Updated Injection Classes. Unit Tests still required.

This commit is contained in:
Konrad Neitzel
2025-04-06 14:57:52 +02:00
parent f37d943cba
commit 8e05dce0d5
25 changed files with 601 additions and 94 deletions
@@ -1,7 +1,9 @@
package de.neitzel.core.commandline;
import lombok.*;
import lombok.extern.log4j.Log4j;
import lombok.Builder;
import lombok.Getter;
import lombok.Setter;
import lombok.Singular;
import lombok.extern.slf4j.Slf4j;
import java.util.List;
@@ -48,7 +48,7 @@ public class Configuration {
*
* @param properties the Properties object containing configuration key-value pairs
*/
public Configuration(Properties properties) {
public Configuration(final Properties properties) {
this.properties = properties;
}
@@ -1,16 +1,20 @@
package de.neitzel.core.image;
import lombok.extern.slf4j.Slf4j;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* Utility class for scaling images while maintaining the aspect ratio.
* Provides methods to create scaled images either as byte arrays or InputStreams.
*/
@Slf4j
public class ImageScaler {
/**
@@ -148,7 +152,8 @@ public class ImageScaler {
ImageIO.write(scaledImage, TARGET_FORMAT, stream);
return stream.toByteArray();
}
} catch (Exception ex) {
} catch (IOException ex) {
log.error("IOException while scaling image.", ex);
return null;
}
}
@@ -0,0 +1,141 @@
package de.neitzel.core.inject;
import de.neitzel.core.inject.annotation.Config;
import java.lang.reflect.Constructor;
import java.util.Map;
import java.util.Objects;
import java.util.stream.Stream;
/**
* Represents the context of the application and serves as the foundation of a dependency
* injection framework.
*
* The {@code ApplicationContext} is responsible for scanning, instantiating, and managing
* the lifecycle of components. Components are identified through the specified base package
* (or derived from a configuration class) and instantiated based on their dependency
* requirements and scope. The framework supports constructor-based dependency injection
* for resolving and creating components.
*/
public class ApplicationContext {
private final Map<Class<?>, ComponentData> components;
/**
* Erstellt einen ApplicationContext auf Basis eines expliziten Package-Namens.
*
* @param basePackage das Basis-Package, das nach Komponenten durchsucht werden soll
*/
public ApplicationContext(String basePackage) {
ComponentScanner scanner = new ComponentScanner(basePackage);
this.components = scanner.getInstantiableComponents();
}
/**
* Erstellt einen ApplicationContext auf Basis einer Startklasse.
* Das zu scannende Package wird aus der @Config Annotation gelesen (basePackage).
* Wenn keine Annotation vorhanden ist oder kein basePackage gesetzt wurde, wird
* das Package der übergebenen Klasse verwendet.
*
* @param configClass Klasse mit oder ohne @Config Annotation
*/
public ApplicationContext(Class<?> configClass) {
String basePackage;
Config config = configClass.getAnnotation(Config.class);
if (config != null && !config.basePackage().isEmpty()) {
basePackage = config.basePackage();
} else {
basePackage = configClass.getPackageName();
}
ComponentScanner scanner = new ComponentScanner(basePackage);
this.components = scanner.getInstantiableComponents();
}
/**
* Retrieves an instance of the specified component type from the application context.
*
* This method uses dependency injection to construct the component if it is not already
* a singleton instance. The component's type and scope are determined by the framework,
* and the appropriate initialization and lifecycle management are performed.
*
* @param <T> the type of the component to retrieve
* @param type the {@code Class} object representing the type of the component
* @return an instance of the requested component type
* @throws IllegalArgumentException if no component is found for the specified type
* @throws IllegalStateException if no suitable constructor is found for the component
* @throws RuntimeException if any error occurs during instantiation
*/
@SuppressWarnings("unchecked")
public <T> T getComponent(Class<? extends T> type) {
ComponentData data = components.get(type);
if (data == null) {
throw new IllegalArgumentException("No component found for type: " + type.getName());
}
Scope scope = data.getScope();
Object instance = data.getInstance();
if (scope == Scope.SINGLETON && instance != null) {
return (T) instance;
}
try {
Constructor<?>[] constructors = data.getType().getConstructors();
for (Constructor<?> constructor : constructors) {
if (canBeInstantiated(constructor, components)) {
Class<?>[] paramTypes = constructor.getParameterTypes();
Object[] parameters = new Object[paramTypes.length];
for (int i = 0; i < paramTypes.length; i++) {
parameters[i] = getComponent(paramTypes[i]);
}
instance = constructor.newInstance(parameters);
if (scope == Scope.SINGLETON) {
data.setInstance(instance);
}
return (T) instance;
}
}
throw new IllegalStateException("Kein passender Konstruktor gefunden für " + type.getName());
} catch (Exception e) {
throw new RuntimeException("Fehler beim Erstellen der Instanz für " + type.getName(), e);
}
}
/**
* Determines if a given constructor can be instantiated using the provided parameter map.
*
* The method evaluates whether every parameter type required by the constructor
* is available in the given parameter map. If all parameter types are present,
* the constructor is considered instantiable.
*
* @param constructor the constructor to check for instantiation feasibility
* @param parameterMap a map containing available parameter types and their associated component data
* @return true if all parameter types required by the constructor are contained in the parameter map, false otherwise
*/
private boolean canBeInstantiated(Constructor<?> constructor, Map<Class<?>, ComponentData> parameterMap) {
return Stream.of(constructor.getParameterTypes()).allMatch(parameterMap::containsKey);
}
/**
* Registers a singleton instance of a specific type into the application context.
*
* This method allows manual addition of singleton components to the context by
* providing a concrete instance of the required type. If the type is already mapped
* to a different instance or type within the context, an {@link IllegalStateException}
* is thrown to prevent replacement of an existing singleton.
*
* @param <T> the type of the component to register
* @param type the class type of the component being added
* @param instance the singleton instance of the component to register
* @throws IllegalStateException if the type is already registered with a different instance
*/
public <T> void addSingleton(Class<? extends T> type, T instance) {
if (components.get(type) == null ||
!Objects.equals(components.get(type).getType().getName(), type.getName())) {
components.put(type, new ComponentData(type, instance));
} else {
throw new IllegalStateException("Type cannot be replaced: " + type.getName());
}
}
}
@@ -0,0 +1,89 @@
package de.neitzel.core.inject;
import lombok.Getter;
/**
* Represents a component in a dependency injection framework.
*
* A component is a unit of functionality that is managed by the framework, allowing
* for controlled instantiation and lifecycle management. The component is associated
* with a specific type and a scope. The scope determines whether the component is
* instantiated as a singleton or as a prototype.
*/
@Getter
public class ComponentData {
/**
* Represents the type of the component being managed by the dependency injection framework.
*
* This variable holds the class object corresponding to the specific type of the component.
* It is used to identify and instantiate the component during the dependency injection process.
* The type is immutable and is specified when the component is created.
*/
private final Class<?> type;
/**
* Defines the lifecycle and instantiation rules for the associated component.
*
* The {@code Scope} determines whether the component is created as a singleton
* (a single shared instance) or as a prototype (a new instance for each request).
*
* This variable is immutable and represents the specific {@code Scope} assigned
* to the component, influencing its behavior within the dependency injection framework.
*/
private final Scope scope;
/**
* Stores the instantiated object associated with the component.
*
* This field holds the actual instance of the component's type within the dependency
* injection framework. For components with a {@code SINGLETON} scope, this field is
* set only once and shared across the entire application. For components with a
* {@code PROTOTYPE} scope, this field may be null since a new instance is created
* upon each request.
*/
private Object instance;
/**
* Constructs a new Component instance with the specified type and scope.
*
* @param type the class type of the component
* @param scope the scope of the component, which determines its lifecycle
*/
public ComponentData(Class<?> type, Scope scope) {
this.type = type;
this.scope = scope;
}
/**
* Constructs a new ComponentData instance with the specified type and an initial instance.
*
* This can be used to add Singletons manually without scanning for them.
*
* @param type the class type of the component
* @param instance the initial instance of the component
*/
public ComponentData(Class<?> type, Object instance) {
this.type = type;
this.scope = Scope.SINGLETON;
this.instance = instance;
}
/**
* Sets the instance for this component if it is configured with a {@code SINGLETON} scope.
* This method ensures that the instance is only set once for a {@code SINGLETON} component.
* If an instance has already been set, it throws an {@link IllegalStateException}.
*
* @param instance the object instance to associate with this component
* @throws IllegalStateException if an instance has already been set for this {@code SINGLETON} component
*/
public void setInstance(Object instance) {
if (scope != Scope.SINGLETON) {
return;
}
if (this.instance != null) {
throw new IllegalStateException("Instance already set for singleton: " + type.getName());
}
this.instance = instance;
}
}
@@ -1,6 +1,7 @@
package de.neitzel.core.inject;
import de.neitzel.core.inject.annotation.Component;
import de.neitzel.core.inject.annotation.Inject;
import org.reflections.Reflections;
import java.lang.reflect.Constructor;
@@ -13,7 +14,7 @@ import java.util.stream.Collectors;
* The resulting analysis identifies unique and shared interfaces/superclasses as well as
* potentially instantiable components, collecting relevant errors if instantiation is not feasible.
*/
public class InjectableComponentScanner {
public class ComponentScanner {
/**
* A set that stores classes annotated with {@code @Component}, representing
@@ -30,7 +31,7 @@ public class InjectableComponentScanner {
* This field is immutable, ensuring thread safety and consistent state
* throughout the lifetime of the {@code InjectableComponentScanner}.
*/
private final Set<Class<?>> fxmlComponents = new HashSet<>();
private final Set<Class<?>> components = new HashSet<>();
/**
* A set of component types that are not uniquely associated with a single implementation.
@@ -75,7 +76,7 @@ public class InjectableComponentScanner {
* The resolution process checks if a component can be instantiated based on its
* constructor dependencies being resolvable using known types or other registered components.
*/
private final Map<Class<?>, Class<?>> instantiableComponents = new HashMap<>();
private final Map<Class<?>, ComponentData> instantiableComponents = new HashMap<>();
/**
* A list of error messages encountered during the scanning and analysis
@@ -96,7 +97,7 @@ public class InjectableComponentScanner {
*
* @param basePackage the base package to scan for injectable components
*/
public InjectableComponentScanner(String basePackage) {
public ComponentScanner(String basePackage) {
scanForComponents(basePackage);
analyzeComponentTypes();
resolveInstantiableComponents();
@@ -110,7 +111,7 @@ public class InjectableComponentScanner {
*/
private void scanForComponents(String basePackage) {
Reflections reflections = new Reflections(basePackage);
fxmlComponents.addAll(reflections.getTypesAnnotatedWith(Component.class));
components.addAll(reflections.getTypesAnnotatedWith(Component.class));
}
/**
@@ -135,7 +136,7 @@ public class InjectableComponentScanner {
private void analyzeComponentTypes() {
Map<Class<?>, List<Class<?>>> superTypesMap = new HashMap<>();
for (Class<?> component : fxmlComponents) {
for (Class<?> component : components) {
Set<Class<?>> allSuperTypes = getAllSuperTypes(component);
for (Class<?> superType : allSuperTypes) {
@@ -156,44 +157,48 @@ public class InjectableComponentScanner {
}
/**
* Resolves components from the set of scanned classes that can be instantiated based on their constructors
* and existing known types. The method iteratively processes classes to identify those whose dependencies
* can be satisfied, marking them as resolved and registering them alongside their supertypes.
* Resolves and identifies instantiable components from a set of scanned components.
* This process determines which components can be instantiated based on their dependencies
* and class relationships, while tracking unresolved types and potential conflicts.
*
* If progress is made during a pass (i.e., a component is resolved), the process continues until no more
* components can be resolved. Any components that remain unresolved are recorded for further inspection.
* The resolution process involves:
* 1. Iteratively determining which components can be instantiated using the known types
* map. A component is resolvable if its dependencies can be satisfied by the current
* set of known types.
* 2. Registering resolvable components and their superclasses/interfaces into the known
* types map for future iterations.
* 3. Removing successfully resolved components from the unresolved set.
* 4. Repeating the process until no further components can be resolved in a given iteration.
*
* The resolved components are stored in a map where each type and its supertypes are associated
* with the component class itself. This map allows for subsequent lookups when verifying dependency satisfiability.
* At the end of the resolution process:
* - Resolvable components are added to the `instantiableComponents` map, which maps types
* to their corresponding instantiable implementations.
* - Unresolved components are identified, and error details are collected to highlight
* dependencies or conflicts preventing their instantiation.
*
* If unresolved components remain after the resolution process, detailed instantiation errors are collected
* for debugging or logging purposes.
*
* This method depends on the following utility methods:
* - {@link #canInstantiate(Class, Set)}: Determines if a component can be instantiated based on existing known types.
* - {@link #registerComponentWithSuperTypes(Class, Map)}: Registers a component and its supertypes in the known types map.
* - {@link #collectInstantiationErrors(Set)}: Collects detailed error messages for unresolved components.
* If errors are encountered due to unresolved components, they are logged for further analysis.
*/
private void resolveInstantiableComponents() {
Set<Class<?>> resolved = new HashSet<>();
Set<Class<?>> unresolved = new HashSet<>(fxmlComponents);
Map<Class<?>, Class<?>> knownTypes = new HashMap<>();
Set<Class<?>> unresolved = new HashSet<>(components);
Map<Class<?>, ComponentData> knownTypes = new HashMap<>();
Set<Class<?>> resolvableNow;
boolean progress;
do {
progress = false;
Iterator<Class<?>> iterator = unresolved.iterator();
resolvableNow = unresolved.stream()
.filter(c -> canInstantiate(c, knownTypes.keySet()))
.collect(Collectors.toSet());
while (iterator.hasNext()) {
Class<?> component = iterator.next();
if (canInstantiate(component, knownTypes.keySet())) {
resolved.add(component);
registerComponentWithSuperTypes(component, knownTypes);
iterator.remove();
progress = true;
}
for (Class<?> clazz : resolvableNow) {
Component annotation = clazz.getAnnotation(Component.class);
ComponentData componentInfo = new ComponentData(clazz, annotation.scope());
resolved.add(clazz);
registerComponentWithSuperTypes(componentInfo, knownTypes);
}
} while (progress);
unresolved.removeAll(resolvableNow);
} while (!resolvableNow.isEmpty());
instantiableComponents.putAll(knownTypes);
@@ -203,16 +208,17 @@ public class InjectableComponentScanner {
}
/**
* Registers the given component class in the provided map. The component is registered along with all of its
* accessible superclasses and interfaces, unless those types are identified as non-unique.
* Registers a component and its superclasses or interfaces in the provided map of known types.
* This method ensures that the component and its inheritance hierarchy are associated with the
* component's data unless the supertype is marked as non-unique.
*
* @param component the component class to register
* @param knownTypes the map where the component and its types will be registered
* @param component the {@code ComponentData} instance representing the component to be registered
* @param knownTypes the map where component types and their data are stored
*/
private void registerComponentWithSuperTypes(Class<?> component, Map<Class<?>, Class<?>> knownTypes) {
knownTypes.put(component, component);
private void registerComponentWithSuperTypes(ComponentData component, Map<Class<?>, ComponentData> knownTypes) {
knownTypes.put(component.getType(), component);
for (Class<?> superType : getAllSuperTypes(component)) {
for (Class<?> superType : getAllSuperTypes(component.getType())) {
if (!notUniqueTypes.contains(superType)) {
knownTypes.put(superType, component);
}
@@ -220,22 +226,38 @@ public class InjectableComponentScanner {
}
/**
* Determines whether a given class can be instantiated based on its constructors and
* the provided known types. A class is considered instantiable if it has a parameterless
* constructor or if all the parameter types of its constructors are present in the known types.
* Determines whether the specified component class can be instantiated based on the provided set
* of known types. A component is considered instantiable if it has at least one constructor where
* all parameter types are contained in the known types set or if it has a no-argument constructor.
* Additionally, all fields annotated with {@code @Inject} must have their types present in the
* known types set.
*
* @param component the class to check for instantiation eligibility
* @param knownTypes the set of types known to be instantiable and available for constructor injection
* @return true if the class can be instantiated; false otherwise
* @param component the class to check for instantiability
* @param knownTypes the set of currently known types that can be used to satisfy dependencies
* @return {@code true} if the component can be instantiated; {@code false} otherwise
*/
private boolean canInstantiate(Class<?> component, Set<Class<?>> knownTypes) {
boolean hasValidConstructor = false;
for (Constructor<?> constructor : component.getConstructors()) {
Class<?>[] paramTypes = constructor.getParameterTypes();
if (paramTypes.length == 0 || Arrays.stream(paramTypes).allMatch(knownTypes::contains)) {
return true;
hasValidConstructor = true;
break;
}
}
return false;
if (!hasValidConstructor) {
return false;
}
for (var field : component.getDeclaredFields()) {
if (field.isAnnotationPresent(Inject.class) && !knownTypes.contains(field.getType())) {
return false;
}
}
return true;
}
/**
@@ -256,7 +278,7 @@ public class InjectableComponentScanner {
Class<?>[] paramTypes = constructor.getParameterTypes();
List<Class<?>> problematicTypes = Arrays.stream(paramTypes)
.filter(t -> !instantiableComponents.containsKey(t) && !notUniqueTypes.contains(t))
.collect(Collectors.toList());
.toList();
if (problematicTypes.isEmpty()) {
possibleWithUniqueTypes = true;
@@ -317,7 +339,7 @@ public class InjectableComponentScanner {
* @return A map where the key is a class type and the value is the corresponding class implementation
* that can be instantiated.
*/
public Map<Class<?>, Class<?>> getInstantiableComponents() {
public Map<Class<?>, ComponentData> getInstantiableComponents() {
return instantiableComponents;
}
@@ -0,0 +1,41 @@
package de.neitzel.core.inject;
/**
* Represents the scope of a component in a dependency injection framework.
* <p>
* The scope determines the lifecycle and visibility of a component instance
* within the framework. The available scope types are:
* <p>
* - {@code SINGLETON}: A single instance of the component is created and
* shared across the entire application.
* - {@code PROTOTYPE}: A new instance of the component is created
* each time it is requested or injected.
* <p>
* This enumeration is typically used in conjunction with the {@code @Component}
* annotation to specify the instantiation behavior of a component.
*/
public enum Scope {
/**
* Specifies that the component should be instantiated as a singleton within the
* dependency injection framework. A single instance of the component is created
* and shared across the entire application lifecycle, ensuring efficient reuse
* of resources and consistent behavior for the component throughout the application.
* <p>
* This scope is typically applied to components where maintaining a single shared
* instance is necessary or beneficial, such as managing shared state or providing
* utility services.
*/
SINGLETON,
/**
* Specifies that the component should be instantiated as a prototype within the
* dependency injection framework. A new instance of the component is created
* each time it is requested or injected, ensuring that no two requests or injections
* share the same instance.
* <p>
* This scope is typically applied to components where maintaining unique instances
* per request is necessary, such as request-specific data processing or handling
* of transient state. It allows for complete isolation between multiple users
* or operations requiring individual resources.
*/
PROTOTYPE
}
@@ -1,5 +1,7 @@
package de.neitzel.core.inject.annotation;
import de.neitzel.core.inject.Scope;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
@@ -24,4 +26,12 @@ import java.lang.annotation.Target;
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
public @interface Component {
/**
* Defines the scope of a component within the dependency injection framework.
* The scope determines whether the component is instantiated as a singleton or
* as a prototype.
*
* @return the scope of the component, defaulting to {@code Scope.SINGLETON}.
*/
Scope scope() default Scope.SINGLETON;
}
@@ -0,0 +1,37 @@
package de.neitzel.core.inject.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Indicates that an annotated class is a configuration class within a dependency
* injection framework. Classes annotated with {@code @Config} are used as markers
* for defining settings and application-specific configurations required by the
* dependency injection mechanism.
*
* Typically, configuration classes provide metadata required for setting up the
* framework, such as specifying the base package to scan for components.
*
* This annotation must be applied at the type level and is retained at runtime to
* facilitate reflection-based processing. It is intended to serve as a declarative
* representation of configuration options for the dependency injection container.
*
* Attributes:
* - {@code basePackage}: Specifies the package name where the framework should scan
* for classes annotated with dependency injection annotations such as {@code @Component}.
*/
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
public @interface Config {
/**
* Specifies the base package for component scanning within the dependency
* injection framework. Classes within the defined package and its sub-packages
* can be scanned and identified as candidates for dependency injection.
*
* @return the base package name as a string; returns an empty string by default
* if no specific package is defined.
*/
String basePackage() default "";
}
@@ -0,0 +1,24 @@
package de.neitzel.core.inject.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Indicates that a field is a candidate for dependency injection within
* a dependency injection framework. Fields annotated with {@code @Inject}
* are automatically populated with the required component instance during runtime,
* typically by the dependency injection container.
*
* This annotation must be applied at the field level and is retained at runtime
* to enable reflection-based identification and assignment of dependencies.
*
* The framework's dependency resolution mechanism identifies the appropriate
* instance to inject based on the field's type or custom configuration,
* ensuring loose coupling and easier testability.
*/
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Inject {
}
@@ -1,6 +1,5 @@
package de.neitzel.core.sql;
import lombok.RequiredArgsConstructor;
import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;
@@ -1,7 +1,5 @@
package de.neitzel.core.sql;
import lombok.RequiredArgsConstructor;
import java.io.InputStream;
import java.io.Reader;
import java.math.BigDecimal;
@@ -1,6 +1,5 @@
package de.neitzel.core.util;
import lombok.extern.log4j.Log4j;
import lombok.extern.slf4j.Slf4j;
import java.io.*;
@@ -1,7 +1,6 @@
package de.neitzel.core.util;
import lombok.NonNull;
import lombok.extern.log4j.Log4j;
import lombok.extern.slf4j.Slf4j;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
@@ -16,7 +16,7 @@ class InjectableComponentScannerTest {
*/
@Test
void testLoadComponents() {
InjectableComponentScanner scanner = new InjectableComponentScanner("de.neitzel.core.inject.testcomponents.test1ok");
ComponentScanner scanner = new ComponentScanner("de.neitzel.core.inject.testcomponents.test1ok");
var instantiableComponents = scanner.getInstantiableComponents();
var nonUniqueTypes = scanner.getNotUniqueTypes();
@@ -37,7 +37,7 @@ class InjectableComponentScannerTest {
*/
@Test
void testComponentsFailWithUnknownParameters() {
InjectableComponentScanner scanner = new InjectableComponentScanner("de.neitzel.core.inject.testcomponents.test2fail");
ComponentScanner scanner = new ComponentScanner("de.neitzel.core.inject.testcomponents.test2fail");
var instantiableComponents = scanner.getInstantiableComponents();
var nonUniqueTypes = scanner.getNotUniqueTypes();
@@ -1,9 +1,9 @@
package de.neitzel.core.inject.testcomponents.test1ok.sub;
import de.neitzel.core.inject.annotation.Component;
import de.neitzel.core.inject.testcomponents.test1ok.SuperClass;
import de.neitzel.core.inject.testcomponents.test1ok.TestInterface1_1;
import de.neitzel.core.inject.testcomponents.test1ok.TestInterface1_2;
import de.neitzel.core.inject.annotation.Component;
@Component
public class TestComponent1_2 extends SuperClass implements TestInterface1_1, TestInterface1_2 {