Java网络通信之HttpClient

HttpClient 是 Apache Jakarta Common 下的子项目，可以用来提供高效的、最新的、功能丰富的支持 HTTP 协议的客户端编程工具包，并且它支持 HTTP 协议最新的版本和建议。在Android系统中内置了HttpClient。Android下可以试试Square的OkHttp。

http://hc./httpcomponents-client-ga/index.html

版本：httpclient-4.2.jar

1、基本请求

Java代码  

1. //创建一个客户端  
2. HttpClient client = new DefaultHttpClient();  
3.   
4. //创建一个get方法  
5. HttpGet get = new HttpGet("http://www.baidu.com");  
6.   
7. //执行请求  
8. HttpResponse res = client.execute(get);  
9.   
10. //获取协议版本???「HTTP/1.1」  
11. System.out.println(res.getProtocolVersion());  
12. //获取返回状态码???「200」  
13. System.out.println(res.getStatusLine().getStatusCode());  
14. //获取原因短语???「OK」  
15. System.out.println(res.getStatusLine().getReasonPhrase());  
16. //获取完整的StatusLine???「HTTP/1.1 200 OK」  
17. System.out.println(res.getStatusLine().toString());  
18.   
19. //获取返回头部信息  
20. Header[] headers = res.getAllHeaders();  
21. for (Header header : headers) {  
22.     System.out.println(header.getName() + ": " + header.getValue());  
23. }  
24.   
25. //获取返回内容  
26. if (res.getEntity() != null) {  
27.     System.out.println(EntityUtils.toString(res.getEntity()));  
28. }  
29.   
30. //关闭流  
31. EntityUtils.consume(res.getEntity());  
32.   
33. //关闭连接  
34. client.getConnectionManager().shutdown();  

2、操作Cookie

Java代码  

1. //生成Cookie  
2. CookieStore cookieStore = new BasicCookieStore();  
3. BasicClientCookie stdCookie = new BasicClientCookie("name", "value");  
4. stdCookie.setVersion(1);  
5. stdCookie.setDomain(".baidu.com");  
6. stdCookie.setPath("/");  
7. stdCookie.setSecure(true);  
8. stdCookie.setAttribute(ClientCookie.VERSION_ATTR, "1");  
9. stdCookie.setAttribute(ClientCookie.DOMAIN_ATTR, ".baidu.com");  
10. cookieStore.addCookie(stdCookie);  
11.   
12. DefaultHttpClient client1 = new DefaultHttpClient();  
13. client1.setCookieStore(cookieStore);  
14.   
15. client1.execute(new HttpGet("http://www.baidu.com/"));  
16.   
17. //获取Cookie  
18. DefaultHttpClient client2 = new DefaultHttpClient();  
19. HttpGet httpget = new HttpGet("http://www.baidu.com/");  
20.   
21. HttpResponse res = client2.execute(httpget);  
22.   
23. List<Cookie> cookies = client2.getCookieStore().getCookies();  
24. for (Cookie cookie : cookies) {  
25.     System.out.println(cookie.getName());  
26.     System.out.println(cookie.getValue());  
27. }  
28.   
29. EntityUtils.consume(res.getEntity());  

3、设置代理

Java代码  

1. //通过连接参数设置代理  
2. DefaultHttpClient client1 = new DefaultHttpClient();  
3.   
4. HttpHost proxy1 = new HttpHost("192.168.2.60", 8080, "HTTP");  
5. client1.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy1);  
6.   
7. HttpGet get1 = new HttpGet("http://www.");  
8. HttpResponse res1 = client1.execute(get1);  
9. if (res1.getEntity() != null) {  
10.     System.out.println(EntityUtils.toString(res1.getEntity()));  
11. }         
12. EntityUtils.consume(res1.getEntity());  
13.   
14. //设置代理认证  
15. //client1.getCredentialsProvider().setCredentials(  
16. //        new AuthScope("localhost", 8080),  
17. //        new UsernamePasswordCredentials("username", "password"));  

4、POST数据

Java代码  

1. //========UrlEncodedFormEntity  
2. List<NameValuePair> formparams = new ArrayList<NameValuePair>();  
3. formparams.add(new BasicNameValuePair("param1", "value1"));  
4. formparams.add(new BasicNameValuePair("param2", "value2"));  
5. UrlEncodedFormEntity entity1 = new UrlEncodedFormEntity(formparams, "UTF-8");  
6.   
7. HttpPost post1 = new HttpPost("http://localhost/post1.do");  
8. post1.setEntity(entity1);  
9.   
10. new DefaultHttpClient().execute(post1);  
11.   
12. //========FileEntity  
13. FileEntity entity2 = new FileEntity(new File("c:\\sample.txt"));  
14. entity2.setContentEncoding("UTF-8");  
15.   
16. HttpPost post2 = new HttpPost("http://localhost/post2.do");  
17. post2.setEntity(entity2);  
18.   
19. new DefaultHttpClient().execute(post2);  
20.   
21. //========MultipartEntity  
22. HttpPost post3 = new HttpPost("http://localhost/post3.do");  
23. File upfile = new File("C:\\test.jpg");  
24. MultipartEntity entity3 = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE, null, Charset.forName("UTF-8"));  
25. entity3.addPart("file_name",     new StringBody(upfile.getName()));  
26. entity3.addPart("file_contents", new FileBody(upfile));  
27. post3.setEntity(entity3);  
28.   
29. new DefaultHttpClient().execute(post3);  

5、URI构建

Java代码  

1. //方法一  
2. URI uri1 = URIUtils.createURI("http", "www.baidu.com", -1, "/s",  
3.         "wd=rensanning&rsv_bp=0&rsv_spt=3&inputT=1766", null);  
4. HttpGet httpget1 = new HttpGet(uri1);  
5.   
6. //http://www.baidu.com/s?wd=rensanning&rsv_bp=0&rsv_spt=3&inputT=1766  
7. System.out.println(httpget1.getURI());  
8.   
9. //方法二  
10. List<NameValuePair> qparams = new ArrayList<NameValuePair>();  
11. qparams.add(new BasicNameValuePair("wd", "rensanning"));  
12. qparams.add(new BasicNameValuePair("rsv_bp", "0"));  
13. qparams.add(new BasicNameValuePair("rsv_spt", "3"));  
14. qparams.add(new BasicNameValuePair("inputT", "1766"));  
15.   
16. URI uri2 = URIUtils.createURI("http", "www.baidu.com", -1, "/s",  
17.         URLEncodedUtils.format(qparams, "UTF-8"), null);  
18. HttpGet httpget2 = new HttpGet(uri2);  
19.   
20. //http://www.baidu.com/s?wd=rensanning&rsv_bp=0&rsv_spt=3&inputT=1766  
21. System.out.println(httpget2.getURI());  

6、使用Scheme

Java代码  

1. DefaultHttpClient  httpclient = new DefaultHttpClient();  
2.   
3. //========将Scheme设置到client中  
4. SSLSocketFactory socketFactory = SSLSocketFactory.getSocketFactory();  
5.   
6. Scheme httpsScheme = new Scheme("https", 443, socketFactory);  
7. httpclient.getConnectionManager().getSchemeRegistry().register(httpsScheme);  
8.   
9. HttpGet httpget = new HttpGet("https://.xxx");  
10. HttpResponse res =  httpclient.execute(httpget);  
11.   
12. System.out.println(EntityUtils.toString(res.getEntity()));  
13.   
14. //========使用证书做SSL连接  
15. KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());  
16. FileInputStream fis = new FileInputStream("c:\\aa.keystore");  
17. try {  
18.     keyStore.load(fis, "password".toCharArray());  
19. } finally {  
20.     fis.close();  
21. }  
22.   
23. @SuppressWarnings("unused")  
24. SSLSocketFactory socketFactory2 = new SSLSocketFactory(keyStore);  
25. //......  

7、认证

Java代码  

1. //========BASIC认证  
2. DefaultHttpClient httpclient1 = new DefaultHttpClient();  
3.   
4. UsernamePasswordCredentials creds1 = new UsernamePasswordCredentials("userid", "password");  
5. AuthScope auth1 = new AuthScope("localhost", 80);  
6.   
7. httpclient1.getCredentialsProvider().setCredentials(auth1, creds1);  
8.   
9. HttpGet httpget1 = new HttpGet("http://localhost/auth1");  
10.   
11. @SuppressWarnings("unused")  
12. HttpResponse res1 =  httpclient1.execute(httpget1);  
13.   
14. //========BASIC认证(HttpContext)  
15. DefaultHttpClient httpclient2 = new DefaultHttpClient();  
16.   
17. UsernamePasswordCredentials creds2 = new UsernamePasswordCredentials("admin", "admin");  
18. AuthScope auth2 = new AuthScope("localhost", 80);  
19.   
20. httpclient2.getCredentialsProvider().setCredentials(auth2, creds2);  
21.   
22. HttpHost targetHost2 = new HttpHost("localhost", 80, "http");  
23.   
24. AuthCache authCache = new BasicAuthCache();  
25. BasicScheme basicAuth = new BasicScheme();  
26. authCache.put(targetHost2, basicAuth);  
27.   
28. BasicHttpContext localcontext2 = new BasicHttpContext();  
29. localcontext2.setAttribute(ClientContext.AUTH_CACHE, authCache);  
30.   
31. HttpGet httpget2 = new HttpGet("http://localhost/auth2");  
32.   
33. @SuppressWarnings("unused")  
34. HttpResponse res2 =  httpclient2.execute(httpget2, localcontext2);  
35.   
36. //========DIGEST认证  
37. DefaultHttpClient httpclient3 = new DefaultHttpClient();  
38.   
39. UsernamePasswordCredentials creds3 = new UsernamePasswordCredentials("admin", "admin");  
40. AuthScope auth3 = new AuthScope("localhost", 80);  
41.   
42. httpclient3.getCredentialsProvider().setCredentials(auth3, creds3);  
43.   
44. HttpHost targetHost3 = new HttpHost("localhost", 80, "http");  
45.   
46. AuthCache authCache3 = new BasicAuthCache();  
47. DigestScheme digestAuth = new DigestScheme();  
48. digestAuth.overrideParamter("realm", "some realm");  
49. digestAuth.overrideParamter("nonce", "whatever");  
50. authCache3.put(targetHost3, digestAuth);  
51.   
52. BasicHttpContext localcontext3 = new BasicHttpContext();  
53. localcontext3.setAttribute(ClientContext.AUTH_CACHE, authCache3);  
54.   
55. HttpGet httpget3 = new HttpGet("http://localhost/auth3");  
56.   
57. @SuppressWarnings("unused")  
58. HttpResponse res3 =  httpclient2.execute(httpget3, localcontext3);  
59.   
60. //========NTLM认证  
61. DefaultHttpClient httpclient4 = new DefaultHttpClient();  
62.   
63. NTCredentials creds4 = new NTCredentials("user", "pwd", "myworkstation", "microsoft.com");  
64.   
65. httpclient4.getCredentialsProvider().setCredentials(AuthScope.ANY, creds4);  
66.   
67. HttpHost targetHost4 = new HttpHost("hostname", 80, "http");  
68.   
69. HttpContext localcontext4 = new BasicHttpContext();  
70.   
71. HttpGet httpget4 = new HttpGet("http://localhost/auth4");  
72.   
73. @SuppressWarnings("unused")  
74. HttpResponse res4 = httpclient3.execute(targetHost4, httpget4, localcontext4);  

8、连接池

Java代码  

1. SchemeRegistry schemeRegistry = new SchemeRegistry();  
2. schemeRegistry.register(new Scheme("http", 80, PlainSocketFactory.getSocketFactory()));  
3. schemeRegistry.register(new Scheme("https", 443, SSLSocketFactory.getSocketFactory()));  
4.   
5. PoolingClientConnectionManager cm = new PoolingClientConnectionManager(schemeRegistry);  
6. //设置连接最大数  
7. cm.setMaxTotal(200);  
8. //设置每个Route的连接最大数  
9. cm.setDefaultMaxPerRoute(20);  
10. //设置指定域的连接最大数  
11. HttpHost localhost = new HttpHost("locahost", 80);  
12. cm.setMaxPerRoute(new HttpRoute(localhost), 50);  
13.   
14. HttpGet httpget = new HttpGet("http://localhost/pool");  
15.   
16. HttpClient client = new DefaultHttpClient(cm);  
17.   
18. @SuppressWarnings("unused")  
19. HttpResponse res = client.execute(httpget);