java Spel with stream API

Question

I have this string 1|1|1|1 and I want to sum the numbers inside spel statement. I tried this one but got wrong expression.

T(java.util.Arrays).stream(SERVICE_CLASS.split('|')).reduce(Integer::sum)

the log :

org.springframework.expression.spel.SpelParseException: Expression [new Object[] {T(java.util.Arrays).stream(SERVICE_CLASS.split('|')).reduce(Integer::sum)}] @81: EL1043E: Unexpected token. Expected 'rparen())' but was 'colon(:)'

the full code :

 @Test fun `test sum values`() {
    val cont = ScriptingContext.default();

    val contextrecord: Map<String, String> = mapOf(
        "value" to "1|1|1|1"
    )


    val context = cont.getEvalContext()
    context.setRootObject(contextrecord)
    val value = cont.parser.parseExpression("new Object[] {T(java.util.Arrays).stream(value.split('|')).reduce(Integer::sum)}").getValue(context) as Array<Object>
    println(value.toString())
    assertEquals(value[0], "4")
}

any suggest to do it ?

*I tried this one but got wrong expression.* Please share the exact message — Jens, Jan 23 '23 at 11:14
By the way, that errors means you're not sharing the full expression. Please include a [example]. — Federico klez Culloca, Jan 23 '23 at 11:17
I'm not familiar with spring-el, but are you absolutely positive it supports method references? Because I can't find anything about them in the documentation, and the text of the error implies it doesn't like `Integer::sum`. — Federico klez Culloca, Jan 23 '23 at 11:31
@FedericoklezCulloca this is my question what should I do to sum this numbers — Anas Altarazi, Jan 23 '23 at 11:32
SpEL stands for Spring Expression **LANGUAGE**. It is not Java; no lambdas, or method references are supported. — Gary Russell, Jan 23 '23 at 14:07

score 1 · Answer 1 · answered Jan 23 '23 at 14:07

1

SpEL stands for Spring Expression LANGUAGE. It is not Java; no lambdas, or method references are supported.

You can, however, register lambdas as SpEL functions; see Spring Expression Language - Java 8 forEach or stream on list

answered Jan 23 '23 at 14:07

Gary Russell

166,535
14
146
179

thanks for your answer, but the requirement said we need to do it without any additional methods. do you have any trick to do it ? – Anas Altarazi Jan 23 '23 at 14:16
No, there is no way to do that. The SpEL was designed mostly for simple properties access and it is significantly slow because it uses a reflection to call all those methods. What you trying to do (no additional methods) is an abuse of SpEL capabilities. Consider to use a scripting feature in Spring Integration instead: https://docs.spring.io/spring-integration/reference/html/scripting.html#scripting – Artem Bilan Jan 23 '23 at 14:39

java Spel with stream API

1 Answers1