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Strings beginner

String.indent() and transform()

Indent text and chain string transformations fluently.

Code Comparison
✕ Java 8 
String[] lines = text.split("\n");
StringBuilder sb = new StringBuilder();
for (String line : lines) {
    sb.append("    ").append(line)
      .append("\n");
}
String indented = sb.toString();
✓ Java 12+ 
String indented = text.indent(4);

String result = text
    .transform(String::strip)
    .transform(s -> s.replace(" ", "-"));
Why the modern way wins
📏

Built-in

Indentation is a common operation — now it's one call.

🔗

Chainable

transform() enables fluent pipelines on strings.

🧹

Clean code

No manual line splitting and StringBuilder loops.

Old Approach
Manual Indentation
Modern Approach
indent() / transform()
Since JDK
12
Difficulty
beginner
JDK Support
String.indent() and transform()
Available

Widely available since JDK 12 (March 2019)

How it works

indent(n) adds n spaces to each line. transform(fn) applies any function and returns the result, enabling fluent chaining of string operations.

Related patterns

Strings beginner

String.isBlank()

Java 8
boolean blank =
    str.trim().isEmpty();
// or: str.trim().length() == 0
Java 11+
boolean blank = str.isBlank();
// handles Unicode whitespace too
Hover to see modern ➜
JDK 11+ →
Strings beginner

String.strip() vs trim()

Java 8
// trim() only removes ASCII whitespace
// (chars <= U+0020)
String clean = str.trim();
Java 11+
// strip() removes all Unicode whitespace
String clean = str.strip();
String left  = str.stripLeading();
String right = str.stripTrailing();
Hover to see modern ➜
JDK 11+ →
Strings beginner

Multiline JSON/SQL/HTML

Java 8
String sql =
    "SELECT u.name, u.email\n" +
    "FROM users u\n" +
    "WHERE u.active = true\n" +
    "ORDER BY u.name";
Java 15+
String sql = """
    SELECT u.name, u.email
    FROM users u
    WHERE u.active = true
    ORDER BY u.name
    """;
Hover to see modern ➜
JDK 15+ →
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