Make SqlVarbinary map serialization consistent with other types

Other Sql* classes are serialized to JSON on-the-wire format,
using @JsonValue annotated toString methods, except for SqlVarbinary
which was serialized using its' getBytes() method that was Base64-encoded
to a map key.

core/trino-main/src/main/java/io/trino/server/protocol/JsonEncodingUtils.java

@@ -49,7 +49,6 @@
 
 import java.io.IOException;
 import java.math.BigDecimal;
-import java.util.Base64;
 import java.util.List;
 import java.util.function.Consumer;
 
@@ -369,13 +368,9 @@ public void encode(JsonGenerator generator, ConnectorSession session, Block bloc
             generator.writeStartObject();
             for (int i = 0; i < map.getSize(); i++) {
                 // Field name is always written as String for backward compatibility,
-                // (except for VarbinaryType where we encode it as Base64 representation of its bytes)
                 // and only value is properly encoded using it's type.
                 // TODO: improve in v2 JSON format
-                switch (mapType.getKeyType().getObjectValue(session, keyBlock, offset + i)) {
-                    case SqlVarbinary varbinary -> generator.writeFieldName(Base64.getEncoder().encodeToString(varbinary.getBytes()));
-                    case Object value -> generator.writeFieldName(value.toString());
-                }
+                generator.writeFieldName(mapType.getKeyType().getObjectValue(session, keyBlock, offset + i).toString());
                 valueEncoder.encode(generator, session, valueBlock, offset + i);
             }
             generator.writeEndObject();

core/trino-spi/pom.xml

@@ -212,6 +212,14 @@
                                 </item>
                                 <!-- Backwards incompatible changes since the previous release -->
                                 <!-- Any exclusions below can be deleted after each release -->
+                                <item>
+                                    <ignore>true</ignore>
+                                    <code>java.annotation.removed</code>
+                                    <old>method byte[] io.trino.spi.type.SqlVarbinary::getBytes()</old>
+                                    <new>method byte[] io.trino.spi.type.SqlVarbinary::getBytes()</new>
+                                    <annotation>@com.fasterxml.jackson.annotation.JsonValue</annotation>
+                                    <justification>On-the-wire representation shouldn't rely on the Jackson format</justification>
+                                </item>
                             </differences>
                         </revapi.differences>
                     </analysisConfiguration>

core/trino-spi/src/main/java/io/trino/spi/type/SqlVarbinary.java

@@ -13,9 +13,8 @@
  */
 package io.trino.spi.type;
 
-import com.fasterxml.jackson.annotation.JsonValue;
-
 import java.util.Arrays;
+import java.util.Base64;
 import java.util.HexFormat;
 
 import static java.lang.Math.min;
@@ -42,7 +41,6 @@ public int compareTo(SqlVarbinary obj)
         return Arrays.compare(bytes, obj.bytes);
     }
 
-    @JsonValue
     public byte[] getBytes()
     {
         return bytes;
@@ -69,6 +67,11 @@ public boolean equals(Object obj)
 
     @Override
     public String toString()
+    {
+        return Base64.getEncoder().encodeToString(bytes);
+    }
+
+    public String toHexString()
     {
         if (bytes.length == 0) {
             return "";

core/trino-spi/src/test/java/io/trino/spi/type/TestSqlVarbinary.java

@@ -15,24 +15,27 @@
 
 import org.junit.jupiter.api.Test;
 
+import java.util.Base64;
+
 import static java.lang.String.format;
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class TestSqlVarbinary
 {
     @Test
-    public void testToString()
+    public void testToHexString()
     {
         for (int lines = 0; lines < 5; lines++) {
             for (int lastLineBytes = 0; lastLineBytes < 32; lastLineBytes++) {
                 byte[] bytes = createBytes(lines, lastLineBytes);
-                String expected = simpleToString(bytes);
-                assertThat(expected).isEqualTo(new SqlVarbinary(bytes).toString());
+                String expectedHex = simpleToHex(bytes);
+                assertThat(expectedHex).isEqualTo(new SqlVarbinary(bytes).toHexString());
+                assertThat(Base64.getEncoder().encodeToString(bytes)).isEqualTo(new SqlVarbinary(bytes).toString());
             }
         }
     }
 
-    private static String simpleToString(byte[] bytes)
+    private static String simpleToHex(byte[] bytes)
     {
         StringBuilder builder = new StringBuilder();