Core Annotation Processing

/**
 * Base class for Querydsl annotation processors, contains the main processing logic
 */
public abstract class AbstractQuerydslProcessor extends AbstractProcessor {
    
    /**
     * Main processing entry point called by the Java compiler
     * @param annotations Set of annotation types being processed
     * @param roundEnv Processing environment for current round
     * @return Whether annotations were claimed by this processor
     */
    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv);
    
    /**
     * Create configuration for this processor - must be implemented by subclasses
     * @param roundEnv Processing environment
     * @return Configuration instance for this processor
     */
    protected abstract Configuration createConfiguration(RoundEnvironment roundEnv);
    
    /**
     * Get supported source version
     * @return Latest supported Java source version
     */
    public SourceVersion getSupportedSourceVersion();
    
    // Static utilities available to all processors
    public static Types TYPES;
    public static Elements ELEMENTS;
    public static final Boolean ALLOW_OTHER_PROCESSORS_TO_CLAIM_ANNOTATIONS = Boolean.FALSE;
}

/**
 * Default annotation processor for Querydsl annotations
 * Handles @QueryEntity, @QuerySupertype, @QueryEmbeddable, @QueryEmbedded, @QueryTransient
 */
@SupportedAnnotationTypes({"com.mysema.query.annotations.*"})
public class QuerydslAnnotationProcessor extends AbstractQuerydslProcessor {
    
    /**
     * Creates configuration for Querydsl-specific annotations
     * @param roundEnv Processing environment
     * @return DefaultConfiguration with Querydsl annotation mappings
     */
    @Override
    protected Configuration createConfiguration(RoundEnvironment roundEnv);
}

import com.mysema.query.annotations.QueryEntity;
import com.mysema.query.annotations.QueryTransient;

@QueryEntity
public class Product {
    private Long id;
    private String name;
    private BigDecimal price;
    
    @QueryTransient  // Will not be included in generated QProduct
    private transient String tempField;
}

// Generates QProduct.java with id, name, and price properties

/**
 * Utility for extracting TypeElement from TypeMirror instances
 */
public class TypeExtractor {
    public TypeExtractor(boolean create);
    public TypeElement visit(TypeMirror type);
}

/**
 * Static utility methods for type processing operations
 */
public class TypeUtils {
    public static boolean hasAnnotationOfType(TypeElement element, Set<Class<? extends Annotation>> annotations);
    public static AnnotationMirror getAnnotationMirrorOfType(Element element, Class<? extends Annotation> type);
    public static TypeMirror getAnnotationValueAsTypeMirror(AnnotationMirror annotation, String key);
    public static Collection<TypeElement> getAnnotationValuesAsElements(AnnotationMirror annotation, String key);
    public static boolean isAnnotationMirrorOfType(AnnotationMirror annotation, Class<? extends Annotation> type);
}

/**
 * Factory for creating extended type representations
 */
public class ExtendedTypeFactory {
    public ExtendedTypeFactory(ProcessingEnvironment env, Configuration conf, ...);
    public EntityType getEntityType(TypeMirror type, boolean create);
    public Collection<EntityType> getEntityTypes();
    public void extendTypes();
}

/**
 * Handler for processing TypeElement instances into entity models
 */
public class TypeElementHandler {
    public TypeElementHandler(Configuration conf, ExtendedTypeFactory factory, TypeMappings typeMappings, QueryTypeFactory queryTypeFactory);
    public EntityType handleEntityType(TypeElement element);
    public EntityType handleProjectionType(TypeElement element);
    public List<Parameter> transformParams(List<? extends VariableElement> parameters);
}

/**
 * Processing context for storing intermediate results
 */
public class Context {
    // Entity type collections organized by category
    public final Map<String, EntityType> entityTypes = new HashMap<>();
    public final Map<String, EntityType> embeddableTypes = new HashMap<>();
    public final Map<String, EntityType> supertypes = new HashMap<>();
    public final Map<String, EntityType> extensionTypes = new HashMap<>(); 
    public final Map<String, EntityType> projectionTypes = new HashMap<>();
    public final Map<String, EntityType> allTypes = new HashMap<>();
    
    // Type element mappings for source tracking
    public final Map<String, Set<TypeElement>> typeElements = new HashMap<>();
    
    public void clean();
}

/**
 * Configuration for controlling property visitor behavior
 */
public enum VisitorConfig {
    /** Visit both fields and getters */
    ALL(true, true, true),
    /** Visit fields only */
    FIELDS_ONLY(true, false, true),
    /** Visit methods only */
    METHODS_ONLY(false, true, true),
    /** Visit none */
    NONE(false, false, false);
    
    public static VisitorConfig get(boolean fields, boolean methods);
    public static VisitorConfig get(boolean fields, boolean methods, VisitorConfig defaultConfig);
    
    public boolean visitFieldProperties();
    public boolean visitMethodProperties();
    public boolean visitConstructors();
}