I/O Framework

/**
 * Binary encoder for writing structured data
 */
public class BinaryEncoder {
    public BinaryEncoder(OutputStream output);
    
    /**
     * Write boolean value
     */
    public void writeBool(boolean value) throws IOException;
    
    /**
     * Write byte value
     */
    public void writeByte(byte value) throws IOException;
    
    /**
     * Write integer value
     */
    public void writeInt(int value) throws IOException;
    
    /**
     * Write long value
     */
    public void writeLong(long value) throws IOException;
    
    /**
     * Write float value
     */
    public void writeFloat(float value) throws IOException;
    
    /**
     * Write double value
     */
    public void writeDouble(double value) throws IOException;
    
    /**
     * Write string value
     */
    public void writeString(String value) throws IOException;
    
    /**
     * Write byte array
     */
    public void writeBytes(byte[] bytes) throws IOException;
    
    /**
     * Flush the encoder
     */
    public void flush() throws IOException;
}

/**
 * Binary decoder for reading structured data
 */
public class BinaryDecoder {
    public BinaryDecoder(InputStream input);
    
    /**
     * Read boolean value
     */
    public boolean readBool() throws IOException;
    
    /**
     * Read byte value
     */
    public byte readByte() throws IOException;
    
    /**
     * Read integer value
     */
    public int readInt() throws IOException;
    
    /**
     * Read long value
     */
    public long readLong() throws IOException;
    
    /**
     * Read float value
     */
    public float readFloat() throws IOException;
    
    /**
     * Read double value
     */
    public double readDouble() throws IOException;
    
    /**
     * Read string value
     */
    public String readString() throws IOException;
    
    /**
     * Read byte array
     */
    public byte[] readBytes() throws IOException;
}

/**
 * Generic codec interface for encoding/decoding objects
 */
public interface Codec<T> {
    /**
     * Encode object to byte array
     */
    byte[] encode(T object) throws IOException;
    
    /**
     * Decode byte array to object
     */
    T decode(byte[] data) throws IOException;
    
    /**
     * Encode object to output stream
     */
    default void encode(T object, OutputStream output) throws IOException;
    
    /**
     * Decode object from input stream
     */
    default T decode(InputStream input) throws IOException;
}

/**
 * Factory for creating location instances with caching
 */
public class CachingLocationFactory implements LocationFactory {
    public CachingLocationFactory(LocationFactory delegate, int cacheSize);
    
    @Override
    public Location create(String path);
    
    @Override
    public Location create(URI uri);
    
    /**
     * Clear location cache
     */
    public void clearCache();
    
    /**
     * Get cache statistics
     */
    public CacheStats getCacheStats();
}

/**
 * Interface for locations that support linking
 */
public interface LinkableLocation extends Location {
    /**
     * Create a symbolic link to this location
     */
    void createSymbolicLink(Location linkLocation) throws IOException;
    
    /**
     * Create a hard link to this location
     */
    void createHardLink(Location linkLocation) throws IOException;
    
    /**
     * Check if this location is a symbolic link
     */
    boolean isSymbolicLink();
    
    /**
     * Get the target of a symbolic link
     */
    Location getLinkTarget() throws IOException;
}

/**
 * Enumeration of location status types
 */
public enum LocationStatus {
    FILE,
    DIRECTORY,
    SYMBOLIC_LINK,
    DOES_NOT_EXIST;
    
    /**
     * Check if status indicates existence
     */
    public boolean exists();
    
    /**
     * Check if status indicates a file
     */
    public boolean isFile();
    
    /**
     * Check if status indicates a directory
     */
    public boolean isDirectory();
}

/**
 * Abstract seekable input stream
 */
public abstract class SeekableInputStream extends InputStream {
    /**
     * Seek to specific position in stream
     */
    public abstract void seek(long pos) throws IOException;
    
    /**
     * Get current position in stream
     */
    public abstract long getPos() throws IOException;
    
    /**
     * Get total length of stream if known
     */
    public abstract long length() throws IOException;
    
    /**
     * Check if stream supports seeking
     */
    public boolean seekable();
}

/**
 * File-based seekable input stream implementation
 */
public class FileSeekableInputStream extends SeekableInputStream {
    public FileSeekableInputStream(File file) throws FileNotFoundException;
    public FileSeekableInputStream(RandomAccessFile raf);
    
    @Override
    public int read() throws IOException;
    
    @Override
    public int read(byte[] b, int off, int len) throws IOException;
    
    @Override
    public void seek(long pos) throws IOException;
    
    @Override
    public long getPos() throws IOException;
    
    @Override
    public long length() throws IOException;
    
    @Override
    public void close() throws IOException;
}

/**
 * Location utility functions
 */
public class Locations {
    /**
     * Copy from one location to another
     */
    public static void copy(Location source, Location destination) throws IOException;
    
    /**
     * Move from one location to another
     */
    public static void move(Location source, Location destination) throws IOException;
    
    /**
     * Delete location recursively
     */
    public static void deleteRecursively(Location location) throws IOException;
    
    /**
     * Create parent directories if they don't exist
     */
    public static void mkdirsIfNotExists(Location location) throws IOException;
    
    /**
     * Get relative path between two locations
     */
    public static String getRelativePath(Location base, Location target);
    
    /**
     * Check if location is under another location
     */
    public static boolean isChild(Location parent, Location child);
}

/**
 * ByteBuffer utility functions
 */
public class ByteBuffers {
    /**
     * Convert byte array to ByteBuffer
     */
    public static ByteBuffer wrap(byte[] bytes);
    
    /**
     * Convert ByteBuffer to byte array
     */
    public static byte[] getBytes(ByteBuffer buffer);
    
    /**
     * Copy ByteBuffer contents
     */
    public static ByteBuffer copy(ByteBuffer source);
    
    /**
     * Merge multiple ByteBuffers
     */
    public static ByteBuffer merge(ByteBuffer... buffers);
    
    /**
     * Compare two ByteBuffers
     */
    public static int compare(ByteBuffer a, ByteBuffer b);
}

/**
 * URL connection utilities
 */
public class URLConnections {
    /**
     * Set common properties for HTTP connections
     */
    public static void setDefaultProperties(URLConnection connection);
    
    /**
     * Set timeout properties
     */
    public static void setTimeout(URLConnection connection, int timeoutMs);
    
    /**
     * Set authentication headers
     */
    public static void setAuthentication(URLConnection connection, String username, String password);
    
    /**
     * Get response as string
     */
    public static String getResponse(URLConnection connection) throws IOException;
    
    /**
     * Download to file
     */
    public static void downloadToFile(URLConnection connection, File destination) throws IOException;
}

import io.cdap.cdap.common.io.*;
import java.nio.ByteBuffer;

// Binary encoding/decoding
public class DataSerializer {
    public byte[] serializeUserData(String username, int age, boolean active) throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        BinaryEncoder encoder = new BinaryEncoder(baos);
        
        encoder.writeString(username);
        encoder.writeInt(age);
        encoder.writeBool(active);
        encoder.flush();
        
        return baos.toByteArray();
    }
    
    public UserData deserializeUserData(byte[] data) throws IOException {
        ByteArrayInputStream bais = new ByteArrayInputStream(data);
        BinaryDecoder decoder = new BinaryDecoder(bais);
        
        String username = decoder.readString();
        int age = decoder.readInt();
        boolean active = decoder.readBool();
        
        return new UserData(username, age, active);
    }
}

// Custom codec implementation
public class JsonCodec<T> implements Codec<T> {
    private final Class<T> type;
    private final ObjectMapper objectMapper;
    
    public JsonCodec(Class<T> type) {
        this.type = type;
        this.objectMapper = new ObjectMapper();
    }
    
    @Override
    public byte[] encode(T object) throws IOException {
        return objectMapper.writeValueAsBytes(object);
    }
    
    @Override
    public T decode(byte[] data) throws IOException {
        return objectMapper.readValue(data, type);
    }
}

// Location management with caching
public class FileManager {
    private final CachingLocationFactory locationFactory;
    
    public FileManager(LocationFactory baseFactory) {
        this.locationFactory = new CachingLocationFactory(baseFactory, 1000);
    }
    
    public void processFiles(String basePath, List<String> filePaths) throws IOException {
        Location baseLocation = locationFactory.create(basePath);
        Locations.mkdirsIfNotExists(baseLocation);
        
        for (String filePath : filePaths) {
            Location fileLocation = locationFactory.create(
                baseLocation.toURI().resolve(filePath).toString()
            );
            
            if (fileLocation.exists()) {
                processFile(fileLocation);
            } else {
                System.out.println("File not found: " + filePath);
            }
        }
        
        // Print cache statistics
        System.out.println("Cache stats: " + locationFactory.getCacheStats());
    }
    
    public void createSymbolicLinks(Location sourceDir, Location linkDir) throws IOException {
        if (sourceDir instanceof LinkableLocation && linkDir instanceof LinkableLocation) {
            LinkableLocation linkableSource = (LinkableLocation) sourceDir;
            LinkableLocation linkableTarget = (LinkableLocation) linkDir;
            
            for (Location file : sourceDir.list()) {
                if (file.isFile()) {
                    Location linkFile = linkDir.append(file.getName());
                    ((LinkableLocation) file).createSymbolicLink(linkFile);
                }
            }
        }
    }
    
    private void processFile(Location location) throws IOException {
        // File processing logic
        System.out.println("Processing: " + location.getName() + 
                          " (size: " + location.length() + " bytes)");
    }
}

// Seekable stream processing
public class LogFileProcessor {
    public void processLogFile(File logFile, long startOffset, long endOffset) throws IOException {
        try (FileSeekableInputStream stream = new FileSeekableInputStream(logFile)) {
            // Seek to start position
            stream.seek(startOffset);
            
            byte[] buffer = new byte[8192];
            long currentPos = stream.getPos();
            
            while (currentPos < endOffset) {
                int bytesToRead = (int) Math.min(buffer.length, endOffset - currentPos);
                int bytesRead = stream.read(buffer, 0, bytesToRead);
                
                if (bytesRead == -1) {
                    break; // End of file
                }
                
                // Process the read data
                processLogData(buffer, 0, bytesRead);
                
                currentPos = stream.getPos();
            }
        }
    }
    
    public void indexLogFile(File logFile) throws IOException {
        try (FileSeekableInputStream stream = new FileSeekableInputStream(logFile)) {
            Map<String, Long> lineIndex = new HashMap<>();
            long position = 0;
            String line;
            
            BufferedReader reader = new BufferedReader(
                new InputStreamReader(stream, StandardCharsets.UTF_8)
            );
            
            while ((line = reader.readLine()) != null) {
                // Extract timestamp or identifier from line
                String key = extractLineKey(line);
                if (key != null) {
                    lineIndex.put(key, position);
                }
                position = stream.getPos();
            }
            
            System.out.println("Indexed " + lineIndex.size() + " lines");
        }
    }
    
    private void processLogData(byte[] data, int offset, int length) {
        // Process log data
        String logData = new String(data, offset, length, StandardCharsets.UTF_8);
        System.out.println("Processing log data: " + logData.length() + " chars");
    }
    
    private String extractLineKey(String line) {
        // Extract timestamp, request ID, etc.
        return line.length() > 20 ? line.substring(0, 20) : null;
    }
}

// Advanced I/O utilities
public class DataTransferService {
    public void transferLargeFile(Location source, Location destination) throws IOException {
        System.out.println("Transferring: " + source.getName() + " -> " + destination.getName());
        
        // Copy with progress tracking
        long totalSize = source.length();
        long transferred = 0;
        
        try (InputStream input = source.getInputStream();
             OutputStream output = destination.getOutputStream()) {
            
            byte[] buffer = new byte[64 * 1024]; // 64KB buffer
            int bytesRead;
            
            while ((bytesRead = input.read(buffer)) != -1) {
                output.write(buffer, 0, bytesRead);
                transferred += bytesRead;
                
                // Report progress
                if (transferred % (1024 * 1024) == 0) { // Every MB
                    double progress = (double) transferred / totalSize * 100;
                    System.out.printf("Progress: %.1f%% (%d/%d bytes)%n", 
                                     progress, transferred, totalSize);
                }
            }
        }
        
        System.out.println("Transfer completed: " + transferred + " bytes");
    }
    
    public void downloadFromUrl(String url, File destination, int timeoutMs) throws IOException {
        URLConnection connection = new URL(url).openConnection();
        URLConnections.setTimeout(connection, timeoutMs);
        URLConnections.setDefaultProperties(connection);
        
        // Download to file
        URLConnections.downloadToFile(connection, destination);
        
        System.out.println("Downloaded: " + url + " -> " + destination.getAbsolutePath());
    }
    
    public void mergeFiles(List<Location> sourceFiles, Location destination) throws IOException {
        try (OutputStream output = destination.getOutputStream()) {
            for (Location sourceFile : sourceFiles) {
                System.out.println("Merging: " + sourceFile.getName());
                
                try (InputStream input = sourceFile.getInputStream()) {
                    byte[] buffer = new byte[32 * 1024];
                    int bytesRead;
                    
                    while ((bytesRead = input.read(buffer)) != -1) {
                        output.write(buffer, 0, bytesRead);
                    }
                }
            }
        }
        
        System.out.println("Merged " + sourceFiles.size() + " files into: " + 
                          destination.getName());
    }
}

// ByteBuffer operations
public class BufferProcessor {
    public void processDataBuffers(List<ByteBuffer> buffers) {
        // Merge all buffers
        ByteBuffer merged = ByteBuffers.merge(buffers.toArray(new ByteBuffer[0]));
        
        System.out.println("Merged buffer size: " + merged.remaining() + " bytes");
        
        // Process merged data
        byte[] data = ByteBuffers.getBytes(merged);
        processData(data);
    }
    
    public void compareBuffers(ByteBuffer buffer1, ByteBuffer buffer2) {
        int comparison = ByteBuffers.compare(buffer1, buffer2);
        
        if (comparison == 0) {
            System.out.println("Buffers are identical");
        } else if (comparison < 0) {
            System.out.println("Buffer1 is lexicographically smaller");
        } else {
            System.out.println("Buffer1 is lexicographically larger");
        }
    }
    
    private void processData(byte[] data) {
        // Data processing logic
        System.out.println("Processing " + data.length + " bytes");
    }
}