Spring Boot 应用程序成功运行，但在尝试获取 POST 请求的响应时，在 Postman 中找不到 404

Question

我是 Spring Boot 新手。我正在尝试为员工管理系统创建我的第一个 CRUD 应用程序。应用程序运行成功，但是当我尝试在 Postman 中获取 POST 请求的响应时，收到 404 not found。

目前没有编译错误。

以下是我的控制器类：

package com.cts.Employee.controller;

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.cts.Employee.model.EmployeeModel;
import com.cts.Employee.service.EmployeeService;

@RestController
@RequestMapping("/api/employees")
public class EmployeeController {
    
    private EmployeeService employeeService;

    public EmployeeController(EmployeeService employeeService) {
        super();
        this.employeeService = employeeService;
    }
    
    // build create employee REST API
    @PostMapping()
    public ResponseEntity<EmployeeModel> saveEmployee(@RequestBody EmployeeModel employee){
        return new ResponseEntity<EmployeeModel>(employeeService.saveEmployee(employee), HttpStatus.CREATED);
    }

}

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 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>2.2.7.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.cts</groupId>
    <artifactId>Employee</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>Employeemanagement</name>
    <description>Employee Management using 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.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.1-api</artifactId>
            <version>1.0.0.Final</version>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.33</version>
            <scope>runtime</scope>
        
        </dependency>
        
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </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>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

application.properties 文件：

spring.datasource.url=jdbc:mysql://localhost:3306/emp
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=Sunetra@26

# Hibernate properties
#spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect
# create, create-drop
spring.jpa.hibernate.ddl-auto=update

我的模特班：

package com.cts.Employee.model;

import javax.persistence.Entity;
import javax.persistence.Column;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

import lombok.Data;

@Data
@Entity
@Table(name="employees")
public class EmployeeModel {
    
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;
    
    @Column(name = "first_name", nullable = false)
    private String firstName;
    
    @Column(name = "last_name")
    private String lastName;
    
    @Column(name="address")
    private String address;
    
}

我的服务界面：

package com.cts.Employee.service;

import com.cts.Employee.model.EmployeeModel;

public interface EmployeeService {
    
    EmployeeModel saveEmployee(EmployeeModel employee);

}

我的serviceimp类：

package com.cts.Employee.service.impl;

import org.springframework.stereotype.Service;

import com.cts.Employee.service.EmployeeService;
import com.cts.Employee.model.EmployeeModel;
import com.cts.Employee.repository.EmployeeRepository;

@Service
public class EmployeeServiceImpl implements EmployeeService{

    private EmployeeRepository employeeRepository;
    
    public EmployeeServiceImpl(EmployeeRepository employeeRepository) {
        super();
        this.employeeRepository = employeeRepository;
    }
    
    @Override
    public EmployeeModel saveEmployee(EmployeeModel employee) {
        return employeeRepository.save(employee);
    }
}

邮递员发帖请求网址：

http://localhost:8080/api/employees

邮递员请求正文：

{
    "firstName": "learning",
    "lastName":"geek",
    "address":"anywhere"
}

邮递员回复正文：

{
    "timestamp": "2023-09-30T13:58:12.254+0000",
    "status": 404,
    "error": "Not Found",
    "message": "No message available",
    "path": "/api/employees"
}

我不明白我需要做出哪些改变才能获得期望的结果。

预期结果是：

{
    "id":1,
    "firstName": "learning",
    "lastName":"geek",
    "address":"anywhere"
}

如何解决这个问题？

Answer 1

您应该在控制器方法上放置

@PostMspping

注释以映射到特定端点。像这样

@PostMapping
public ResponseEntity<EmployeeModel> saveEmployee(@RequestBody EmployeeModel employee)
    

---

要了解 Spring 中的请求映射，请阅读 文档：