maven依赖

1 
     
      2       
      
       org.apache.httpcomponents
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       httpclient
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       4.5.2
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GET请求：

1、参数直接拼接到URL后面，即http://test.com?a=1&b=2的形式

1 /** 2      * get请求，参数拼接在地址上 3      * @param url 请求地址加参数 4      * @return 响应 5      */ 6     public String get(String url) 7     { 8         String result = null; 9         CloseableHttpClient httpClient = HttpClients.createDefault();10         HttpGet get = new HttpGet(url);11         CloseableHttpResponse response = null;12         try {13             response = httpClient.execute(get);14             if(response != null && response.getStatusLine().getStatusCode() == 200)15             {16                 HttpEntity entity = response.getEntity();17                 result = entityToString(entity);18             }19             return result;20         } catch (IOException e) {21             e.printStackTrace();22         }finally {23             try {24                 httpClient.close();25                 if(response != null)26                 {27                     response.close();28                 }29             } catch (IOException e) {30                 e.printStackTrace();31             }32         }33         return null;34     }

2、参数放置到一个map中

1 /** 2      * get请求，参数放在map里 3      * @param url 请求地址 4      * @param map 参数map 5      * @return 响应 6      */ 7     public String getMap(String url,Map
     
       map) 8     { 9         String result = null;10         CloseableHttpClient httpClient = HttpClients.createDefault();11         List
      
        pairs = new ArrayList
       
        ();12         for(Map.Entry
        
          entry : map.entrySet())13         {14             pairs.add(new BasicNameValuePair(entry.getKey(),entry.getValue()));15         }16         CloseableHttpResponse response = null;17         try {18             URIBuilder builder = new URIBuilder(url);19             builder.setParameters(pairs);20             HttpGet get = new HttpGet(builder.build());21             response = httpClient.execute(get);22             if(response != null && response.getStatusLine().getStatusCode() == 200)23             {24                 HttpEntity entity = response.getEntity();25                 result = entityToString(entity);26             }27             return result;28         } catch (URISyntaxException e) {29             e.printStackTrace();30         } catch (ClientProtocolException e) {31             e.printStackTrace();32         } catch (IOException e) {33             e.printStackTrace();34         }finally {35             try {36                 httpClient.close();37                 if(response != null)38                 {39                     response.close();40                 }41             } catch (IOException e) {42                 e.printStackTrace();43             }44         }45 46         return null;47     }
        
       
      
     

POST请求：

1、参数放到map中

1 /** 2      * 发送post请求，参数用map接收 3      * @param url 地址 4      * @param map 参数 5      * @return 返回值 6      */ 7     public String postMap(String url,Map
     
       map) { 8         String result = null; 9         CloseableHttpClient httpClient = HttpClients.createDefault();10         HttpPost post = new HttpPost(url);11         List
      
        pairs = new ArrayList
       
        ();12         for(Map.Entry
        
          entry : map.entrySet())13         {14             pairs.add(new BasicNameValuePair(entry.getKey(),entry.getValue()));15         }16         CloseableHttpResponse response = null;17         try {18             post.setEntity(new UrlEncodedFormEntity(pairs,"UTF-8"));19             response = httpClient.execute(post);20             if(response != null && response.getStatusLine().getStatusCode() == 200)21             {22                 HttpEntity entity = response.getEntity();23                 result = entityToString(entity);24             }25             return result;26         } catch (UnsupportedEncodingException e) {27             e.printStackTrace();28         } catch (ClientProtocolException e) {29             e.printStackTrace();30         } catch (IOException e) {31             e.printStackTrace();32         }finally {33             try {34                 httpClient.close();35                 if(response != null)36                 {37                     response.close();38                 }39             } catch (IOException e) {40                 e.printStackTrace();41             }42 43         }44         return null;45     }
        
       
      
     

2、参数是json字符串

1 /** 2      * post请求，参数为json字符串 3      * @param url 请求地址 4      * @param jsonString json字符串 5      * @return 响应 6      */ 7     public String postJson(String url,String jsonString) 8     { 9         String result = null;10         CloseableHttpClient httpClient = HttpClients.createDefault();11         HttpPost post = new HttpPost(url);12         CloseableHttpResponse response = null;13         try {14             post.setEntity(new ByteArrayEntity(jsonString.getBytes("UTF-8")));15             response = httpClient.execute(post);16             if(response != null && response.getStatusLine().getStatusCode() == 200)17             {18                 HttpEntity entity = response.getEntity();19                 result = entityToString(entity);20             }21             return result;22         } catch (UnsupportedEncodingException e) {23             e.printStackTrace();24         } catch (ClientProtocolException e) {25             e.printStackTrace();26         } catch (IOException e) {27             e.printStackTrace();28         }finally {29             try {30                 httpClient.close();31                 if(response != null)32                 {33                     response.close();34                 }35             } catch (IOException e) {36                 e.printStackTrace();37             }38         }39         return null;40     }

entityToString方法：

1 private String entityToString(HttpEntity entity) throws IOException { 2         String result = null; 3         if(entity != null) 4         { 5             long lenth = entity.getContentLength(); 6             if(lenth != -1 && lenth < 2048) 7             { 8                 result = EntityUtils.toString(entity,"UTF-8"); 9             }else {10                 InputStreamReader reader1 = new InputStreamReader(entity.getContent(), "UTF-8");11                 CharArrayBuffer buffer = new CharArrayBuffer(2048);12                 char[] tmp = new char[1024];13                 int l;14                 while((l = reader1.read(tmp)) != -1) {15                     buffer.append(tmp, 0, l);16                 }17                 result = buffer.toString();18             }19         }20         return result;21     }