httpclient模拟post请求json封装表单数据

以下代码包括最基本的GET、POST、JSON参数的POST方式的请求。（相当于POSTMAN中使用raw编写的参数）

  1package com.chinecredit.eccis.utils;
  2
  3import java.io.IOException;
  4import java.io.UnsupportedEncodingException;
  5import java.util.ArrayList;
  6import java.util.List;
  7import java.util.Map;
  8import java.util.Set;
  9
 10import org.apache.http.HttpEntity;
 11import org.apache.http.HttpStatus;
 12import org.apache.http.NameValuePair;
 13import org.apache.http.ParseException;
 14import org.apache.http.client.ClientProtocolException;
 15import org.apache.http.client.entity.UrlEncodedFormEntity;
 16import org.apache.http.client.methods.CloseableHttpResponse;
 17import org.apache.http.client.methods.HttpGet;
 18import org.apache.http.client.methods.HttpPost;
 19import org.apache.http.entity.StringEntity;
 20import org.apache.http.impl.client.CloseableHttpClient;
 21import org.apache.http.impl.client.HttpClients;
 22import org.apache.http.message.BasicNameValuePair;
 23import org.apache.http.util.EntityUtils;
 24import org.slf4j.Logger;
 25import org.slf4j.LoggerFactory;
 26
 27import com.alibaba.fastjson.JSONObject;
 28
 29/**
 30 * http访问方法实现
 31 * @author 王俊南 
 32 * @date: 2018-11-22
 33 */
 34public class HttpRequestUtils {
 35    private static Logger logger = LoggerFactory
 36            .getLogger(HttpRequestUtils.class); // 日志记录
 37
 38    /**
 39     * GET提交
 40     * 
 41     * @return
 42     */
 43    public static String doGet(String url) {
 44        String strResult = "";
 45        // 1. 创建一个默认的client实例
 46        CloseableHttpClient client = HttpClients.createDefault();
 47        try {
 48            // 2. 创建一个httpget对象
 49            HttpGet httpGet = new HttpGet(url);
 50            System.out.println("executing GET request " + httpGet.getURI());
 51
 52            // 3. 执行GET请求并获取响应对象
 53            CloseableHttpResponse resp = client.execute(httpGet);
 54            try {
 55                // 6. 打印响应长度和响应内容
 56                if (resp.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
 57                    // 4. 获取响应体
 58                    HttpEntity entity = resp.getEntity();
 59                    System.out.println("Response content length = "
 60                            + entity.getContentLength());
 61                    System.out.println("------");
 62                    strResult = EntityUtils.toString(resp.getEntity());
 63                }
 64            } finally {
 65                //无论请求成功与否都要关闭resp
 66                resp.close();
 67            }
 68        } catch (ClientProtocolException e) {
 69            logger.error("get请求失败:", e);
 70            // e.printStackTrace();
 71        } catch (ParseException e) {
 72            logger.error("get请求解析出错:", e);
 73            // e.printStackTrace();
 74        } catch (IOException e) {
 75            logger.error("get请求IO出错:", e);
 76            // e.printStackTrace();
 77        } finally {
 78            // 8. 最终要关闭连接，释放资源
 79            try {
 80                client.close();
 81            } catch (Exception e) {
 82                logger.error("get请求完毕关闭连接出错:", e);
 83                // e.printStackTrace();
 84            }
 85        }
 86        return strResult;
 87    }
 88
 89    /**
 90     * 普通POST提交
 91     * @param url
 92     * @param map
 93     * @return
 94     */
 95    public static String doPost(String url, Map<String, Object> map) {
 96        String strResult = "";
 97        // 1. 获取默认的client实例
 98        CloseableHttpClient client = HttpClients.createDefault();
 99        // 2. 创建httppost实例
100        HttpPost httpPost = new HttpPost(url);
101        // 3. 创建参数队列（键值对列表）
102        List<NameValuePair> paramPairs = new ArrayList<>();
103        Set<String> keySet = map.keySet();
104        for (String key : keySet) {
105            Object val = map.get(key);
106            paramPairs.add(new BasicNameValuePair(key, val.toString()));
107        }
108        UrlEncodedFormEntity entity;
109        try {
110            // 4. 将参数设置到entity对象中
111            entity = new UrlEncodedFormEntity(paramPairs, "UTF-8");
112            // 5. 将entity对象设置到httppost对象中
113            httpPost.setEntity(entity);
114            // 6. 发送请求并回去响应
115            CloseableHttpResponse resp = client.execute(httpPost);
116            try {
117                // 7. 获取响应entity
118                HttpEntity respEntity = resp.getEntity();
119                strResult = EntityUtils.toString(respEntity, "UTF-8");
120            } finally {
121                // 9. 关闭响应对象
122                resp.close();
123            }
124
125        } catch (ClientProtocolException e) {
126            e.printStackTrace();
127        } catch (UnsupportedEncodingException e) {
128            e.printStackTrace();
129        } catch (IOException e) {
130            e.printStackTrace();
131        } finally {
132            // 10. 关闭连接，释放资源
133            try {
134                client.close();
135            } catch (Exception e) {
136                e.printStackTrace();
137            }
138        }
139        return strResult;
140    }
141
142    /**
143     * json参数方式POST提交
144     * @param url
145     * @param params
146     * @return
147     */
148    public static String doPost(String url, JSONObject params){
149        String strResult = "";
150        // 1. 获取默认的client实例
151        CloseableHttpClient client = HttpClients.createDefault();
152        // 2. 创建httppost实例
153        HttpPost httpPost = new HttpPost(url);
154        httpPost.addHeader("Content-Type", "application/json;charset=utf-8"); //添加请求头
155        try {
156            httpPost.setEntity(new StringEntity(params.toJSONString(),"utf-8"));
157            CloseableHttpResponse resp = client.execute(httpPost);
158            try {
159                // 7. 获取响应entity
160                HttpEntity respEntity = resp.getEntity();
161                strResult = EntityUtils.toString(respEntity, "UTF-8");
162            } finally {
163                resp.close();
164            }
165        } catch (ClientProtocolException e) {
166            e.printStackTrace();
167        } catch (UnsupportedEncodingException e) {
168            e.printStackTrace();
169        } catch (IOException e) {
170            e.printStackTrace();
171        } finally {
172            try {
173                client.close();
174            } catch (Exception e) {
175                e.printStackTrace();
176            }
177        }
178        return strResult;
179    }
180}