From caab99f7055e1b74891c344dcbdcf30c11df56cd Mon Sep 17 00:00:00 2001 From: Kristina Shpilchyna Date: Tue, 11 Jul 2023 21:48:09 +0200 Subject: [PATCH 1/2] implemented Injector --- src/main/java/mate.academy/lib/Component.java | 7 ++ src/main/java/mate.academy/lib/Inject.java | 4 ++ src/main/java/mate.academy/lib/Injector.java | 66 ++++++++++++++++++- .../service/impl/FileReaderServiceImpl.java | 2 + .../service/impl/ProductParserImpl.java | 2 + .../service/impl/ProductServiceImpl.java | 5 ++ 6 files changed, 85 insertions(+), 1 deletion(-) diff --git a/src/main/java/mate.academy/lib/Component.java b/src/main/java/mate.academy/lib/Component.java index c7e830420..0cf5e1cf7 100644 --- a/src/main/java/mate.academy/lib/Component.java +++ b/src/main/java/mate.academy/lib/Component.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.TYPE) 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..5ade41b90 100644 --- a/src/main/java/mate.academy/lib/Injector.java +++ b/src/main/java/mate.academy/lib/Injector.java @@ -1,13 +1,77 @@ 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 final Map, Object> instances = new HashMap<>(); + private final Map, Class> interfaceImplementations = Map.of( + FileReaderService.class, FileReaderServiceImpl.class, + ProductParser.class, ProductParserImpl.class, + ProductService.class, ProductServiceImpl.class); public static Injector getInjector() { return injector; } public Object getInstance(Class interfaceClazz) { - return null; + Class clazz = findImplementation(interfaceClazz); + Field[] declaredFields = clazz.getDeclaredFields(); + Object clazzImplementationInstance = null; + + if (!clazz.isAnnotationPresent(Component.class)) { + throw new RuntimeException("Can't create object. " + + "Class don't have annotation @Component " + "Class: " + clazz); + } + 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 (ReflectiveOperationException e) { + throw new RuntimeException("Can't create a new instance of " + clazz.getName()); + } + + } + + private Class findImplementation(Class interfaceClazz) { + 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..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 9fedfcf666c0476d814101f07a5e2c13000d424d Mon Sep 17 00:00:00 2001 From: Kristina Shpilchyna Date: Tue, 11 Jul 2023 21:51:38 +0200 Subject: [PATCH 2/2] added Target --- src/main/java/mate.academy/lib/Inject.java | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/main/java/mate.academy/lib/Inject.java b/src/main/java/mate.academy/lib/Inject.java index 32775efe1..ad8411675 100644 --- a/src/main/java/mate.academy/lib/Inject.java +++ b/src/main/java/mate.academy/lib/Inject.java @@ -1,9 +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 { }