主方法的非顺序输出

Question

我尝试了一个简单的应用程序，但在运行时我得到non-sequential输出，但我想要sequential输出。每次我运行程序System.err.println()以不同的顺序执行。有什么办法解决这个请帮忙。

这是源代码的一部分 -

private static final BookDAO bookDao = (BookDAO) new BookDAOImpl();
    public static void main(String[] args) {

        System.err.println("Listing all Books:");
        findAllBooks();
        System.out.println();

        System.err.println("Search book by keyword in book title : Groovy:");

        searchBooks("Groovy");
        System.out.println();

        System.err.println("Search book by keyword in author's name : Josh:");

        searchBooks("Josh");
    }

    private static void findAllBooks() {
        List<Books> book = bookDao.findAllBooks();
        for (Books books : book) {
            System.out.println(books);
        }
    }
    private static void searchBooks(String keyWord) {

        List<Books> books = bookDao.searchBooksByKeyword(keyWord);
        for (Books book : books) {
            System.out.println(book);
        }
    }

输出应该是这样的 -

Listing all Books:
Book - Id: 1, Book Title: Practical Clojure
Book - Id: 2, Book Title: Beginning Groovy, Gr
Book - Id: 3, Book Title: Definitive Guide to 
Book - Id: 4, Book Title: Groovy and Grails Re
Book - Id: 5, Book Title: Modern Java Web Deve
Book - Id: 6, Book Title: Java 7 Recipes
Book - Id: 7, Book Title: Java EE 7 Recipes
Book - Id: 8, Book Title: Beginning Java 7 
Book - Id: 9, Book Title: Pro Java 7 NIO.2
Book - Id: 10, Book Title: Java 7 for Absolute 
Book - Id: 11, Book Title: Oracle Certified Jav
Book - Id: 12, Book Title: Beginning Scala

Search book by keyword in book title : Groovy:
Book - Id: 2, Book Title: Beginning Groovy, Gr
Book - Id: 4, Book Title: Groovy and Grails Re

Search book by keyword in author's name : Josh:
Book - Id: 6, Book Title: Java 7 Recipes
Book - Id: 7, Book Title: Java EE 7 Recipes

我得到了这样的输出 -