Java spring boot restcontroller not working

Question

I wrote simple java spring boot application code In the application, I have 3 class file

1. DemoApplication -- contains main method

2. Student class- POCO class contains following code

   package student;
   

   import java.time.LocalDate;

   public class Student {

   private Long id;
   private String name;
   private String email;
   private LocalDate dob;
   private int age;
   public Long getId() {
    return id;
   }
   public void setId(Long id) {
    this.id = id;
   }
   public String getName() {
    return name;
   }
   public void setName(String name) {
    this.name = name;
   }
   public String getEmail() {
    return email;
   }
   public void setEmail(String email) {
    this.email = email;
   }
   public LocalDate getDob() {
    return dob;
   }
   public void setDob(LocalDate dob) {
    this.dob = dob;
   }
   public int getAge() {
    return age;
   }
   public void setAge(int age) {
    this.age = age;
   }
   public Student(Long id, String name, String email, LocalDate dob, int age) {
    super();
    this.id = id;
    this.name = name;
    this.email = email;
    this.dob = dob;
    this.age = age;
   }
   @Override
   public String toString() {
    return "Student [id=" + id + ", name=" + name + ", email=" + email + ", dob=" + dob + ", age=" + age + "]";
   }
   

   }

3. StudentController class-- controller contains following code

   package student;

   import java.time.LocalDate; import java.util.List;

   import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController;

   @RestController @RequestMapping(path="/api/student") public class StudentController {

    @GetMapping(path="/all")
    public List<Student> getStudents()
    {
    return List.of(
    new Student(
    1L,
    "Yuvraj Meshram",
    "[email protected]",
    LocalDate.of(2001, 5, 6),
    21
    )
    );
    }
   

   }

If I run the application,it started without any error on localhost:8080, but when I hit the url "localhost:8080/api/student/all" , it show me error page "WhiteLabel Error Page".

My pom.xml contains following code

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <parent>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-parent</artifactId>
 <version>2.7.1</version>
 <relativePath/> <!-- lookup parent from repository -->
 </parent>
 <groupId>com.example</groupId>
 <artifactId>demo</artifactId>
 <version>0.0.1-SNAPSHOT</version>
 <name>demo</name>
 <description>Demo project for Spring Boot</description>
 <properties>
 <java.version>17</java.version>
 </properties>
 <dependencies>
 <!-- 
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-data-jpa</artifactId>
 </dependency>
 -->
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-web</artifactId>
 </dependency>
 <dependency>
 <groupId>org.postgresql</groupId>
 <artifactId>postgresql</artifactId>
 <scope>runtime</scope>
 </dependency>
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-test</artifactId>
 <scope>test</scope>
 </dependency>
 </dependencies>
 <build>
 <plugins>
 <plugin>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-maven-plugin</artifactId>
 </plugin>
 </plugins>
 </build>
</project>

Please help me with this guys.

• tgdavies: What http status code do you get?
• Harsh: Is your DemoApplication in a different package than of Controller's? If yes, Add @ComponentScan(basePackages={student}) on top of DemoApplication class and see if it works!
• vladtkachuk: Small recommendation: read about projectlombok.org and you won't need to write hundreds of lines of getters and setters, and some others
• YUVRAJ: Thanks @vladtkachuk for suggestion. I already know about it, but want to start from basic.

Answer 1

Try adding a @ComponentScan on top of your DemoApplication class. It is probably a package issue.