Some configuration items may be commented out when merging old version configuration files

iotdb-core/datanode/src/test/java/org/apache/iotdb/db/utils/ConfigurationFileUtilsTest.java

@@ -0,0 +1,80 @@
+/*
+ * 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.
+ */
+
+package org.apache.iotdb.db.utils;
+
+import org.apache.iotdb.commons.conf.ConfigurationFileUtils;
+import org.apache.iotdb.db.utils.constant.TestConstant;
+
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.util.Objects;
+import java.util.Properties;
+
+public class ConfigurationFileUtilsTest {
+
+  private File dir =
+      new File(TestConstant.BASE_OUTPUT_PATH + File.separator + "ConfigurationFileUtilsTest");
+
+  @After
+  public void tearDown() throws IOException {
+    if (!dir.exists()) {
+      return;
+    }
+    for (File file : Objects.requireNonNull(dir.listFiles())) {
+      Files.delete(file.toPath());
+    }
+    Files.delete(dir.toPath());
+  }
+
+  @Test
+  public void testMergeOldVersionFiles() throws IOException, InterruptedException {
+    dir.mkdirs();
+    File confignodeConfigFile = new File(dir + File.separator + "iotdb-confignode.properties");
+    File datanodeConfigFile = new File(dir + File.separator + "iotdb-datanode.properties");
+    File commonConfigFile = new File(dir + File.separator + "iotdb-common.properties");
+    File systemConfigFile = new File(dir + File.separator + "iotdb-system.properties");
+    generateFile(confignodeConfigFile, "a=1");
+    generateFile(datanodeConfigFile, "b=2");
+    generateFile(commonConfigFile, "c=3");
+    ConfigurationFileUtils.checkAndMayUpdate(
+        systemConfigFile.toURI().toURL(),
+        confignodeConfigFile.toURI().toURL(),
+        datanodeConfigFile.toURI().toURL(),
+        commonConfigFile.toURI().toURL());
+    Assert.assertTrue(systemConfigFile.exists());
+    Properties properties = new Properties();
+    try (FileReader fileReader = new FileReader(systemConfigFile)) {
+      properties.load(fileReader);
+    }
+    Assert.assertEquals("1", properties.getProperty("a"));
+    Assert.assertEquals("2", properties.getProperty("b"));
+    Assert.assertEquals("3", properties.getProperty("c"));
+  }
+
+  private void generateFile(File file, String content) throws IOException {
+    Files.write(file.toPath(), content.getBytes());
+  }
+}

iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/conf/ConfigurationFileUtils.java

@@ -299,7 +299,7 @@ private static String readConfigLinesWithoutLicense(File file) throws IOExceptio
     }
     byte[] bytes = Files.readAllBytes(file.toPath());
     String content = new String(bytes);
-    return content.replace(license, "");
+    return lineSeparator + content.replace(license, "");
   }
 
   private static String readConfigLines(File file) throws IOException {