Android平台上经常有使用https的需求，对于https服务器使用的根证书是受信任的证书的话，实现https是非常简单的，直接用httpclient库就行了，与使用http几乎没有区别。但是在大多数情况下，服务器所使用的根证书是自签名的，或者签名机构不在设备的信任证书列表中，这样使用httpclient进行https连接就会失败。解决这个问题的办法有两种，一是在发起https连接之前将服务器证书加到httpclient的信任证书列表中，这个相对来说比较复杂一些，很容易出错；另一种办法是让httpclient信任所有的服务器证书，这种办法相对来说简单很多，但安全性则差一些，但在某些场合下有一定的应用场景。这里要举例说明的就是后一种方法：实例化HttpClinet对象时要进行一些处理主要是绑定https连接所使用的端口号，这里绑定了443和8443：
1. schemeRegistry = new SchemeRegistry();
2. schemeRegistry.register(new Scheme("https",
3. new EasySSLSocketFactory(), 443));
4. schemeRegistry.register(new Scheme("https",
5. new EasySSLSocketFactory(), 8443));
6. connManager = new ThreadSafeClientConnManager(params, schemeRegistry);
7. httpClient = new DefaultHttpClient(connManager, params);
上面的EasySSLSocketFactory类是我们自定义的，主要目的就是让httpclient接受所有的服务器证书，能够正常的进行https数据读取。相关代码如下：
1. public class EasySSLSocketFactory implements SocketFactory,
2. LayeredSocketFactory {
3.
4. private SSLContext sslcontext = null;
5.
6. private static SSLContext createEasySSLContext() throws IOException {
7. try {
8. SSLContext context = SSLContext.getInstance("TLS");
9. context.init(null, new TrustManager[] { new EasyX509TrustManager(
10. null) }, null);
11. return context;
12. } catch (Exception e) {
13. throw new IOException(e.getMessage());
14. }
15. }
16.
17. private SSLContext getSSLContext() throws IOException {
18. if (this.sslcontext == null) {
19. this.sslcontext = createEasySSLContext();
20. }
21. return this.sslcontext;
22. }
23.
24.
25. public Socket connectSocket(Socket sock, String host, int port,
26. InetAddress localAddress, int localPort, HttpParams params)
27. throws IOException, UnknownHostException, ConnectTimeoutException {
28. int connTimeout = HttpConnectionParams.getConnectionTimeout(params);
29. int soTimeout = HttpConnectionParams.getSoTimeout(params);
30.
31. InetSocketAddress remoteAddress = new InetSocketAddress(host, port);
32. SSLSocket sslsock = (SSLSocket) ((sock != null) ? sock : createSocket());
33.
34. if ((localAddress != null) || (localPort > 0)) {
35. // we need to bind explicitly
36. if (localPort < 0) {
37. localPort = 0; // indicates "any"
38. }
39. InetSocketAddress isa = new InetSocketAddress(localAddress,
40. localPort);
41. sslsock.bind(isa);
42. }
43.
44. sslsock.connect(remoteAddress, connTimeout);
45. sslsock.setSoTimeout(soTimeout);
46. return sslsock;
47.
48. }
49.
50.
51. public Socket createSocket() throws IOException {
52. return getSSLContext().getSocketFactory().createSocket();
53. }
54.
55.
56. public boolean isSecure(Socket socket) throws IllegalArgumentException {
57. return true;
58. }
59.
60.
61. public Socket createSocket(Socket socket, String host, int port,
62. boolean autoClose) throws IOException, UnknownHostException {
63. return getSSLContext().getSocketFactory().createSocket(socket, host,
64. port, autoClose);
65. }
66.
67. // -------------------------------------------------------------------
68. // javadoc in org.apache.http.conn.scheme.SocketFactory says :
69. // Both Object.equals() and Object.hashCode() must be overridden
70. // for the correct operation of some connection managers
71. // -------------------------------------------------------------------
72.
73. public boolean equals(Object obj) {
74. return ((obj != null) && obj.getClass().equals(
75. EasySSLSocketFactory.class));
76. }
77.
78. public int hashCode() {
79. return EasySSLSocketFactory.class.hashCode();
80. }
81. }
82.
83. public class EasyX509TrustManager implements X509TrustManager {
84.
85. private X509TrustManager standardTrustManager = null;
86.
87.
88. public EasyX509TrustManager(KeyStore keystore)
89. throws NoSuchAlgorithmException, KeyStoreException {
90. super();
91. TrustManagerFactory factory = TrustManagerFactory
92. .getInstance(TrustManagerFactory.getDefaultAlgorithm());
93. factory.init(keystore);
94. TrustManager[] trustmanagers = factory.getTrustManagers();
95. if (trustmanagers.length == 0) {
96. throw new NoSuchAlgorithmException("no trust manager found");
97. }
98. this.standardTrustManager = (X509TrustManager) trustmanagers[0];
99. }
100.
101.
102. public void checkClientTrusted(X509Certificate[] certificates,
103. String authType) throws CertificateException {
104. standardTrustManager.checkClientTrusted(certificates, authType);
105. }
106.
107.
108. public void checkServerTrusted(X509Certificate[] certificates,
109. String authType) throws CertificateException {
110. if ((certificates != null) && (certificates.length == 1)) {
111. certificates[0].checkValidity();
112. } else {
113. standardTrustManager.checkServerTrusted(certificates, authType);
114. }
115. }
116.
117.
118. public X509Certificate[] getAcceptedIssuers() {
119. return this.standardTrustManager.getAcceptedIssuers();
120. }
121. }
