项目里需要访问其他接口，通过http/https协议。我们一般是用HttpClient类来实现具体的http/https协议接口的调用。
// Init a HttpClient
HttpClient client = new HttpClient();
String url=http://www.xxx.com/xxx;
// Init a HttpMethod
HttpMethod get = new GetMethod(url);
get.setDoAuthentication(true);
get.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, new DefaultHttpMethodRetryHandler(1, false));
// Call http interface
try {
client.executeMethod(get);
// Handle the response from http interface
InputStream in = get.getResponseBodyAsStream();
SAXReader reader = new SAXReader();
Document doc = reader.read(in);
} finally {
// Release the http connection
get.releaseConnection();
}
以上代码在通过普通的http协议是没有问题的，但如果是https协议的话，就会有证书文件的要求了。一般情况下，是这样去做的。
// Init a HttpClient
HttpClient client = new HttpClient();
String url=https://www.xxx.com/xxx;
if (url.startsWith("https:")) {
System.setProperty("javax.net.ssl.trustStore", "/.sis.cer");
System.setProperty("javax.net.ssl.trustStorePassword", "public");
}
......
于是，这里就需要事先生成一个.sis.cer的文件，生成这个文件的方法一般是先通过浏览器访问https://，导出证书文件，再用JAVA keytool command 生成证书
# $JAVA_HOME/bin/keytool -import -file sis.cer -keystore .sis.cer
但这样做，一比较麻烦，二来证书也有有效期，过了有效期之后，又需要重新生成一次证书。如果能够避开生成证书文件的方式来使用https的话，就比较好了。
还好，在最近的项目里，我们终于找到了方法。
// Init a HttpClient
HttpClient client = new HttpClient();
String url=https://www.xxx.com/xxx;
if (url.startsWith("https:")) {
this.supportSSL(url, client);
}
......
这里用到了supportSSL(url, client)这个方法，看看这个方法是如何实现的。
private void supportSSL(String url, HttpClient client) {
if(StringUtils.isBlank(url)) {
return;
}
String siteUrl = StringUtils.lowerCase(url);
if (!(siteUrl.startsWith("https"))) {
return;
}
try {
setSSLProtocol(siteUrl, client);
} catch (Exception e) {
logger.error("setProtocol error ", e);
}
Security.setProperty( "ssl.SocketFactory.provider",
"com.tool.util.DummySSLSocketFactory");
}
private static void setSSLProtocol(String strUrl, HttpClient client) throws Exception {
URL url = new URL(strUrl);
String host = url.getHost();
int port = url.getPort();
if (port <= 0) {
port = 443;
}
ProtocolSocketFactory factory = new SSLSocketFactory();
Protocol authhttps = new Protocol("https", factory, port);
Protocol.registerProtocol("https", authhttps);
// set https protocol
client.getHostConfiguration().setHost(host, port, authhttps);
}
在supportSSL方法里，调用了Security.setProperty( "ssl.SocketFactory.provider",
"com.tool.util.DummySSLSocketFactory");
那么这个com.tool.util.DummySSLSocketFactory是这样的：
public class public class DummySSLSocketFactory implements SecureProtocolSocketFactory {
private SSLContext sslcontext = null;
private SSLContext createSSLContext() {
SSLContext sslcontext=null;
try {
sslcontext = SSLContext.getInstance("SSL");
sslcontext.init(null, new TrustManager[]{new TrustAnyTrustManager()}, new java.security.SecureRandom());
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (KeyManagementException e) {
e.printStackTrace();
}
return sslcontext;
}
private SSLContext getSSLContext() {
if (this.sslcontext == null) {
this.sslcontext = createSSLContext();
}
return this.sslcontext;
}
public Socket createSocket(Socket socket, String host, int port, boolean autoClose)
throws IOException, UnknownHostException {
return getSSLContext().getSocketFactory().createSocket(
socket,
host,
port,
autoClose
);
}
public Socket createSocket(String host, int port) throws IOException,
UnknownHostException {
return getSSLContext().getSocketFactory().createSocket(
host,
port
);
}
public Socket createSocket(String host, int port, InetAddress clientHost, int clientPort)
throws IOException, UnknownHostException {
return getSSLContext().getSocketFactory().createSocket(host, port, clientHost, clientPort);
}
public Socket createSocket(String host, int port, InetAddress localAddress,
int localPort, HttpConnectionParams params) throws IOException,
UnknownHostException, ConnectTimeoutException {
if (params == null) {
throw new IllegalArgumentException("Parameters may not be null");
}
int timeout = params.getConnectionTimeout();
SocketFactory socketfactory = getSSLContext().getSocketFactory();
if (timeout == 0) {
return socketfactory.createSocket(host, port, localAddress, localPort);
} else {
Socket socket = socketfactory.createSocket();
SocketAddress localaddr = new InetSocketAddress(localAddress, localPort);
SocketAddress remoteaddr = new InetSocketAddress(host, port);
socket.bind(localaddr);
socket.connect(remoteaddr, timeout);
return socket;
}
}
private static class TrustAnyTrustManager implements X509TrustManager {
public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
}
public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
}
public X509Certificate[] getAcceptedIssuers() {
return new X509Certificate[]{};
}
}
}implements SecureProtocolSocketFactory {
private SSLContext sslcontext = null;
private SSLContext createSSLContext() {
SSLContext sslcontext=null;
try {
sslcontext = SSLContext.getInstance("SSL");
sslcontext.init(null, new TrustManager[]{new TrustAnyTrustManager()}, new java.security.SecureRandom());
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (KeyManagementException e) {
e.printStackTrace();
}
return sslcontext;
}
private SSLContext getSSLContext() {
if (this.sslcontext == null) {
this.sslcontext = createSSLContext();
}
return this.sslcontext;
}
public Socket createSocket(Socket socket, String host, int port, boolean autoClose)
throws IOException, UnknownHostException {
return getSSLContext().getSocketFactory().createSocket(
socket,
host,
port,
autoClose
);
}
public Socket createSocket(String host, int port) throws IOException,
UnknownHostException {
return getSSLContext().getSocketFactory().createSocket(
host,
port
);
}
public Socket createSocket(String host, int port, InetAddress clientHost, int clientPort)
throws IOException, UnknownHostException {
return getSSLContext().getSocketFactory().createSocket(host, port, clientHost, clientPort);
}
public Socket createSocket(String host, int port, InetAddress localAddress,
int localPort, HttpConnectionParams params) throws IOException,
UnknownHostException, ConnectTimeoutException {
if (params == null) {
throw new IllegalArgumentException("Parameters may not be null");
}
int timeout = params.getConnectionTimeout();
SocketFactory socketfactory = getSSLContext().getSocketFactory();
if (timeout == 0) {
return socketfactory.createSocket(host, port, localAddress, localPort);
} else {
Socket socket = socketfactory.createSocket();
SocketAddress localaddr = new InetSocketAddress(localAddress, localPort);
SocketAddress remoteaddr = new InetSocketAddress(host, port);
socket.bind(localaddr);
socket.connect(remoteaddr, timeout);
return socket;
}
}
private static class TrustAnyTrustManager implements X509TrustManager {
public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
}
public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
}
public X509Certificate[] getAcceptedIssuers() {
return new X509Certificate[]{};
}
}
}