/**
* Cancel the statement with the given id.
*
* @param id the statement id
*/
public void cancelStatement(int id) {
for (Transfer transfer : transferList) {
try {
Transfer trans = transfer.openNewConnection();
trans.init();
trans.writeInt(clientVersion);
trans.writeInt(clientVersion);
trans.writeString(null);
trans.writeString(null);
trans.writeString(sessionId);
trans.writeInt(SessionRemote.SESSION_CANCEL_STATEMENT);
trans.writeInt(id);
trans.close();
} catch (IOException e) {
trace.debug(e, "could not cancel statement");
}
}
}
private Transfer initTransfer(ConnectionInfo ci, String db, String server) throws IOException {
Socket socket = NetUtils.createSocket(server, Constants.DEFAULT_TCP_PORT, ci.isSSL());
Transfer trans = new Transfer(this);
trans.setSocket(socket);
trans.setSSL(ci.isSSL());
trans.init();
trans.writeInt(Constants.TCP_PROTOCOL_VERSION_6);
trans.writeInt(Constants.TCP_PROTOCOL_VERSION_15);
trans.writeString(db);
trans.writeString(ci.getOriginalURL());
trans.writeString(ci.getUserName());
trans.writeBytes(ci.getUserPasswordHash());
trans.writeBytes(ci.getFilePasswordHash());
String[] keys = ci.getKeys();
trans.writeInt(keys.length);
for (String key : keys) {
trans.writeString(key).writeString(ci.getProperty(key));
}
try {
done(trans);
clientVersion = trans.readInt();
trans.setVersion(clientVersion);
if (clientVersion >= Constants.TCP_PROTOCOL_VERSION_14) {
if (ci.getFileEncryptionKey() != null) {
trans.writeBytes(ci.getFileEncryptionKey());
}
}
trans.writeInt(SessionRemote.SESSION_SET_ID);
trans.writeString(sessionId);
done(trans);
if (clientVersion >= Constants.TCP_PROTOCOL_VERSION_15) {
autoCommit = trans.readBoolean();
} else {
autoCommit = true;
}
return trans;
} catch (DbException e) {
trans.close();
throw e;
}
}
@Override
public void run() {
try {
transfer.init();
trace("Connect");
// TODO server: should support a list of allowed databases
// and a list of allowed clients
try {
// 如果没有加-tcpAllowOthers参数，那么只接受本地连接
if (!server.allow(transfer.getSocket())) {
throw DbException.get(ErrorCode.REMOTE_CONNECTION_NOT_ALLOWED);
}
int minClientVersion = transfer.readInt();
if (minClientVersion < Constants.TCP_PROTOCOL_VERSION_6) {
throw DbException.get(
ErrorCode.DRIVER_VERSION_ERROR_2,
"" + clientVersion,
"" + Constants.TCP_PROTOCOL_VERSION_6);
} else if (minClientVersion > Constants.TCP_PROTOCOL_VERSION_12) {
throw DbException.get(
ErrorCode.DRIVER_VERSION_ERROR_2,
"" + clientVersion,
"" + Constants.TCP_PROTOCOL_VERSION_12);
}
int maxClientVersion = transfer.readInt();
if (maxClientVersion >= Constants.TCP_PROTOCOL_VERSION_12) {
clientVersion = Constants.TCP_PROTOCOL_VERSION_12;
} else {
clientVersion = minClientVersion;
}
transfer.setVersion(clientVersion);
String db = transfer.readString();
String originalURL = transfer.readString();
if (db == null && originalURL == null) {
String targetSessionId = transfer.readString();
int command = transfer.readInt();
stop = true;
if (command == SessionRemote.SESSION_CANCEL_STATEMENT) {
// cancel a running statement
int statementId = transfer.readInt();
server.cancelStatement(targetSessionId, statementId);
} else if (command == SessionRemote.SESSION_CHECK_KEY) {
// check if this is the correct server
db = server.checkKeyAndGetDatabaseName(targetSessionId);
if (!targetSessionId.equals(db)) {
transfer.writeInt(SessionRemote.STATUS_OK);
} else {
transfer.writeInt(SessionRemote.STATUS_ERROR);
}
}
}
// 启动TcpServer时加"-baseDir"或者像这样System.setProperty("h2.baseDir", "E:\\H2\\baseDir")
String baseDir = server.getBaseDir();
if (baseDir == null) {
baseDir = SysProperties.getBaseDir();
}
// 例如启动TcpServer时，指定了"-key mydb mydatabase"，
// 如果db变量是mydb，那么实际上就是mydatabase，相当于做一次映射
// 如果db变量不是mydb，那么抛错: org.h2.jdbc.JdbcSQLException: Wrong user name or password [28000-170]
db = server.checkKeyAndGetDatabaseName(db);
ConnectionInfo ci = new ConnectionInfo(db);
ci.setOriginalURL(originalURL);
ci.setUserName(transfer.readString());
// password参数的值已经转换成userPasswordHash和filePasswordHash了，
// 不能由userPasswordHash和filePasswordHash得到原始的password
ci.setUserPasswordHash(transfer.readBytes());
ci.setFilePasswordHash(transfer.readBytes()); // 只有指定"CIPHER"参数时filePasswordHash才是非null的
int len = transfer.readInt();
for (int i = 0; i < len; i++) {
ci.setProperty(transfer.readString(), transfer.readString());
}
// override client's requested properties with server settings
if (baseDir != null) {
ci.setBaseDir(baseDir);
}
if (server.getIfExists()) {
// 启动TcpServer时加"-ifExists"，限制只有数据库存在时客户端才能连接，也就是不允许在客户端创建数据库
ci.setProperty("IFEXISTS", "TRUE");
}
session = Engine.getInstance().createSession(ci);
transfer.setSession(session);
transfer.writeInt(SessionRemote.STATUS_OK);
transfer.writeInt(clientVersion);
transfer.flush();
// 每建立一个新的Session对象时，把它保存到内存数据库management_db_9092的SESSIONS表
server.addConnection(threadId, originalURL, ci.getUserName());
trace("Connected");
} catch (Throwable e) {
sendError(e);
stop = true;
}
while (!stop) {
try {
process();
} catch (Throwable e) {
sendError(e);
}
}
trace("Disconnect");
} catch (Throwable e) {
server.traceError(e);
} finally {
close();
}
}