前言

本节内容我们主要介绍一下web访问的另一种形式，通过函数式web实现一个restful风格的http请求案例。函数式web是spring5.2之后的一个新特性，可以通过函数去定义web请求的处理流程，使得代码更为简洁，耦合性也降低了。

正文

函数式web的四大核心对象

RouterFunction：定义路由信息

RequestPredicates：定义请求规则，包括请求参数、请求方式等

ServerRequest：封装请求参数

ServerResponse：封装响应参数

定义一个函数式web的路由组件WebFunctionConfig配置类

实现代码

package com.yundi.isbc.config;

import com.yundi.isbc.handler.PersonHandlerService;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.web.servlet.function.RequestPredicates;
import org.springframework.web.servlet.function.RouterFunction;
import org.springframework.web.servlet.function.RouterFunctions;
import org.springframework.web.servlet.function.ServerResponse;

@Configuration
public class WebFunctionConfig {
  /**
   * 用户信息管理
   *
   * @param personHandlerService
   * @return
   */
  @Bean
  public RouterFunction<ServerResponse> personRouter(PersonHandlerService personHandlerService) {
      RouterFunction<ServerResponse> personRouterFunction = RouterFunctions.route()
              .GET("/person/{id}", RequestPredicates.accept(MediaType.ALL), personHandlerService::getPerson)
              .GET("/persons", personHandlerService::getPersons)
              .POST("/person", RequestPredicates.accept(MediaType.APPLICATION_JSON), personHandlerService::savePerson)
              .PUT("/person", RequestPredicates.accept(MediaType.APPLICATION_JSON), personHandlerService::updatePerson)
              .DELETE("/person/{id}", personHandlerService::deletePerson)
              .build();
      return personRouterFunction;
  }
}
在该类中实现了restful风格的请求完成用户管理功能的开发

用户person对象的实体类

用户Person类

package com.yundi.isbc.entity;

import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;
import lombok.Data;
import lombok.experimental.Accessors;

import java.util.ArrayList;
import java.util.List;

@Accessors(chain = true)
@Data
public class Person {
/**
* id
*/
private String id;
  /**
   * 名称
   */
  private String name;

  /**
   * 年龄
   */
  private Integer age;

  /**
   * 手机号
   */
  private String phone;

  /**
   * 住址
   */
  private List<Address> addresses = new ArrayList<>();
}
用户地址类

package com.yundi.isbc.entity;

import lombok.Data;
import lombok.experimental.Accessors;

@Accessors(chain = true)
@Data
public class Address {
/**
* 地址名称
*/
private String addressName;
}

定义业务实现接口PersonHandlerService

实现代码

package com.yundi.isbc.handler;

import jakarta.servlet.ServletException;
import org.springframework.web.servlet.function.ServerRequest;
import org.springframework.web.servlet.function.ServerResponse;

import java.io.IOException;

public interface PersonHandlerService {
/**
* 根据id获取用户信息
*
* @param serverRequest
* @return
*/
ServerResponse getPerson(ServerRequest serverRequest);
  /**
   * 获取全部用户
   * @param serverRequest
   * @return
   */
  ServerResponse getPersons(ServerRequest serverRequest);

  /**
   * 保存用户
   * @param serverRequest
   * @return
   */
  ServerResponse savePerson(ServerRequest serverRequest) throws ServletException, IOException;

  /**
   * 更新用户信息
   * @param serverRequest
   * @return
   */
  ServerResponse updatePerson(ServerRequest serverRequest) throws ServletException, IOException;

  /**
   * 删除用户
   * @param serverRequest
   * @return
   */
  ServerResponse deletePerson(ServerRequest serverRequest);
}
定义各功能业务实现接口方法

定义业务实现类PersonHandlerServiceImpl

实现代码

package com.yundi.isbc.handler.impl;

import com.yundi.isbc.entity.Address;
import com.yundi.isbc.entity.Person;
import com.yundi.isbc.handler.PersonHandlerService;
import jakarta.servlet.ServletException;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.web.servlet.function.ServerRequest;
import org.springframework.web.servlet.function.ServerResponse;

import java.io.IOException;
import java.util.Arrays;

@Slf4j
@Service
public class PersonHandlerServiceImpl implements PersonHandlerService {

  @Override
  public ServerResponse getPerson(ServerRequest serverRequest) {
      log.info("==================获取用户信息==================");
      String id = serverRequest.pathVariable("id");
      log.info("用户id:{}", id);
      return ServerResponse
              .ok()
              .body(new Person()
                      .setId("1")
                      .setName("xiaoming")
                      .setAge(18)
                      .setPhone("18288474612")
                      .setAddresses(Arrays.asList(new Address().setAddressName("北京市朝阳区"))));
  }

  @Override
  public ServerResponse getPersons(ServerRequest serverRequest) {
      log.info("==================获取全部用户信息==================");
      return ServerResponse
              .ok()
              .body(Arrays.asList(new Person()
                      .setId("1")
                      .setName("xiaoming")
                      .setAge(18)
                      .setPhone("18288474612")
                      .setAddresses(Arrays.asList(new Address().setAddressName("北京市朝阳区")))));
  }

  @Override
  public ServerResponse savePerson(ServerRequest serverRequest) throws ServletException, IOException {
      log.info("==================保存用户信息==================");
      Person person = serverRequest.body(Person.class);
      log.info("用户信息：{}", person);
      return ServerResponse.ok().build();
  }

  @Override
  public ServerResponse updatePerson(ServerRequest serverRequest) throws ServletException, IOException {
      log.info("==================更新用户信息==================");
      Person person = serverRequest.body(Person.class);
      log.info("用户信息：{}", person);
      return ServerResponse.ok().build();
  }

  @Override
  public ServerResponse deletePerson(ServerRequest serverRequest) {
      log.info("==================删除用户信息==================");
      String id = serverRequest.pathVariable("id");
      log.info("用户id:{}", id);
      return ServerResponse.ok().build();
  }

}