From ac49b28cab770a5ba938faab0747b8fdd589ac6d Mon Sep 17 00:00:00 2001
From: t8y2 <1156263951@qq.com>
Date: Fri, 31 Jul 2026 20:51:07 +0800
Subject: [PATCH] fix(agent): read JDBC blobs through Blob values

---
 .../main/java/com/dbx/agent/JdbcExecutor.java | 19 +++++-
 .../java/com/dbx/agent/JdbcExecutorTest.java  | 65 +++++++++++++++++--
 2 files changed, 76 insertions(+), 8 deletions(-)

diff --git a/agents/common/src/main/java/com/dbx/agent/JdbcExecutor.java b/agents/common/src/main/java/com/dbx/agent/JdbcExecutor.java
index a7e2898d83..acd69e65f5 100644
--- a/agents/common/src/main/java/com/dbx/agent/JdbcExecutor.java
+++ b/agents/common/src/main/java/com/dbx/agent/JdbcExecutor.java
@@ -455,9 +455,11 @@ public final class JdbcExecutor {
             case Types.BINARY:
             case Types.VARBINARY:
             case Types.LONGVARBINARY:
-            case Types.BLOB:
                 value = bytesToHex(rs.getBytes(index));
                 break;
+            case Types.BLOB:
+                value = blobResultValue(rs, index);
+                break;
             case Types.SQLXML:
                 value = sqlXmlToString(rs.getSQLXML(index));
                 break;
@@ -474,9 +476,11 @@ public final class JdbcExecutor {
             case Types.BINARY:
             case Types.VARBINARY:
             case Types.LONGVARBINARY:
-            case Types.BLOB:
                 value = bytesToHex(rs.getBytes(index));
                 break;
+            case Types.BLOB:
+                value = blobResultValue(rs, index);
+                break;
             case Types.SQLXML:
                 value = sqlXmlToString(rs.getSQLXML(index));
                 break;
@@ -487,6 +491,17 @@ public final class JdbcExecutor {
         return rs.wasNull() ? null : value;
     }
 
+    private static Object blobResultValue(ResultSet rs, int index) throws SQLException {
+        Object value = rs.getObject(index);
+        if (value instanceof Blob || value instanceof byte[]) {
+            return normalizeResultValue(value);
+        }
+        if (value == null && rs.wasNull()) {
+            return null;
+        }
+        return bytesToHex(rs.getBytes(index));
+    }
+
     public static Object normalizeResultValue(Object value) throws SQLException {
         if (value == null) {
             return null;
diff --git a/agents/common/src/test/java/com/dbx/agent/JdbcExecutorTest.java b/agents/common/src/test/java/com/dbx/agent/JdbcExecutorTest.java
index 45955dc00c..ca659389c8 100644
--- a/agents/common/src/test/java/com/dbx/agent/JdbcExecutorTest.java
+++ b/agents/common/src/test/java/com/dbx/agent/JdbcExecutorTest.java
@@ -20,21 +20,60 @@ import java.util.concurrent.atomic.AtomicInteger;
 import javax.sql.rowset.serial.SerialBlob;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 class JdbcExecutorTest {
     @Test
-    void stringResultValueFormatsBlobWithoutUsingStringConversion() throws Exception {
+    void blobResultValuesPreferBlobObjectsWhenGetBytesFails() throws Exception {
         ResultSet rs = resultSet(
-            new byte[]{0x01, 0x2A, (byte) 0xFF},
-            () -> {
-                throw new AssertionError("BLOB columns should not be read with getString");
-            }
+            new SerialBlob(new byte[]{0x01, 0x2A, (byte) 0xFF}),
+            null,
+            null,
+            false,
+            new SQLException("ORA-00932: expected NUMBER got BLOB")
         );
 
+        assertEquals("0x012aff", JdbcExecutor.INSTANCE.defaultResultValue(rs, 1, Types.BLOB));
         assertEquals("0x012aff", JdbcExecutor.stringResultValue(rs, 1, Types.BLOB));
     }
 
+    @Test
+    void blobResultValuesFallBackToBytesWhenObjectIsUnavailable() throws Exception {
+        ResultSet rs = resultSet(null, new byte[]{0x0A, 0x0B}, null, false, null);
+
+        assertEquals("0x0a0b", JdbcExecutor.INSTANCE.defaultResultValue(rs, 1, Types.BLOB));
+        assertEquals("0x0a0b", JdbcExecutor.stringResultValue(rs, 1, Types.BLOB));
+    }
+
+    @Test
+    void blobResultValuesPreserveSqlNullWithoutReadingBytes() throws Exception {
+        ResultSet rs = resultSet(
+            null,
+            null,
+            null,
+            true,
+            new SQLException("getBytes should not be called for SQL NULL")
+        );
+
+        assertNull(JdbcExecutor.INSTANCE.defaultResultValue(rs, 1, Types.BLOB));
+        assertNull(JdbcExecutor.stringResultValue(rs, 1, Types.BLOB));
+    }
+
+    @Test
+    void binaryResultValuesContinueReadingBytesDirectly() throws Exception {
+        ResultSet rs = resultSet(
+            new SerialBlob(new byte[]{0x01}),
+            new byte[]{0x02},
+            null,
+            false,
+            null
+        );
+
+        assertEquals("0x02", JdbcExecutor.INSTANCE.defaultResultValue(rs, 1, Types.BINARY));
+        assertEquals("0x02", JdbcExecutor.stringResultValue(rs, 1, Types.BINARY));
+    }
+
     @Test
     void defaultResultValueReadsClobColumnsAsText() throws Exception {
         ResultSet rs = resultSet(null, () -> "hello clob");
@@ -262,12 +301,26 @@ class JdbcExecutorTest {
     }
 
     private static ResultSet resultSet(Object objectValue, StringSupplier stringSupplier, boolean wasNull) {
+        byte[] bytesValue = objectValue instanceof byte[] ? (byte[]) objectValue : null;
+        return resultSet(objectValue, bytesValue, stringSupplier, wasNull, null);
+    }
+
+    private static ResultSet resultSet(
+        Object objectValue,
+        byte[] bytesValue,
+        StringSupplier stringSupplier,
+        boolean wasNull,
+        SQLException getBytesFailure
+    ) {
         InvocationHandler handler = (Object unused, Method method, Object[] args) -> {
             switch (method.getName()) {
                 case "getObject":
                     return objectValue;
                 case "getBytes":
-                    return objectValue instanceof byte[] ? objectValue : null;
+                    if (getBytesFailure != null) {
+                        throw getBytesFailure;
+                    }
+                    return bytesValue;
                 case "getString":
                     return stringSupplier == null ? null : stringSupplier.get();
                 case "wasNull":