kotlin协程flow retry retryWhen（2）

kotlin协程flow retry retryWhen（2）

一、retry

import kotlinx.coroutines.flow.*
import kotlinx.coroutines.runBlockingfun main(args: Array<String>) {runBlocking {(1..5).asFlow().onEach {if (it == 3) {println("-")throw RuntimeException("error $it")}}.retry(2) {if (it is RuntimeException) {println("--")return@retry true}false}.onEach {println("onEach $it")}.catch {println("catch $it")}.onCompletion {println("onCompletion")}.collect {println("collect $it")}}
}

onEach 1
collect 1
onEach 2
collect 2
-
--
onEach 1
collect 1
onEach 2
collect 2
-
--
onEach 1
collect 1
onEach 2
collect 2
-
catch java.lang.RuntimeException: error 3
onCompletion

二、retryWhen

import kotlinx.coroutines.flow.*
import kotlinx.coroutines.runBlockingfun main(args: Array<String>) {runBlocking {(1..5).asFlow().onEach {if (it == 3) {println("-")throw RuntimeException("error $it")}}.retryWhen { cause, attempt ->if (cause is RuntimeException) {println("--")}attempt < 2}.onEach {println("onEach $it")}.catch {println("catch $it")}.onCompletion {println("onCompletion")}.collect {println("collect $it")}}
}

onEach 1
collect 1
onEach 2
collect 2
-
--
onEach 1
collect 1
onEach 2
collect 2
-
--
onEach 1
collect 1
onEach 2
collect 2
-
--
catch java.lang.RuntimeException: error 3
onCompletion

import kotlinx.coroutines.flow.*
import kotlinx.coroutines.runBlockingfun main(args: Array<String>) {runBlocking {(1..5).asFlow().onEach {println("-----")var p: Int = (Math.random() * 10).toInt() % 3println("it=$it p=$p")if (it == p) {println("error=$p")throw RuntimeException("error-$it")} else {println("onEach $it")}}.retryWhen { cause, attempt ->if (cause is RuntimeException) {println("cause RuntimeException")}attempt < 2}.catch {println("catch $it")}.onCompletion {println("onCompletion")}.collect {println("collect $it")}}
}

随机跑一次：

-----
it=1 p=0
onEach 1
collect 1
-----
it=2 p=1
onEach 2
collect 2
-----
it=3 p=0
onEach 3
collect 3
-----
it=4 p=2
onEach 4
collect 4
-----
it=5 p=1
onEach 5
collect 5
onCompletion

再跑：

-----
it=1 p=0
onEach 1
collect 1
-----
it=2 p=2
error=2
cause RuntimeException
-----
it=1 p=0
onEach 1
collect 1
-----
it=2 p=2
error=2
cause RuntimeException
-----
it=1 p=2
onEach 1
collect 1
-----
it=2 p=2
error=2
cause RuntimeException
catch java.lang.RuntimeException: error-2
onCompletion

又跑：

-----
it=1 p=0
onEach 1
collect 1
-----
it=2 p=2
error=2
cause RuntimeException
-----
it=1 p=2
onEach 1
collect 1
-----
it=2 p=1
onEach 2
collect 2
-----
it=3 p=2
onEach 3
collect 3
-----
it=4 p=2
onEach 4
collect 4
-----
it=5 p=2
onEach 5
collect 5
onCompletion

https://zhangphil.blog.csdn.net/article/details/130084723https://zhangphil.blog.csdn.net/article/details/130084723