GET以及POST(x-www-form-urlencoded、multipart/form-data）

迈不过友情╰ 2021-09-03 04:11 271阅读 0赞

> **同样使用URLencode转码，这种post格式跟get的区别在于，get把转换、拼接完的字符串用‘?’直接与表单的action连接作为URL使用，所以请求体里没有数据；而post把转换、拼接后的字符串放在了请求体里，不会在浏览器的地址栏显示，因而更安全一些。**

# GET请求 #

> *服务器知道参数用符号&间隔，如果参数值中需要&，则必须对其进行编码*

public void method(String username,String password,String ip,String port,String content) {
            //在content中会包含非法字符，所以这里需要对content中的内容进行编码
            try {
                content = URLEncoder.encode(content);
                HttpHeaders httpHeaders = new HttpHeaders();
                httpHeaders.setContentType(MediaType.APPLICATION_JSON);
                httpHeaders.setAccept(CollectionUtils.arrayToList(MediaType.ALL_VALUE));
                String content = JSONObject.toJSONString(ckAlarmInfoDto);
                String url = "http://" + ip + ":" + port + "/api?username=" + username + "&password=" + password + "&method=CK_ALARM&" + content;
                ResponseEntity<ApiResponse> entity = restTemplate.getForEntity(URI.create(url), ApiResponse.class);
            } catch (Exception e) {
                e.getMessage());
            }
    
        }

# post请求 #

> ***application/x-www-form-urlencoded： 数据被编码为名称/值对。这是标准的编码格式。***

## 使用x-www-form-urlencoded ##

public void method(String username,String password, String ip ,String port,String content) {
            try {
                String url = "http://" + ip + ":" + port + "/api";
               
                PostMethod postMethod = null;
                postMethod = new PostMethod(url);
                postMethod.setRequestHeader("Content-Type", "application/x-www-form-urlencoded;charset=utf-8");
                //参数设置，需要注意的就是里边不能传NULL，要传空字符串
                NameValuePair[] data = {
                    new NameValuePair("username", username),
                    new NameValuePair("password", password),
                    new NameValuePair("method", "CK_ALARM"),
                    new NameValuePair("content", content)
                };
                postMethod.setRequestBody(data);
                HttpClient httpClient = new HttpClient();
                logger.info("发布事件发送的参数:{}",JSONObject.toJSONString(data));
                int response = httpClient.executeMethod(postMethod); // 执行POST方法
                String result =  postMethod.getResponseBodyAsString();
                JSONObject obj= JSONObject.parseObject(result);
                String respCode=null;
                if(ObjectUtils.isNotEmpty(obj.get("respCode"))){
                    respCode=obj.get("respCode").toString();
                    logger.info("=====respCode的值为:{}",respCode);
                }
            } catch (Exception e) {
                logger.info("请求异常" + e.getMessage(), e);
                throw new RuntimeException(e.getMessage());
            }
        }

## 使用multipart/form-data ##

> ***`multipart/form-data`常用于文件等二进制，也可用于键值对参数，最后连接成一串字符传输。****对于一段utf8编码的字节，用application/x-www-form-urlencoded传输其中的ascii字符没有问题，但对于非ascii字符传输效率就很低了（汉字‘丁’从三字节变成了九字节），因此在传很长的字节（如文件）时应用multipart/form-data格式。*multipart/form-data将请求的内容转为了一个由boundary分割的小格式，没有转码，直接将utf8字节拼接到请求体中，在本地有多少字节实际就发送多少字节，极大提高了效率，适合传输长字节。 
> 
> 注解：以下代码暂未使用，仅供参考。

private static String method(String strUrl, Map<String, String> params, String boundary) {
        String result = "";
    
        try {
            URL url = new URL(strUrl);
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestMethod("POST");
            urlConnection.setConnectTimeout(30000);
            urlConnection.setReadTimeout(30000);
            urlConnection.setDoOutput(true);
            //设置通用请求属性为multipart/form-data
            urlConnection.setRequestProperty("content-type", "multipart/form-data;boundary=" + boundary);
            DataOutputStream dataOutputStream = new DataOutputStream(urlConnection.getOutputStream());
    
            for (String key : params.keySet()) {
                String value = params.get(key);
                //注意！此处是\r(回车：将当前位置移到本行开头)、\n(换行：将当前位置移到下行开头)要一起使用
                dataOutputStream.writeBytes("--" + boundary + "\r\n");
                dataOutputStream.writeBytes("Content-Disposition: form-data; name=\"" + encode(key) + "\"\r\n");
                dataOutputStream.writeBytes("\r\n");
                dataOutputStream.writeBytes(encode(value) + "\r\n");
            }
            //最后一个分隔符的结尾后面要跟"--"
            dataOutputStream.writeBytes("--" + boundary + "--");
            dataOutputStream.flush();
            dataOutputStream.close();
            InputStream inputStream = urlConnection.getInputStream();
            byte[] data = new byte[1024];
            StringBuilder sb = new StringBuilder();
            while (inputStream.read(data) != -1) {
                String s = new String(data, Charset.forName("utf-8"));
                sb.append(s);
            }
            result = sb.toString();
            inputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    
        return result;
    }
    
    private static String encode(String value) throws UnsupportedEncodingException {
        return URLEncoder.encode(value, "UTF-8");
    }

# 测试 #

> 测试代码，适用于GET以及POST。

@RestController
    public class ReceiveTest {
        org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(ReceiveTest.class);
    
        @PostMapping("/api")
        public RespResult test(@RequestParam("username") String username,
                               @RequestParam("password") String password,
                               @RequestParam("content") String content) {
            logger.info("传的参数为" + username, password, content);
            RespResult apiResponse=new RespResult();
            apiResponse.setRespCode(Constant.PUSH_SUCCESS_CODE);
            apiResponse.setRespDesc("OK");
            return apiResponse;
        }
    }