Java spring boot restcontroller不工作

Question

我写了简单的java spring boot应用程序代码在应用程序中，我有3个类文件

1. DemoApplication -- 包含 main 方法

2. 学生类- POCO 类包含以下代码

   package student;

   导入 java.time.LocalDate；

   公共课学生{

    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 类——控制器包含以下代码

   打包学生；

   导入 java.time.LocalDate； 导入 java.util.List；

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

   @RestController @RequestMapping(path="/api/student") 公共类 StudentController {

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

   }

如果我运行应用程序，它在 localhost:8080 上启动时没有任何错误，但是当我点击 url "localhost:8080/api/student/all" 时，它显示错误页面 "WhiteLabel Error Page"。

我的 pom.xml 包含以下代码

<?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>

请帮我解决这些问题。

Answer 1

尝试在您的 DemoApplication 类之上添加一个 @ComponentScan。 应该是包的问题。