MVEL is a powerful expression language for Java-based applications.
MVEL is a powerful expression language for Java-based applications.
Questions tagged [mvel]
201 questions
1
vote
2 answers
How do I avoid MVEL PropertyAccessExceptions
How do you get around PropertyAccessExceptions when the top level key in the hash map may or may not exist?
In the example below, if the property exists, it works just fine, but if the property does not exist in the variable map, it throws a…
mcampster
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1
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0 answers
drools doesn't recognize ! with custom operators
I am getting issue when i use ! along with drools string operations like matches, str[startsWith] .
Any idea why drools doesn't allow ! with operators like matches , not matches, str[startsWith], str[endsWith], length
The ! works for other…
Sandesh Jayaprakash
- 29
- 3
1
vote
2 answers
How to evaluate if a value is in a list of values in DROOLS
In DROOLS, if we are looking to see if the value "foo" is in the list {fu, fa, fe, fi, fo, foo, fum, doodle, dee}, when MVEL parses that into a DRL we get something like this:
if("foo" == "fu" || "foo" == "fa" || "foo" == "fe" || ...)
Which is fine…
JTryon
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1 answer
Drools unable to resolve logger
I have a rule similar to the below one. When I use logger.debug in THEN sections of the rule, it works and not while I use it in WHEN sections.
Any ideas why?
package com.util;
import com.rulemodel.*;
global org.slf4j.Logger logger;
rule "My…
Spear A1
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1
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2 answers
Easy-Rules Rule engine, cannot fire on multiple facts at once
I am trying to extend the Shop Tutorial for easy rules (shop) to run on multiple facts. While writing the conditions in the rule we call functions using the "fact name" as below,
condition: "people.isAdult() == false"
Since, people is just the name…
E.Bülbül
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0 answers
Loop over the properties of member variable for conditional check in MVEL
Member variable categories must have MAIN type and url.
Stream
boolean mainCatImage=categories.stream()
.anyMatch(categories -> categories.getType()
.equals("MAIN") && StringUtils.isNotBlank(categories.getUrl()));
I have rewritten the same…
Patan
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1 answer
Drools MVEL Dialect - Semi-Colon Requirement
I am just curious as to why my Eclipse Drools compiler (6.5.0) requires semi-colons at the end of statements in the For loop, as below:
Map businessRulesRequest = $root.containsKey("BusinessRulesRequest") ? $root.get("BusinessRulesRequest") :…
Neil
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1
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2 answers
Comparing a field in a List of objects with a List of Strings in Drools
Assume I have a Policy object in Drools, that object contains a List of Cover objects, called covers and a List of String objects, which are called requestedCovers.
The Cover object contains type field, which is a String object.
I want to fire a…
Martijn Burger
- 7,315
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1 answer
Can't import static method using MVEL
According to MVEL's documentation, it's possible to import static java methods in a script: http://mvel.codehaus.org/Programmatic+Imports+for+2.0 . The following example is taken from that page, however is not working (I get an Error: unable to…
Óscar López
- 232,561
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1
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1 answer
Mule expression language unable to resolve method
I'm having an issue with this :
package com.acme;
Class CircuitBreakerUtil {
public static boolean canAttempt(String breakerName) {
return true;
}
}
my spring declaration
Pat B
- 1,915
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1
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1 answer
Intercept input and output of each function in an MVEL expression
I am quite new to MVEL. What I am trying to achieve is to log input and outputs of every function in an expression.
For example, having the following expression
h.function1('value1') != h.function2('value2')
what I am trying to log is the input…
riccardo.cardin
- 7,971
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1
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1 answer
MVEL case-insensentive
anybody knows how to adjust MVEL to use case-insensetive comparison?
Map map = new HashMap<>();
map.put("Name", "Igor");
String property = "name";
Object res = MVEL.eval(property, map);
System.out.println(res);
In this case I got…
idmitriev
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1
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1 answer
String replace for Roman numerals
I am getting user Input like following.
"Both ix is viii are roman numeral.
mcmlxxxvii is wow year.
Year is mmxvi."
I have to search all roman numerals present in i/p and convert it to upper case. So i want to use string replace like below where xxx…
Satyabrata Mahapatra
- 41
- 6
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1 answer
Does MVEL or Drools cannot resolve fact that its type is Map>?
my rules are just like this:
rule "calcitonin evaluation"
lock-on-active true
salience 0
when
$p : Patient($labtestItem : labtests.get("calcitonin").get("0"))
LabTestItem($result : result.substring(1,(result.length)-1),…
Young Harry
- 97
- 2
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1
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1 answer
MVEL Expression not evaluating properly when pre-compiled
Lets assume a, b are integers, and pets is of type HashMap
When I pre-compile the expression below, the pets.containsKey(\"Dogs\") node is a null inside the CompiledExpression object.
CompiledExpression compiledExpression = new…
Ramie
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