jdbc: support for sub-set of JDBC escape syntax

Add a driver SQL pre-processing before sending it to the server. The
driver supports sub-set of scalar functions defined by the spec
(appendix C), outer joins, escape clause for SQL LIKE operator, and
limit/offset clause. The processed result can be received using
Connection.nativeSQL() method.

Closes #79
Closes #76
Closes #81
Closes #83
Closes #84
Affects: #108

Author: nicktorwald

src/main/java/org/tarantool/jdbc/EscapeSyntaxParser.java

@@ -63,12 +63,15 @@ public class SQLConnection implements TarantoolConnection {
     private DatabaseMetaData cachedMetadata;
     private int resultSetHoldability = UNSET_HOLDABILITY;
 
+    private final EscapeSyntaxParser escapeSyntaxParser;
+
     public SQLConnection(String url, Properties properties) throws SQLException {
         this.url = url;
         this.properties = properties;
 
         try {
             client = makeSqlClient(makeAddress(properties), makeConfigFromProperties(properties));
+            escapeSyntaxParser = new EscapeSyntaxParser(this);
         } catch (Exception e) {
             throw new SQLException("Couldn't initiate connection using " + SQLDriver.diagProperties(properties), e);
         }
@@ -189,7 +192,7 @@ public CallableStatement prepareCall(String sql,
     @Override
     public String nativeSQL(String sql) throws SQLException {
         checkNotClosed();
-        throw new SQLFeatureNotSupportedException();
+        return escapeSyntaxParser.translate(sql, true);
     }
 
     @Override

src/main/java/org/tarantool/jdbc/EscapedFunctions.java

@@ -6,6 +6,7 @@
 import org.tarantool.Version;
 import org.tarantool.jdbc.type.TarantoolSqlType;
 import org.tarantool.util.ServerVersion;
+import org.tarantool.util.StringUtils;
 import org.tarantool.util.TupleTwo;
 
 import java.sql.Connection;
@@ -179,17 +180,17 @@ public String getSQLKeywords() throws SQLException {
 
     @Override
     public String getNumericFunctions() throws SQLException {
-        return "";
+        return StringUtils.toCsvList(EscapedFunctions.NumericFunction.values());
     }
 
     @Override
     public String getStringFunctions() throws SQLException {
-        return "";
+        return StringUtils.toCsvList(EscapedFunctions.StringFunction.values());
     }
 
     @Override
     public String getSystemFunctions() throws SQLException {
-        return "";
+        return StringUtils.toCsvList(EscapedFunctions.SystemFunction.values());
     }
 
     @Override
@@ -274,7 +275,7 @@ public boolean supportsGroupByBeyondSelect() throws SQLException {
 
     @Override
     public boolean supportsLikeEscapeClause() throws SQLException {
-        return false;
+        return true;
     }
 
     @Override

src/main/java/org/tarantool/jdbc/SQLConnection.java

@@ -43,7 +43,7 @@ public class SQLPreparedStatement extends SQLStatement implements PreparedStatem
 
     public SQLPreparedStatement(SQLConnection connection, String sql, int autoGeneratedKeys) throws SQLException {
         super(connection);
-        this.sql = sql;
+        this.sql = translateQuery(sql);
         this.parameters = new HashMap<>();
         this.autoGeneratedKeys = autoGeneratedKeys;
         setPoolable(true);
@@ -55,7 +55,7 @@ public SQLPreparedStatement(SQLConnection connection,
                                 int resultSetConcurrency,
                                 int resultSetHoldability) throws SQLException {
         super(connection, resultSetType, resultSetConcurrency, resultSetHoldability);
-        this.sql = sql;
+        this.sql = translateQuery(sql);
         this.parameters = new HashMap<>();
         this.autoGeneratedKeys = NO_GENERATED_KEYS;
         setPoolable(true);

src/main/java/org/tarantool/jdbc/SQLDatabaseMetadata.java

@@ -45,6 +45,7 @@ public class SQLStatement implements TarantoolStatement {
     private List<String> batchQueries = new ArrayList<>();
 
     private boolean isCloseOnCompletion;
+    private boolean useEscapeProcessing = true;
 
     private final int resultSetType;
     private final int resultSetConcurrency;
@@ -91,7 +92,7 @@ protected SQLStatement(SQLConnection sqlConnection,
     @Override
     public ResultSet executeQuery(String sql) throws SQLException {
         checkNotClosed();
-        if (!executeInternal(NO_GENERATED_KEYS, sql)) {
+        if (!executeInternal(NO_GENERATED_KEYS, translateQuery(sql))) {
             throw new SQLException("No results were returned", SQLStates.NO_DATA.getSqlState());
         }
         return resultSet;
@@ -106,7 +107,7 @@ public int executeUpdate(String sql) throws SQLException {
     public int executeUpdate(String sql, int autoGeneratedKeys) throws SQLException {
         checkNotClosed();
         JdbcConstants.checkGeneratedKeysConstant(autoGeneratedKeys);
-        if (executeInternal(autoGeneratedKeys, sql)) {
+        if (executeInternal(autoGeneratedKeys, translateQuery(sql))) {
             throw new SQLException(
                 "Result was returned but nothing was expected",
                 SQLStates.TOO_MANY_RESULTS.getSqlState()
@@ -166,7 +167,8 @@ public void setMaxRows(int maxRows) throws SQLException {
 
     @Override
     public void setEscapeProcessing(boolean enable) throws SQLException {
-        throw new SQLFeatureNotSupportedException();
+        checkNotClosed();
+        useEscapeProcessing = enable;
     }
 
     @Override
@@ -208,7 +210,7 @@ public void setCursorName(String name) throws SQLException {
     @Override
     public boolean execute(String sql) throws SQLException {
         checkNotClosed();
-        return executeInternal(NO_GENERATED_KEYS, sql);
+        return executeInternal(NO_GENERATED_KEYS, translateQuery(sql));
     }
 
     @Override
@@ -511,4 +513,8 @@ protected SQLResultSet executeGeneratedKeys(List<Integer> generatedKeys) throws
         return createResultSet(SQLResultHolder.ofQuery(Collections.singletonList(sqlMetaData), rows));
     }
 
+    protected String translateQuery(String sql) throws SQLException {
+        return useEscapeProcessing ? connection.nativeSQL(sql) : sql;
+    }
+
 }

src/main/java/org/tarantool/jdbc/SQLPreparedStatement.java

@@ -7,7 +7,8 @@ public enum SQLStates {
     CONNECTION_DOES_NOT_EXIST("08003"),
     INVALID_PARAMETER_VALUE("22023"),
     INVALID_CURSOR_STATE("24000"),
-    INVALID_TRANSACTION_STATE("25000");
+    INVALID_TRANSACTION_STATE("25000"),
+    SYNTAX_ERROR("42000");
 
     private final String sqlState;
 

src/main/java/org/tarantool/jdbc/SQLStatement.java

@@ -1,5 +1,8 @@
 package org.tarantool.util;
 
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
 public class StringUtils {
 
     public static boolean isEmpty(String string) {
@@ -18,4 +21,10 @@ public static boolean isNotBlank(String string) {
         return !isBlank(string);
     }
 
+    public static String toCsvList(Enum<?>[] values) {
+        return Stream.of(values)
+            .map(Enum::name)
+            .collect(Collectors.joining(","));
+    }
+
 }

src/main/java/org/tarantool/util/SQLStates.java

@@ -0,0 +1,27 @@
+package org.tarantool.util;
+
+/**
+ * Represents a function that accepts two arguments and
+ * produces a result or throws an exception.
+ *
+ * @param <T> type of the first argument to the function
+ * @param <U> type of the second argument to the function
+ * @param <R> type of the result of the function
+ * @param <E> type of the exception in case of error
+ */
+@FunctionalInterface
+public interface ThrowingBiFunction<T, U, R, E extends Exception> {
+
+    /**
+     * Applies this function to the given arguments.
+     *
+     * @param argument1 first argument
+     * @param argument2 second argument
+     *
+     * @return function result
+     *
+     * @throws E if any error occurs
+     */
+    R apply(T argument1, U argument2) throws E;
+
+}