Java doesn't accept 2 methods with the same name
I need to run the below code (derived from: Which Cipher Suites to enable for SSL Socket? ).
The problem is that the code contains several methods named: createSocket with different types of arguments. Eclipse is showing me an error:
I read that Java can have multiple methods with the same name if the arguments are different (method overloading). I don't know why this is causing me the problem here?
Code:
class SSLSocketFactoryEx extends SSLSocketFactory
{
public SSLSocketFactoryEx() throws NoSuchAlgorithmException, KeyManagementException
{
initSSLSocketFactoryEx(null,null,null);
}
public SSLSocketFactoryEx(KeyManager[] km, TrustManager[] tm, SecureRandom random) throws NoSuchAlgorithmException, KeyManagementException
{
initSSLSocketFactoryEx(km, tm, random);
}
public SSLSocketFactoryEx(SSLContext ctx) throws NoSuchAlgorithmException, KeyManagementException
{
initSSLSocketFactoryEx(ctx);
}
public String[] getDefaultCipherSuites()
{
return m_ciphers;
}
public String[] getSupportedCipherSuites()
{
return m_ciphers;
}
public String[] getDefaultProtocols()
{
return m_protocols;
}
public String[] getSupportedProtocols()
{
return m_protocols;
}
public Socket createSocket(Socket s, String host, int port, boolean autoClose) throws IOException
{
SSLSocketFactory factory = m_ctx.getSocketFactory();
SSLSocket ss = (SSLSocket)factory.createSocket(s, host, port, autoClose);
ss.setEnabledProtocols(m_protocols);
ss.setEnabledCipherSuites(m_ciphers);
return ss;
}
public Socket createSocket(InetAddress address, int port, InetAddress localAddress, int localPort) throws IOException
{
SSLSocketFactory factory = m_ctx.getSocketFactory();
SSLSocket ss = (SSLSocket)factory.createSocket(address, port, localAddress, localPort);
ss.setEnabledProtocols(m_protocols);
ss.setEnabledCipherSuites(m_ciphers);
return ss;
}
public Socket createSocket(String host, int port, InetAddress localHost, int localPort) throws IOException
{
SSLSocketFactory factory = m_ctx.getSocketFactory();
SSLSocket ss = (SSLSocket)factory.createSocket(host, port, localHost, localPort);
ss.setEnabledProtocols(m_protocols);
ss.setEnabledCipherSuites(m_ciphers);
return ss;
}
public Socket createSocket(InetAddress host, int port) throws IOException
{
SSLSocketFactory factory = m_ctx.getSocketFactory();
SSLSocket ss = (SSLSocket)factory.createSocket(host, port);
ss.setEnabledProtocols(m_protocols);
ss.setEnabledCipherSuites(m_ciphers);
return ss;
}
public Socket createSocket(String host, int port) throws IOException
{
SSLSocketFactory factory = m_ctx.getSocketFactory();
SSLSocket ss = (SSLSocket)factory.createSocket(host, port);
ss.setEnabledProtocols(m_protocols);
ss.setEnabledCipherSuites(m_ciphers);
return ss;
}
private void initSSLSocketFactoryEx(KeyManager[] km, TrustManager[] tm, SecureRandom random)
throws NoSuchAlgorithmException, KeyManagementException
{
m_ctx = SSLContext.getInstance("TLS");
m_ctx.init(km, tm, random);
m_protocols = GetProtocolList();
m_ciphers = GetCipherList();
}
private void initSSLSocketFactoryEx(SSLContext ctx)
throws NoSuchAlgorithmException, KeyManagementException
{
m_ctx = ctx;
m_protocols = GetProtocolList();
m_ciphers = GetCipherList();
}
protected String[] GetProtocolList()
{
String[] preferredProtocols = { "TLSv1", "TLSv1.1", "TLSv1.2", "TLSv1.3" };
String[] availableProtocols = null;
SSLSocket socket = null;
try
{
SSLSocketFactory factory = m_ctx.getSocketFactory();
socket = (SSLSocket)factory.createSocket();
availableProtocols = socket.getSupportedProtocols();
Arrays.sort(availableProtocols);
}
catch(Exception e)
{
return new String[]{ "TLSv1" };
}
finally
{
if(socket != null)
socket.close();
}
List<String> aa = new ArrayList<String>();
for(int i = 0; i < preferredProtocols.length; i++)
{
int idx = Arrays.binarySearch(availableProtocols, preferredProtocols[i]);
if(idx >= 0)
aa.add(preferredProtocols[i]);
}
return aa.toArray(new String[0]);
}
protected String[] GetCipherList()
{
String[] preferredCiphers = {
// *_CHACHA20_POLY1305 are 3x to 4x faster than existing cipher suites.
// http://googleonlinesecurity.blogspot.com/2014/04/speeding-up-and-strengthening-https.html
// Use them if available. Normative names can be found at (TLS spec depends on IPSec spec):
// http://tools.ietf.org/html/draft-nir-ipsecme-chacha20-poly1305-01
// http://tools.ietf.org/html/draft-mavrogiannopoulos-chacha-tls-02
"TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305",
"TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305",
"TLS_ECDHE_ECDSA_WITH_CHACHA20_SHA",
"TLS_ECDHE_RSA_WITH_CHACHA20_SHA",
"TLS_DHE_RSA_WITH_CHACHA20_POLY1305",
"TLS_RSA_WITH_CHACHA20_POLY1305",
"TLS_DHE_RSA_WITH_CHACHA20_SHA",
"TLS_RSA_WITH_CHACHA20_SHA",
// Done with bleeding edge, back to TLS v1.2 and below
"TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384",
"TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384",
"TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256",
"TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256",
"TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384",
"TLS_DHE_DSS_WITH_AES_256_GCM_SHA384",
"TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
"TLS_DHE_DSS_WITH_AES_128_GCM_SHA256",
// TLS v1.0 (with some SSLv3 interop)
"TLS_DHE_RSA_WITH_AES_256_CBC_SHA384",
"TLS_DHE_DSS_WITH_AES_256_CBC_SHA256",
"TLS_DHE_RSA_WITH_AES_128_CBC_SHA",
"TLS_DHE_DSS_WITH_AES_128_CBC_SHA",
"TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA",
"TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA",
"SSL_DH_RSA_WITH_3DES_EDE_CBC_SHA",
"SSL_DH_DSS_WITH_3DES_EDE_CBC_SHA",
// RSA key transport sucks, but they are needed as a fallback.
// For example, microsoft.com fails under all versions of TLS
// if they are not included. If only TLS 1.0 is available at
// the client, then google.com will fail too. TLS v1.3 is
// trying to deprecate them, so it will be interesteng to see
// what happens.
"TLS_RSA_WITH_AES_256_CBC_SHA256",
"TLS_RSA_WITH_AES_256_CBC_SHA",
"TLS_RSA_WITH_AES_128_CBC_SHA256",
"TLS_RSA_WITH_AES_128_CBC_SHA"
};
String[] availableCiphers = null;
try
{
SSLSocketFactory factory = m_ctx.getSocketFactory();
availableCiphers = factory.getSupportedCipherSuites();
Arrays.sort(availableCiphers);
}
catch(Exception e)
{
return new String[] {
"TLS_DHE_DSS_WITH_AES_128_CBC_SHA",
"TLS_DHE_DSS_WITH_AES_256_CBC_SHA",
"TLS_DHE_RSA_WITH_AES_128_CBC_SHA",
"TLS_DHE_RSA_WITH_AES_256_CBC_SHA",
"TLS_RSA_WITH_AES_256_CBC_SHA256",
"TLS_RSA_WITH_AES_256_CBC_SHA",
"TLS_RSA_WITH_AES_128_CBC_SHA256",
"TLS_RSA_WITH_AES_128_CBC_SHA",
"TLS_EMPTY_RENEGOTIATION_INFO_SCSV"
};
}
List<String> aa = new ArrayList<String>();
for(int i = 0; i < preferredCiphers.length; i++)
{
int idx = Arrays.binarySearch(availableCiphers, preferredCiphers[i]);
if(idx >= 0)
aa.add(preferredCiphers[i]);
}
aa.add("TLS_EMPTY_RENEGOTIATION_INFO_SCSV");
return aa.toArray(new String[0]);
}
private SSLContext m_ctx;
private String[] m_ciphers;
private String[] m_protocols;
}
EDIT: I tried using @override before the corresponding method:
@Override
public Socket createSocket(Socket s, String host, int port, boolean autoClose) throws IOException
{
SSLSocketFactory factory = m_ctx.getSocketFactory();
SSLSocket ss = (SSLSocket)factory.createSocket(s, host, port, autoClose);
ss.setEnabledProtocols(m_protocols);
ss.setEnabledCipherSuites(m_ciphers);
return ss;
}
Nothing has changed, the problem still exists.
Also, please note that there is this part at the end of the code:
@Override
public Socket createSocket(Socket arg0, String arg1, int arg2, boolean arg3)
throws IOException {
// TODO Auto-generated method stub
return null;
}
The error went away when I commented out this method. SSLFactory is built in a class. How can I rewrite it to test its code?
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Your problem is something that createSocket(Socket, String, int, boolean)
already exists in the superclass you are extending ( SSLSocketFactory
).
When extending a class in Java, the methods in that superclass become methods in the subclass (unless the method allows it ). So when you add a method createSocket(Socket, String, int, boolean)
to your subclass, eclipse thinks that you are trying to define a new method with the same signature as the superclass's method. Try adding an annotation @Override
above your version of the method.
Or, since the superclass already implements this method, you can remove your implementation and still be able to call createSocket(Socket, String, int, boolean)
through your class SSLSocketFactoryEx
.
Edit: Given the information you provided, I need to revisit this answer. For you, it's not just that you tried to override the super-method, but rather that the super-method was already overridden in your class. If you need to preserve the functionality of your method (i.e. the implementation is SSLSocketFactory
createSocket(Socket, String, int, boolean)
not sufficient for your needs), you should remove the other Overridden method. Overriding only works once for each subclass, so you cannot override the same method twice. So just remove one of the Overridden methods and paste your code in the other so that you only have one implementation in your class.
Be aware that Java allows methods with the same name with different parameters. But simply renaming parameters does not count as different parameters. Both of these methods in your class have the same signature createSocket(Socket, String, int, boolean)
regardless of the parameter names.
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