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# 快速上手 - Java
以下示例使用 **表模型** Java API(`ITsFileWriter`、`TableSchema`、`Tablet`)。树模型读写请参考 C++ 的 `TsFileTreeReader` / `TsFileTreeWriter` 及其他语言接口。
## 依赖
- JDK >=1.8
- Maven >=3.6
## 安装
在 Maven 中引用 TsFile API:
```shell
<dependency>
<groupId>org.apache.tsfile</groupId>
<artifactId>tsfile</artifactId>
<version>2.3.0</version>
</dependency>
```
## 写入示例
### 构造 ITsFileWriter
```shell
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();
```
### 写入数据
```shell
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);
```
### 关闭文件
```shell
writer.close();
```
### 示例代码
使用这些接口的示例代码位于:<https://github.com/apache/tsfile/blob/develop/java/examples/src/main/java/org/apache/tsfile/v4/WriteTabletWithITsFileWriter.java>
## 查询示例
### 构造 ITsFileReader
```shell
String path = "test.tsfile";
File f = FSFactoryProducer.getFSFactory().getFile(path);
ITsFileReader reader =
new TsFileReaderBuilder()
.file(f)
.build();
```
### 构建查询请求
```shell
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"));
```
### 查询数据
```shell
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());
}
```
### 关闭文件
```shell
reader.close();
```
### 示例代码
使用这些接口的示例代码位于:<https://github.com/apache/tsfile/blob/develop/java/examples/src/main/java/org/apache/tsfile/v4/ITsFileReaderAndITsFileWriter.java>
> 注意:以上读写示例均基于表模型接口,接口定义介绍可见[Java 接口定义](./InterfaceDefinition/InterfaceDefinition-Java.md)。若需了解树模型相关内容,请联系我们。