HttpClient调用其他接口

步骤:
1. 创建HttpClient对象。2. 创建请求方法的实例，并指定请求URL。如果需要发送GET请求，创建HttpGet对象；如果需要发送POST请求，创建HttpPost对象。3. 如果需要发送请求参数，可调用HttpGet、HttpPost共同的setParams(HetpParams params)方法来添加请求参数；对于HttpPost对象而言，也可调用setEntity(HttpEntity entity)方法来设置请求参数。4. 调用HttpClient对象的execute(HttpUriRequest request)发送请求，该方法返回一个HttpResponse。5. 调用HttpResponse的getAllHeaders()、getHeaders(String name)等方法可获取服务器的响应头；调用HttpResponse的getEntity()方法可获取HttpEntity对象，该对象包装了服务器的响应内容。程序可通过该对象获取服务器的响应内容。6. 释放连接。无论执行方法是否成功，都必须释放连接
代码:/**
* httpClient post请求
* @param url 请求url
* @param header 头部信息
* @param param 请求参数 form提交适用
* @param entity 请求实体 json/xml提交适用
* @return 可能为空 需要处理
* @throws Exception
*
*/
public static String post(String url, Map<String, String> header, Map<String, String> param, HttpEntity entity) throws Exception {
String result = "";
CloseableHttpClient httpClient = null;
try {
httpClient = getHttpClient();
HttpPost httpPost = new HttpPost(url);
// 设置头信息
if (MapUtils.isNotEmpty(header)) {
for (Map.Entry<String, String> entry : header.entrySet()) {
httpPost.addHeader(entry.getKey(), entry.getValue());
}
}
// 设置请求参数
if (MapUtils.isNotEmpty(param)) {
List<NameValuePair> formparams = new ArrayList<NameValuePair>();
for (Map.Entry<String, String> entry : param.entrySet()) {
//给参数赋值
formparams.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
}
UrlEncodedFormEntity urlEncodedFormEntity = new UrlEncodedFormEntity(formparams, Consts.UTF_8);
httpPost.setEntity(urlEncodedFormEntity);
}
// 设置实体 优先级高
if (entity != null) {
httpPost.setEntity(entity);
}
HttpResponse httpResponse = httpClient.execute(httpPost);
int statusCode = httpResponse.getStatusLine().getStatusCode();
if (statusCode == HttpStatus.SC_OK) {
HttpEntity resEntity = httpResponse.getEntity();
result = EntityUtils.toString(resEntity);
} else {
readHttpResponse(httpResponse);
}
} catch (Exception e) {throw e;
} finally {
if (httpClient != null) {
httpClient.close();
}
}
return result;
}

public static String readHttpResponse(HttpResponse httpResponse)
throws ParseException, IOException {
StringBuilder builder = new StringBuilder();
// 获取响应消息实体
HttpEntity entity = httpResponse.getEntity();
// 响应状态
builder.append("status:" + httpResponse.getStatusLine());
builder.append("headers:");
HeaderIterator iterator = httpResponse.headerIterator();
while (iterator.hasNext()) {
builder.append("\t" + iterator.next());
}
// 判断响应实体是否为空
if (entity != null) {
String responseString = EntityUtils.toString(entity);
builder.append("response length:" + responseString.length());
builder.append("response content:" + responseString.replace("\r\n", ""));
}
return builder.toString();
}

public static CloseableHttpClient getHttpClient() throws Exception {
CloseableHttpClient httpClient = HttpClients.custom()
.setSSLSocketFactory(sslsf)
.setConnectionManager(cm)
.setConnectionManagerShared(true)
.build();
return httpClient;
}