RestTemplate的学习使用-蒲公英云

RestTemplate的学习使用

以你之姓@ 2023-09-23 22:57 96阅读 0赞

引言

最近的项目需求中有使用到后端发送http请求，在网上寻找资料后发现可以使用spring自带的RestTemplate类实现，故作此记录

项目使用

将下述代码引入spring容器中（RestTemplate是spring自带的发送http请求的类）

@Bean
public RestTemplate restTemplate(ClientHttpRequestFactory factory) {
    RestTemplate restTemplate = new RestTemplate(factory);
    return restTemplate;
}
@Bean
public ClientHttpRequestFactory simpleClientHttpRequestFactory() {
    SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
    factory.setReadTimeout(5000);
    factory.setConnectTimeout(15000);
    // 设置代理
    //factory.setProxy(null);
    return factory;
}

在需要使用的类中直接引入即可

@Autowired
private RestTemplate restTemplate;

代码示例

这里简单示例下post请求，如果又其它需求的可以去搜索一下其它文章

**注意：**发送的post的传参的类型一定要是LinkedMultiValueMap（不能使用jsonobject），否则会报找不到数据的错误
```
@GetMapping("send")
public String testPost(@RequestParam("code") Integer code){
```

        String url = "http://localhost:8888/oauth/return";
        LinkedMultiValueMap<String, Object> stringObjectLinkedMultiValueMap = new LinkedMultiValueMap<>();
        stringObjectLinkedMultiValueMap.set("code",code);
        HttpEntity<LinkedMultiValueMap<String, Object>> jsonObjectHttpEntity = new HttpEntity<>(stringObjectLinkedMultiValueMap);
        ResponseEntity<String> stringResponseEntity = restTemplate.postForEntity(url, jsonObjectHttpEntity, String.class);
        String body = stringResponseEntity.getBody();
        return body;
    }
    @PostMapping("return")
    public String returnPost(@RequestParam Integer code){
        return "哈首府帕斯发";
    }

踩坑记录

发送POST请求传参的问题

如下代码，如果使用jsonobject来装载数据发送post请求是会报错的，只能使用LinkedMultiValueMap

@GetMapping("keycloak/getToken")
public String keycloakGetToken(@RequestParam Map<String,String> map){
    //String code = requestObj.getString("code");
    String url = "http://localhost:8081/auth/realms/myRealm/protocol/openid-connect/token";
    String code = map.get("code");
    System.out.println("传进来的code："+code);
    //HttpHeaders headers = new HttpHeaders();
    //JSONObject jsonObject = new JSONObject();
    //jsonObject.put("grant_type","authorization_code");
    //jsonObject.put("code",code);
    //jsonObject.put("client_id","myclient");
    //jsonObject.put("client_secret","LsvDoZ5g0BQhRDR9ydYqV9tjal8YDeAI");
    //jsonObject.put("scope","openid");
    //jsonObject.put("redirect_uri","http://localhost:8888/oauth/keycloak/getToken");
    //HttpEntity<JSONObject> jsonObjectHttpEntity = new HttpEntity<>(jsonObject,headers);
    LinkedMultiValueMap<String, Object> stringObjectLinkedMultiValueMap = new LinkedMultiValueMap<>();
    stringObjectLinkedMultiValueMap.set("grant_type","authorization_code");
    stringObjectLinkedMultiValueMap.set("code",code);
    stringObjectLinkedMultiValueMap.set("client_id","myclient");
    stringObjectLinkedMultiValueMap.set("client_secret","LsvDoZ5g0BQhRDR9ydYqV9tjal8YDeAI");
    stringObjectLinkedMultiValueMap.set("scope","openid");
    stringObjectLinkedMultiValueMap.set("redirect_uri","http://localhost:8888/oauth/keycloak/getToken");
    HttpEntity<LinkedMultiValueMap<String, Object>> jsonObjectHttpEntity = new HttpEntity<>(stringObjectLinkedMultiValueMap);
    ResponseEntity<String> responseEntity = restTemplate.postForEntity(url, jsonObjectHttpEntity, String.class);
    String body = responseEntity.getBody();
    return body;
}