DataStructure (Javadocs [I2P+ 2.13.0+]

All Known Implementing Classes:
AbuseReason, AbuseSeverity, Certificate, DatabaseEntry, DataStructureImpl, DateAndFlags, DeliveryInstructions, Destination, EncryptedBuildRecord, EncryptedLeaseSet, GarlicClove, Hash, Hash384, Hash512, InfoHash, KeyCertificate, KeysAndCert, Lease, Lease2, LeaseSet, LeaseSet2, LocalHash, MetaLease, MetaLeaseSet, NextSessionKey, NID, NodeInfo, Payload, Peer, PrivateKey, PublicKey, RouterAddress, RouterIdentity, RouterInfo, RSASigningPrivateCrtKey, SendMessageOptions, SessionConfig, SessionKey, SessionKeyAndNonce, SHA1Hash, ShortEncryptedBuildRecord, Signature, SigningPrivateKey, SigningPublicKey, SimpleDataStructure, TokenKey, VerifiedDestination
```
public interface DataStructure
```
Base interface defining standard binary representation for I2P data structures.
DataStructure provides the foundation for all I2P protocol data:
- Binary Protocol: Defines exact bit-level representation
- Serialization: Standard methods for reading/writing to streams
- Network Compatibility: Ensures consistent data encoding
- Validation: Built-in integrity and format checking
Core Operations:
- readBytes(InputStream) - Deserialize from binary stream
- writeBytes(OutputStream) - Serialize to binary stream
- Format Compliance: Follows I2P data structure specification
- Error Handling: Proper exception reporting for invalid data
Integrity Protection:
- Immutable After Initialization: Prevents modification after deserialization
- IllegalStateException: Thrown when modification is attempted
- NetDb Protection: Safeguards network database from corruption
- Message Safety: Protects I2NP messages during transmission
Usage Throughout I2P:
- I2NP Messages: All protocol messages implement DataStructure
- NetDb Entries: RouterInfo and LeaseSet storage format
- I2CP Protocol: Client-router communication data
- Cryptography: Keys, signatures, and certificates
- Routing: Tunnel IDs, leases, and routing information
Implementation Guidelines:
- Do Not Reuse: Create new instances for each data element
- Thread Safety: Protection is not guaranteed to be thread-safe
- Corruption Prevention: Multiple protection layers but not foolproof
- Direct Modification: Avoid modifying internal byte[] arrays
Security Considerations:
- Input Validation: Always validate deserialized data
- Bounds Checking: Prevent buffer overflows and underflows
- Exception Handling: Properly handle DataFormatException
- Memory Safety: Be cautious with direct byte array access
Performance Aspects:
- Efficient Serialization: Optimized for network transmission
- Minimal Overhead: Compact binary representation
- Fast Validation: Quick integrity and format checking
- Memory Management: Careful allocation and cleanup
Common Implementations:
- DataStructureImpl - Base class with common functionality
- SimpleDataStructure - Fixed-size byte array structures
- DatabaseEntry - NetDb-storable objects with signatures
- All I2P protocol message classes

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`Hash`	`calculateHash()` Calculate the SHA256 value of this object (useful for a few scenarios)
`void`	`fromBase64(String data)` Load the structure from the provided base64 string.
`void`	`fromByteArray(byte[] data)` Loads structure from the data provided Warning - many classes will throw IllegalStateException if data is already set.
`void`	`readBytes(InputStream in)` Load up the current object with data from the given stream.
`String`	`toBase64()` render the structure into modified base 64 notation
`byte[]`	`toByteArray()` Convert the structure to a byte array.
`void`	`writeBytes(OutputStream out)` Write out the data structure to the stream, using the format defined in the I2P data structure specification.

- Method Detail
  - calculateHash
```
Hash calculateHash()
```
    Calculate the SHA256 value of this object (useful for a few scenarios)
    Returns:
    SHA256 hash, or null if there were problems (data format or io errors)
  - fromBase64
```
void fromBase64(String data)
         throws DataFormatException
```
    Load the structure from the provided base64 string. Warning - many classes will throw IllegalStateException if data is already set. Warning - many classes will throw IllegalArgumentException if data is the wrong size.
    Parameters:
    data - base64 encoded string to load from
    Throws:
    DataFormatException - if the data format is invalid
  - fromByteArray
```
void fromByteArray(byte[] data)
            throws DataFormatException
```
    Loads structure from the data provided Warning - many classes will throw IllegalStateException if data is already set. Warning - many classes will throw IllegalArgumentException if data is the wrong size.
    Parameters:
    data - byte array to load from
    Throws:
    DataFormatException - if the data format is invalid
  - readBytes
```
void readBytes(InputStream in)
        throws DataFormatException,
               IOException
```
    Load up the current object with data from the given stream. Data loaded this way must match the I2P data structure specification. Warning - many classes will throw IllegalStateException if data is already set.
    Parameters:
    in - stream to read from
    Throws:
    DataFormatException - if the data is improperly formatted
    IOException - if there was a problem reading the stream
  - toBase64
```
String toBase64()
```
    render the structure into modified base 64 notation
    Returns:
    null on error
  - toByteArray
```
byte[] toByteArray()
```
    Convert the structure to a byte array.
    Returns:
    may be null if data is not set
  - writeBytes
```
void writeBytes(OutputStream out)
         throws DataFormatException,
                IOException
```
    Write out the data structure to the stream, using the format defined in the I2P data structure specification.
    Parameters:
    out - stream to write to
    Throws:
    DataFormatException - if the data was incomplete or not yet ready to be written
    IOException - if there was a problem writing to the stream

Interface DataStructure

Method Summary

Method Detail

calculateHash

fromBase64

fromByteArray

readBytes

toBase64

toByteArray

writeBytes