Text and charsets
The text flows allow to translate a stream of text data according to the used character sets. It supports conversion between ByteString and String, as well as conversion of the character set in binary text data in the form of ByteStrings.
The main use case for these flows is the transcoding of text read from a source with a certain character set, which may not be usable with other flows or sinks. For example may CSV data arrive in UTF-16 encoding, but the Alpakka CSV parser does only support UTF-8.
Project Info: Alpakka Text | |
---|---|
Artifact | com.lightbend.akka
akka-stream-alpakka-text
1.1.2
|
JDK versions | OpenJDK 8 |
Scala versions | 2.12.7, 2.11.12, 2.13.0 |
JPMS module name | akka.stream.alpakka.text |
License | |
Readiness level |
Since 0.20, 2018-07-04
|
Home page | https://doc.akka.io/docs/alpakka/current |
API documentation | |
Forums | |
Release notes | In the documentation |
Issues | Github issues |
Sources | https://github.com/akka/alpakka |
Artifacts
- sbt
libraryDependencies += "com.lightbend.akka" %% "akka-stream-alpakka-text" % "1.1.2"
- Maven
<dependency> <groupId>com.lightbend.akka</groupId> <artifactId>akka-stream-alpakka-text_2.12</artifactId> <version>1.1.2</version> </dependency>
- Gradle
dependencies { compile group: 'com.lightbend.akka', name: 'akka-stream-alpakka-text_2.12', version: '1.1.2' }
The table below shows direct dependencies of this module and the second tab shows all libraries it depends on transitively.
- Direct dependencies
Organization Artifact Version License com.typesafe.akka akka-stream_2.12 2.5.23 Apache License, Version 2.0 org.scala-lang scala-library 2.12.7 BSD 3-Clause - Dependency tree
com.typesafe.akka akka-stream_2.12 2.5.23 Apache License, Version 2.0 com.typesafe.akka akka-actor_2.12 2.5.23 Apache License, Version 2.0 com.typesafe config 1.3.3 Apache License, Version 2.0 org.scala-lang.modules scala-java8-compat_2.12 0.8.0 BSD 3-clause org.scala-lang scala-library 2.12.7 BSD 3-Clause org.scala-lang scala-library 2.12.7 BSD 3-Clause com.typesafe.akka akka-protobuf_2.12 2.5.23 Apache License, Version 2.0 org.scala-lang scala-library 2.12.7 BSD 3-Clause com.typesafe ssl-config-core_2.12 0.3.7 Apache-2.0 com.typesafe config 1.3.3 Apache License, Version 2.0 org.scala-lang.modules scala-parser-combinators_2.12 1.1.1 BSD 3-clause org.scala-lang scala-library 2.12.7 BSD 3-Clause org.scala-lang scala-library 2.12.7 BSD 3-Clause org.reactivestreams reactive-streams 1.0.2 CC0 org.scala-lang scala-library 2.12.7 BSD 3-Clause org.scala-lang scala-library 2.12.7 BSD 3-Clause
Text transcoding
The text transcoding flow converts incoming binary text data (ByteString) to binary text data of another character encoding.
The flow fails with an UnmappableCharacterException
, if a character is not representable in the targeted character set.
- Scala
-
import java.nio.charset.StandardCharsets import akka.stream.scaladsl.FileIO import akka.stream.alpakka.text.scaladsl.TextFlow val byteStringSource: Source[ByteString, _] = // ... byteStringSource .via(TextFlow.transcoding(StandardCharsets.UTF_16, StandardCharsets.UTF_8)) .runWith(FileIO.toPath(targetFile))
- Java
-
Source<ByteString, ?> byteStringSource = // ... byteStringSource .via(TextFlow.transcoding(StandardCharsets.UTF_16, StandardCharsets.UTF_8)) .runWith(FileIO.toPath(targetFile), materializer);
Text encoding
The text encoding flow converts incoming Strings to binary text data (ByteString) with the given character encoding.
The flow fails with an UnmappableCharacterException
, if a character is not representable in the targeted character set.
- Scala
-
import java.nio.charset.StandardCharsets import akka.stream.alpakka.text.scaladsl.TextFlow import akka.stream.scaladsl.FileIO val stringSource: Source[String, _] = // ... stringSource .via(TextFlow.encoding(StandardCharsets.US_ASCII)) .intersperse(ByteString("\n")) .runWith(FileIO.toPath(targetFile))
- Java
-
import akka.stream.alpakka.text.javadsl.TextFlow; import akka.stream.IOResult; import akka.stream.javadsl.FileIO; import akka.stream.javadsl.Sink; import akka.stream.javadsl.Source; import akka.util.ByteString; import java.nio.charset.StandardCharsets; Source<String, ?> stringSource = // ... stringSource .via(TextFlow.encoding(StandardCharsets.US_ASCII)) .intersperse(ByteString.fromString("\n")) .runWith(FileIO.toPath(targetFile), materializer);
Text decoding
The text decoding flow converts incoming ByteStrings to Strings using the given character encoding.
- Scala
-
import java.nio.charset.StandardCharsets import akka.stream.alpakka.text.scaladsl.TextFlow val byteStringSource: Source[ByteString, _] = // ... val result: Future[immutable.Seq[String]] = byteStringSource .via(TextFlow.decoding(StandardCharsets.UTF_16)) .runWith(Sink.seq)
- Java
-
Source<ByteString, ?> byteStringSource = // ... byteStringSource .via(TextFlow.decoding(StandardCharsets.UTF_16)) .runWith(Sink.seq(), materializer);