From f4b9fdf037142d8425327f471e765b175d2212af Mon Sep 17 00:00:00 2001 From: Zakharchenko Date: Fri, 14 Jul 2023 14:21:00 +0300 Subject: [PATCH 1/2] jv-dependency-injection-hw20-v1.0-ready-to-check --- src/main/java/mate.academy/Main.java | 4 +- src/main/java/mate.academy/lib/Component.java | 5 ++ src/main/java/mate.academy/lib/Inject.java | 7 ++ src/main/java/mate.academy/lib/Injector.java | 64 ++++++++++++++++++- .../service/impl/FileReaderServiceImpl.java | 2 + .../service/impl/ProductParserImpl.java | 2 + .../service/impl/ProductServiceImpl.java | 5 ++ 7 files changed, 86 insertions(+), 3 deletions(-) diff --git a/src/main/java/mate.academy/Main.java b/src/main/java/mate.academy/Main.java index 9be740020..7dbe545b3 100644 --- a/src/main/java/mate.academy/Main.java +++ b/src/main/java/mate.academy/Main.java @@ -10,8 +10,8 @@ public class Main { public static void main(String[] args) { // Please test your Injector here. Feel free to push this class as a part of your solution Injector injector = Injector.getInjector(); - ProductService productService = null; - List products = productService.getAllFromFile("products.txt"); + ProductService productService = (ProductService) injector.getInstance(ProductService.class); + List products = productService.getAllFromFile("src/main/resources/products.txt"); products.forEach(System.out::println); } } diff --git a/src/main/java/mate.academy/lib/Component.java b/src/main/java/mate.academy/lib/Component.java index c7e830420..8fe73cbfb 100644 --- a/src/main/java/mate.academy/lib/Component.java +++ b/src/main/java/mate.academy/lib/Component.java @@ -1,5 +1,10 @@ package mate.academy.lib; +import java.lang.annotation.Retention; +import java.lang.annotation.RetentionPolicy; + +@Retention(RetentionPolicy.RUNTIME) public @interface Component { + } diff --git a/src/main/java/mate.academy/lib/Inject.java b/src/main/java/mate.academy/lib/Inject.java index 1741f9df9..ad8411675 100644 --- a/src/main/java/mate.academy/lib/Inject.java +++ b/src/main/java/mate.academy/lib/Inject.java @@ -1,5 +1,12 @@ package mate.academy.lib; +import java.lang.annotation.ElementType; +import java.lang.annotation.Retention; +import java.lang.annotation.RetentionPolicy; +import java.lang.annotation.Target; + +@Retention(RetentionPolicy.RUNTIME) +@Target(ElementType.FIELD) public @interface Inject { } diff --git a/src/main/java/mate.academy/lib/Injector.java b/src/main/java/mate.academy/lib/Injector.java index e87b914ad..4836629ff 100644 --- a/src/main/java/mate.academy/lib/Injector.java +++ b/src/main/java/mate.academy/lib/Injector.java @@ -1,13 +1,75 @@ package mate.academy.lib; +import java.lang.reflect.Constructor; +import java.lang.reflect.Field; +import java.util.HashMap; +import java.util.Map; +import mate.academy.service.FileReaderService; +import mate.academy.service.ProductParser; +import mate.academy.service.ProductService; +import mate.academy.service.impl.FileReaderServiceImpl; +import mate.academy.service.impl.ProductParserImpl; +import mate.academy.service.impl.ProductServiceImpl; + public class Injector { private static final Injector injector = new Injector(); + private Map, Object> instances = new HashMap<>(); public static Injector getInjector() { return injector; } public Object getInstance(Class interfaceClazz) { - return null; + Object clazzImplementationInstance = null; + Class clazz = findImplementation(interfaceClazz); + + Field[] declaredFields = clazz.getDeclaredFields(); + for (Field field : declaredFields) { + if (field.isAnnotationPresent(Inject.class)) { + Object fieldInstance = getInstance(field.getType()); + clazzImplementationInstance = createNewInstance(clazz); + try { + field.setAccessible(true); + field.set(clazzImplementationInstance, fieldInstance); + } catch (IllegalAccessException e) { + throw new RuntimeException("Can't initialize field value. Class: " + + clazz.getName() + ". Field: " + field.getName()); + } + } + } + if (clazzImplementationInstance == null) { + clazzImplementationInstance = createNewInstance(clazz); + } + return clazzImplementationInstance; + } + + private Object createNewInstance(Class clazz) { + if (clazz.isAnnotationPresent(Component.class)) { + if (instances.containsKey(clazz)) { + return instances.get(clazz); + } + try { + Constructor constructor = clazz.getConstructor(); + Object instance = constructor.newInstance(); + instances.put(clazz, instance); + return instance; + } catch (ReflectiveOperationException e) { + throw new RuntimeException("Can't create a new instance of " + clazz.getName()); + } + } else { + throw new RuntimeException("Can't create implementation " + + clazz.getName() + ". Component annotation is absent."); + } + } + + private Class findImplementation(Class interfaceClazz) { + Map, Class> interfaseImplementations = new HashMap<>(); + interfaseImplementations.put(FileReaderService.class, FileReaderServiceImpl.class); + interfaseImplementations.put(ProductParser.class, ProductParserImpl.class); + interfaseImplementations.put(ProductService.class, ProductServiceImpl.class); + if (interfaceClazz.isInterface()) { + return interfaseImplementations.get(interfaceClazz); + } + return interfaseImplementations.get(interfaceClazz); } } diff --git a/src/main/java/mate.academy/service/impl/FileReaderServiceImpl.java b/src/main/java/mate.academy/service/impl/FileReaderServiceImpl.java index 58540d301..752474e0d 100644 --- a/src/main/java/mate.academy/service/impl/FileReaderServiceImpl.java +++ b/src/main/java/mate.academy/service/impl/FileReaderServiceImpl.java @@ -4,8 +4,10 @@ import java.io.IOException; import java.nio.file.Files; import java.util.List; +import mate.academy.lib.Component; import mate.academy.service.FileReaderService; +@Component public class FileReaderServiceImpl implements FileReaderService { @Override public List readFile(String fileName) { diff --git a/src/main/java/mate.academy/service/impl/ProductParserImpl.java b/src/main/java/mate.academy/service/impl/ProductParserImpl.java index 00837f28d..03ea21a56 100644 --- a/src/main/java/mate.academy/service/impl/ProductParserImpl.java +++ b/src/main/java/mate.academy/service/impl/ProductParserImpl.java @@ -1,9 +1,11 @@ package mate.academy.service.impl; import java.math.BigDecimal; +import mate.academy.lib.Component; import mate.academy.model.Product; import mate.academy.service.ProductParser; +@Component public class ProductParserImpl implements ProductParser { public static final int ID_POSITION = 0; public static final int NAME_POSITION = 1; diff --git a/src/main/java/mate.academy/service/impl/ProductServiceImpl.java b/src/main/java/mate.academy/service/impl/ProductServiceImpl.java index 755304777..425ca5552 100644 --- a/src/main/java/mate.academy/service/impl/ProductServiceImpl.java +++ b/src/main/java/mate.academy/service/impl/ProductServiceImpl.java @@ -2,13 +2,18 @@ import java.util.List; import java.util.stream.Collectors; +import mate.academy.lib.Component; +import mate.academy.lib.Inject; import mate.academy.model.Product; import mate.academy.service.FileReaderService; import mate.academy.service.ProductParser; import mate.academy.service.ProductService; +@Component public class ProductServiceImpl implements ProductService { + @Inject private ProductParser productParser; + @Inject private FileReaderService fileReaderService; @Override From 0e8907a6be4df438b9a59ec04bf7f1f95124d2f8 Mon Sep 17 00:00:00 2001 From: Zakharchenko Date: Fri, 14 Jul 2023 14:21:10 +0300 Subject: [PATCH 2/2] jv-dependency-injection-hw20-v1.0-ready-to-check --- src/main/resources/products.txt | 3 +++ 1 file changed, 3 insertions(+) create mode 100644 src/main/resources/products.txt diff --git a/src/main/resources/products.txt b/src/main/resources/products.txt new file mode 100644 index 000000000..5447133f1 --- /dev/null +++ b/src/main/resources/products.txt @@ -0,0 +1,3 @@ +0,name1,Cat1,Desc1,4 +1,name2,Cat2,Desc2,44 +2,name3,Cat3,Desc3,64 \ No newline at end of file