Committee member and the proposal was initiated by that member, then the proposal will be successful。

updateGovernor¶

In the case of a new governance committee, add an address and weight。If you are deleting a governance member, you can set the weight of a governance member to 0。

Parameters

-account: account address -weight: account weight

Return value