Adding Struct Support

Author: akuzin1

src/main/java/org/opensearch/jdbc/ConnectionImpl.java

@@ -41,6 +41,7 @@
 import java.sql.Savepoint;
 import java.sql.Statement;
 import java.sql.Struct;
+import java.util.Arrays;
 import java.util.Map;
 import java.util.Properties;
 import java.util.concurrent.Executor;
@@ -436,7 +437,7 @@ public Array createArrayOf(String typeName, Object[] elements) throws SQLExcepti
 
     @Override
     public Struct createStruct(String typeName, Object[] attributes) throws SQLException {
-        throw new SQLFeatureNotSupportedException("Struct is not supported.");
+        return new StructImpl(typeName, attributes);
     }
 
     @Override

src/main/java/org/opensearch/jdbc/StructImpl.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+
+package org.opensearch.jdbc;
+
+import java.sql.SQLException;
+import java.sql.Struct;
+import java.util.Map;
+
+public class StructImpl implements Struct{
+    private final String typeName;
+    private final Object[] attributes;
+
+    public StructImpl(String typeName, Object[] attributes) {
+        this.typeName = typeName;
+        this.attributes = attributes;
+    }
+
+    public String getSQLTypeName() throws SQLException {
+        return this.typeName;
+    }
+
+    public Object[] getAttributes() throws SQLException {
+        return attributes;
+    }
+
+    public Object[] getAttributes(Map<String,Class<?>> map) throws SQLException {
+        throw new java.lang.UnsupportedOperationException("Not supported yet.");
+    }
+}

src/main/java/org/opensearch/jdbc/types/BaseTypeConverter.java

@@ -8,6 +8,7 @@
 
 import java.sql.Date;
 import java.sql.SQLException;
+import java.sql.Struct;
 import java.sql.Time;
 import java.sql.Timestamp;
 import java.util.HashMap;
@@ -35,6 +36,9 @@ public abstract class BaseTypeConverter implements TypeConverter {
         typeHandlerMap.put(Date.class, DateType.INSTANCE);
         typeHandlerMap.put(Time.class, TimeType.INSTANCE);
 
+        // Adding Struct Support
+        typeHandlerMap.put(Struct.class, StructType.INSTANCE);
+
     }
 
     @Override

src/main/java/org/opensearch/jdbc/types/OpenSearchType.java

@@ -90,6 +90,9 @@ public enum OpenSearchType {
         jdbcTypeToOpenSearchTypeMap.put(JDBCType.TIME, TIME);
         jdbcTypeToOpenSearchTypeMap.put(JDBCType.DATE, DATE);
         jdbcTypeToOpenSearchTypeMap.put(JDBCType.VARBINARY, BINARY);
+
+        // Adding Struct Support
+        jdbcTypeToOpenSearchTypeMap.put(JDBCType.STRUCT, OBJECT);
     }
 
     /**

src/main/java/org/opensearch/jdbc/types/StructType.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package org.opensearch.jdbc.types;
+
+import java.sql.Struct;
+import java.util.Map;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.LinkedHashMap;
+
+
+
+import org.opensearch.jdbc.StructImpl;
+ 
+public class StructType implements TypeHelper<Struct> {
+
+    public static final StructType INSTANCE = new StructType();
+
+    private StructType() {
+
+    }
+
+    @Override
+    public String getTypeName() {
+        return "Struct";
+    }
+
+    @Override
+    public Struct fromValue(Object value, Map<String, Object> conversionParams) {
+        int i = 0;
+        Map<String, Object> structKeyValues = (Map<String, Object>) value;
+        Object[] attributes = new Map.Entry[structKeyValues.size()];
+
+        for(Map.Entry<String, Object> entry: structKeyValues.entrySet()) {
+            attributes[i++] = entry;
+        }
+        return new StructImpl(getTypeName(), attributes);
+    }
+ }

src/main/java/org/opensearch/jdbc/types/TypeConverters.java

@@ -9,6 +9,7 @@
 import java.sql.Date;
 import java.sql.JDBCType;
 import java.sql.SQLException;
+import java.sql.Struct;
 import java.sql.Time;
 import java.sql.Timestamp;
 import java.util.Arrays;
@@ -56,12 +57,37 @@ public class TypeConverters {
         tcMap.put(JDBCType.BINARY, new BinaryTypeConverter());
 
         tcMap.put(JDBCType.NULL, new NullTypeConverter());
+
+        // Adding Struct Support
+        tcMap.put(JDBCType.STRUCT, new StructTypeConverter());
     }
 
     public static TypeConverter getInstance(JDBCType jdbcType) {
         return tcMap.get(jdbcType);
     }
 
+    public static class StructTypeConverter extends BaseTypeConverter {
+
+        private static final Set<Class> supportedJavaClasses = Collections.unmodifiableSet(
+                new HashSet<>(Arrays.asList(
+                        Struct.class
+                )));
+
+        StructTypeConverter() {
+
+        }
+
+        @Override
+        public Class getDefaultJavaClass() {
+            return Struct.class;
+        }
+
+        @Override
+        public Set<Class> getSupportedJavaClasses() {
+            return supportedJavaClasses;
+        }
+    }
+
     public static class TimestampTypeConverter extends BaseTypeConverter {
 
         private static final Set<Class> supportedJavaClasses = Collections.unmodifiableSet(