RestTemplate 发送 get 请求使用误区 多个参数传值为null（转载）

首先看一下官方文档是怎么描述的，传递多个值的情况(注意例子中用到的@pathParam,一般要用@queryParam)

RestTemplate 实例

@Configuration
public class RestConfiguration {

    @Bean
    @ConditionalOnMissingBean({RestOperations.class, RestTemplate.class})
    public RestOperations restOperations() {
        SimpleClientHttpRequestFactory requestFactory = new SimpleClientHttpRequestFactory();
        requestFactory.setReadTimeout(5000);
        requestFactory.setConnectTimeout(5000);

        RestTemplate restTemplate = new RestTemplate(requestFactory);

        // 使用 utf-8 编码集的 conver 替换默认的 conver（默认的 string conver 的编码集为 "ISO-8859-1"）
        List<HttpMessageConverter<?>> messageConverters = restTemplate.getMessageConverters();
        Iterator<HttpMessageConverter<?>> iterator = messageConverters.iterator();
        while (iterator.hasNext()) {
            HttpMessageConverter<?> converter = iterator.next();
            if (converter instanceof StringHttpMessageConverter) {
                iterator.remove();
            }
        }
        messageConverters.add(new StringHttpMessageConverter(Charset.forName("UTF-8")));

        return restTemplate;
    }

}

---

请求地址

get 请求 url 为

http://localhost:8080/test/sendSms?phone=手机号&msg=短信内容

---

错误使用

@Autowired
private RestOperations restOperations;

public void test() throws Exception{
    String url = "http://localhost:8080/test/sendSms";

    Map<String, Object> uriVariables = new HashMap<String, Object>();
    uriVariables.put("phone", "151xxxxxxxx");
    uriVariables.put("msg", "测试短信内容");

    String result = restOperations.getForObject(url, String.class, uriVariables);
}

服务器接收的时候你会发现，接收的该请求时没有参数的

---

正确使用

@Autowired
private RestOperations restOperations;

public void test() throws Exception{
    String url = "http://localhost:8080/test/sendSms?phone={phone}&msg={phone}";

    Map<String, Object> uriVariables = new HashMap<String, Object>();
    uriVariables.put("phone", "151xxxxxxxx");
    uriVariables.put("msg", "测试短信内容");

    String result = restOperations.getForObject(url, String.class, uriVariables);
}

等价于

@Autowired
private RestOperations restOperations;

public void test() throws Exception{
    String url = "http://localhost:8080/test/sendSms?phone={phone}&msg={phone}";

    String result = restOperations.getForObject(url, String.class,  "151xxxxxxxx", "测试短信内容");
}