At the time of writing this book, JDK 12 had a proposal for adding multiline strings known as JEP 326: Raw String Literals. But this was dropped at the last minute. 

Starting with JDK 13, the idea was reconsidered and, unlike the declined raw string literals, text blocks are surrounded by three double quotes, """, as follows:

String text = """My high school,
the Illinois Mathematics and Science Academy,
showed me that anything is possible
and that you're never too young to think big.""";

Nevertheless, there are several surrogate solutions that can be used before JDK 13. These solutions have a common point—the use of the line separator:

private static final String LS = System.lineSeparator();

Starting with JDK 8, a solution may rely on String.join(), as follows:

String text = String.join(LS,
  "My high school, ",
  "the Illinois Mathematics and Science Academy,",
  "showed me that anything is possible ",
  "and that you're never too young to think big.");

Before JDK 8, an elegant solution may have relied on StringBuilder. This solution is available in the code bundled with this book.

While the preceding solutions are good fits for a relatively large number of strings, the following two are okay if we just have a few strings. The first one uses the + operator:

String text = "My high school, " + LS +
  "the Illinois Mathematics and Science Academy," + LS +
  "showed me that anything is possible " + LS +
  "and that you're never too young to think big.";

The second one uses String.format():

String text = String.format("%s" + LS + "%s" + LS + "%s" + LS + "%s",
  "My high school, ",
  "the Illinois Mathematics and Science Academy,",
  "showed me that anything is possible ",
  "and that you're never too young to think big.");