Add generic constraint on StringDataType

Author: pan3793

clickhouse-native-jdbc/src/main/java/com/github/housepower/jdbc/data/IDataType.java

@@ -41,7 +41,7 @@ default String[] getAliases() {
 
     int sqlTypeId();
 
-    Class<T> javaTypeClass();
+    Class<? extends T> javaTypeClass();
 
     boolean nullable();
 

clickhouse-native-jdbc/src/main/java/com/github/housepower/jdbc/data/type/complex/DataTypeString.java

@@ -16,6 +16,7 @@
 
 import com.github.housepower.jdbc.connect.NativeContext;
 import com.github.housepower.jdbc.data.IDataType;
+import com.github.housepower.jdbc.misc.BytesCharSeq;
 import com.github.housepower.jdbc.misc.SQLLexer;
 import com.github.housepower.jdbc.serde.BinaryDeserializer;
 import com.github.housepower.jdbc.serde.BinarySerializer;
@@ -25,7 +26,7 @@
 import java.sql.SQLException;
 import java.sql.Types;
 
-public class DataTypeString implements IDataType {
+public class DataTypeString implements IDataType<CharSequence> {
 
     public static DataTypeCreator CREATOR = (lexer, serverContext) -> new DataTypeString(serverContext);
 
@@ -46,12 +47,13 @@ public int sqlTypeId() {
     }
 
     @Override
-    public Object defaultValue() {
+    public String defaultValue() {
         return "";
     }
 
+    // TODO FIX Later
     @Override
-    public Class javaTypeClass() {
+    public Class<String> javaTypeClass() {
         return String.class;
     }
 
@@ -71,12 +73,12 @@ public int getScale() {
     }
 
     @Override
-    public void serializeBinary(Object data, BinarySerializer serializer) throws SQLException, IOException {
-        if (data instanceof CharSequence) {
-            serializer.writeStringBinary(data.toString(), charset);
-        } else {
-            serializer.writeBytesBinary((byte[]) data);
+    public void serializeBinary(CharSequence data, BinarySerializer serializer) throws SQLException, IOException {
+        if (data instanceof BytesCharSeq) {
+            serializer.writeBytesBinary(((BytesCharSeq) data).bytes());
+            return;
         }
+        serializer.writeStringBinary(data.toString(), charset);
     }
 
     /**
@@ -90,7 +92,7 @@ public String deserializeBinary(BinaryDeserializer deserializer) throws SQLExcep
     }
 
     @Override
-    public Object[] deserializeBinaryBulk(int rowCnt, BinaryDeserializer deserializer) throws SQLException, IOException {
+    public String[] deserializeBinaryBulk(int rowCnt, BinaryDeserializer deserializer) throws SQLException, IOException {
         String[] data = new String[rowCnt];
         for (int row = 0; row < rowCnt; row++) {
             byte[] bs = deserializer.readBytesBinary();
@@ -115,7 +117,7 @@ public String[] getAliases() {
     }
 
     @Override
-    public Object deserializeTextQuoted(SQLLexer lexer) throws SQLException {
+    public CharSequence deserializeTextQuoted(SQLLexer lexer) throws SQLException {
         return lexer.stringView();
     }
 }

clickhouse-native-jdbc/src/main/java/com/github/housepower/jdbc/misc/BytesCharSeq.java

@@ -0,0 +1,50 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.github.housepower.jdbc.misc;
+
+public class BytesCharSeq implements CharSequence {
+
+    private final byte[] bytes;
+
+    public BytesCharSeq(byte[] bytes) {
+        this.bytes = bytes;
+    }
+
+    @Override
+    public int length() {
+        return bytes.length;
+    }
+
+    @Override
+    public char charAt(int index) {
+        return (char) bytes[index];
+    }
+
+    @Override
+    public CharSequence subSequence(int start, int end) {
+        byte[] newBytes = new byte[end - start];
+        System.arraycopy(bytes, start, newBytes, 0, end - start);
+        return new BytesCharSeq(newBytes);
+    }
+
+    @Override
+    public String toString() {
+        return "BytesCharSeq, length: " + length();
+    }
+
+    public byte[] bytes() {
+        return bytes;
+    }
+}