add example

java/examples/src/main/java/org/apache/tsfile/v4/WriteTabletWithITsFileWriter.java

@@ -0,0 +1,121 @@
+/*
+ * 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.tsfile.v4;
+
+import org.apache.tsfile.enums.TSDataType;
+import org.apache.tsfile.exception.write.WriteProcessException;
+import org.apache.tsfile.file.metadata.ColumnSchemaBuilder;
+import org.apache.tsfile.file.metadata.TableSchema;
+import org.apache.tsfile.fileSystem.FSFactoryProducer;
+import org.apache.tsfile.write.record.Tablet;
+import org.apache.tsfile.write.v4.ITsFileWriter;
+import org.apache.tsfile.write.v4.TsFileWriterBuilder;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.util.Arrays;
+
+public class WriteTabletWithITsFileWriter {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(WriteTabletWithITsFileWriter.class);
+
+  public static void main(String[] args) throws IOException {
+    String path = "test.tsfile";
+    File f = FSFactoryProducer.getFSFactory().getFile(path);
+    if (f.exists()) {
+      Files.delete(f.toPath());
+    }
+
+    String tableName = "table1";
+
+    TableSchema tableSchema =
+        new TableSchema(
+            tableName,
+            Arrays.asList(
+                new ColumnSchemaBuilder()
+                    .name("id1")
+                    .dataType(TSDataType.STRING)
+                    .category(Tablet.ColumnCategory.ID)
+                    .build(),
+                new ColumnSchemaBuilder()
+                    .name("id2")
+                    .dataType(TSDataType.STRING)
+                    .category(Tablet.ColumnCategory.ID)
+                    .build(),
+                new ColumnSchemaBuilder()
+                    .name("s1")
+                    .dataType(TSDataType.INT32)
+                    .category(Tablet.ColumnCategory.MEASUREMENT)
+                    .build(),
+                new ColumnSchemaBuilder().name("s2").dataType(TSDataType.BOOLEAN).build()));
+
+    long memoryThreshold = 10 * 1024 * 1024;
+    // tableSchema and file are required. memoryThreshold is an optional parameter, default value is
+    // 32 * 1024 * 1024 byte.
+    try (ITsFileWriter writer =
+        new TsFileWriterBuilder()
+            .file(f)
+            .tableSchema(tableSchema)
+            .memoryThreshold(memoryThreshold)
+            .build()) {
+      Tablet tablet =
+          new Tablet(
+              Arrays.asList("id1", "id2", "s1", "s2"),
+              Arrays.asList(
+                  TSDataType.STRING, TSDataType.STRING, TSDataType.INT32, TSDataType.BOOLEAN));
+      for (int row = 0; row < 5; row++) {
+        long timestamp = row;
+        tablet.addTimestamp(row, timestamp);
+        tablet.addValue(row, "id1", "id1_filed_1");
+        tablet.addValue(row, "id2", "id2_filed_1");
+        tablet.addValue(row, "s1", row);
+        tablet.addValue(row, "s2", true);
+      }
+      writer.write(tablet);
+
+      // reset tablet
+      tablet.reset();
+
+      for (int timestamp = 0; timestamp < 5; timestamp++) {
+        int rowIndex = tablet.getRowSize();
+        // rowSize may be changed after addTimestamp
+        tablet.addTimestamp(rowIndex, timestamp);
+
+        // id1 column
+        tablet.addValue(rowIndex, 0, "id1_field_2");
+
+        // id2 column
+        tablet.addValue(rowIndex, 1, "id1_field_2");
+
+        tablet.addValue(rowIndex, 2, timestamp);
+
+        // s2 column
+        tablet.addValue(rowIndex, 3, false);
+      }
+      writer.write(tablet);
+    } catch (WriteProcessException e) {
+      LOGGER.error("meet error in TsFileWrite ", e);
+    }
+  }
+}

java/tsfile/src/main/java/org/apache/tsfile/write/v4/TsFileWriterBuilder.java

@@ -57,7 +57,7 @@ public TsFileWriterBuilder memoryThreshold(long memoryThreshold) {
   }
 
   private void validateParameters() {
-    if (file == null || !file.exists() || file.isDirectory()) {
+    if (file == null || file.isDirectory()) {
       throw new IllegalArgumentException("The file must be a non-null and non-directory File.");
     }
     if (this.tableSchema == null) {