httpClient的post方法使用form格式数据调用接口

Http使用post调用接口，接口只接受form表单数据格式问题？

这个问题的关键是form表单提交的是数据格式是什么样子的，使用httpClient工具类时Header信息如何写。

会影响解决问题思路的因素：

1、一致以来都是使用json数据格式调用接口的，form表单是什么格式一时向不起来。

2、使用form表单数据情况，多是在前台页面使用form表单提交，或使用JavaScript中的FormData对象处理提交。如果是后台httpClient工具接口如何提交

解决思路：

1、先百度看网上怎么说的，找到一个有用的帖子：https://www.cnblogs.com/zhang-can/p/7631262.html 中有一句：

ajax发送的data是个字典，是键值对的形式，在http的post请求过程中，把这种键值对转换成

k1=xxx&k2=xxx这种格式，并且会带上一个请求头：

content-type : application/x-www-form-urlencoded

2、前台访问后台实际实现也是http协议，那使用谷歌的调试工具，模拟一个form表单提交看看请求header和Form Data的情况：

点击“view source”显示的格式：

这是我们熟悉的格式。

根据上面的测试，修改httpClient的post工具类：

关键的地方是：post请求的Header设置

httpPost.addHeader("Content-type", "application/x-www-form-urlencoded; charset=utf-8");

在post中的参数格式为：param1=小明&param2=12

调用时实例：

HttpRequestUtil.post(url地址
, “param1=小明&param2=12”);

测试结果：

返回参数：{"data":{},"code":"0","msg":"处理成功"}

工具类代码：

  1 import org.apache.http.client.config.RequestConfig;
  2 import org.apache.http.client.methods.CloseableHttpResponse;
  3 import org.apache.http.client.methods.HttpGet;
  4 import org.apache.http.client.methods.HttpPost;
  5 import org.apache.http.entity.StringEntity;
  6 import org.apache.http.impl.client.CloseableHttpClient;
  7 import org.apache.http.impl.client.HttpClients;
  8 import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
  9 
 10 import java.io.BufferedReader;
 11 import java.io.IOException;
 12 import java.io.InputStreamReader;
 13 import java.nio.charset.Charset;
 14 
 15 /**
 16  * Created by guoyanan on 2018/8/7 0007.
 17  * 接口调用工具类
 18  */
 19 public class HttpRequestUtil {
 20     private static CloseableHttpClient httpClient;
 21 
 22     static {
 23         PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
 24         cm.setMaxTotal(100);
 25         cm.setDefaultMaxPerRoute(20);
 26         cm.setDefaultMaxPerRoute(50);
 27         httpClient = HttpClients.custom().setConnectionManager(cm).build();
 28     }
 29 
 30     public static String get(String url) {
 31         CloseableHttpResponse response = null;
 32         BufferedReader in = null;
 33         String result = "";
 34         try {
 35             HttpGet httpGet = new HttpGet(url);
 36             RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(30000).setConnectionRequestTimeout(30000).setSocketTimeout(30000).build();
 37             httpGet.setConfig(requestConfig);
 38             httpGet.setConfig(requestConfig);
 39             httpGet.addHeader("Content-type", "application/json; charset=utf-8");
 40             httpGet.setHeader("Accept", "application/json");
 41             response = httpClient.execute(httpGet);
 42             in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
 43             StringBuffer sb = new StringBuffer("");
 44             String line = "";
 45             String NL = System.getProperty("line.separator");
 46             while ((line = in.readLine()) != null) {
 47                 sb.append(line + NL);
 48             }
 49             in.close();
 50             result = sb.toString();
 51         } catch (IOException e) {
 52             e.printStackTrace();
 53         } finally {
 54             try {
 55                 if (null != response) {
 56                     response.close();
 57                 }
 58             } catch (IOException e) {
 59                 e.printStackTrace();
 60             }
 61         }
 62         return result;
 63     }
 64 
 65     public static String post(String url, String jsonString) {
 66         CloseableHttpResponse response = null;
 67         BufferedReader in = null;
 68         String result = "";
 69         try {
 70             HttpPost httpPost = new HttpPost(url);
 71             RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(30000).setConnectionRequestTimeout(30000).setSocketTimeout(30000).build();
 72             httpPost.setConfig(requestConfig);
 73             httpPost.setConfig(requestConfig);
 74             httpPost.addHeader("Content-type", "application/x-www-form-urlencoded; charset=utf-8");
 75             httpPost.setHeader("Accept", "application/json");
 76             httpPost.setEntity(new StringEntity(jsonString, Charset.forName("UTF-8")));
 77 
 78             response = httpClient.execute(httpPost);
 79             in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
 80             StringBuffer sb = new StringBuffer("");
 81             String line = "";
 82             String NL = System.getProperty("line.separator");
 83             while ((line = in.readLine()) != null) {
 84                 sb.append(line + NL);
 85             }
 86             in.close();
 87             result = sb.toString();
 88         } catch (IOException e) {
 89             e.printStackTrace();
 90         } finally {
 91             try {
 92                 if (null != response) {
 93                     response.close();
 94                 }
 95             } catch (IOException e) {
 96                 e.printStackTrace();
 97             }
 98         }
 99         return result;
100     }
101 
102 }