关于http请求传参的总结

http请求的参数可以放到headers里面，也可以放到body里面，可以get请求也可以post请求
1.post请求方式：
1.1 传参：参数放到headers里面（postman工具可以测试所有的场景）

public static String sendPost(String url, Map headers, String data) {

String response = null;

try {

    CloseableHttpClient httpclient = null;

    CloseableHttpResponse httpresponse = null;

    try {

        httpclient = HttpClients.createDefault();

        HttpPost httppost = new HttpPost(url);
        //数据放到body里面
        StringEntity stringentity = new StringEntity(data, ContentType.create("application/json", "UTF-8"));

        httppost.setEntity(stringentity);

       // 循环添加header  数据放到header里面
        Iterator headerIterator = headers.entrySet().iterator();

        while (headerIterator.hasNext()) {

            Entry elem = (Entry) headerIterator.next();
            httppost.addHeader((String) elem.getKey(), (String) elem.getValue());

        }

       //发post请求
       httpresponse = httpclient.execute(httppost);

       //utf-8参数防止中文乱码
       response = EntityUtils.toString(httpresponse.getEntity(), "utf-8");

    } finally {

        if (httpclient != null) {
            httpclient.close();

        }

        if (httpresponse != null) {
            httpresponse.close();

        }

    }

} catch (Exception e) {
    e.printStackTrace();

}

return response;

}

1.2 获取headers里面的方法
public static Map<String, String> getHeadersInfo(HttpServletRequest request) {
Map<String, String> map = new HashMap<String, String>();
Enumeration headerNames = request.getHeaderNames();
while (headerNames.hasMoreElements()) {
String key = (String) headerNames.nextElement();
String value = request.getHeader(key);
map.put(key, value);
}
return map;
}

1.3 获取body里面数据的方法（用流的方式读取）

public static String getHttpBody(HttpServletRequest request) {
String data = "";

try {
    InputStream in = request.getInputStream();
    InputStreamReader isr = new InputStreamReader(in, "utf-8");
    BufferedReader br = new BufferedReader(isr);

    for(String temp = ""; (temp = br.readLine()) != null; data = data + temp) {
        ;
    }
} catch (IOException var7) {
    var7.printStackTrace();
}

if (data.indexOf("BODY_DATA") != -1) {
    try {
        data = URLDecoder.decode(data.substring("BODY_DATA=".length()), "utf-8");
    } catch (UnsupportedEncodingException var6) {
        var6.printStackTrace();
    }
}

return data;

}

2.参数放到body里面

2.1
public static String invokeHttpPost(String requestUrl, String param) throws Exception {
logger.info("调用远程接口参数:{}", param);
HttpClient client = new HttpClient();
PostMethod postMethod = new PostMethod(requestUrl);
StringRequestEntity entity = null;
String response = "";
try {
entity = new StringRequestEntity(param, "application/json; charset=utf-8", "UTF-8");
postMethod.setRequestEntity(entity);
int statusCode = client.executeMethod(postMethod);
if (statusCode == HttpStatus.SC_OK) {
response = new String(postMethod.getResponseBody(), "utf-8");
logger.info("远程调用接口:{},返回数据:{}", requestUrl, response);
} else {
logger.info("调用远程接口异常 httpStatus:{}", statusCode);
throw new Exception("调用远程接口异常 httpStatus:" + statusCode);
}
postMethod.releaseConnection();
logger.info(response);
return response;
} catch (Exception e) {
logger.info("请求远程接口异常:{}", requestUrl, e);
throw new Exception("请求接口异常");
}
}

2.2
获取body里面数据的方法（用流的方式读取）

public static String getHttpBody(HttpServletRequest request) {
String data = "";

try {
    InputStream in = request.getInputStream();
    InputStreamReader isr = new InputStreamReader(in, "utf-8");
    BufferedReader br = new BufferedReader(isr);

    for(String temp = ""; (temp = br.readLine()) != null; data = data + temp) {
        ;
    }
} catch (IOException var7) {
    var7.printStackTrace();
}

if (data.indexOf("BODY_DATA") != -1) {
    try {
        data = URLDecoder.decode(data.substring("BODY_DATA=".length()), "utf-8");
    } catch (UnsupportedEncodingException var6) {
        var6.printStackTrace();
    }
}

return data;

}

get请求

1.正常的get请求获取?后面参数的方法：
//第一种
String ss = request.getQueryString(); 结果：username=password

//第二种
Enumeration<string> paraNames=request.getParameterNames();</string>

    for(Enumeration<String> e=paraNames;e.hasMoreElements();){

        String thisName=e.nextElement()+"";  //name名

        String thisValue=request.getParameter(thisName);   //name名对应的值
        System.out.println(thisName+" : "+thisValue);

    }

request.getInputStream() / request.getReader()只能获取POST请求的参数，即请求体的参数。且请求体中的数据仅能调用 request.getInputStream()， request.getReader()和request.getParameter("key") 方法读取一次，即仅第一次能读到数据，后面读到的数据为null。

详细参见其他人博客：https://blog.csdn.net/xybz1993/article/details/80655991