docs(06-annotations): Добавлено задание в README

labs/06-annotations/app/build.gradle.kts

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+/*
+ * This file was generated by the Gradle 'init' task.
+ *
+ * This generated file contains a sample Java application project to get you started.
+ * For more details on building Java & JVM projects, please refer to https://docs.gradle.org/8.10.2/userguide/building_java_projects.html in the Gradle documentation.
+ */
+
+plugins {
+    // Apply the application plugin to add support for building a CLI application in Java.
+    application
+}
+
+repositories {
+    // Use Maven Central for resolving dependencies.
+    mavenCentral()
+}
+
+dependencies {
+    // This dependency is used by the application.
+    implementation(libs.guava)
+}
+
+// Apply a specific Java toolchain to ease working on different environments.
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(23)
+    }
+}
+
+application {
+    // Define the main class for the application.
+    mainClass = "ru.mrqiz.annotations.App"
+}
+
+tasks.named<Test>("test") {
+    // Use JUnit Platform for unit tests.
+    useJUnitPlatform()
+}
+
+tasks.named<JavaExec>("run") {
+   standardInput = System.`in`
+}
+

labs/06-annotations/app/src/main/java/ru/mrqiz/annotations/App.java

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+package ru.mrqiz.annotations;
+
+public class App {
+    public static void main(String[] args) {
+        Data dataToSave = new Data(10, 20, 30, 40, 50);
+        SaveData saveData = new SaveData("/tmp/data.json", "/tmp/save.log");
+        saveData.save(dataToSave);
+    }
+}
+

labs/06-annotations/app/src/main/java/ru/mrqiz/annotations/Data.java

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+package ru.mrqiz.annotations;
+
+public class Data {
+    @Ok
+    private Integer field1;
+
+    @Ok
+    private Integer field2;
+
+    @Ugly(k = 10)
+    private Integer field3;
+
+    @Ugly
+    private Integer field4;
+
+    private Integer field5;
+
+    public Data(
+        Integer field1,
+        Integer field2,
+        Integer field3,
+        Integer field4,
+        Integer field5
+      ) {
+        this.field1 = field1;
+        this.field2 = field2;
+        this.field3 = field3;
+        this.field4 = field4;
+        this.field5 = field5;
+    }
+
+    public Integer getField1() {
+        return field1;
+    }
+
+    public Integer getField2() {
+        return field2;
+    }
+
+    public Integer getField3() {
+        return field3;
+    }
+
+    public Integer getField4() {
+        return field4;
+    }
+
+    public Integer getField5() {
+        return field5;
+    }
+}
+

labs/06-annotations/app/src/main/java/ru/mrqiz/annotations/Ok.java

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+package ru.mrqiz.annotations;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.lang.annotation.ElementType;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface Ok {
+}
+

labs/06-annotations/app/src/main/java/ru/mrqiz/annotations/SaveData.java

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+package ru.mrqiz.annotations;
+
+import java.io.BufferedWriter;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.lang.reflect.Field;
+import java.util.Random;
+import java.util.logging.Logger;
+import java.io.IOException;
+import java.util.logging.FileHandler;
+import java.util.logging.Logger;
+import java.util.logging.SimpleFormatter;
+
+public class SaveData {
+    private static final Logger logger = Logger.getLogger(SaveData.class.getName());
+
+    private String logFileName;
+    private String dataFileName;
+
+    public SaveData(String dataFileName, String logFileName) {
+        this.logFileName = logFileName;
+        this.dataFileName = dataFileName;
+        setupLogger();
+    }
+
+    private void setupLogger() {
+        try {
+            FileHandler fileHandler = new FileHandler(logFileName, true);
+            fileHandler.setFormatter(new SimpleFormatter());
+            logger.addHandler(fileHandler);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public void save(Data data) {
+        StringBuilder jsonBuilder = new StringBuilder();
+        jsonBuilder.append("{\n");
+
+        boolean hasOkFields = false;
+
+        Field[] fields = data.getClass().getDeclaredFields();
+        Random random = new Random();
+
+        for (Field field : fields) {
+            field.setAccessible(true);
+            try {
+                if (field.isAnnotationPresent(Ok.class)) {
+                    hasOkFields = true;
+                    jsonBuilder.append(String.format("    \"%s\": \"%d\",\n", field.getName(), field.get(data)));
+                } else if (field.isAnnotationPresent(Ugly.class)) {
+                    hasOkFields = true;
+                    Ugly uglyAnnotation = field.getAnnotation(Ugly.class);
+                    int k = uglyAnnotation.k();
+                    int randomValue = random.nextInt(2 * k + 1) - k;
+                    jsonBuilder.append(String.format("    \"%s\": \"%d\",\n", field.getName(), randomValue));
+                } else {
+                    logger.warning("cant find annotations at '" + field.getName() + "', not writing in file.");
+                }
+            } catch (IllegalAccessException e) {
+                logger.severe("unable to get access to field: " + e.getMessage());
+            }
+        }
+
+        if (hasOkFields) {
+            jsonBuilder.setLength(jsonBuilder.length() - 2);
+            jsonBuilder.append("\n}");
+            writeToFile(jsonBuilder.toString());
+        }
+    }
+
+    private void writeToFile(String json) {
+        try (BufferedWriter writer = new BufferedWriter(new FileWriter(dataFileName))) {
+            writer.write(json);
+        } catch (IOException e) {
+            logger.severe("unable to read to file: " + e.getMessage());
+        }
+    }
+}
+

labs/06-annotations/app/src/main/java/ru/mrqiz/annotations/Ugly.java

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+package ru.mrqiz.annotations;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.lang.annotation.ElementType;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface Ugly {
+    int k() default 5;
+}
+