使用RestTemplate

配置bean注入的方式

@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);
        factory.setConnectTimeout(5000);
        return factory;
    }
}

配置拦截器

实现ClientHttpRequestInterceptor

public class HttpInterceptor implements ClientHttpRequestInterceptor {

    private Logger log = LoggerFactory.getLogger(HttpInterceptor.class);

    @Override
    public ClientHttpResponse intercept(HttpRequest request, byte[] body,
            ClientHttpRequestExecution execution) throws IOException {
        log.info("请求地址：{}", request.getURI());
        log.info("请求方法： {}", request.getMethod());
        log.info("请求内容：{}", new String(body));
        log.info("请求头：{}", request.getHeaders());
        return execution.execute(request, body);
    }
}

修改生成RestTemplate的bean,添加拦截器

    @Bean
    public RestTemplate restTemplate(ClientHttpRequestFactory factory) {
        RestTemplate restTemplate = new RestTemplate(factory);
        restTemplate.getInterceptors().add(new HttpInterceptor());
        return restTemplate;
    }

使用RestTemplate

RequestBean requestBean = new RequestBean();
        requestBean.setTest1("1");
        requestBean.setTest2("2");
        requestBean.setTest3("3");
        RestTemplate restTemplate = new RestTemplate();
        ResponseBean responseBean = restTemplate.postForObject(url, requestBean, ResponseBean.class);

返回的数据中带有泛型

上面的例子是普通的类型确定的返回值，通常我们请求接口是有一个固定的返回bean，会有一个泛型的data，RestTemplate需要知道泛型的类型(在Apache-HttpClient中是接收String的json字符串，然后用json序列化工具反序列化成特定类型)。RestTemplate提供了一个ParameterizedTypeReference可以解决这个问题。具体使用如下

        ResponseEntity<RequestModel<LoginResultDTO>> responseEntity = this.restTemplate
                .exchange(LOGIN_URL, HttpMethod.POST,
                        new HttpEntity<LoginRequestDTO>(login),
                        new ParameterizedTypeReference<RequestModel<LoginResultDTO>>() {
                        });