/*
* Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.engine;
import java.io.IOException;
import java.net.Socket;
import java.util.ArrayList;
import org.h2.api.DatabaseEventListener;
import org.h2.api.ErrorCode;
import org.h2.api.JavaObjectSerializer;
import org.h2.command.CommandInterface;
import org.h2.command.CommandRemote;
import org.h2.command.dml.SetTypes;
import org.h2.jdbc.JdbcSQLException;
import org.h2.message.DbException;
import org.h2.message.Trace;
import org.h2.message.TraceSystem;
import org.h2.result.ResultInterface;
import org.h2.store.DataHandler;
import org.h2.store.FileStore;
import org.h2.store.LobStorageFrontend;
import org.h2.store.LobStorageInterface;
import org.h2.store.fs.FileUtils;
import org.h2.util.JdbcUtils;
import org.h2.util.MathUtils;
import org.h2.util.NetUtils;
import org.h2.util.New;
import org.h2.util.SmallLRUCache;
import org.h2.util.StringUtils;
import org.h2.util.TempFileDeleter;
import org.h2.value.CompareMode;
import org.h2.value.Transfer;
import org.h2.value.Value;
/**
* The client side part of a session when using the server mode. This object
* communicates with a Session on the server side.
*/
public class SessionRemote extends SessionWithState implements DataHandler {
public static final int SESSION_PREPARE = 0;
public static final int SESSION_CLOSE = 1;
public static final int COMMAND_EXECUTE_QUERY = 2;
public static final int COMMAND_EXECUTE_UPDATE = 3;
public static final int COMMAND_CLOSE = 4;
public static final int RESULT_FETCH_ROWS = 5;
public static final int RESULT_RESET = 6;
public static final int RESULT_CLOSE = 7;
public static final int COMMAND_COMMIT = 8;
public static final int CHANGE_ID = 9;
public static final int COMMAND_GET_META_DATA = 10;
public static final int SESSION_PREPARE_READ_PARAMS = 11;
public static final int SESSION_SET_ID = 12;
public static final int SESSION_CANCEL_STATEMENT = 13;
public static final int SESSION_CHECK_KEY = 14;
public static final int SESSION_SET_AUTOCOMMIT = 15;
public static final int SESSION_HAS_PENDING_TRANSACTION = 16;
public static final int LOB_READ = 17;
public static final int SESSION_PREPARE_READ_PARAMS2 = 18;
public static final int STATUS_ERROR = 0;
public static final int STATUS_OK = 1;
public static final int STATUS_CLOSED = 2;
public static final int STATUS_OK_STATE_CHANGED = 3;
private static SessionFactory sessionFactory;
//只有connectionInfo.isRemote()为true时traceSystem才有值，
//否则是一个内存数据库，connectEmbeddedOrServer返回的是org.h2.engine.Session,
//此时由org.h2.engine.Session得到traceSystem
private TraceSystem traceSystem;
private Trace trace;
private ArrayList<Transfer> transferList = New.arrayList();
private int nextId;
private boolean autoCommit = true; //集群环境上这个参数其实没意义
private CommandInterface autoCommitFalse, autoCommitTrue;
private ConnectionInfo connectionInfo;
private String databaseName;
private String cipher;
private byte[] fileEncryptionKey;
private final Object lobSyncObject = new Object();
private String sessionId;
private int clientVersion;
private boolean autoReconnect;
private int lastReconnect;
private SessionInterface embedded;
private DatabaseEventListener eventListener;
private LobStorageFrontend lobStorage;
private boolean cluster;
private TempFileDeleter tempFileDeleter;
private JavaObjectSerializer javaObjectSerializer;
private volatile boolean javaObjectSerializerInitialized;
private CompareMode compareMode = CompareMode.getInstance(null, 0);
public SessionRemote(ConnectionInfo ci) {
this.connectionInfo = ci;
}
@Override
public ArrayList<String> getClusterServers() {
ArrayList<String> serverList = new ArrayList<String>();
for (int i = 0; i < transferList.size(); i++) {
Transfer transfer = transferList.get(i);
serverList.add(transfer.getSocket().getInetAddress().
getHostAddress() + ":" +
transfer.getSocket().getPort());
}
return serverList;
}
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_16);
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 boolean hasPendingTransaction() {
if (clientVersion < Constants.TCP_PROTOCOL_VERSION_10) {
return true;
}
for (int i = 0, count = 0; i < transferList.size(); i++) {
Transfer transfer = transferList.get(i);
try {
traceOperation("SESSION_HAS_PENDING_TRANSACTION", 0);
transfer.writeInt(
SessionRemote.SESSION_HAS_PENDING_TRANSACTION);
done(transfer);
return transfer.readInt() != 0;
} catch (IOException e) {
removeServer(e, i--, ++count);
}
}
return true;
}
@Override
public void cancel() {
// this method is called when closing the connection
// the statement that is currently running is not canceled in this case
// however Statement.cancel is supported
}
/**
* 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 void checkClusterDisableAutoCommit(String serverList) {
if (autoCommit && transferList.size() > 1) {
setAutoCommitSend(false);
CommandInterface c = prepareCommand(
"SET CLUSTER " + serverList, Integer.MAX_VALUE);
// this will set autoCommit to false
c.executeUpdate();
// so we need to switch it on
autoCommit = true;
cluster = true;
}
}
public int getClientVersion() {
return clientVersion;
}
@Override
public boolean getAutoCommit() {
return autoCommit;
}
@Override
public void setAutoCommit(boolean autoCommit) {
if (!cluster) {
setAutoCommitSend(autoCommit);
}
this.autoCommit = autoCommit;
}
public void setAutoCommitFromServer(boolean autoCommit) {
if (cluster) {
if (autoCommit) {
// the user executed SET AUTOCOMMIT TRUE
setAutoCommitSend(false);
this.autoCommit = true;
}
} else {
this.autoCommit = autoCommit;
}
}
// VERSION_8开始通过SESSION_SET_AUTOCOMMIT协议指令，以前的版本通过SET AUTOCOMMIT语句
// 对于commit和rollback则没有对应的协议指令，只能通过COMMIT、ROLLBACK语句
private synchronized void setAutoCommitSend(boolean autoCommit) {
if (clientVersion >= Constants.TCP_PROTOCOL_VERSION_8) {
for (int i = 0, count = 0; i < transferList.size(); i++) {
Transfer transfer = transferList.get(i);
try {
traceOperation("SESSION_SET_AUTOCOMMIT", autoCommit ? 1 : 0);
transfer.writeInt(SessionRemote.SESSION_SET_AUTOCOMMIT).
writeBoolean(autoCommit);
done(transfer);
} catch (IOException e) {
removeServer(e, i--, ++count);
}
}
} else {
if (autoCommit) {
if (autoCommitTrue == null) {
autoCommitTrue = prepareCommand(
"SET AUTOCOMMIT TRUE", Integer.MAX_VALUE);
}
autoCommitTrue.executeUpdate();
} else {
if (autoCommitFalse == null) {
autoCommitFalse = prepareCommand(
"SET AUTOCOMMIT FALSE", Integer.MAX_VALUE);
}
autoCommitFalse.executeUpdate();
}
}
}
/**
* Calls COMMIT if the session is in cluster mode.
*/
public void autoCommitIfCluster() {
if (autoCommit && cluster) {
// server side auto commit is off because of race conditions
// (update set id=1 where id=0, but update set id=2 where id=0 is
// faster)
for (int i = 0, count = 0; i < transferList.size(); i++) {
Transfer transfer = transferList.get(i);
try {
traceOperation("COMMAND_COMMIT", 0);
transfer.writeInt(SessionRemote.COMMAND_COMMIT);
done(transfer);
} catch (IOException e) {
removeServer(e, i--, ++count);
}
}
}
}
private String getFilePrefix(String dir) {
StringBuilder buff = new StringBuilder(dir);
buff.append('/');
for (int i = 0; i < databaseName.length(); i++) {
char ch = databaseName.charAt(i);
if (Character.isLetterOrDigit(ch)) {
buff.append(ch);
} else {
buff.append('_');
}
}
return buff.toString();
}
@Override
public int getPowerOffCount() {
return 0;
}
@Override
public void setPowerOffCount(int count) {
throw DbException.getUnsupportedException("remote");
}
/**
* Open a new (remote or embedded) session.
*
* @param openNew whether to open a new session in any case
* @return the session
*/
public SessionInterface connectEmbeddedOrServer(boolean openNew) {
ConnectionInfo ci = connectionInfo;
//TCP远程数据库
if (ci.isRemote()) {
connectServer(ci);
return this;
}
//下面的代码是用于嵌入式或内存数据库的场景
// create the session using reflection,
// so that the JDBC layer can be compiled without it
boolean autoServerMode = Boolean.parseBoolean(
ci.getProperty("AUTO_SERVER", "false"));
ConnectionInfo backup = null;
try {
if (autoServerMode) {
backup = ci.clone();
connectionInfo = ci.clone();
}
if (openNew) {
ci.setProperty("OPEN_NEW", "true");
}
if (sessionFactory == null) {
sessionFactory = (SessionFactory) Class.forName(
"org.h2.engine.Engine").getMethod("getInstance").invoke(null);
}
return sessionFactory.createSession(ci);
} catch (Exception re) {
DbException e = DbException.convert(re);
if (e.getErrorCode() == ErrorCode.DATABASE_ALREADY_OPEN_1) {
if (autoServerMode) {
String serverKey = ((JdbcSQLException) e.getSQLException()).
getSQL();
if (serverKey != null) {
backup.setServerKey(serverKey);
// OPEN_NEW must be removed now, otherwise
// opening a session with AUTO_SERVER fails
// if another connection is already open
backup.removeProperty("OPEN_NEW", null);
connectServer(backup);
return this;
}
}
}
throw e;
}
}
private void connectServer(ConnectionInfo ci) {
String name = ci.getName(); //例如: "//localhost:9092/mydb"
if (name.startsWith("//")) {
name = name.substring("//".length()); //变成"localhost:9092/mydb"
}
int idx = name.indexOf('/');
if (idx < 0) {
throw ci.getFormatException();
}
databaseName = name.substring(idx + 1); //是"mydb"
String server = name.substring(0, idx); //是"localhost:9092"
traceSystem = new TraceSystem(null);
//不是跟踪级别文件，是文件跟踪级别
//跟下面的traceLevelSystemOut对应(SystemOut跟踪级别)
//两者都是一个数字，如:
//-------------------------------
//prop.setProperty("TRACE_LEVEL_FILE", "10");
//prop.setProperty("TRACE_LEVEL_SYSTEM_OUT", "20");
//-------------------------------
String traceLevelFile = ci.getProperty(SetTypes.TRACE_LEVEL_FILE, null);
if (traceLevelFile != null) {
int level = Integer.parseInt(traceLevelFile);
String prefix = getFilePrefix(SysProperties.CLIENT_TRACE_DIRECTORY); //如: "trace.db//mydb"
try {
traceSystem.setLevelFile(level);
if (level > 0 && level < 4) {
//如: E:/H2/eclipse-workspace-client/trace.db/mydb.1647ee04bd9fa205.0.trace.db
String file = FileUtils.createTempFile(prefix, Constants.SUFFIX_TRACE_FILE, false, false);
traceSystem.setFileName(file);
}
} catch (IOException e) {
throw DbException.convertIOException(e, prefix);
}
}
String traceLevelSystemOut = ci.getProperty(
SetTypes.TRACE_LEVEL_SYSTEM_OUT, null);
if (traceLevelSystemOut != null) {
int level = Integer.parseInt(traceLevelSystemOut);
traceSystem.setLevelSystemOut(level);
}
trace = traceSystem.getTrace(Trace.JDBC);
String serverList = null;
if (server.indexOf(',') >= 0) {
serverList = StringUtils.quoteStringSQL(server);
ci.setProperty("CLUSTER", Constants.CLUSTERING_ENABLED);
}
autoReconnect = Boolean.parseBoolean(ci.getProperty(
"AUTO_RECONNECT", "false"));
// AUTO_SERVER implies AUTO_RECONNECT
boolean autoServer = Boolean.parseBoolean(ci.getProperty(
"AUTO_SERVER", "false"));
if (autoServer && serverList != null) {
throw DbException
.getUnsupportedException("autoServer && serverList != null");
}
autoReconnect |= autoServer;
if (autoReconnect) {
String className = ci.getProperty("DATABASE_EVENT_LISTENER");
if (className != null) {
className = StringUtils.trim(className, true, true, "'");
try {
//在server端还会重新new出实例
//这里的实例只是在client端用
eventListener = (DatabaseEventListener) JdbcUtils
.loadUserClass(className).newInstance();
} catch (Throwable e) {
throw DbException.convert(e);
}
}
}
//同一个数据库第一次打开时如果没使用CIPHER，那么接下来打开也不能用CIPHER了，
//如果第一次用了CIPHER，那么就一直要用CIPHER连它
cipher = ci.getProperty("CIPHER"); //只支持XTEA、AES、FOG
if (cipher != null) {
fileEncryptionKey = MathUtils.secureRandomBytes(32); //只是在client端用
}
String[] servers = StringUtils.arraySplit(server, ',', true);
int len = servers.length;
transferList.clear();
sessionId = StringUtils.convertBytesToHex(MathUtils.secureRandomBytes(32));
// TODO cluster: support more than 2 connections
boolean switchOffCluster = false;
try {
for (int i = 0; i < len; i++) {
String s = servers[i];
try {
Transfer trans = initTransfer(ci, databaseName, s);
transferList.add(trans);
} catch (IOException e) {
if (len == 1) {
throw DbException.get(ErrorCode.CONNECTION_BROKEN_1, e, e + ": " + s);
}
switchOffCluster = true;
}
}
//如果没有一台server初始化成功，那么这里直接抛异常了
checkClosed();
if (switchOffCluster) { //集群中只要有一台server初始化失败就关掉集群
switchOffCluster();
}
//如果是集群，这里头会把所有server对应的session的autoCommit设为false
checkClusterDisableAutoCommit(serverList);
} catch (DbException e) {
traceSystem.close();
throw e;
}
}
private void switchOffCluster() {
CommandInterface ci = prepareCommand("SET CLUSTER ''", Integer.MAX_VALUE);
ci.executeUpdate();
}
/**
* Remove a server from the list of cluster nodes and disables the cluster
* mode.
*
* @param e the exception (used for debugging)
* @param i the index of the server to remove
* @param count the retry count index
*/
public void removeServer(IOException e, int i, int count) {
trace.error(e, "removing server because of exception");
transferList.remove(i);
if (transferList.size() == 0 && autoReconnect(count)) {
return;
}
checkClosed();
switchOffCluster();
}
@Override
public synchronized CommandInterface prepareCommand(String sql, int fetchSize) {
checkClosed();
return new CommandRemote(this, transferList, sql, fetchSize);
}
/**
* Automatically re-connect if necessary and if configured to do so.
*
* @param count the retry count index
* @return true if reconnected
*/
private boolean autoReconnect(int count) {
//如果没有关闭则不重连
if (!isClosed()) {
return false;
}
//如果AUTO_RECONNECT参数是false则不重连
if (!autoReconnect) {
return false;
}
//非集群环境，并且是非自动提交模式，则不重连
if (!cluster && !autoCommit) {
return false;
}
//重连次数大于h2.maxReconnect(默认三次)，则不再重连
if (count > SysProperties.MAX_RECONNECT) {
return false;
}
lastReconnect++;
while (true) {
try {
embedded = connectEmbeddedOrServer(false);
break;
} catch (DbException e) {
if (e.getErrorCode() != ErrorCode.DATABASE_IS_IN_EXCLUSIVE_MODE) {
throw e;
}
// exclusive mode: re-try endlessly
try {
Thread.sleep(500);
} catch (Exception e2) {
// ignore
}
}
}
if (embedded == this) {
// connected to a server somewhere else
embedded = null;
} else {
// opened an embedded connection now -
// must connect to this database in server mode
// unfortunately
connectEmbeddedOrServer(true);
}
recreateSessionState();
if (eventListener != null) {
eventListener.setProgress(DatabaseEventListener.STATE_RECONNECTED,
databaseName, count, SysProperties.MAX_RECONNECT);
}
return true;
}
/**
* Check if this session is closed and throws an exception if so.
*
* @throws DbException if the session is closed
*/
public void checkClosed() {
if (isClosed()) {
throw DbException.get(ErrorCode.CONNECTION_BROKEN_1, "session closed");
}
}
//关闭连接时才关session，调用些方法会使用server端释放session相关的资源，比如线程结束
@Override
public void close() {
RuntimeException closeError = null;
if (transferList != null) {
synchronized (this) {
for (Transfer transfer : transferList) {
try {
traceOperation("SESSION_CLOSE", 0);
transfer.writeInt(SessionRemote.SESSION_CLOSE);
done(transfer);
transfer.close();
} catch (RuntimeException e) {
trace.error(e, "close");
closeError = e;
} catch (Exception e) {
trace.error(e, "close");
}
}
}
transferList = null;
}
traceSystem.close();
if (embedded != null) {
embedded.close();
embedded = null;
}
if (closeError != null) {
throw closeError;
}
}
@Override
public Trace getTrace() {
return traceSystem.getTrace(Trace.JDBC);
}
public int getNextId() {
return nextId++;
}
public int getCurrentId() {
return nextId;
}
/**
* Called to flush the output after data has been sent to the server and
* just before receiving data. This method also reads the status code from
* the server and throws any exception the server sent.
*
* @param transfer the transfer object
* @throws DbException if the server sent an exception
* @throws IOException if there is a communication problem between client
* and server
*/
public void done(Transfer transfer) throws IOException {
transfer.flush();
int status = transfer.readInt();
if (status == STATUS_ERROR) {
String sqlstate = transfer.readString();
String message = transfer.readString();
String sql = transfer.readString();
int errorCode = transfer.readInt();
String stackTrace = transfer.readString();
JdbcSQLException s = new JdbcSQLException(message, sql, sqlstate,
errorCode, null, stackTrace);
if (errorCode == ErrorCode.CONNECTION_BROKEN_1) {
// allow re-connect
IOException e = new IOException(s.toString(), s);
throw e;
}
throw DbException.convert(s);
} else if (status == STATUS_CLOSED) {
transferList = null;
} else if (status == STATUS_OK_STATE_CHANGED) {
sessionStateChanged = true;
} else if (status == STATUS_OK) {
// ok
} else {
throw DbException.get(ErrorCode.CONNECTION_BROKEN_1,
"unexpected status " + status);
}
}
/**
* Returns true if the connection was opened in cluster mode.
*
* @return true if it is
*/
public boolean isClustered() {
return cluster;
}
@Override
public boolean isClosed() {
return transferList == null || transferList.size() == 0;
}
/**
* Write the operation to the trace system if debug trace is enabled.
*
* @param operation the operation performed
* @param id the id of the operation
*/
public void traceOperation(String operation, int id) {
if (trace.isDebugEnabled()) {
trace.debug("{0} {1}", operation, id);
}
}
@Override
public void checkPowerOff() {
// ok
}
@Override
public void checkWritingAllowed() {
// ok
}
@Override
public String getDatabasePath() {
return "";
}
@Override
public String getLobCompressionAlgorithm(int type) {
return null;
}
@Override
public int getMaxLengthInplaceLob() {
return SysProperties.LOB_CLIENT_MAX_SIZE_MEMORY;
}
@Override
public FileStore openFile(String name, String mode, boolean mustExist) {
if (mustExist && !FileUtils.exists(name)) {
throw DbException.get(ErrorCode.FILE_NOT_FOUND_1, name);
}
FileStore store;
if (cipher == null) {
store = FileStore.open(this, name, mode);
} else {
store = FileStore.open(this, name, mode, cipher, fileEncryptionKey, 0);
}
store.setCheckedWriting(false);
try {
store.init();
} catch (DbException e) {
store.closeSilently();
throw e;
}
return store;
}
@Override
public DataHandler getDataHandler() {
return this;
}
@Override
public Object getLobSyncObject() {
return lobSyncObject;
}
@Override
public SmallLRUCache<String, String[]> getLobFileListCache() {
return null;
}
public int getLastReconnect() {
return lastReconnect;
}
@Override
public TempFileDeleter getTempFileDeleter() {
if (tempFileDeleter == null) {
tempFileDeleter = TempFileDeleter.getInstance();
}
return tempFileDeleter;
}
@Override
public boolean isReconnectNeeded(boolean write) {
return false;
}
@Override
public SessionInterface reconnect(boolean write) {
return this;
}
@Override
public void afterWriting() {
// nothing to do
}
@Override
public LobStorageInterface getLobStorage() {
if (lobStorage == null) {
lobStorage = new LobStorageFrontend(this);
}
return lobStorage;
}
@Override
public synchronized int readLob(long lobId, byte[] hmac, long offset,
byte[] buff, int off, int length) {
checkClosed();
for (int i = 0, count = 0; i < transferList.size(); i++) {
Transfer transfer = transferList.get(i);
try {
traceOperation("LOB_READ", (int) lobId);
transfer.writeInt(SessionRemote.LOB_READ);
transfer.writeLong(lobId);
if (clientVersion >= Constants.TCP_PROTOCOL_VERSION_12) {
transfer.writeBytes(hmac);
}
transfer.writeLong(offset);
transfer.writeInt(length);
done(transfer);
length = transfer.readInt();
if (length <= 0) {
return length;
}
transfer.readBytes(buff, off, length);
return length;
} catch (IOException e) {
removeServer(e, i--, ++count);
}
}
return 1;
}
@Override
public JavaObjectSerializer getJavaObjectSerializer() {
initJavaObjectSerializer();
return javaObjectSerializer;
}
private void initJavaObjectSerializer() {
if (javaObjectSerializerInitialized) {
return;
}
synchronized (this) {
if (javaObjectSerializerInitialized) {
return;
}
String serializerFQN = readSerializationSettings();
if (serializerFQN != null) {
serializerFQN = serializerFQN.trim();
if (!serializerFQN.isEmpty() && !serializerFQN.equals("null")) {
try {
javaObjectSerializer = (JavaObjectSerializer) JdbcUtils
.loadUserClass(serializerFQN).newInstance();
} catch (Exception e) {
throw DbException.convert(e);
}
}
}
javaObjectSerializerInitialized = true;
}
}
/**
* Read the serializer name from the persistent database settings.
*
* @return the serializer
*/
private String readSerializationSettings() {
String javaObjectSerializerFQN = null;
CommandInterface ci = prepareCommand(
"SELECT VALUE FROM INFORMATION_SCHEMA.SETTINGS "+
" WHERE NAME='JAVA_OBJECT_SERIALIZER'", Integer.MAX_VALUE);
try {
ResultInterface result = ci.executeQuery(0, false);
if (result.next()) {
Value[] row = result.currentRow();
javaObjectSerializerFQN = row[0].getString();
}
} finally {
ci.close();
}
return javaObjectSerializerFQN;
}
@Override
public void addTemporaryLob(Value v) {
// do nothing
}
@Override
public CompareMode getCompareMode() {
return compareMode;
}
@Override
public boolean isRemote() {
return true;
}
@Override
public String getCurrentSchemaName() {
throw DbException.getUnsupportedException("getSchema && remote session");
}
@Override
public void setCurrentSchemaName(String schema) {
throw DbException.getUnsupportedException("setSchema && remote session");
}
}