java - 每个循环都遇到麻烦

Question

所以我试图制作这个 swing GUI 来搜索书籍列表，然后在 JTextArea 中显示该书籍。这是我的 actionPerformed 方法

public void actionPerformed(ActionEvent e) {
    if (e.getActionCommand().equals("Search Books")){
        String bookName = JOptionPane.showInputDialog(this, "Enter books to search"); // prompts user to enter book title
        if (bookName == null){
            sArea.append("Enter a Book");
        }else{
            for (Book b: ban.getListOfBooks()){ //going through list of books to find matching title
                if (bookName.equals(b.getTitle())){ // appends string if it is equal to one of the book names
                    sArea.append(bookName);
                }else{ 
                    sArea.append("Book not found");
                }
            }
        }
    }else{
        ...

所以我的问题是 foreach 循环。当然，它会为列表中每个不相等的元素打印“未找到书籍”。因此，如果我有十本书，并且我输入第一本书的名称，它会打印该书，然后“找不到书”九次。我怎样才能重新格式化它以只打印一件东西？

Answer 1

您可以使用 boolean 值找到标志，然后检查是否在循环末尾找到了该书

    }else{
        boolean found = false;
        for (Book b: ban.getListOfBooks()){ //going through list of books to find matching title
            if (bookName.equals(b.getTitle())){ // appends string if it is equal to one of the book names
                sArea.append(bookName);
                found = true;
            }else{ 
            }
        }
        if (!found) sArea.append("Book not found");

    }