Implement createArrayOf and setArray (#418)

Currently java.sql.Array is only supported when returned from the
database. Passing arrays to the database is not supported.
Connection#createArrayOf, PreparedStatement#setArray and
PreparedStatement#setObject with a java.sql.Array are not supported.

This pull requests implements passing java.sql.Array objects to the
database and includes the following changes:

 - implement Connection#createArrayOf
 - implement PreparedStatement#setArray
 - implement array support in ResultSet#getObject
 - implement conversion from java.sql.Array to Value
 - update DataType#convertTo to support arrays as well
 - add tests for #createArrayOf, #setArray and #setObject
 - add tests for #getObject with an array argument
 - remove the test for Connection#createArrayOf being unsupported
 - remove the test for PreparedStatement#setArray being unsupported

The typeName passed to #createArrayOf is ignored, this is in accordance
with JdbcArray#getBaseTypeName returning "NULL" and
JdbcArray#getBaseType returning Types.NULL even if the backing array is
homogeneous.

h2/src/main/org/h2/jdbc/JdbcArray.java

@@ -28,7 +28,7 @@ public class JdbcArray extends TraceObject implements Array {
     /**
      * INTERNAL
      */
-    JdbcArray(JdbcConnection conn, Value value, int id) {
+    public JdbcArray(JdbcConnection conn, Value value, int id) {
         setTrace(conn.getSession().getTrace(), TraceObject.ARRAY, id);
         this.conn = conn;
         this.value = value;

h2/src/main/org/h2/jdbc/JdbcConnection.java

@@ -48,6 +48,7 @@ import org.h2.util.CloseWatcher;
 import org.h2.util.JdbcUtils;
 import org.h2.util.Utils;
 import org.h2.value.CompareMode;
+import org.h2.value.DataType;
 import org.h2.value.Value;
 import org.h2.value.ValueInt;
 import org.h2.value.ValueNull;
@@ -1634,12 +1635,22 @@ public class JdbcConnection extends TraceObject implements Connection,
     }
 
     /**
-     * [Not supported] Create a new empty Array object.
+     * Create a new Array object.
+     *
+     * @return the array
      */
     @Override
     public Array createArrayOf(String typeName, Object[] elements)
             throws SQLException {
-        throw unsupported("createArray");
+        try {
+            int id = getNextId(TraceObject.ARRAY);
+            debugCodeAssign("Array", TraceObject.ARRAY, id, "createArrayOf()");
+            checkClosed();
+            Value value = DataType.convertToValue(session, elements, Value.ARRAY);
+            return new JdbcArray(this, value, id);
+        } catch (Exception e) {
+            throw logAndConvert(e);
+        }
     }
 
     /**

h2/src/main/org/h2/jdbc/JdbcPreparedStatement.java

@@ -875,11 +875,29 @@ public class JdbcPreparedStatement extends JdbcStatement implements
     }
 
     /**
-     * [Not supported] Sets the value of a parameter as a Array.
+     * Sets the value of a parameter as an Array.
+     *
+     * @param parameterIndex the parameter index (1, 2, ...)
+     * @param x the value
+     * @throws SQLException if this object is closed
      */
     @Override
     public void setArray(int parameterIndex, Array x) throws SQLException {
-        throw unsupported("setArray");
+        try {
+            if (isDebugEnabled()) {
+                debugCode("setArray("+parameterIndex+", x);");
+            }
+            checkClosed();
+            Value v;
+            if (x == null) {
+                v = ValueNull.INSTANCE;
+            } else {
+                v = DataType.convertToValue(session, x.getArray(), Value.ARRAY);
+            }
+            setParameter(parameterIndex, v);
+        } catch (Exception e) {
+            throw logAndConvert(e);
+        }
     }
 
     /**

h2/src/main/org/h2/jdbc/JdbcResultSet.java

@@ -3782,6 +3782,9 @@ public class JdbcResultSet extends TraceObject implements ResultSet, JdbcResultS
             return type.cast(value.getObject());
         } else if (type == byte[].class) {
             return type.cast(value.getBytes());
+        } else if (type == java.sql.Array.class) {
+            int id = getNextId(TraceObject.ARRAY);
+            return type.cast(value == ValueNull.INSTANCE ? null : new JdbcArray(conn, value, id));
         } else if (type == TimestampWithTimeZone.class) {
             return type.cast(value.getObject());
         } else if (DataType.isGeometryClass(type)) {

h2/src/main/org/h2/value/DataType.java

@@ -28,6 +28,7 @@ import org.h2.api.TimestampWithTimeZone;
 import org.h2.engine.Constants;
 import org.h2.engine.SessionInterface;
 import org.h2.engine.SysProperties;
+import org.h2.jdbc.JdbcArray;
 import org.h2.jdbc.JdbcBlob;
 import org.h2.jdbc.JdbcClob;
 import org.h2.jdbc.JdbcConnection;
@@ -1051,6 +1052,13 @@ public class DataType {
             } catch (SQLException e) {
                 throw DbException.convert(e);
             }
+        } else if (x instanceof java.sql.Array) {
+            java.sql.Array array = (java.sql.Array) x;
+            try {
+                return convertToValue(session, array.getArray(), Value.ARRAY);
+            } catch (SQLException e) {
+                throw DbException.convert(e);
+            }
         } else if (x instanceof ResultSet) {
             if (x instanceof SimpleResultSet) {
                 return ValueResultSet.get((ResultSet) x);
@@ -1238,6 +1246,8 @@ public class DataType {
             return new JdbcBlob(conn, v, 0);
         } else if (paramClass == Clob.class) {
             return new JdbcClob(conn, v, 0);
+        } else if (paramClass == Array.class) {
+            return new JdbcArray(conn, v, 0);
         }
         if (v.getType() == Value.JAVA_OBJECT) {
             Object o = SysProperties.serializeJavaObject ? JdbcUtils.deserialize(v.getBytes(),

h2/src/test/org/h2/test/TestBase.java

@@ -662,7 +662,9 @@ public abstract class TestBase {
     }
 
     /**
-     * Check if two values are equal, and if not throw an exception.
+     * Check if two arrays are equal, and if not throw an exception.
+     * If some of the elements in the arrays are themselves arrays this
+     * check is called recursively.
      *
      * @param expected the expected value
      * @param actual the actual value
@@ -679,6 +681,8 @@ public abstract class TestBase {
                 if (expected[i] != actual[i]) {
                     fail("[" + i + "]: expected: " + expected[i] + " actual: " + actual[i]);
                 }
+            } else if (expected[i] instanceof Object[] && actual[i] instanceof Object[]) {
+                assertEquals((Object[]) expected[i], (Object[]) actual[i]);
             } else if (!expected[i].equals(actual[i])) {
                 fail("[" + i + "]: expected: " + expected[i] + " actual: " + actual[i]);
             }

h2/src/test/org/h2/test/jdbc/TestCallableStatement.java

@@ -10,6 +10,7 @@ import java.io.Reader;
 import java.io.StringReader;
 import java.math.BigDecimal;
 import java.net.URL;
+import java.sql.Array;
 import java.sql.CallableStatement;
 import java.sql.Connection;
 import java.sql.Ref;
@@ -56,6 +57,8 @@ public class TestCallableStatement extends TestBase {
         testCallWithResult(conn);
         testPrepare(conn);
         testClassLoader(conn);
+        testArrayArgument(conn);
+        testArrayReturnValue(conn);
         conn.close();
         deleteDb("callableStatement");
     }
@@ -419,6 +422,88 @@ public class TestCallableStatement extends TestBase {
         }
     }
 
+    private void testArrayArgument(Connection connection) throws SQLException {
+        Array array = connection.createArrayOf("Int", new Object[] {0, 1, 2});
+        try (Statement statement = connection.createStatement()) {
+            statement.execute("CREATE ALIAS getArrayLength FOR \"" +
+                            getClass().getName() + ".getArrayLength\"");
+
+            // test setArray
+            try (CallableStatement callableStatement = connection.prepareCall("{call getArrayLength(?)}")) {
+                callableStatement.setArray(1, array);
+                assertTrue(callableStatement.execute());
+
+                try (ResultSet resultSet = callableStatement.getResultSet()) {
+                    assertTrue(resultSet.next());
+                    assertEquals(3, resultSet.getInt(1));
+                    assertFalse(resultSet.next());
+                }
+            }
+
+            // test setObject
+            try (CallableStatement callableStatement = connection.prepareCall("{call getArrayLength(?)}")) {
+                callableStatement.setObject(1, array);
+                assertTrue(callableStatement.execute());
+
+                try (ResultSet resultSet = callableStatement.getResultSet()) {
+                    assertTrue(resultSet.next());
+                    assertEquals(3, resultSet.getInt(1));
+                    assertFalse(resultSet.next());
+                }
+            }
+        } finally {
+            array.free();
+        }
+    }
+
+    private void testArrayReturnValue(Connection connection) throws SQLException {
+        Object[][] arraysToTest = new Object[][] {
+            new Object[] {0, 1, 2},
+            new Object[] {0, "1", 2},
+            new Object[] {0, null, 2},
+            new Object[] {0, new Object[] {"s", 1}, new Object[] {null, 1L}},
+        };
+        try (Statement statement = connection.createStatement()) {
+            statement.execute("CREATE ALIAS arrayIdentiy FOR \"" +
+                            getClass().getName() + ".arrayIdentiy\"");
+
+            for (Object[] arrayToTest : arraysToTest) {
+                Array sqlInputArray = connection.createArrayOf("ignored",arrayToTest);
+                try {
+                    try (CallableStatement callableStatement = connection.prepareCall("{call arrayIdentiy(?)}")) {
+                        callableStatement.setArray(1, sqlInputArray);
+                        assertTrue(callableStatement.execute());
+
+                        try (ResultSet resultSet = callableStatement.getResultSet()) {
+                            assertTrue(resultSet.next());
+
+                            // test getArray()
+                            Array sqlReturnArray = resultSet.getArray(1);
+                            try {
+                                assertEquals((Object[]) sqlInputArray.getArray(), (Object[]) sqlReturnArray.getArray());
+                            } finally {
+                                sqlReturnArray.free();
+                            }
+
+                            // test getObject(Array.class)
+                            sqlReturnArray = resultSet.getObject(1, Array.class);
+                            try {
+                                assertEquals((Object[]) sqlInputArray.getArray(), (Object[]) sqlReturnArray.getArray());
+                            } finally {
+                                sqlReturnArray.free();
+                            }
+
+                            assertFalse(resultSet.next());
+                        }
+                    }
+                } finally {
+                    sqlInputArray.free();
+                }
+
+            }
+        }
+    }
+
     /**
      * Class factory unit test
      * @param b boolean value
@@ -428,6 +513,26 @@ public class TestCallableStatement extends TestBase {
         return !b;
     }
 
+    /**
+     * This method is called via reflection from the database.
+     *
+     * @param array the array
+     * @return the length of the array
+     */
+    public static int getArrayLength(Object[] array) {
+        return array == null ? 0 : array.length;
+    }
+
+    /**
+     * This method is called via reflection from the database.
+     *
+     * @param array the array
+     * @return the array
+     */
+    public static Object[] arrayIdentiy(Object[] array) {
+        return array;
+    }
+
     /**
      * This method is called via reflection from the database.
      *

h2/src/test/org/h2/test/jdbc/TestPreparedStatement.java

@@ -12,7 +12,6 @@ import java.io.StringReader;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.net.URL;
-import java.sql.Array;
 import java.sql.Connection;
 import java.sql.ParameterMetaData;
 import java.sql.PreparedStatement;
@@ -142,15 +141,11 @@ public class TestPreparedStatement extends TestBase {
             setRowId(1, (RowId) null);
         assertThrows(ErrorCode.FEATURE_NOT_SUPPORTED_1, prep).
             setUnicodeStream(1, (InputStream) null, 0);
-        assertThrows(ErrorCode.FEATURE_NOT_SUPPORTED_1, prep).
-            setArray(1, (Array) null);
 
         ParameterMetaData meta = prep.getParameterMetaData();
         assertTrue(meta.toString(), meta.toString().endsWith("parameterCount=1"));
         assertThrows(ErrorCode.FEATURE_NOT_SUPPORTED_1, conn).
                 createSQLXML();
-        assertThrows(ErrorCode.FEATURE_NOT_SUPPORTED_1, conn).
-                createArrayOf("Integer", new Object[0]);
         assertThrows(ErrorCode.FEATURE_NOT_SUPPORTED_1, conn).
                 createStruct("Integer", new Object[0]);
     }