Spring http服务远程调用实现过程解析

脚本专栏 2024/11/8 佚名

3 2 1

最近公司有个新的需求，写了一个接口，想要把服务暴露出去，但是这个服务所在的进程是非web项目，（可以理解成schedule/batch等进程项目），所以没有tomcat等容器，而且只有这一个服务，无论是加dubbo服务还是加tomcat等容器都显得复杂了。那么应该如何将服务暴露出去？

经过网上搜索后，最终解决问题，记录在此。

为了快速搭建，使用springboot来搭建项目：

项目结构如图：

首先需要创建一个接口，服务的提供者和服务的调用方都依赖这个模块。

package com.xiazhi.spring.service.api;

import com.sun.istack.internal.NotNull;
import com.sun.istack.internal.Nullable;

/**
 * @author 赵帅
 * @date 2020/6/8
 */
public interface IUserService {

  /**
   * 获取姓名
   * @return 姓名
   */
  String getName();

  /**
   * 根据姓名获取年龄
   * @param name 姓名
   * @return 年龄
   */
  @NotNull
  Integer getAge(@Nullable String name);
}

然后在service模块中，实现接口作为服务的提供方，需要依赖的jar包有：

<dependencies>
    <dependency>
      <groupId>com.xiazhi</groupId>
      <artifactId>spring-service-api</artifactId>
      <version>${project.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
      <exclusions>
        <exclusion>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-tomcat</artifactId>
        </exclusion>
      </exclusions>
    </dependency>

    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>servlet-api</artifactId>
      <version>2.5</version>
    </dependency>
  </dependencies>

配置文件需要加上：

spring.main.web-application-type=none

实现接口：

package com.xiazhi.spring.service.impl;

import com.sun.istack.internal.NotNull;
import com.sun.istack.internal.Nullable;
import com.xiazhi.spring.service.api.IUserService;
import org.springframework.stereotype.Service;

/**
 * @author 赵帅
 * @date 2020/6/8
 */
@Service
public class UserServiceImpl implements IUserService {

  @Override
  public String getName() {
    return "张一";
  }

  @Override
  @NotNull
  public Integer getAge(@Nullable String name) {
    if ("".equals(name)) {
      return 10;
    }
    return 18;
  }
}

暴露服务：

package com.xiazhi.spring.service.config;

import com.sun.net.httpserver.HttpHandler;
import com.xiazhi.spring.service.api.IUserService;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.task.TaskExecutor;
import org.springframework.remoting.httpinvoker.SimpleHttpInvokerServiceExporter;
import org.springframework.remoting.support.SimpleHttpServerFactoryBean;

import java.util.HashMap;
import java.util.Map;

/**
 * @author 赵帅
 * @date 2020/6/8
 */
@Configuration
public class HttpInvokerConfiguration {

  private final IUserService userService;
  private final TaskExecutor taskExecutor;

  public HttpInvokerConfiguration(IUserService userService, TaskExecutor taskExecutor) {
    this.userService = userService;
    this.taskExecutor = taskExecutor;
  }

  /**
   * 将IUserService服务暴露出去
   */
  @Bean
  public SimpleHttpInvokerServiceExporter serviceExporter() {
    SimpleHttpInvokerServiceExporter exporter = new SimpleHttpInvokerServiceExporter();
    exporter.setService(userService);
    exporter.setServiceInterface(IUserService.class);
    return exporter;
  }

  /**
   * 为暴露的服务启用http服务
   * @return httpServer工厂类
   */
  @Bean
  public SimpleHttpServerFactoryBean serverFactoryBean() {
    SimpleHttpServerFactoryBean factoryBean = new SimpleHttpServerFactoryBean();
    Map<String, HttpHandler> map = new HashMap<>(2);
    factoryBean.setContexts(map);
    factoryBean.setPort(9999);
    factoryBean.setExecutor(taskExecutor);
    return factoryBean;
  }
}

启动服务。

然后是服务的调用方，依赖有：

<dependencies>
    <dependency>
      <groupId>com.xiazhi</groupId>
      <artifactId>spring-service-api</artifactId>
      <version>${project.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
  </dependencies>

配置文件：

package com.xiazhi.spring.config;

import com.xiazhi.spring.service.api.IUserService;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.remoting.httpinvoker.HttpInvokerProxyFactoryBean;

/**
 * @author 赵帅
 * @date 2020/6/8
 */
@Configuration
public class HttpServiceConfiguration {

  /**
   * 使用http代理工厂调用服务
   * @return http代理工厂创建代理对象
   */
  @Bean
  public HttpInvokerProxyFactoryBean httpInvokerProxyFactoryBean() {
    HttpInvokerProxyFactoryBean factoryBean = new HttpInvokerProxyFactoryBean();
    factoryBean.setServiceUrl("http://localhost:9999/userService");
    factoryBean.setServiceInterface(IUserService.class);
    return factoryBean;
  }
}

使用接口，调用方法：

package com.xiazhi.spring.controller;

import com.xiazhi.spring.service.api.IUserService;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author 赵帅
 * @date 2020/6/8
 */
@RestController
public class UserController {

  private final IUserService userService;

  public UserController(IUserService userService) {
    this.userService = userService;
  }

  @GetMapping("/test")
  public String test() {
    String name = userService.getName();
    Integer age = userService.getAge(null);
    System.out.println(String.format("姓名：[%s],age:[%s]", name, age));
    return name;
  }
}

运行，调用test路径测试调用结果。

项目完整结构：