Java知识体系

Appearance

通过RestTemplate进行远程调用

RestTemplate 是从 Spring3.0 开始支持的一个 HTTP 请求工具，它提供了常见的REST请求方案的模版。对于远程请求进行了一定封装，从而通过建议配置可以实现远程调用。

他底层用的是 JDK 的 HTTP 请求

  1. 添加依赖
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-web</artifactId>
    <version>5.2.2.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.7</version>
</dependency>
  1. 配置类
package com.example.demo.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;

/**
 * RestTemplate配置类
 */
@Configuration
public class RestTemplateConfig {

    @Bean
    public RestTemplate restTemplate(ClientHttpRequestFactory factory){
        return new RestTemplate(factory);
    }

    @Bean
    public ClientHttpRequestFactory simpleClientHttpRequestFactory(){
        SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
        factory.setReadTimeout(5000);//单位为ms
        factory.setConnectTimeout(5000);//单位为ms
        return factory;
    }
}
  1. 示例调用操作
@RestController
@Slf4j
public class OrderController {

    public static final String PAYMENT_URL = "http://localhost:8001";

    @Resource
    private RestTemplate restTemplate;

    //因为浏览器只支持get请求，为了方便这里就用get
    @GetMapping("/consumer/payment/create")
    public CommonResult<Payment> create(Payment payment){
        log.info("********插入的数据：" + payment);
        //postForObject分别有三个参数：请求地址，请求参数，返回的对象类型
        return restTemplate.postForObject(PAYMENT_URL + "/payment/create", payment, CommonResult.class);
    }

    @GetMapping("/consumer/payment/get/{id}")
    public CommonResult<Payment> getPayment(@PathVariable("id") Long id){
        log.info("********查询的id：" + id);
        //getForObject两个参数：请求地址，返回的对象类型
        return restTemplate.getForObject(PAYMENT_URL + "/payment/get/" + id, CommonResult.class);
    }
}

参考