轻量级规则引擎

朱雀 2022-12-10 14:49 181阅读 0赞

## 一、aviator规则引擎 ##

依赖：

<dependency>
                <groupId>com.googlecode.aviator</groupId>
                <artifactId>aviator</artifactId>
                <version>5.1.4</version>
            </dependency>

代码：

import com.googlecode.aviator.*;
    import com.googlecode.aviator.runtime.function.AbstractFunction;
    import com.googlecode.aviator.runtime.function.FunctionUtils;
    import com.googlecode.aviator.runtime.type.AviatorDouble;
    import com.googlecode.aviator.runtime.type.AviatorObject;
    import com.googlecode.aviator.script.AviatorScriptEngine;
    
    import javax.script.ScriptEngine;
    import javax.script.ScriptEngineManager;
    import javax.script.ScriptException;
    import java.io.IOException;
    import java.util.HashMap;
    import java.util.Map;
    
    public class AviatorDemo { 
    
    
        public static void main(String[] args) throws IOException, ScriptException { 
            test1();
            test2();
            test3();
            test4();
            test5();
        }
    
    
        public static void test1(){ 
            String name = "测试";
            Map<String, Object> env = new HashMap<>(1);
            env.put("name", name);
            String result = (String) AviatorEvaluator.execute(" 'hello ' + name ", env);
            System.out.println(result);
        }
    
    
        private static void test2() throws IOException { 
            //注册函数
            AviatorEvaluator.addFunction(new AddFunction());
            System.out.println(AviatorEvaluator.execute("add(1, 2)"));           // 3.0
            System.out.println(AviatorEvaluator.execute("add(add(1, 2), 100)")); // 103.0
        }
    
    
        private static void test3(){ 
            String expression = "a-(b-c) > 100";
            Expression compiledExp = AviatorEvaluator.compile(expression);
            // Execute with injected variables.
            Boolean result = (Boolean) compiledExp.execute(compiledExp.newEnv("a", 100.3, "b", 45, "c", -199.100));
            System.out.println(result);
            // Compile a script
            Expression script = AviatorEvaluator.getInstance().compile("println('Hello, AviatorScript!');");
            script.execute();
        }
    
        /** * ## examples/statements.av * let a = 1; * let b = 2; * c = a + b; * @throws IOException */
        private static void test4() throws IOException { 
            Expression exp = AviatorEvaluator.getInstance().compileScript("examples/statements.av");
            Object result = exp.execute();
            System.out.println(result);
        }
    
    
        private static void test5() throws ScriptException { 
            final ScriptEngineManager sem = new ScriptEngineManager();
            ScriptEngine engine = sem.getEngineByName("AviatorScript");
            AviatorEvaluatorInstance instance = ((AviatorScriptEngine) engine).getEngine();
            // Use compatible feature set
            instance.setOption(Options.FEATURE_SET, Feature.getCompatibleFeatures());
            // Doesn't support if in compatible feature set mode.
            engine.eval("if(true) { println('support if'); }");
        }
    
        /** * 自定义函数 */
        static class AddFunction extends AbstractFunction { 
            @Override
            public AviatorObject call(Map<String, Object> env, AviatorObject arg1, AviatorObject arg2) { 
                Number left = FunctionUtils.getNumberValue(arg1, env);
                Number right = FunctionUtils.getNumberValue(arg2, env);
                return new AviatorDouble(left.doubleValue() + right.doubleValue());
            }
            @Override
            public String getName() { 
                return "add";
            }
        }
    
    }

## 二、Groovy规则引擎 ##

依赖：

<dependency>
                <groupId>org.codehaus.groovy</groupId>
                <artifactId>groovy</artifactId>
                <version>3.0.3</version>
            </dependency>
             <dependency>
                <groupId>org.codehaus.groovy</groupId>
                <artifactId>groovy-all</artifactId>
                <version>3.0.3</version>
            </dependency>

代码：

import groovy.lang.Binding;
    import groovy.lang.GroovyShell;
    import groovy.lang.Script;
    
    public class GroovyDemo { 
    
        public String testQuery(long id){ 
            return "Test query success, id is " + id;
        }
    
        public static void main(String[] args) { 
            test1();
        }
    
        private static void test1(){ 
            Binding groovyBinding = new Binding();
            GroovyShell groovyShell = new GroovyShell(groovyBinding);
            String scriptContent = "import com.citydo.faceadd.aviator.GroovyDemo\n" +
                    "def query = new GroovyDemo().testQuery(1L);\n" +
                    "query";
            Script script = groovyShell.parse(scriptContent);
            System.out.println(script.run());
        }
    
    
        private static void test2(){ 
            Binding groovyBinding = new Binding();
            groovyBinding.setVariable("GroovyDemo", new GroovyDemo());
            GroovyShell groovyShell = new GroovyShell(groovyBinding);
            String scriptContent = "def query = GroovyDemo.testQuery(2L);\n" +
                    "query";
            Script script = groovyShell.parse(scriptContent);
            System.out.println(script.run());
    
        }
    
    }

import groovy.lang.Binding;
    import org.springframework.beans.BeansException;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.ApplicationContextAware;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    import java.util.Map;
    
    @Configuration
    public class GroovyBindingConfig implements ApplicationContextAware { 
    
        private ApplicationContext applicationContext;
    
        @Bean("groovyBinding")
        public Binding groovyBinding() { 
            Binding groovyBinding = new Binding();
    
            Map<String, Object> beanMap = applicationContext.getBeansOfType(Object.class);
            //遍历设置所有bean,可以根据需求在循环中对bean做过滤
            for (String beanName : beanMap.keySet()) { 
                groovyBinding.setVariable(beanName, beanMap.get(beanName));
            }
            return groovyBinding;
        }
    
        /*@Bean("groovyBinding1") public Binding groovyBinding1() { Map<String, Object> beanMap = applicationContext.getBeansOfType(Object.class); return new Binding(beanMap); //如果不需要对bean做过滤，直接用beanMap构造Binding对象即可 }*/
    
        @Override
        public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { 
            this.applicationContext = applicationContext;
    
        }
    }

import groovy.lang.Binding;
    import groovy.lang.GroovyClassLoader;
    import groovy.lang.GroovyShell;
    import groovy.lang.Script;
    import org.codehaus.groovy.control.CompilerConfiguration;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestBody;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RestController;
    import com.citydo.faceadd.aviator.GroovyDemo;
    
    import javax.annotation.PostConstruct;
    
    @RestController
    @RequestMapping("/groovy/script")
    public class GroovyScriptController { 
    
        @Autowired
        private Binding groovyBinding;
    
        private GroovyShell groovyShell;
    
        @PostConstruct
        public void init(){ 
            GroovyClassLoader groovyClassLoader = new GroovyClassLoader(this.getClass().getClassLoader());
            CompilerConfiguration compilerConfiguration = new CompilerConfiguration();
            compilerConfiguration.setSourceEncoding("utf-8");
            compilerConfiguration.setScriptBaseClass(GroovyDemo.class.getName());
    
            groovyShell = new GroovyShell(groovyClassLoader, groovyBinding, compilerConfiguration);
        }
    
        @RequestMapping(value = "/execute", method = RequestMethod.POST)
        public String execute(@RequestBody String scriptContent) { 
            Script script = groovyShell.parse(scriptContent);
            return String.valueOf(script.run());
        }
    }

参考：[https://www.yuque.com/boyan-avfmj/aviatorscript/fycwgt][https_www.yuque.com_boyan-avfmj_aviatorscript_fycwgt]  
参考：[https://www.jianshu.com/p/c7803626c09d][https_www.jianshu.com_p_c7803626c09d]

[https_www.yuque.com_boyan-avfmj_aviatorscript_fycwgt]: https://www.yuque.com/boyan-avfmj/aviatorscript/fycwgt
[https_www.jianshu.com_p_c7803626c09d]: https://www.jianshu.com/p/c7803626c09d