From fb77c17ddb320e6859f4ddc339c127e2bdd9e46f Mon Sep 17 00:00:00 2001 From: Vitalii Date: Tue, 8 Aug 2023 16:30:50 +0300 Subject: [PATCH] implemented Injector --- src/main/java/mate.academy/Main.java | 4 +- src/main/java/mate.academy/lib/Component.java | 4 ++ src/main/java/mate.academy/lib/Inject.java | 4 ++ src/main/java/mate.academy/lib/Injector.java | 71 ++++++++++++++++++- .../service/impl/FileReaderServiceImpl.java | 3 + .../service/impl/ProductParserImpl.java | 3 + .../service/impl/ProductServiceImpl.java | 6 ++ 7 files changed, 92 insertions(+), 3 deletions(-) diff --git a/src/main/java/mate.academy/Main.java b/src/main/java/mate.academy/Main.java index 9be740020..b38fa9ad7 100644 --- a/src/main/java/mate.academy/Main.java +++ b/src/main/java/mate.academy/Main.java @@ -4,13 +4,13 @@ import mate.academy.lib.Injector; import mate.academy.model.Product; import mate.academy.service.ProductService; +import mate.academy.service.impl.ProductServiceImpl; 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; + ProductService productService = (ProductService) injector.getInstance(ProductServiceImpl.class); List products = productService.getAllFromFile("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..76fb98e9c 100644 --- a/src/main/java/mate.academy/lib/Component.java +++ b/src/main/java/mate.academy/lib/Component.java @@ -1,5 +1,9 @@ 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..32775efe1 100644 --- a/src/main/java/mate.academy/lib/Inject.java +++ b/src/main/java/mate.academy/lib/Inject.java @@ -1,5 +1,9 @@ package mate.academy.lib; +import java.lang.annotation.Retention; +import java.lang.annotation.RetentionPolicy; + +@Retention(RetentionPolicy.RUNTIME) 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..a0757687a 100644 --- a/src/main/java/mate.academy/lib/Injector.java +++ b/src/main/java/mate.academy/lib/Injector.java @@ -1,13 +1,82 @@ package mate.academy.lib; +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 java.lang.reflect.Constructor; +import mate.academy.service.impl.ProductServiceImpl; +import java.lang.reflect.Field; +import java.lang.reflect.InvocationTargetException; +import java.util.HashMap; +import java.util.Map; + public class Injector { private static final Injector injector = new Injector(); public static Injector getInjector() { return injector; } + private final Map, Object> instances = new HashMap<>(); public Object getInstance(Class interfaceClazz) { - return null; + Object clazzImplementationInstance = null; + Class clazz = findImplementation(interfaceClazz); + isComponentOfClazz(clazz); + Field[] declaredFields = clazz.getDeclaredFields(); + for (Field field : declaredFields) { + if (field.isAnnotationPresent(Inject.class)) { + Object fieldInstance = getInstance(field.getType()); + + clazzImplementationInstance = createNewInstance(clazz); + field.setAccessible(true); + try { + 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 (instances.containsKey(clazz)) { + return instances.get(clazz); + } + try { + Constructor constructor = clazz.getConstructor(); + Object instance = constructor.newInstance(); + instances.put(clazz, instance); + return instance; + } catch (NoSuchMethodException | InvocationTargetException + | InstantiationException | IllegalAccessException e) { + throw new RuntimeException("Can`t create a instance of " + clazz.getName()); + } + } + + private void isComponentOfClazz(Class clazz) { + if (!clazz.isAnnotationPresent(Component.class)) { + throw new RuntimeException("You can`t create an instance of " + + clazz + ". Need @Component annotation"); + } + } + + private Class findImplementation(Class interfaceClazz) { + Map, Class> interfaceImplementations = new HashMap<>(); + interfaceImplementations.put(ProductService.class, ProductServiceImpl.class); + interfaceImplementations.put(FileReaderService.class, FileReaderServiceImpl.class); + interfaceImplementations.put(ProductParser.class, ProductParserImpl.class); + if (interfaceClazz.isInterface()) { + return interfaceImplementations.get(interfaceClazz); + } + return 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..8aa09f210 100644 --- a/src/main/java/mate.academy/service/impl/FileReaderServiceImpl.java +++ b/src/main/java/mate.academy/service/impl/FileReaderServiceImpl.java @@ -4,8 +4,11 @@ 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..a22de55e9 100644 --- a/src/main/java/mate.academy/service/impl/ProductParserImpl.java +++ b/src/main/java/mate.academy/service/impl/ProductParserImpl.java @@ -1,9 +1,12 @@ 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..cd5b094b5 100644 --- a/src/main/java/mate.academy/service/impl/ProductServiceImpl.java +++ b/src/main/java/mate.academy/service/impl/ProductServiceImpl.java @@ -2,13 +2,19 @@ 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