+spring rest example

Java/spring/rest/src/main/java/com/example/rest/LoadDatabase.java

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+package myPackage;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import com.github.javafaker.Faker;
+
+@Configuration
+class LoadDatabase {
+
+  private static final Logger log = LoggerFactory.getLogger(LoadDatabase.class);
+
+  @Bean
+  CommandLineRunner initDatabase(StudentRepository repository) {
+
+    return args -> {
+		Faker faker =  new Faker();
+		for (int i = 0; i < 100; i++) {
+			log.info("Preloading " + repository.save(
+		  		new Student(
+					faker.name().firstName(),
+					faker.number().numberBetween(18, 22),
+					faker.number().numberBetween(0, 300))
+				)
+			);
+		}
+    };
+  }
+}

Java/spring/rest/src/main/java/com/example/rest/NOTES.txt

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+./
+├── LoadDatabase.java
+├── RestApplication.java
+├── StudentController.java
+├── Student.java
+└── StudentRepository.java

Java/spring/rest/src/main/java/com/example/rest/RestApplication.java

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+package myPackage;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class RestApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(RestApplication.class, args);
+	}
+
+}

Java/spring/rest/src/main/java/com/example/rest/Student.java

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+package myPackage;
+
+
+import java.util.Objects;
+
+import jakarta.persistence.*;
+
+@Entity
+public class Student {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+	public int age;
+	public String name;
+	public int credit;
+
+	public void setId(Long id){
+		this.id = id;
+	}
+
+	public Long getId(){
+		return this.id;
+	}
+
+	Student() {}
+	Student(String n, int a, int c) {
+		this.age = a;
+		this.credit = c;
+		this.name = n;
+	}
+
+	@Override
+	public String toString() {
+		return String.format("(Student){%s, %d, %d}", this.name, this.age, this.credit);
+	}
+}

Java/spring/rest/src/main/java/com/example/rest/StudentController.java

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+package myPackage;
+
+import java.util.List;
+
+import org.springframework.web.bind.annotation.*;
+
+@RestController
+class StudentController {
+
+  private final StudentRepository repository;
+
+  StudentController(StudentRepository repository) {
+    this.repository = repository;
+  }
+
+  @GetMapping("/students")
+  List<Student> all() {
+    return repository.findAll();
+  }
+  
+  @GetMapping("/students/{id}")
+  Student one(@PathVariable Long id) {
+    
+    return repository.findById(id).orElse(null);
+  }
+
+  @PostMapping("/students")
+  Student newStudent(@RequestBody Student newStudent) {
+    return repository.save(newStudent);
+  }
+
+  @PutMapping("/students/{id}")
+  Student replaceStudent(@RequestBody Student newStudent, @PathVariable Long id) {
+    
+    return repository.findById(id)
+      .map(student -> {
+        student.name = newStudent.name;
+        student.age = newStudent.age;
+        student.credit = newStudent.credit;
+        return repository.save(student);
+      })
+      .orElseGet(() -> {
+        newStudent.setId(id);
+        return repository.save(newStudent);
+      });
+  }
+
+  @DeleteMapping("/students/{id}")
+  void deleteStudent(@PathVariable Long id) {
+    repository.deleteById(id);
+  }
+}

Java/spring/rest/src/main/java/com/example/rest/StudentRepository.java

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+package myPackage;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+interface StudentRepository extends JpaRepository<Student, Long> {}

Java/spring/rest/src/main/resources/application.properties

@@ -0,0 +1 @@
+

Java/spring/rest/src/test/java/com/example/rest/RestApplicationTests.java

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+package com.example.rest;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class RestApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}