Quick Start - Java

The following steps use the table-model Java API (ITsFileWriter, TableSchema, Tablet). C/C++/Python tree-oriented APIs are described in the per-language quick starts and interface pages.

Dependencies

• JDK >=1.8
• Maven >=3.6

Installation Method

Using TsFile API with Maven:

<dependency>
    <groupId>org.apache.tsfile</groupId>
    <artifactId>tsfile</artifactId>
    <version>2.3.0</version>
</dependency>

Writing Process

Construct ITsFileWriter

String path = "test.tsfile";
File f = FSFactoryProducer.getFSFactory().getFile(path);

String tableName = "table1";

TableSchema tableSchema =
        new TableSchema(
                tableName,
                Arrays.asList(
                        new ColumnSchemaBuilder()
                                .name("id1")
                                .dataType(TSDataType.STRING)
                                .category(Tablet.ColumnCategory.TAG)
                                .build(),
                        new ColumnSchemaBuilder()
                                .name("id2")
                                .dataType(TSDataType.STRING)
                                .category(Tablet.ColumnCategory.TAG)
                                .build(),
                        new ColumnSchemaBuilder()
                                .name("s1")
                                .dataType(TSDataType.INT32)
                                .category(Tablet.ColumnCategory.FIELD)
                                .build(),
                        new ColumnSchemaBuilder()
                                .name("s2").
                                dataType(TSDataType.BOOLEAN)
                                .build()));

long memoryThreshold = 10 * 1024 * 1024;

ITsFileWriter writer =
             new TsFileWriterBuilder()
                     .file(f)
                     .tableSchema(tableSchema)
                     .memoryThreshold(memoryThreshold)
                     .build();

Write Data

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);

Close File

writer.close();

Sample Code

The sample code of using these interfaces is in https://github.com/apache/tsfile/blob/develop/java/examples/src/main/java/org/apache/tsfile/v4/WriteTabletWithITsFileWriter.java

Query Process

Construct ITsFileReader

String path = "test.tsfile";
File f = FSFactoryProducer.getFSFactory().getFile(path);

ITsFileReader reader = 
             new TsFileReaderBuilder()
                     .file(f)
                     .build();

Construct Query Request

TableSchema schema = reader.getTableSchemas(tableName);
TagFilterBuilder filterBuilder = new TagFilterBuilder(schema);
ResultSet resultSet = reader.query(tableName, Arrays.asList("id1", "id2", "s1", "s2"), 
    2, 8, filterBuilder.eq("id1", "id1_filed_1"));

Query Data

ResultSetMetadata metadata = resultSet.getMetadata();
System.out.println(metadata);

StringJoiner sj = new StringJoiner(" ");
for (int column = 1; column <= 5; column++) {
    sj.add(metadata.getColumnName(column) + "(" + metadata.getColumnType(column) + ") ");
}
System.out.println(sj.toString());

while (resultSet.next()) {
    Long timeField = resultSet.getLong("Time");
    String id1Field = resultSet.isNull("id1") ? null : resultSet.getString("id1");
    String id2Field = resultSet.isNull("id2") ? null : resultSet.getString("id2");
    Integer s1Field = resultSet.isNull("s1") ? null : resultSet.getInt(4);
    Boolean s2Field = resultSet.isNull("s2") ? null : resultSet.getBoolean(5);
    sj = new StringJoiner(" ");
    System.out.println(
            sj.add(timeField + "")
                    .add(id1Field)
                    .add(id2Field)
                    .add(s1Field + "")
                    .add(s2Field + "")
                    .toString());
}

Close File

reader.close();

Sample Code

The sample code of using these interfaces is in https://github.com/apache/tsfile/blob/develop/java/examples/src/main/java/org/apache/tsfile/v4/ITsFileReaderAndITsFileWriter.java

Note: The above read/write examples are all based on the table model interface. For details about the interface definition, please refer to Java Interface Definition. If you need information regarding the tree model, please contact us.