用java生成drools drl文件

Question

rule "Demo_testing"
when
    $employee : EmployeeModel( department contains "Accounts" )
then
//

我在这里找到了drools编译器中可用的描述符列表，但我不知道需要使用哪个描述符以及如何定义。？

请任何人帮助我重新爱上这一个。提前谢了。

PatternDescr employeePatternDescr=new PatternDescr();
employeePatternDescr.setIdentifier("$employee");
employeePatternDescr.setObjectType("EmployeeModel");
RelationalExprDescr relationalExprDescr = null;
constraintDescr.setExpression("department");
ExprConstraintDescr constraintDescr2=new ExprConstraintDescr();
constraintDescr2.setExpression("Accounts" );
relationalExprDescr = new RelationalExprDescr("contains" ,false, null, constraintDescr, constraintDescr2);
employeePatternDescr.addConstraint(relationalExprDescr);
andDescr.addDescr(employeePatternDescr);
ruleDescr.setLhs(andDescr);

Answer 1

嗨，谢谢你的建议，最后我用FromDescr做了。

根据我的要求，我可以使用下面的java代码来genrate规则drl文件。

PatternDescr employeePatternDescr=new PatternDescr();
employeePatternDescr.setIdentifier("$employee");
employeePatternDescr.setObjectType("EmployeeModel");
**FromDescr fromDescr = new FromDescr();
fromDescr.setDataSource( new MVELExprDescr( "$employeeList") );
employeePatternDescr.setSource(fromDescr);**
RelationalExprDescr relationalExprDescr = null;
constraintDescr.setExpression("department");
ExprConstraintDescr constraintDescr2=new ExprConstraintDescr();
constraintDescr2.setExpression("Accounts" );
relationalExprDescr = new RelationalExprDescr("contains" ,false, null, 
constraintDescr, constraintDescr2);
employeePatternDescr.addConstraint(relationalExprDescr);
andDescr.addDescr(employeePatternDescr);
ruleDescr.setLhs(andDescr);

此代码生成的规则如下所示

rule "Demo_testing"
when
    $employee : EmployeeModel( department contains "Accounts" ) from $employeeList
then
System.out.println("Rule executed");