[Feature][Transforms-V2] LLM transforms Support custom field name

docs/en/transform-v2/llm.md

@@ -11,11 +11,12 @@ more.
 ## Options
 
 | name                   | type   | required | default value |
-| ---------------------- | ------ | -------- | ------------- |
+|------------------------| ------ | -------- | ------------- |
 | model_provider         | enum   | yes      |               |
 | output_data_type       | enum   | no       | String        |
+| output_column_name     | string | no       | String        |
 | prompt                 | string | yes      |               |
-| inference_columns   | list   | no       |               |
+| inference_columns      | list   | no       |               |
 | model                  | string | yes      |               |
 | api_key                | string | yes      |               |
 | api_path               | string | no       |               |
@@ -35,6 +36,10 @@ The data type of the output data. The available options are:
 STRING,INT,BIGINT,DOUBLE,BOOLEAN.
 Default value is STRING.
 
+### output_column_name
+
+Custom output data field name. A custom field name that is the same as an existing field name is replaced with 'llm_output'.
+
 ### prompt
 
 The prompt to send to the LLM. This parameter defines how LLM will process and return data, eg:

docs/zh/transform-v2/llm.md

@@ -8,12 +8,13 @@
 
 ## 属性
 
-| 名称                   | 类型   | 是否必须 | 默认值 |
-| ---------------------- | ------ | -------- | ------ |
+| 名称                     | 类型   | 是否必须 | 默认值    |
+|------------------------| ------ | -------- |--------|
 | model_provider         | enum   | yes      |        |
 | output_data_type       | enum   | no       | String |
+| output_column_name     | string | no       |        |
 | prompt                 | string | yes      |        |
-| inference_columns   | list   | no       |        |
+| inference_columns      | list   | no       |        |
 | model                  | string | yes      |        |
 | api_key                | string | yes      |        |
 | api_path               | string | no       |        |
@@ -33,6 +34,10 @@ OPENAI、DOUBAO、CUSTOM
 STRING,INT,BIGINT,DOUBLE,BOOLEAN.
 默认值为 STRING。
 
+### output_column_name
+
+自定义输出数据字段名称。自定义字段名称与现有字段名称相同时,将替换为`llm_output`。
+
 ### prompt
 
 发送到 LLM 的提示。此参数定义 LLM 将如何处理和返回数据，例如:

seatunnel-e2e/seatunnel-transforms-v2-e2e/seatunnel-transforms-v2-e2e-part-1/src/test/java/org/apache/seatunnel/e2e/transform/TestLLMIT.java

@@ -93,6 +93,7 @@ public void testLLMWithOpenAIBoolean(TestContainer container)
             throws IOException, InterruptedException {
         Container.ExecResult execResult =
                 container.executeJob("/llm_openai_transform_boolean.conf");
+        Assertions.assertEquals(0, execResult.getExitCode());
     }
 
     @TestTemplate
@@ -103,6 +104,14 @@ public void testLLMWithOpenAIColumns(TestContainer container)
         Assertions.assertEquals(0, execResult.getExitCode());
     }
 
+    @TestTemplate
+    public void testLLMWithOpenAIOutputColumnName(TestContainer container)
+            throws IOException, InterruptedException {
+        Container.ExecResult execResult =
+                container.executeJob("/llm_openai_transform_custom_output_name.conf");
+        Assertions.assertEquals(0, execResult.getExitCode());
+    }
+
     @TestTemplate
     public void testLLMWithCustomModel(TestContainer container)
             throws IOException, InterruptedException {

seatunnel-e2e/seatunnel-transforms-v2-e2e/seatunnel-transforms-v2-e2e-part-1/src/test/resources/llm_openai_transform_custom_output_name.conf

@@ -0,0 +1,76 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You 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.
+#
+######
+###### This config file is a demonstration of streaming processing in seatunnel config
+######
+
+env {
+  job.mode = "BATCH"
+}
+
+source {
+  FakeSource {
+    row.num = 5
+    schema = {
+      fields {
+        id = "int"
+        name = "string"
+      }
+    }
+    rows = [
+      {fields = [1, "Jia Fan"], kind = INSERT}
+      {fields = [2, "Hailin Wang"], kind = INSERT}
+      {fields = [3, "Tomas"], kind = INSERT}
+      {fields = [4, "Eric"], kind = INSERT}
+      {fields = [5, "Guangdong Liu"], kind = INSERT}
+    ]
+    result_table_name = "fake"
+  }
+}
+
+transform {
+  LLM {
+    source_table_name = "fake"
+    model_provider = OPENAI
+    model = gpt-4o-mini
+    api_key = sk-xxx
+    output_column_name = "nationality"
+    prompt = "Determine whether someone is Chinese or American by their name"
+    openai.api_path = "http://mockserver:1080/v1/chat/completions"
+    result_table_name = "llm_output"
+  }
+}
+
+sink {
+  Assert {
+    source_table_name = "llm_output"
+    rules =
+      {
+        field_rules = [
+          {
+            field_name = "nationality"
+            field_type = string
+            field_value = [
+              {
+                rule_type = NOT_NULL
+              }
+            ]
+          }
+        ]
+      }
+  }
+}

seatunnel-transforms-v2/src/main/java/org/apache/seatunnel/transform/nlpmodel/llm/LLMTransform.java

@@ -32,9 +32,12 @@
 import org.apache.seatunnel.transform.nlpmodel.llm.remote.custom.CustomModel;
 import org.apache.seatunnel.transform.nlpmodel.llm.remote.openai.OpenAIModel;
 
+import org.apache.commons.lang3.StringUtils;
+
 import lombok.NonNull;
 import lombok.SneakyThrows;
 
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
@@ -139,8 +142,18 @@ protected Object getOutputFieldValue(SeaTunnelRowAccessor inputRow) {
 
     @Override
     protected Column getOutputColumn() {
+        String customFieldName = config.get(LLMTransformConfig.OUTPUT_COLUMN_NAME);
+        String[] fieldNames = inputCatalogTable.getTableSchema().getFieldNames();
+        boolean isExist = Arrays.asList(fieldNames).contains(customFieldName);
+        if (isExist) {
+            throw new IllegalArgumentException(
+                    String.format("Field name %s already exists", customFieldName));
+        }
+        if (StringUtils.isEmpty(customFieldName)) {
+            customFieldName = "llm_output";
+        }
         return PhysicalColumn.of(
-                "llm_output", outputDataType, (Long) null, true, null, "Output column of LLM");
+                customFieldName, outputDataType, (Long) null, true, null, "Output column of LLM");
     }
 
     @SneakyThrows

seatunnel-transforms-v2/src/main/java/org/apache/seatunnel/transform/nlpmodel/llm/LLMTransformConfig.java

@@ -37,6 +37,12 @@ public class LLMTransformConfig extends ModelTransformConfig {
                     .noDefaultValue()
                     .withDescription("The row projection field of each inference");
 
+    public static final Option<String> OUTPUT_COLUMN_NAME =
+            Options.key("output_column_name")
+                    .stringType()
+                    .noDefaultValue()
+                    .withDescription("custom field name for the llm output data");
+
     public static final Option<Integer> INFERENCE_BATCH_SIZE =
             Options.key("inference_batch_size")
                     .intType()