Java发送http get/post请求，调用接口/方法

由于项目中要用，所以找了一些资料，整理下来。

GitHub地址: https://github.com/iamyong    转自：http://blog.youkuaiyun.com/capmiachael/article/details/51833531

例1：使用 HttpClient （commons-httpclient-3.0.jar 

 1 import java.io.ByteArrayInputStream;
 2 import java.io.ByteArrayOutputStream;
 3 import java.io.IOException;
 4 import java.io.InputStream;
 5 
 6 import org.apache.commons.httpclient.HttpClient;
 7 import org.apache.commons.httpclient.methods.InputStreamRequestEntity;
 8 import org.apache.commons.httpclient.methods.PostMethod;
 9 import org.apache.commons.httpclient.methods.RequestEntity;
10 
11 public class HttpTool {
12 
13     /**
14      * 发送post请求
15      * 
16      * @param params
17      *            参数
18      * @param requestUrl
19      *            请求地址
20      * @param authorization
21      *            授权书
22      * @return 返回结果
23      * @throws IOException
24      */
25     public static String sendPost(String params, String requestUrl,
26             String authorization) throws IOException {
27 
28         byte[] requestBytes = params.getBytes("utf-8"); // 将参数转为二进制流
29         HttpClient httpClient = new HttpClient();// 客户端实例化
30         PostMethod postMethod = new PostMethod(requestUrl);
31         //设置请求头Authorization
32         postMethod.setRequestHeader("Authorization", "Basic " + authorization);
33         // 设置请求头  Content-Type
34         postMethod.setRequestHeader("Content-Type", "application/json");
35         InputStream inputStream = new ByteArrayInputStream(requestBytes, 0,
36                 requestBytes.length);
37         RequestEntity requestEntity = new InputStreamRequestEntity(inputStream,
38                 requestBytes.length, "application/json; charset=utf-8"); // 请求体
39         postMethod.setRequestEntity(requestEntity);
40         httpClient.executeMethod(postMethod);// 执行请求
41         InputStream soapResponseStream = postMethod.getResponseBodyAsStream();// 获取返回的流
42         byte[] datas = null;
43         try {
44             datas = readInputStream(soapResponseStream);// 从输入流中读取数据
45         } catch (Exception e) {
46             e.printStackTrace();
47         }
48         String result = new String(datas, "UTF-8");// 将二进制流转为String
49         // 打印返回结果
50         // System.out.println(result);
51 
52         return result;
53 
54     }
55 
56     /**
57      * 从输入流中读取数据
58      * 
59      * @param inStream
60      * @return
61      * @throws Exception
62      */
63     public static byte[] readInputStream(InputStream inStream) throws Exception {
64         ByteArrayOutputStream outStream = new ByteArrayOutputStream();
65         byte[] buffer = new byte[1024];
66         int len = 0;
67         while ((len = inStream.read(buffer)) != -1) {
68             outStream.write(buffer, 0, len);
69         }
70         byte[] data = outStream.toByteArray();
71         outStream.close();
72         inStream.close();
73         return data;
74     }
75 }

 

例2：

 

  1 import java.io.BufferedReader;  
  2 import java.io.IOException;
  3 import java.io.InputStream;  
  4 import java.io.InputStreamReader;  
  5 import java.io.OutputStreamWriter;
  6 import java.io.UnsupportedEncodingException;  
  7 import java.net.HttpURLConnection;  
  8 import java.net.InetSocketAddress;
  9 import java.net.Proxy;
 10 import java.net.URL; 
 11 import java.net.URLConnection;
 12 import java.util.List;
 13 import java.util.Map;
 14 
 15 /** 
 16  * Http请求工具类 
 17  */
 18 public class HttpRequestUtil {
 19     static boolean proxySet = false;
 20     static String proxyHost = "127.0.0.1";
 21     static int proxyPort = 8087;
 22     /** 
 23      * 编码 
 24      * @param source 
 25      * @return 
 26      */ 
 27     public static String urlEncode(String source,String encode) {  
 28         String result = source;  
 29         try {  
 30             result = java.net.URLEncoder.encode(source,encode);  
 31         } catch (UnsupportedEncodingException e) {  
 32             e.printStackTrace();  
 33             return "0";  
 34         }  
 35         return result;  
 36     }
 37     public static String urlEncodeGBK(String source) {  
 38         String result = source;  
 39         try {  
 40             result = java.net.URLEncoder.encode(source,"GBK");  
 41         } catch (UnsupportedEncodingException e) {  
 42             e.printStackTrace();  
 43             return "0";  
 44         }  
 45         return result;  
 46     }
 47     /** 
 48      * 发起http请求获取返回结果 
 49      * @param req_url 请求地址 
 50      * @return 
 51      */ 
 52     public static String httpRequest(String req_url) {
 53         StringBuffer buffer = new StringBuffer();  
 54         try {  
 55             URL url = new URL(req_url);  
 56             HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection();  
 57 
 58             httpUrlConn.setDoOutput(false);  
 59             httpUrlConn.setDoInput(true);  
 60             httpUrlConn.setUseCaches(false);  
 61 
 62             httpUrlConn.setRequestMethod("GET");  
 63             httpUrlConn.connect();  
 64 
 65             // 将返回的输入流转换成字符串  
 66             InputStream inputStream = httpUrlConn.getInputStream();  
 67             InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8");  
 68             BufferedReader bufferedReader = new BufferedReader(inputStreamReader);  
 69 
 70             String str = null;  
 71             while ((str = bufferedReader.readLine()) != null) {  
 72                 buffer.append(str);  
 73             }  
 74             bufferedReader.close();  
 75             inputStreamReader.close();  
 76             // 释放资源  
 77             inputStream.close();  
 78             inputStream = null;  
 79             httpUrlConn.disconnect();  
 80 
 81         } catch (Exception e) {  
 82             System.out.println(e.getStackTrace());  
 83         }  
 84         return buffer.toString();  
 85     }  
 86 
 87     /** 
 88      * 发送http请求取得返回的输入流 
 89      * @param requestUrl 请求地址 
 90      * @return InputStream 
 91      */ 
 92     public static InputStream httpRequestIO(String requestUrl) {  
 93         InputStream inputStream = null;  
 94         try {  
 95             URL url = new URL(requestUrl);  
 96             HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection();  
 97             httpUrlConn.setDoInput(true);  
 98             httpUrlConn.setRequestMethod("GET");  
 99             httpUrlConn.connect();  
100             // 获得返回的输入流  
101             inputStream = httpUrlConn.getInputStream();  
102         } catch (Exception e) {  
103             e.printStackTrace();  
104         }  
105         return inputStream;  
106     }
107 
108 
109     /**
110      * 向指定URL发送GET方法的请求
111      * 
112      * @param url
113      *            发送请求的URL
114      * @param param
115      *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
116      * @return URL 所代表远程资源的响应结果
117      */
118     public static String sendGet(String url, String param) {
119         String result = "";
120         BufferedReader in = null;
121         try {
122             String urlNameString = url + "?" + param;
123             URL realUrl = new URL(urlNameString);
124             // 打开和URL之间的连接
125             URLConnection connection = realUrl.openConnection();
126             // 设置通用的请求属性
127             connection.setRequestProperty("accept", "*/*");
128             connection.setRequestProperty("connection", "Keep-Alive");
129             connection.setRequestProperty("user-agent",
130                     "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
131             // 建立实际的连接
132             connection.connect();
133             // 获取所有响应头字段
134             Map<String, List<String>> map = connection.getHeaderFields();
135             // 遍历所有的响应头字段
136             for (String key : map.keySet()) {
137                 System.out.println(key + "--->" + map.get(key));
138             }
139             // 定义 BufferedReader输入流来读取URL的响应
140             in = new BufferedReader(new InputStreamReader(
141                     connection.getInputStream()));
142             String line;
143             while ((line = in.readLine()) != null) {
144                 result += line;
145             }
146         } catch (Exception e) {
147             System.out.println("发送GET请求出现异常！" + e);
148             e.printStackTrace();
149         }
150         // 使用finally块来关闭输入流
151         finally {
152             try {
153                 if (in != null) {
154                     in.close();
155                 }
156             } catch (Exception e2) {
157                 e2.printStackTrace();
158             }
159         }
160         return result;
161     }
162 
163     /**
164      * 向指定 URL 发送POST方法的请求
165      * 
166      * @param url
167      *            发送请求的 URL
168      * @param param
169      *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
170      * @param isproxy
171      *               是否使用代理模式
172      * @return 所代表远程资源的响应结果
173      */
174     public static String sendPost(String url, String param,boolean isproxy) {
175         OutputStreamWriter out = null;
176         BufferedReader in = null;
177         String result = "";
178         try {
179             URL realUrl = new URL(url);
180             HttpURLConnection conn = null;
181             if(isproxy){//使用代理模式
182                 @SuppressWarnings("static-access")
183                 Proxy proxy = new Proxy(Proxy.Type.DIRECT.HTTP, new InetSocketAddress(proxyHost, proxyPort));
184                 conn = (HttpURLConnection) realUrl.openConnection(proxy);
185             }else{
186                 conn = (HttpURLConnection) realUrl.openConnection();
187             }
188             // 打开和URL之间的连接
189 
190             // 发送POST请求必须设置如下两行
191             conn.setDoOutput(true);
192             conn.setDoInput(true);
193             conn.setRequestMethod("POST");    // POST方法
194 
195 
196             // 设置通用的请求属性
197 
198             conn.setRequestProperty("accept", "*/*");
199             conn.setRequestProperty("connection", "Keep-Alive");
200             conn.setRequestProperty("user-agent",
201                     "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
202             conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
203 
204             conn.connect();
205 
206             // 获取URLConnection对象对应的输出流
207             out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8");
208             // 发送请求参数
209             out.write(param);
210             // flush输出流的缓冲
211             out.flush();
212             // 定义BufferedReader输入流来读取URL的响应
213             in = new BufferedReader(
214                     new InputStreamReader(conn.getInputStream()));
215             String line;
216             while ((line = in.readLine()) != null) {
217                 result += line;
218             }
219         } catch (Exception e) {
220             System.out.println("发送 POST 请求出现异常！"+e);
221             e.printStackTrace();
222         }
223         //使用finally块来关闭输出流、输入流
224         finally{
225             try{
226                 if(out!=null){
227                     out.close();
228                 }
229                 if(in!=null){
230                     in.close();
231                 }
232             }
233             catch(IOException ex){
234                 ex.printStackTrace();
235             }
236         }
237         return result;
238     }    
239 
240     public static void main(String[] args) {
241         //demo:代理访问
242         String url = "http://api.adf.ly/api.php";
243         String para = "key=youkeyid&youuid=uid&advert_type=int&domain=adf.ly&url=http://somewebsite.com";
244 
245         String sr=HttpRequestUtil.sendPost(url,para,true);
246         System.out.println(sr);
247     }
248 
249 }

例3

 

 1 /**
 2      * 发送Http post请求
 3      * 
 4      * @param xmlInfo
 5      *            json转化成的字符串
 6      * @param URL
 7      *            请求url
 8      * @return 返回信息
 9      */
10     public static String doHttpPost(String xmlInfo, String URL) {
11         System.out.println("发起的数据:" + xmlInfo);
12         byte[] xmlData = xmlInfo.getBytes();
13         InputStream instr = null;
14         java.io.ByteArrayOutputStream out = null;
15         try {
16             URL url = new URL(URL);
17             URLConnection urlCon = url.openConnection();
18             urlCon.setDoOutput(true);
19             urlCon.setDoInput(true);
20             urlCon.setUseCaches(false);
21             urlCon.setRequestProperty("content-Type", "application/json");
22             urlCon.setRequestProperty("charset", "utf-8");
23             urlCon.setRequestProperty("Content-length",
24                     String.valueOf(xmlData.length));
25             System.out.println(String.valueOf(xmlData.length));
26             DataOutputStream printout = new DataOutputStream(
27                     urlCon.getOutputStream());
28             printout.write(xmlData);
29             printout.flush();
30             printout.close();
31             instr = urlCon.getInputStream();
32             byte[] bis = IOUtils.toByteArray(instr);
33             String ResponseString = new String(bis, "UTF-8");
34             if ((ResponseString == null) || ("".equals(ResponseString.trim()))) {
35                 System.out.println("返回空");
36             }
37             System.out.println("返回数据为:" + ResponseString);
38             return ResponseString;
39 
40         } catch (Exception e) {
41             e.printStackTrace();
42             return "0";
43         } finally {
44             try {
45                 out.close();
46                 instr.close();
47 
48             } catch (Exception ex) {
49                 return "0";
50             }
51         }
52     }