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java14-text-block-improvement.md

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Small improvements in Text Block support in Java 14

In Java 14, there are two small improvements added in Text Block.

Two new escape sequences were added in Java 14. First, you can use the new \s escape sequence to mean a single space.

For example,

String whitespaceEscapes = """
                                \s Hello,\s Java 14!\s
                                   """;

        System.out.println("Escaped whitespaces by a \\s char in Java 14:\n" + whitespaceEscapes.replaceAll(" ", "."));

It will print the result in the console.

Escaped whitespaces by a \s char in Java 14:
..Hello,..Java.14!.

It inserted white spaces at the beginning and ending of this line which changed the incident characters processing.

Second, you can use a backslash, \, as a way to suppress the insertion of a new line character at the end of a line. This is helpful when you have a very long line that you want to split up for ease of readability inside a text block.

The processing is similar with the multi lines command in bash shell. To input a long command in the Linux terminal, you can break it into multi lines by appending a \ at the ending of every lines. The result is equivalent to a long single-line based string .

Let's have a look at an example.

String noNewlines = """
    mvn archetype:generate -DgroupId=com.example
        -DartifactId=demo
        -DarchetypeArtifactId=maven-archetype-webapp
        -DinteractiveMode=false
        """;
        System.out.println("No line delimiters at the end of every lines:\n" + noNewlines.replaceAll(" ", "."));

String newlines = """
    mvn archetype:generate -DgroupId=com.example                 \
        -DartifactId=demo                            \
        -DarchetypeArtifactId=maven-archetype-webapp \
        -DinteractiveMode=false                      \
        """;
        System.out.println("New line delimiters added at the end of every lines:\n" + newlines.replaceAll(" ", "."));

It will print the following result. Compared the result of the two samples, the second result is a long single-line string without new line breaks.

mvn.archetype:generate.-DgroupId=com.example
..............	-DartifactId=demo
...............	-DarchetypeArtifactId=maven-archetype-webapp
..............	-DinteractiveMode=false

New line delimiters added at the end of every lines:
mvn.archetype:generate.-DgroupId=com.example.........................	-DartifactId=demo....................................	-DarchetypeArtifactId=maven-archetype-webapp.........	-DinteractiveMode=false......................