| 1 | package be.nikiroo.utils.serial.server; |
| 2 | |
| 3 | import java.io.IOException; |
| 4 | import java.net.Socket; |
| 5 | |
| 6 | import javax.net.ssl.SSLException; |
| 7 | |
| 8 | /** |
| 9 | * Base class used for the server basic handling. |
| 10 | * <p> |
| 11 | * It represents a single action: a server is expected to execute one action for |
| 12 | * each client action. |
| 13 | * |
| 14 | * @author niki |
| 15 | */ |
| 16 | abstract class ConnectActionServer { |
| 17 | private boolean closing; |
| 18 | |
| 19 | /** |
| 20 | * The underlying {@link ConnectAction}. |
| 21 | * <p> |
| 22 | * Cannot be NULL. |
| 23 | */ |
| 24 | protected ConnectAction action; |
| 25 | |
| 26 | /** |
| 27 | * Create a new {@link ConnectActionServer}. |
| 28 | * |
| 29 | * @param s |
| 30 | * the socket to bind to |
| 31 | * @param key |
| 32 | * an optional key to encrypt all the communications (if NULL, |
| 33 | * everything will be sent in clear text) |
| 34 | */ |
| 35 | public ConnectActionServer(Socket s, String key) { |
| 36 | action = new ConnectAction(s, true, key) { |
| 37 | @Override |
| 38 | protected void action() throws Exception { |
| 39 | ConnectActionServer.this.serverHello(); |
| 40 | ConnectActionServer.this.action(); |
| 41 | } |
| 42 | |
| 43 | @Override |
| 44 | protected void onError(Exception e) { |
| 45 | ConnectActionServer.this.onError(e); |
| 46 | } |
| 47 | }; |
| 48 | } |
| 49 | |
| 50 | /** |
| 51 | * Send the HELLO message (check that the client sends a String "HELLO" and |
| 52 | * send it back, to check I/O and encryption modes). |
| 53 | * |
| 54 | * @throws IOException |
| 55 | * in case of I/O error |
| 56 | * @throws SSLException |
| 57 | * in case of encryption error |
| 58 | */ |
| 59 | protected void serverHello() throws IOException, SSLException { |
| 60 | String HELLO = action.recString(); |
| 61 | if (!"HELLO".equals(HELLO)) { |
| 62 | throw new SSLException("Server did not accept the encryption key"); |
| 63 | } |
| 64 | action.sendString(HELLO); |
| 65 | } |
| 66 | |
| 67 | /** |
| 68 | * Actually start the process and call the action (synchronous). |
| 69 | */ |
| 70 | public void connect() { |
| 71 | action.connect(); |
| 72 | } |
| 73 | |
| 74 | /** |
| 75 | * Actually start the process and call the action (asynchronous). |
| 76 | */ |
| 77 | public void connectAsync() { |
| 78 | new Thread(new Runnable() { |
| 79 | @Override |
| 80 | public void run() { |
| 81 | connect(); |
| 82 | } |
| 83 | }).start(); |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * Stop the client/server connection on behalf of the server (usually, the |
| 88 | * client connects then is allowed to send as many requests as it wants; in |
| 89 | * some cases, though, the server may wish to forcefully close the |
| 90 | * connection and can do via this value, when it is set to TRUE). |
| 91 | * <p> |
| 92 | * Example of usage: the client failed an authentication check, cut the |
| 93 | * connection here and now. |
| 94 | * |
| 95 | * @return TRUE when it is |
| 96 | */ |
| 97 | public boolean isClosing() { |
| 98 | return closing; |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * Can be called to stop the client/server connection on behalf of the |
| 103 | * server (usually, the client connects then is allowed to send as many |
| 104 | * requests as it wants; in some cases, though, the server may wish to |
| 105 | * forcefully close the connection and can do so by calling this method). |
| 106 | * <p> |
| 107 | * Example of usage: the client failed an authentication check, cut the |
| 108 | * connection here and now. |
| 109 | */ |
| 110 | public void close() { |
| 111 | closing = true; |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * The total amount of bytes received. |
| 116 | * |
| 117 | * @return the amount of bytes received |
| 118 | */ |
| 119 | public long getBytesReceived() { |
| 120 | return action.getBytesReceived(); |
| 121 | } |
| 122 | |
| 123 | /** |
| 124 | * The total amount of bytes sent. |
| 125 | * |
| 126 | * @return the amount of bytes sent |
| 127 | */ |
| 128 | public long getBytesSent() { |
| 129 | return action.getBytesWritten(); |
| 130 | } |
| 131 | |
| 132 | /** |
| 133 | * Method that will be called when an action is performed on the server. |
| 134 | * |
| 135 | * @throws Exception |
| 136 | * in case of I/O error |
| 137 | */ |
| 138 | @SuppressWarnings("unused") |
| 139 | public void action() throws Exception { |
| 140 | } |
| 141 | |
| 142 | /** |
| 143 | * Handler called when an unexpected error occurs in the code. |
| 144 | * <p> |
| 145 | * Will just ignore the error by default. |
| 146 | * |
| 147 | * @param e |
| 148 | * the exception that occurred |
| 149 | */ |
| 150 | protected void onError(@SuppressWarnings("unused") Exception e) { |
| 151 | } |
| 152 | } |