SpringBoot使用RestTemplate发起http请求

依赖

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

简易配置

@Configuration
public class RestTemplateConfig {
    @Bean
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

使用到的json输出工具类

public class JsonUtil {
    /**
     * 美化输出
     */
    public static void prettyPrint(Object obj) {
        ObjectMapper objectMapper = new ObjectMapper();

        try {
            String json = objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(obj);
            System.out.println(json);
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
    }
}

发起GET请求

@Autowired
private RestTemplate restTemplate;

@Test
void get() {
    String url = "https://httpbin.org/get";
    Object result = restTemplate.getForObject(url, Object.class);
    JsonUtil.prettyPrint(result);
}

输出结果

{
  "args" : { },
  "headers" : {
    "Accept" : "application/json, application/*+json",
    "Host" : "httpbin.org",
    "User-Agent" : "Java/1.8.0_361",
    "X-Amzn-Trace-Id" : "Root=1-667ba9cc-14747a9c186d63e3726b4411"
  },
  "origin" : "61.48.42.110",
  "url" : "https://httpbin.org/get"
}

详细配置

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

    @Bean
    public ClientHttpRequestFactory simpleClientHttpRequestFactory() {
        SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();

        // 连接超时时间
        factory.setConnectTimeout(150 * 1000); // 150s
        // 数据读取超时时间
        factory.setReadTimeout(150 * 1000); // 150s
        return factory;
    }
}

GET请求

可以替换url上的变量

String url = "https://httpbin.org/get?name={name}&age={age}";

Map<String, Object> params = new HashMap<>();
params.put("name", "Tom");
params.put("age", 18);

Object result = restTemplate.getForObject(url, Object.class, params);
JsonUtil.prettyPrint(result);

输出结果

{
  "args" : {
    "age" : "18",
    "name" : "Tom"
  },
  "headers" : {
    "Accept" : "application/json, application/*+json",
    "Host" : "httpbin.org",
    "User-Agent" : "Java/1.8.0_361",
    "X-Amzn-Trace-Id" : "Root=1-667bae21-22fba9c27d6e844a13c3da48"
  },
  "origin" : "1.202.253.34",
  "url" : "https://httpbin.org/get?name=Tom&age=18"
}

POST请求

String url = "https://httpbin.org/post";

Map<String, Object> form = new HashMap<>();
form.put("name", "Tom");
form.put("age", 18);

Object result = restTemplate.postForObject(url, form, Object.class);
JsonUtil.prettyPrint(result);

输出结果

{
  "args" : { },
  "data" : "{\"name\":\"Tom\",\"age\":18}",
  "files" : { },
  "form" : { },
  "headers" : {
    "Accept" : "application/json, application/*+json",
    "Content-Length" : "23",
    "Content-Type" : "application/json",
    "Host" : "httpbin.org",
    "User-Agent" : "Java/1.8.0_361",
    "X-Amzn-Trace-Id" : "Root=1-667bae9e-7b8e49815c7afb9f5019b5a4"
  },
  "json" : {
    "age" : 18,
    "name" : "Tom"
  },
  "origin" : "1.202.253.34",
  "url" : "https://httpbin.org/post"
}

参考文章

1. Springboot之restTemplate配置及使用