Drools (5): drools advanced syntax

Advanced Grammar

keyword	describe
package	Package name , Limited to logical management , Same as ⼀ The query or function under the package name can be called directly ⽤
import	⽤ Yu Dao ⼊ Class or static ⽅ Law
global	Global variables
function	⾃ Defined function
query	Inquire about
rule end	Regular form

global Global variables

Global variables ,⼀ like ⽤ Act and hold ⾏ The result data after the rule is returned or a specific service is called ⽤ etc. , Such as ⼀ Examples of email services , In tune ⽤ Rule engine integration code , obtain emailService object , Then set it to ⼯ As in memory .

The grammatical structure is ：global object type Object name

Example ：

package rules

import java.util.List;

global java.util.List myGlobalList;
// If in the rule ⽂ Make... In the piece ⽤ It's a global variable , Then it must be regulated   Then set the global variable value in the engine 
rule "global_rule1"
    when
        eval( true )
    then
        myGlobalList.add( "Hello World" );
    // System.out.println("global_rule1 is execution...");
end
rule "global_rule2"
    when
        eval( true )
    then
        System.out.println("myGlobalList The number of elements in the set :"+myGlobalList.size());
        System.out.println("global_rule2 is execution...");
end

test ：

    @Test
    public void test13() throws InterruptedException {
        KieServices kieServices = KieServices.Factory.get();
        KieContainer kieClasspathContainer = kieServices.getKieClasspathContainer();
        KieSession kieSession = kieClasspathContainer.newKieSession();
        List list = new ArrayList();
         Set global variables , Name and type must match rules ⽂ The global variable name defined in the file corresponds to 
        kieSession.setGlobal("myGlobalList", list);
        // Activate rule engine , If the match is successful, execute ⾏ The rules 
        kieSession.fireAllRules();
        kieSession.dispose();
        System.out.println("list.size():" + list.size());
    }

 

test result ：