Using Java Text Blocks to Simplify Multi‑line String Literals

Motivation: embedding large multi‑line strings such as HTML, XML, SQL, or JSON directly in Java code using traditional concatenation with "\n" or "+" makes the code hard to read, so developers often resort to StringBuilder for better performance.

Java Text Blocks (introduced in Java 15) provide a three‑quote syntax (""" ... """) that allows multi‑line string literals without most escape sequences, preserving formatting automatically.

Example of a traditional concatenated SQL query is shown, followed by the equivalent Text Block version, which is much cleaner.

String query = """
    SELECT "EMP_ID", "LAST_NAME" FROM "EMPLOYEE_TB"
    WHERE "CITY" = 'INDIANAPOLIS'
    ORDER BY "EMP_ID", "LAST_NAME";
""" ;

Text Blocks can also represent empty strings, though it requires two lines of code, and misuse (e.g., placing the three quotes on the same line) leads to compilation errors, as demonstrated.

The article explains that a Text Block is a constant expression of type String ; during compilation the Java compiler translates line terminators to LF, removes incidental indentation, and processes escape sequences, storing the result as a CONSTANT_String_info entry in the class file.

At runtime, the Text Block yields a regular String instance, indistinguishable from a literal, and identical content blocks share the same interned instance.

Verification steps using javap -c -v on the compiled class show that the constant pool contains the raw string, confirming that Text Blocks are syntactic sugar.