HttpClient用法
1.一般步骤：
1.创建链接： DefaultHttpClient httpClient = new DefaultHttpClient(); 2.创建请求： HttpPost post = new HttpPost(URL); 3.设置参数： post.setEntity(new StringEntity(paramList)); 4.设置头部： post.setHeader("X-Auth0-Token",token)) //自己规定的一些参数 post.setHeader("Content-Type","application/json;charset=utf-8") //json格式 5.执行请求、并接收返回： HttpResponse res = new httpClient.execute(post); 6.获取返回的信息体： String responseContent = EntityUtils.toString(res.getEntity(),"UTF-8"); 7.解析返回的JSON： JSONObject json = JSON.parseObject(responseContent); **8.判断是否请求成功：** if(res.getStatusLine().getStatusCode() == HttpStatus.SC_OK){}
注意：出现错误“HttpClient请求返回403”
//User-Agent会告诉网站服务器，访问者是通过什么工具来请求的，如果是爬虫请求，一般会拒绝，如果是用户浏览器，就会应答。所以添加一个请求信息告诉网站服务器自己是用户浏览器就可以啦。 httpGet.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.87 Safari/537.36");
2.参数问题：
1.参数为Map<>的： { "mobile":"1238293223" } HttpPost post_userId = new HttpPost(UserIdURL); //获取userId Gson gson = new Gson(); post_userId.setEntity(new StringEntity(gson.toJson(map))); HttpResponse res = httpClient.execute(post_userId); if(res != null){ String responseContent = EntityUtils.toString(res.getEntity()); JSONObject json = JSONObject.parseObject(responseContent); userid = json.getString("userid"); } 2.参数为JSONArray： JSONArray array = JSONArray.parseArray(JSON.toJSONString(paramList)); post.setEntity(new StringEntity(array.toString(), ContentType.APPLICATION_JSON)); 3.参数为&name类型： //设置参数 Map<String,String> map List<NameValuePair> list = new ArrayList<NameValuePair>(); Iterator iterator = map.entrySet().iterator(); while(iterator.hasNext()){ Entry<String,String> elem = (Entry<String, String>) iterator.next(); list.add(new BasicNameValuePair(elem.getKey(),elem.getValue())); } if(list.size() > 0){ UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list,charset); //转为& httpPost.setEntity(entity); } 4.参数为list<map<>>： //List<Map<String,Object>> paramList，转为JSONArry HttpResponse res = null; JSONArray array = JSONArray.parseArray(JSON.toJSONString(paramList)); post.setEntity(new StringEntity(array.toString(), StandardCharsets.UTF_8));
3.get请求：
DefaultHttpClient httpClient = new DefaultHttpClient(); /* ***** 1. 请求 */ HttpGet get = new HttpGet(apiURL+"?"+appId+"&"+appSecret); /* ****** 2. 请求结束，返回结果 */ HttpResponse res = httpClient.execute(get); /* 服务器成功地返回响应 */ HttpEntity httpEntity = res.getEntity(); String responseContent = EntityUtils.toString(httpEntity, "UTF-8"); /* 将响应内容转化为json对象 */ JSONObject json = JSONObject.parseObject(responseContent);
4.post请求：
DefaultHttpClient httpClient = new DefaultHttpClient(); /* ***** 1. 请求 */ HttpPost post = new HttpPost(apiURL_create); /* ****** 2. 请求结束，返回结果 */ HttpResponse res = null; JSONArray array = JSONArray.parseArray(JSON.toJSONString(paramList)); post.setEntity(new StringEntity(array.toString(), StandardCharsets.UTF_8)); //设置头部参数 post.setHeader("Content-Type","application/json;charset=utf-8"); post.setHeader("X-Auth0-Token",getTokenByApptype(appType)); res = httpClient.execute(post); /* 服务器是否成功地返回响应 */ if(res != null){ /* 解析响应，判断状态码 */ if(res.getStatusLine().getStatusCode() == HttpStatus.SC_OK){ String responseContent = EntityUtils.toString(res.getEntity(),"UTF-8"); // logger.info("success -----> "+responseContent); /* 将响应内容转化为json对象 */ JSONObject json = JSONObject.parseObject(responseContent); JSONObject data = json.getJSONObject("data"); //若传入的参数有误 if(data == null){ taskId_list.add(json.getString("msg")); taskId_list.add(json.getString("code")); return taskId_list; } JSONArray jsonArray = data.getJSONArray("taskIds"); taskId_list = JSONObject.parseArray(jsonArray.toJSONString(),String.class); //一个失败，所有的都失败 if(taskId_list.size() < paramList.size()){ taskId_list.clear(); taskId_list.add("全部创建失败！"); } return taskId_list; //"执行成功" }
}
5.代码样例：
package com.kingdee.eas.custom.cfinv.utils; import com.kingdee.bos.ui.face.CoreUIObject; import java.io.BufferedReader; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.UnsupportedEncodingException; import java.security.KeyManagementException; import java.security.KeyStoreException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.security.cert.CertificateException; import java.security.cert.X509Certificate; import java.util.List; import javax.net.ssl.SSLContext; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.NameValuePair; import org.apache.http.StatusLine; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; import org.apache.http.client.HttpResponseException; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.config.Registry; import org.apache.http.config.RegistryBuilder; import org.apache.http.conn.socket.PlainConnectionSocketFactory; import org.apache.http.conn.ssl.SSLConnectionSocketFactory; import org.apache.http.conn.ssl.SSLContextBuilder; import org.apache.http.conn.ssl.SSLContexts; import org.apache.http.conn.ssl.TrustStrategy; import org.apache.http.entity.StringEntity; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClientBuilder; import org.apache.http.impl.client.HttpClients; import org.apache.http.impl.conn.PoolingHttpClientConnectionManager; import org.apache.http.message.BasicHeader; import org.apache.http.util.EntityUtils; import org.apache.log4j.Logger; import org.json.JSONException; import org.json.JSONObject; public class HttpUtils { private static Logger logger = CoreUIObject.getLogger(HttpUtils.class); public static HttpClient getHttpClient() { CloseableHttpClient httpClient = HttpClients.custom() .setConnectionManager(ConnectionManager.manager).build(); return httpClient; } public static JSONObject doPost(String url, String params, String charset) throws Exception { logger.error("HttpUtils:start-----doPost"); HttpClient hc = getHttpClient(); HttpPost httpPost = new HttpPost(url); BufferedReader bufferedReader = null; try { logger.error("获取到response之前"); StringEntity se = new StringEntity(params, charset); se.setContentEncoding(new BasicHeader("Content-Type", "application/json")); httpPost.setEntity(se); HttpResponse response = hc.execute(httpPost); HttpEntity e = response.getEntity(); StringBuffer buffer = new StringBuffer(); logger.error("获取到response之后"); if (e != null) { Long len = Long.valueOf(e.getContentLength()); if ((len.longValue() != -1L) && (len.longValue() < 2048L)) { logger.error("2048L"); logger.error("2048L"+buffer.toString()); buffer.append(EntityUtils.toString(e, charset)); } else { logger.error("追加"+buffer.toString()); bufferedReader = new BufferedReader( new InputStreamReader(e.getContent(), charset)); String str = null; while ((str = bufferedReader.readLine()) != null) { buffer.append(str); } } } logger.error("报文："+buffer.toString()); if (response.getStatusLine().getStatusCode() >= 300) { logger.error("code大于300："+buffer.toString()); throw new HttpResponseException( response.getStatusLine().getStatusCode(), response.getStatusLine().getReasonPhrase()); } if (e == null) { logger.error("返回内容为空"); throw new ClientProtocolException("返回内容为空"); } logger.error("HttpUtils.doPost=\r\n"+response.getStatusLine().getStatusCode() + "\n" + buffer.toString()); JSONObject resultObject = new JSONObject(buffer.toString()); logger.error("HttpUtils.resultObject=\r\n"+resultObject); return resultObject; } catch (Exception e) { logger.error("doPost错误:"+e.getMessage(), e); throw new Exception(e); } finally { if (bufferedReader != null) { try { bufferedReader.close(); } catch (IOException e) { e.printStackTrace(); logger.error("dopost错误:"+e,e); throw new RuntimeException(e); } } logger.error("dopost关闭"); // httpPost.releaseConnection(); } } public static byte[] downloadFile(String url) { logger.error("HttpUtils:start-----downloadFile"); HttpClient hc = getHttpClient(); HttpGet httpGet = new HttpGet(url); InputStream in = null; byte[] b = (byte[])null; try { HttpResponse response = hc.execute(httpGet); HttpEntity e = response.getEntity(); if (response.getStatusLine().getStatusCode() >= 300) { throw new HttpResponseException( response.getStatusLine().getStatusCode(), response.getStatusLine().getReasonPhrase()); } if (e != null) { in = e.getContent(); ByteArrayOutputStream out = new ByteArrayOutputStream(); int l = 0; byte[] tmp = new byte[1024]; while ((l = in.read(tmp)) != -1) { out.write(tmp, 0, l); } b = out.toByteArray(); out.close(); } else { throw new ClientProtocolException("返回内容为空"); } return b; } catch (Exception e) { } finally { if (in != null) { try { in.close(); } catch (IOException e) { e.printStackTrace(); logger.error("downloadFile错误:"+e,e); throw new RuntimeException(e); } } // httpGet.releaseConnection(); } return null; } public static String encode(String[] args) { char[] hexDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; if ((args == null) || (args.length == 0)) return ""; StringBuffer sb = new StringBuffer(); for (String str : args) { sb.append(str); } byte[] bytes = sb.toString().getBytes(); try { MessageDigest mdInst = MessageDigest.getInstance("MD5"); mdInst.update(bytes); byte[] md = mdInst.digest(); char[] ciphertext = new char[2 * md.length]; int k = 0; for (int j = 0; j < md.length; ++j) { byte b0 = md[j]; ciphertext[(k++)] = hexDigits[(b0 >>> 4 & 0xF)]; ciphertext[(k++)] = hexDigits[(b0 & 0xF)]; } return new String(ciphertext); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); logger.error("encode错误:"+e,e); throw new RuntimeException(e); } } public static JSONObject doGet(String url, String charset) { logger.error("HttpUtils:start-----doGet"); HttpClient hc = getHttpClient(); HttpGet httpGet = new HttpGet(url); BufferedReader bufferedReader = null; try { HttpResponse response = hc.execute(httpGet); HttpEntity e = response.getEntity(); StringBuffer buffer = new StringBuffer(); if (e != null) { Long len = Long.valueOf(e.getContentLength()); if ((len.longValue() != -1L) && (len.longValue() < 2048L)) { buffer.append(EntityUtils.toString(e, charset)); } else { bufferedReader = new BufferedReader( new InputStreamReader(e.getContent(), charset)); String str = null; while ((str = bufferedReader.readLine()) != null) { buffer.append(str); } } } if (response.getStatusLine().getStatusCode() >= 300) { throw new HttpResponseException(response.getStatusLine().getStatusCode(), response.getStatusLine().getReasonPhrase()); } if (e == null) { throw new ClientProtocolException("返回内容为空"); } logger.error("doGet报文状态码"+response.getStatusLine().getStatusCode() + "\n" + buffer.toString()); logger.info(response.getStatusLine().getStatusCode() + "\n" + buffer.toString()); return new JSONObject(buffer.toString()); } catch (UnsupportedEncodingException e1) { logger.error("doGet错误:"+e1,e1); } catch (ClientProtocolException e) { logger.error("doGet错误:"+e,e); } catch (IOException e) { logger.error("doGet错误:"+e,e); } catch (JSONException e) { logger.error("doGet错误:"+e,e); } finally { if (bufferedReader != null) { try { bufferedReader.close(); } catch (IOException e) { e.printStackTrace(); logger.error("doGet错误:"+e,e); throw new RuntimeException(e); } } // httpGet.releaseConnection(); } return null; } public static JSONObject doPost(String url, List<NameValuePair> params, String charset) { HttpClient hc = getHttpClient(); HttpPost httpPost = new HttpPost(url); BufferedReader bufferedReader = null; try { StringEntity se = new UrlEncodedFormEntity(params, "UTF-8"); se.setContentEncoding(new BasicHeader("Content-Type", "application/x-www-form-urlencoded")); httpPost.setEntity(se); HttpResponse response = hc.execute(httpPost); HttpEntity e = response.getEntity(); StringBuffer buffer = new StringBuffer(); if (e != null) { Long len = Long.valueOf(e.getContentLength()); if ((len.longValue() != -1L) && (len.longValue() < 2048L)) { buffer.append(EntityUtils.toString(e, charset)); } else { bufferedReader = new BufferedReader( new InputStreamReader(e.getContent(), charset)); String str = null; while ((str = bufferedReader.readLine()) != null) { buffer.append(str); } } } if (response.getStatusLine().getStatusCode() >= 300) { throw new HttpResponseException( response.getStatusLine().getStatusCode(), response.getStatusLine().getReasonPhrase()); } if (e == null) { throw new ClientProtocolException("返回内容为空"); } logger.info(response.getStatusLine().getStatusCode() + "\n" + buffer.toString()); return new JSONObject(buffer.toString()); } catch (Exception e) { } finally { if (bufferedReader != null) { try { bufferedReader.close(); } catch (IOException e) { e.printStackTrace(); throw new RuntimeException(e); } } // httpPost.releaseConnection(); } return null; } public static String doGet4String(String url, String charset) { HttpClient hc = getHttpClient(); HttpGet httpGet = new HttpGet(url); BufferedReader bufferedReader = null; try { HttpResponse response = hc.execute(httpGet); HttpEntity e = response.getEntity(); StringBuffer buffer = new StringBuffer(); if (e != null) { Long len = Long.valueOf(e.getContentLength()); if ((len.longValue() != -1L) && (len.longValue() < 2048L)) { buffer.append(EntityUtils.toString(e, charset)); } else { bufferedReader = new BufferedReader( new InputStreamReader(e.getContent(), charset)); String str = null; while ((str = bufferedReader.readLine()) != null) { buffer.append(str); } } } if (response.getStatusLine().getStatusCode() >= 300) { throw new HttpResponseException(response.getStatusLine().getStatusCode(), response.getStatusLine().getReasonPhrase()); } if (e == null) { throw new ClientProtocolException("返回内容为空"); } logger.info(response.getStatusLine().getStatusCode() + "\n" + buffer.toString()); return buffer.toString(); } catch (Exception e) { } finally { if (bufferedReader != null) { try { bufferedReader.close(); } catch (IOException e) { e.printStackTrace(); throw new RuntimeException(e); } } // httpGet.releaseConnection(); } return null; } public static JSONObject doPost(String url, HttpEntity entity, String charset) { HttpClient hc = getHttpClient(); HttpPost httpPost = new HttpPost(url); BufferedReader bufferedReader = null; try { httpPost.setEntity(entity); HttpResponse response = hc.execute(httpPost); HttpEntity e = response.getEntity(); StringBuffer buffer = new StringBuffer(); if (e != null) { Long len = Long.valueOf(e.getContentLength()); if ((len.longValue() != -1L) && (len.longValue() < 2048L)) { buffer.append(EntityUtils.toString(e, charset)); } else { bufferedReader = new BufferedReader( new InputStreamReader(e.getContent(), charset)); String str = null; while ((str = bufferedReader.readLine()) != null) { buffer.append(str); } } } if (response.getStatusLine().getStatusCode() >= 300) { throw new HttpResponseException( response.getStatusLine().getStatusCode(), response.getStatusLine().getReasonPhrase()); } if (e == null) { throw new ClientProtocolException("返回内容为空"); } logger.info(response.getStatusLine().getStatusCode() + "\n" + buffer.toString()); return new JSONObject(buffer.toString()); } catch (Exception e) { } finally { if (bufferedReader != null) { try { bufferedReader.close(); } catch (IOException e) { e.printStackTrace(); throw new RuntimeException(e); } } // httpPost.releaseConnection(); } return null; } private static class ConnectionManager { private static PoolingHttpClientConnectionManager manager = null; static { SSLContext sslContext = null; try { sslContext = SSLContexts.custom().loadTrustMaterial( null, new TrustStrategy() { public boolean isTrusted(X509Certificate[] arg0, String arg1) throws CertificateException { return true; } }).build(); } catch (KeyManagementException e) { e.printStackTrace(); throw new RuntimeException(e); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); throw new RuntimeException(e); } catch (KeyStoreException e) { e.printStackTrace(); throw new RuntimeException(e); } SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory( sslContext, new String[] { "TLSv1" }, null, SSLConnectionSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER); Registry registry = RegistryBuilder.create().register( "http", PlainConnectionSocketFactory.INSTANCE) .register("https", sslsf).build(); manager = new PoolingHttpClientConnectionManager(registry); manager.setDefaultMaxPerRoute(20); } } }
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