Finished the homework

.gitignore

+**/target/

ClearDatabase.sh

+mongosh --file RemoveStudentsCollection.js

README.md

+### Project Structure
+
+ClearDatabase.sh (clear student_db manually although the code clear it before it starts running)
+README.md (This File !!!)
+RemoveStudentsCollection.js (file used by ClearDatabase.sh can be ignored)
+Report (report for this project pdf file)
+SpringMongo (java commandline project (not web) using springboot and mongodb)
+
+
+### Before running make sure mongodb is running using the following command
+
+``` sudo systemctl status mongod ```
+
+check mongodb port 
+``` nmap localhost -p- ```
+or 
+``` sudo ss --tunlp ```

RemoveStudentsCollection.js

+
+
+db = db.getSiblingDB('student_db');
+
+db.students.drop();

SpringMongo/.vscode/settings.json

+{
+    "snyk.advanced.autoSelectOrganization": true
+}
\ No newline at end of file

SpringMongo/pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.mongo</groupId>
+    <artifactId>SpringMongo</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <!-- 1. Add Spring Boot Parent -->
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>3.2.0</version>
+        <relativePath/> 
+    </parent>
+
+    <properties>
+        <java.version>17</java.version>
+    </properties>
+
+    <dependencies>
+        <!-- 2. Spring Data MongoDB Starter -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-mongodb</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <!-- 3. Spring Boot Build Plugin -->
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+</project>
\ No newline at end of file

SpringMongo/src/main/java/com/mongo/App.java

+package com.mongo;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.data.mongodb.core.query.Criteria;
+import org.springframework.data.mongodb.core.query.Query;
+import org.springframework.util.StopWatch;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Stream;
+
+@SpringBootApplication
+public class App implements CommandLineRunner {
+
+    @Autowired
+    private MongoTemplate mongoTemplate;
+
+    public static void main(String[] args) {
+        SpringApplication.run(App.class, args);
+    }
+
+    @Override
+    public void run(String... args) {
+        // Configuration
+        int totalRecords = 2_000_000;
+        int batchSize = 10_000;
+
+        // Clean database before starting 
+        mongoTemplate.dropCollection(Student.class);
+
+        // Run Tests
+        performWriteTest(totalRecords, batchSize);
+        performReadTest();
+    }
+
+    /**
+     * Measures batch write performance for 1 million records
+     */
+    private void performWriteTest(int totalRecords, int batchSize) {
+        System.out.println("\n STARTING WRITE BENCHMARK ");
+        StopWatch watch = new StopWatch();
+        watch.start();
+
+        for (int i = 0; i < totalRecords / batchSize; i++) {
+            List<Student> batch = new ArrayList<>();
+            for (int j = 0; j < batchSize; j++) {
+                
+                batch.add(new Student("Student_" + (i * batchSize + j), "ID_" + (i * batchSize + j)));
+            }
+            //insert here is faster than save() because we don't worry about duplication here
+            mongoTemplate.insert(batch, Student.class);
+        }
+
+        watch.stop();
+        System.out.printf("WRITE COMPLETE: %d records in %.2f seconds (%d ops/sec)%n", 
+                totalRecords, watch.getTotalTimeSeconds(), (int)(totalRecords / watch.getTotalTimeSeconds()));
+    }
+
+    /**
+     * Measures smart read performance (Indexed vs Streaming)
+     */
+    private void performReadTest() {
+        System.out.println("\n STARTING SMART READ BENCHMARK ");
+
+        
+        // We pick a random ID from the middle of the set
+        String searchId = "ID_543210"; 
+        StopWatch pointWatch = new StopWatch();
+        pointWatch.start();
+
+        Query query = new Query(Criteria.where("studentId").is(searchId));
+        Student found = mongoTemplate.findOne(query, Student.class);
+
+        pointWatch.stop();
+        System.out.println("1. POINT READ (Indexed Search):");
+        System.out.println("   - Found: " + found);
+        System.out.println("   - Time: " + pointWatch.getTotalTimeMillis() + " ms");
+
+        //  Full Stream Read (Testing Retrieval Speed without crashing RAM)
+        StopWatch streamWatch = new StopWatch();
+        streamWatch.start();
+        
+        long count = 0;
+        // Using Stream ensures we don't load 1M objects into RAM at once
+        try (Stream<Student> studentStream = mongoTemplate.stream(new Query(), Student.class)) {
+            count = studentStream.count();
+        }
+
+        streamWatch.stop();
+        System.out.println("2. STREAM READ (Full Collection Scan):");
+        System.out.println("   - Processed: " + count + " records");
+        System.out.println("   - Time: " + streamWatch.getTotalTimeSeconds() + " seconds");
+    }
+}
\ No newline at end of file

SpringMongo/src/main/java/com/mongo/Student.java

+package com.mongo;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.index.Indexed;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+@Document(collection = "students")
+public class Student {
+    @Id
+    private String id;
+    private String name;
+
+    @Indexed 
+    private String studentId;
+
+    public Student(String name, String studentId) {
+        this.name = name;
+        this.studentId = studentId;
+    }
+    
+   
+    public String getStudentId() { return studentId; }
+
+    @Override
+    public String toString() {
+        return "Student{name='" + name + "', studentId='" + studentId + "'}";
+    }
+}
\ No newline at end of file

SpringMongo/src/main/resources/application.properties

+# Connect to localhost on default port and use student_db
+spring.data.mongodb.uri=mongodb://localhost:27017/student_db
+
+# Optional: This shows the actual Mongo queries in your console for debugging
+#logging.level.org.springframework.data.mongodb.core.MongoTemplate=DEBUG

SpringMongo/src/test/java/com/mongo/AppTest.java

+package com.mongo;
+
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * Unit test for simple App.
+ */
+public class AppTest {
+
+    @Test
+    public void shouldAnswerWithTrue() {
+        assertTrue(true);
+    }
+}