Add FAQ for org.apache.hadoop.mapred.JobConf (#15)

Author: linghengqian

README.md

@@ -102,6 +102,10 @@ you can use `1.4.0` of `io.github.linghengqian:hive-server2-jdbc-driver-thin` or
 For the Docker Image of `apache/hive:4.0.1`, 
 you can use `1.6.0` of `io.github.linghengqian:hive-server2-jdbc-driver-thin` or `io.github.linghengqian:hive-server2-jdbc-driver-uber`.
 
+## FAQ
+
+Refer to [FAQ](./doc/FAQ.md).
+
 ## Background
 
 Refer to [Background](./doc/Background.md).

doc/FAQ.md

@@ -0,0 +1,44 @@
+# FAQ
+
+## Where is the `org.apache.hadoop.mapred.JobConf` class?
+
+For HiveServer2 JDBC Driver `org.apache.hive:hive-jdbc:4.0.1` or `org.apache.hive:hive-jdbc:4.0.1` with `classifier` as `standalone`,
+there is actually no additional dependency on `org.apache.hadoop:hadoop-mapreduce-client-core:3.3.6`.
+
+In some cases, users may need to do this.
+
+```java
+import org.apache.hadoop.hive.conf.HiveConf;
+import org.apache.hadoop.hive.metastore.HiveMetaStoreClient;
+import org.apache.hadoop.hive.metastore.api.MetaException;
+public class ExampleTest {
+
+    void test() throws MetaException {
+        HiveConf hiveConf = new HiveConf();
+        hiveConf.set("hive.metastore.uris", "thrift://metastore:9083");
+        HiveMetaStoreClient storeClient = new HiveMetaStoreClient(hiveConf);
+        storeClient.close();
+    }
+}
+```
+
+Using `org.apache.hadoop.hive.conf.HiveConf` specifically requires a dependency on the `org.apache.hadoop.mapred.JobConf` class. 
+This class belongs to `org.apache.hadoop:hadoop-mapreduce-client-core:3.3.6`.
+
+When users need to use `org.apache.hadoop.hive.conf.HiveConf` directly in business code, 
+they can additionally introduce the following dependencies.
+Since only the `org.apache.hadoop.mapred.JobConf` class is needed, excluding all sub-dependencies is no problem.
+
+```xml
+<dependency>
+    <groupId>org.apache.hadoop</groupId>
+    <artifactId>hadoop-mapreduce-client-core</artifactId>
+    <version>3.3.6</version>
+    <exclusions>
+        <exclusion>
+            <groupId>*</groupId>
+            <artifactId>*</artifactId>
+        </exclusion>
+    </exclusions>
+</dependency>
+```

hive-server2-jdbc-driver-thin/src/test/java/io/github/linghengqian/hive/server2/jdbc/driver/thin/ClassExistTest.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2024 Qiheng He
+ *
+ * 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 io.github.linghengqian.hive.server2.jdbc.driver.thin;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+public class ClassExistTest {
+
+    @Test
+    void test() {
+        assertDoesNotThrow(() -> {
+            Class.forName("org.apache.hadoop.hive.conf.HiveConf");
+        });
+        assertThrows(ClassNotFoundException.class, () -> Class.forName("org.apache.hadoop.mapred.JobConf"));
+    }
+}

hive-server2-jdbc-driver-uber/src/test/java/io/github/linghengqian/hive/server2/jdbc/driver/uber/ClassExistTest.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2024 Qiheng He
+ *
+ * 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 io.github.linghengqian.hive.server2.jdbc.driver.uber;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+public class ClassExistTest {
+
+    @Test
+    void test() {
+        assertDoesNotThrow(() -> {
+            Class.forName("org.apache.hadoop.hive.conf.HiveConf");
+        });
+        assertThrows(ClassNotFoundException.class, () -> Class.forName("org.apache.hadoop.mapred.JobConf"));
+    }
+}