Github user xubo245 commented on a diff in the pull request:
https://github.com/apache/carbondata/pull/2353#discussion_r191360475
--- Diff: store/sdk/src/main/java/org/apache/carbondata/sdk/file/CarbonSchemaReader.java ---
@@ -0,0 +1,108 @@
+/*
+ * 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.carbondata.sdk.file;
+
+import java.io.DataInputStream;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.carbondata.core.datastore.filesystem.CarbonFile;
+import org.apache.carbondata.core.datastore.impl.FileFactory;
+import org.apache.carbondata.core.metadata.converter.SchemaConverter;
+import org.apache.carbondata.core.metadata.converter.ThriftWrapperSchemaConverterImpl;
+import org.apache.carbondata.core.metadata.schema.table.column.ColumnSchema;
+import org.apache.carbondata.core.reader.CarbonHeaderReader;
+import org.apache.carbondata.core.reader.CarbonIndexFileReader;
+import org.apache.carbondata.core.util.CarbonUtil;
+import org.apache.carbondata.core.util.path.CarbonTablePath;
+
+import static org.apache.carbondata.core.util.CarbonUtil.thriftColumnSchemaToWrapperColumnSchema;
+
+/**
+ * Schema reader for carbon files, including carbondata file, carbonindex file, and schema file
+ */
+public class CarbonSchemaReader {
+
+ /**
+ * Read schema file and return the schema
+ *
+ * @param schemaFilePath complete path including schema file name
+ * @return schema object
+ * @throws IOException
+ */
+ public static Schema readSchemaInSchemaFile(String schemaFilePath) throws IOException {
+ org.apache.carbondata.format.TableInfo tableInfo = CarbonUtil.readSchemaFile(schemaFilePath);
+ SchemaConverter schemaConverter = new ThriftWrapperSchemaConverterImpl();
+ List<ColumnSchema> schemaList = schemaConverter
+ .fromExternalToWrapperTableInfo(tableInfo, "", "", "")
+ .getFactTable()
+ .getListOfColumns();
+ return new Schema(schemaList);
+ }
+
+ /**
+ * Read carbondata file and return the schema
+ *
+ * @param dataFilePath complete path including carbondata file name
+ * @return Schema object
+ * @throws IOException
+ */
+ public static Schema readSchemaInDataFile(String dataFilePath) throws IOException {
+ CarbonHeaderReader reader = new CarbonHeaderReader(dataFilePath);
+ return new Schema(reader.readSchema());
+ }
+
+ /**
+ * Read carbonindex file and return the schema
+ *
+ * @param indexFilePath complete path including index file name
+ * @return schema object
+ * @throws IOException
+ */
+ public static Schema readSchemaInIndexFile(String indexFilePath) throws IOException {
+ CarbonFile indexFile =
+ FileFactory.getCarbonFile(indexFilePath, FileFactory.getFileType(indexFilePath));
--- End diff --
This method is developed by ajantha in
https://github.com/apache/carbondata/pull/2345, after his PR merged, I will change the PR to invoke his method.
---
Locked
