Document Rendering

public interface Renderer extends Serializable {
    /**
     * Returns the set of media types supported by this renderer
     * @param context parse context for renderer configuration
     * @return immutable set of supported media types
     */
    Set<MediaType> getSupportedTypes(ParseContext context);
    
    /**
     * Renders document content based on provided render requests  
     * @param is input stream containing document data
     * @param metadata document metadata
     * @param parseContext parsing context
     * @param requests variable number of render requests
     * @return collection of render results
     * @throws IOException if I/O error occurs during rendering
     * @throws TikaException if rendering fails
     */
    RenderResults render(InputStream is, Metadata metadata, ParseContext parseContext,
                         RenderRequest... requests) throws IOException, TikaException;
}

public class CompositeRenderer implements Renderer, Initializable {
    /**
     * Creates composite renderer with service-loaded renderers
     * @param serviceLoader service loader for renderer discovery
     */
    public CompositeRenderer(ServiceLoader serviceLoader);
    
    /**
     * Creates composite renderer with provided renderer list
     * @param renderers list of renderers to compose
     */
    public CompositeRenderer(List<Renderer> renderers);
    
    /**
     * Gets the specific renderer for a media type
     * @param mt media type to find renderer for
     * @return renderer instance or null if not found
     */
    public Renderer getLeafRenderer(MediaType mt);
}

/**
 * Base interface for rendering requests - extensible for different document types
 */
public interface RenderRequest {
    // Marker interface - implementations define specific request parameters
}

/**
 * Request for rendering specific page ranges in page-based documents
 */
public class PageRangeRequest implements RenderRequest {
    /** Constant for rendering all pages */
    public static final PageRangeRequest RENDER_ALL = new PageRangeRequest(1, -1);
    
    /**
     * Creates page range request
     * @param from starting page number (1-based)
     * @param to ending page number (1-based, inclusive, -1 for all)
     */
    public PageRangeRequest(int from, int to);
    
    /** @return starting page number */
    public int getFrom();
    
    /** @return ending page number */
    public int getTo();
}

/**
 * Individual render result with status, content, and metadata
 */
public class RenderResult implements Closeable {
    /**
     * Status enumeration for render results
     */
    public enum STATUS {
        SUCCESS,   // Rendering completed successfully
        EXCEPTION, // Rendering failed with exception  
        TIMEOUT    // Rendering timed out
    }
    
    /**
     * Creates render result
     * @param status rendering status
     * @param id unique identifier for this result
     * @param result rendered content (Path or other object)
     * @param metadata associated metadata
     */
    public RenderResult(STATUS status, int id, Object result, Metadata metadata);
    
    /** @return input stream for rendered content */
    public InputStream getInputStream() throws IOException;
    
    /** @return associated metadata */
    public Metadata getMetadata();
    
    /** @return rendering status */
    public STATUS getStatus();
    
    /** @return unique result identifier */
    public int getId();
}

/**
 * Collection of render results with resource management
 */
public class RenderResults implements Closeable {
    /**
     * Creates render results collection
     * @param tmp temporary resources manager
     */
    public RenderResults(TemporaryResources tmp);
    
    /**
     * Adds render result to collection
     * @param result render result to add
     */
    public void add(RenderResult result);
    
    /** @return list of all render results */
    public List<RenderResult> getResults();
}

/**
 * Page-organized render results for page-based documents
 */
public class PageBasedRenderResults extends RenderResults {
    /**
     * Creates page-based render results
     * @param tmp temporary resources manager
     */
    public PageBasedRenderResults(TemporaryResources tmp);
    
    /**
     * Gets render results for specific page
     * @param pageNumber page number to retrieve
     * @return list of render results for the page
     */
    public List<RenderResult> getPage(int pageNumber);
}

import org.apache.tika.renderer.*;
import org.apache.tika.config.TikaConfig;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.metadata.TikaCoreProperties;
import org.apache.tika.parser.ParseContext;
import java.io.FileInputStream;
import java.io.InputStream;

// Setup renderer
TikaConfig config = TikaConfig.getDefaultConfig();
CompositeRenderer renderer = new CompositeRenderer(config.getServiceLoader());

// Setup document metadata
Metadata metadata = new Metadata();
metadata.set(TikaCoreProperties.TYPE, "application/pdf");

// Render all pages
try (InputStream stream = new FileInputStream("document.pdf")) {
    RenderResults results = renderer.render(stream, metadata, new ParseContext(),
                                          PageRangeRequest.RENDER_ALL);
    
    // Process results
    for (RenderResult result : results.getResults()) {
        if (result.getStatus() == RenderResult.STATUS.SUCCESS) {
            try (InputStream renderedContent = result.getInputStream()) {
                // Process rendered content (e.g., save as image)
                // renderedContent contains the visual representation
            }
        }
    }
}

// Render specific page range (pages 2-5)
PageRangeRequest pageRequest = new PageRangeRequest(2, 5);

try (InputStream stream = new FileInputStream("document.pdf")) {
    RenderResults results = renderer.render(stream, metadata, new ParseContext(), pageRequest);
    
    // Use page-based results for organized access
    if (results instanceof PageBasedRenderResults) {
        PageBasedRenderResults pageResults = (PageBasedRenderResults) results;
        
        // Get results for specific page
        List<RenderResult> page3Results = pageResults.getPage(3);
        for (RenderResult result : page3Results) {
            System.out.println("Page 3 render result ID: " + result.getId());
        }
    }
}

public class CustomImageRenderer implements Renderer {
    @Override
    public Set<MediaType> getSupportedTypes(ParseContext context) {
        return Set.of(MediaType.image("jpeg"), MediaType.image("png"));
    }
    
    @Override
    public RenderResults render(InputStream is, Metadata metadata, ParseContext parseContext,
                               RenderRequest... requests) throws IOException, TikaException {
        RenderResults results = new RenderResults(new TemporaryResources());
        
        // Custom rendering logic for images
        // Process input stream and create rendered output
        
        return results;
    }
}