利用httpclient發送GET/POST請求__java基礎

暫時唯寫post

import com.alibaba.fastjson.JSON;import org.apache.commons.lang.StringUtils;import org.apache.commons.lang.Validate;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.HttpStatus;import org.apache.http.client.methods.HttpPost;import org.apache.http.entity.ContentType;import org.apache.http.entity.StringEntity;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.util.EntityUtils;import java.io.IOException;import java.util.HashMap;import java.util.Map;private Header[] headers = {new BasicHeader("User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; " +              "Windows NT 5.1; SV1; .NET CLR 2.0.50727; CIBA)"),               new BasicHeader("Accept-Language", "zh-cn"),               new BasicHeader("Accept", " image/gif, image/x-xbitmap, image/jpeg, " +                      "image/pjpeg, application/x-silverlight, application/vnd.ms-excel, " +                      "application/vnd.ms-powerpoint, application/msword, application/x-shockwave-flash, */*"),               new BasicHeader("Content-Type", "application/x-www-form-urlencoded"),               new BasicHeader("Accept-Encoding", "gzip, deflate")};  public static String post(String url, Map<String, String> params) throws IOException {        CloseableHttpClient httpClient = null;        String res = null;        try {            httpClient = HttpClients.createDefault();            HttpPost post = new HttpPost(url);            post.setHeaders(headers);            //如果有參數則設定參數            //StringEntity是最簡單的傳輸類型，UrlEncodedFormEntity繼承StringEntity，一般用於表單上傳，在StringEntity中，表單項的格式是key=value&key=value，            // 因為這裡只有一項表單，所以我用StringEntity            StringEntity stringEntity = new StringEntity("param="+JSON.toJSONString(params), ContentType.create("application/x-www-form-urlencoded", "UTF-8"));            //這個設定同上面的設定是不一樣的，上面的UTF-8是解析StringEntity中的傳入string的字元集，將其轉換為byte            stringEntity.setContentEncoding("utf-8");            post.setEntity(stringEntity);////            List<BasicNameValuePair> paramList = new ArrayList<BasicNameValuePair>();//            paramList.add(new BasicNameValuePair("param", JSON.toJSONString(params)));//            post.setEntity(new UrlEncodedFormEntity(paramList, "UTF-8"));            HttpResponse response = httpClient.execute(post);            int statusCode = response.getStatusLine().getStatusCode();            if (statusCode != HttpStatus.SC_OK) {                System.out.println("錯誤碼[" + statusCode + "]");            }            HttpEntity entity = response.getEntity();            if (entity != null) {                res = EntityUtils.toString(entity, "UTF-8");            }        } catch (Exception e) {            e.printStackTrace();            return null;        } finally {            if (null != httpClient) {                httpClient.close();            }        }        return res;    }