HttpClient 是Apache Jakarta Common 下的子项目，可以用来提供高效的、最新的、功能丰富的支持 HTTP 协议的客户端编程工具包，并且它支持 HTTP 协议最新的版本和建议。

在这里先介绍 HttpClient的xml ，json和form表单格式的调用;对不同格式的可进行封装调用

public class HttpUtils {

private static Logger Log = LoggerFactory.getLogger(HttpUtils.class);

// 1.使用get方式发送报文

public static String getData(String url) {

CloseableHttpClient client = HttpClients.createDefault();

HttpGet get = new HttpGet(url);

try{

CloseableHttpResponse response = client.execute(get);

int statusCode = response.getStatusLine().getStatusCode();

if(statusCode==200){

Log.info("远程调用成功.line={}",response.getStatusLine());

HttpEntity entity = response.getEntity();

return EntityUtils.toString(entity,"UTF-8");

}

return null;

}catch (IOException e){

Log.error("远程调用失败.e={}",e.getMessage());

}

return null;

}

public static String post(String type,String url,String data){

String result = "";

switch (type){

case "xml":

result = postData(url,data,ContentType.APPLICATION_XML.toString());

break;

case "json":

result = postData(url,data,ContentType.APPLICATION_JSON.toString());

break;

default:

break;

}

return result;

}

// 使用POST方法发送XML或者json数据

public static String postData(String url, String xmlData,String contentType){

CloseableHttpClient client = HttpClients.createDefault();

HttpPost post = new HttpPost(url);

post.addHeader("Content-type",contentType);

try{

StringEntity entity = new StringEntity(xmlData);

post.setEntity(entity);

CloseableHttpResponse response = client.execute(post);

int statusCode = response.getStatusLine().getStatusCode();

if(statusCode==200){

Log.info("远程调用成功.line={}",response.getStatusLine());

HttpEntity responseEntity = response.getEntity();

return EntityUtils.toString(responseEntity);

}

}catch (IOException e){

Log.error("远程调用失败.e={}",e.getMessage());

}

return null;

}

// 使用POST方法发送FORM表单数据

public static String postForm(String url, Map map){

CloseableHttpClient client = HttpClients.createDefault();

HttpPost post = new HttpPost(url);

post.addHeader("Content-type",ContentType.APPLICATION_FORM_URLENCODED.toString());

try{

List list = new ArrayList<>();

for(Map.Entry entry : map.entrySet()){

list.add(new BasicNameValuePair(entry.getKey(),entry.getValue()));

}

UrlEncodedFormEntity urlEncodedFormEntity = new UrlEncodedFormEntity(list);

post.setEntity(urlEncodedFormEntity);

CloseableHttpResponse response = client.execute(post);

int statusCode = response.getStatusLine().getStatusCode();

if(statusCode==200){

Log.info("远程调用成功.line={}",response.getStatusLine());

HttpEntity responseEntity = response.getEntity();

return EntityUtils.toString(responseEntity);

}

}catch (IOException e){

Log.error("远程调用失败.e={}",e.getMessage());

}

return null;

}

}