Java

Java 16 Second Preview of Text Blocks (JEP 378)

Bil Al

• 1 min read

Java 16 introduced the second preview of text blocks, which is a new feature that allows you to define multi-line string literals in Java. Text blocks are a more convenient and expressive way to define multi-line strings in Java, as they allow you to specify the string content directly in your code without the need to escape special characters or to concatenate multiple strings.

Here is an example of how to use text blocks in Java:

String html = """
  <html>
    <body>
      <h1>Hello, World!</h1>
    </body>
  </html>
""";

In this example, we are using a text block to define a multi-line string literal containing some HTML code. The text block is defined using three double quotes (""") and it can contain any characters, including newlines and special characters. The leading and trailing white space of the text block is preserved, so you don't need to worry about indentation or aligning the text block with your code.

Text blocks also support string interpolation, which allows you to include expressions within the text block by enclosing them in ${}:

String message = """
  Hello, ${name}!
  You are ${age} years old.
""";

In this example, we are using string interpolation to include the values of the name and age variables within the text block.

Text blocks are an improvement over traditional string literals because they allow you to define multi-line strings more conveniently and expressively, without the need to escape special characters or to concatenate multiple strings. They also support string interpolation, which can be useful for constructing strings that contain dynamic values.

One important thing to note about text blocks is that they are currently in preview, which means that they are experimental and may change in future releases. They are also subject to additional restrictions and requirements, such as the need to enable the preview feature explicitly and the need to comply with the terms of the Text Blocks preview license.