For example:

    Simple Retry Example

    Simple Retry Example

    1.     @Retryable
    2.     List<Book> listBooks() {
    3.         // ...

    Simple Retry Example

    1.     @Retryable
    2.     open fun listBooks(): List<Book> {
    3.         // ...

    The multiplier value of the @Retryable annotation can be used to configure a multiplier used to calculate the delay between retries, thus allowing exponential retry support.

    Note also that the annotation can be applied on interfaces and the behaviour will be inherited through annotation metadata. The implication of this is that @Retryable can be used in combination with such as the HTTP Client annotation.

    To customize retry behaviour you can set the attempts and delay members, For example to configure 5 attempts with a 2 second delay:

    Setting Retry Attempts

    1.                 delay = "2s" )
    2.     Book findBook(String title) {
    3.         // ...

    Setting Retry Attempts

    1.     @Retryable(attempts = "5", delay = "2s")
    2.     open fun findBook(title: String): Book {
    3.         // ...

    Notice how both and delay are defined as strings. This is to support configurability through annotation metadata. For example you can allow the retry policy to be configured using property placeholder resolution:

    Setting Retry via Configuration

    Setting Retry via Configuration

    1.             delay = "\${book.retry.delay:1s}")
    2.     Book getBook(String title) {
    3.         // ...
    1.     @Retryable(attempts = "\${book.retry.attempts:3}", delay = "\${book.retry.delay:1s}")
    2.     open fun getBook(title: String): Book {
    3.         // ...

    With the above in place if book.retry.attempts is specified in configuration it wil be bound the value of the attempts member of the annotation via annotation metadata.