原创

Spring Boot集成Aviator实现参数校验

1.什么是aviator？

Aviator是一个高性能、轻量级的java语言实现的表达式求值引擎，主要用于各种表达式的动态求值。现在已经有很多开源可用的java表达式求值引擎，为什么还需要Avaitor呢？ Aviator的设计目标是轻量级和高性能 ，相比于Groovy、JRuby的笨重，Aviator非常小，加上依赖包也才450K,不算依赖包的话只有70K；当然，Aviator的语法是受限的，它不是一门完整的语言，而只是语言的一小部分集合。其次，Aviator的实现思路与其他轻量级的求值器很不相同，其他求值器一般都是通过解释的方式运行，而Aviator则是直接将表达式编译成Java字节码，交给JVM去执行。简单来说，Aviator的定位是介于Groovy这样的重量级脚本语言和IKExpression这样的轻量级表达式引擎之间

Aviator的特性

支持大部分运算操作符，包括算术操作符、关系运算符、逻辑操作符、位运算符、正则匹配操作符(=~)、三元表达式?: ，并且支持操作符的优先级和括号强制优先级，具体请看后面的操作符列表。
支持大整数和精度运算（2.3.0版本引入）
支持函数调用和自定义函数
内置支持正则表达式匹配，类似Ruby、Perl的匹配语法，并且支持类Ruby的$digit指向匹配分组。
自动类型转换，当执行操作的时候，会自动判断操作数类型并做相应转换，无法转换即抛异常。
支持传入变量，支持类似a.b.c的嵌套变量访问。
函数式风格的seq库，操作集合和数组
性能优秀

Aviator的限制

没有if else、do while等语句，没有赋值语句，仅支持逻辑表达式、算术表达式、三元表达式和正则匹配。
不支持八进制数字字面量，仅支持十进制和十六进制数字字面量。

使用场景

规则判断以及规则引擎
公式计算
动态脚本控制

2.代码工程

实验目的

利用aviator+aop实现参数校验

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springboot-demo</artifactId>
        <groupId>com.et</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>Aviator</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-autoconfigure</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--AOP-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>

        <!--Aviator-->
        <dependency>
            <groupId>com.googlecode.aviator</groupId>
            <artifactId>aviator</artifactId>
            <version>3.3.0</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.56</version>
        </dependency>

        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.8.1</version>
        </dependency>

    </dependencies>
</project>

controller

在方法上加伤aviator校验规则

package com.et.controller;

import com.et.annotation.Check;
import com.et.exception.HttpResult;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.HashMap;
import java.util.Map;

@RestController
public class HelloWorldController {
    @RequestMapping("/hello")
    public Map<String, Object> showHelloWorld(){
        Map<String, Object> map = new HashMap<>();
        map.put("msg", "HelloWorld");
        return map;
    }
    @GetMapping("/simple")
    @Check(ex = "name != null", msg = "Name cannot be empty")
    @Check(ex = "age != null", msg = "Age cannot be empty")
    @Check(ex = "age > 18", msg = "Age must be over 18 years old")
    @Check(ex = "phone != null", msg = "phone cannot be empty")
    @Check(ex = "phone =~ /^(1)[0-9]{10}$/", msg = "The phone number format is incorrect")
    @Check(ex = "string.startsWith(phone,\"1\")", msg = "The phone number must start with 1")
    @Check(ex = "idCard != null", msg = "ID number cannot be empty")
    @Check(ex = "idCard =~ /^[1-9]\\d{5}[1-9]\\d{3}((0[1-9])||(1[0-2]))((0[1-9])||(1\\d)||(2\\d)||(3[0-1]))\\d{3}([0-9]||X)$/", msg = "ID number format is incorrect")
    @Check(ex = "gender == 1", msg = "sex")
    @Check(ex = "date =~ /^[1-9][0-9]{3}-((0)[1-9]|(1)[0-2])-((0)[1-9]|[1,2][0-9]|(3)[0,1])$/", msg = "Wrong date format")
    @Check(ex = "date > '2019-12-20 00:00:00:00'", msg = "The date must be greater than 2019-12-20")
    public HttpResult simple(String name, Integer age, String phone, String idCard, String date) {
        System.out.println("name = " + name);
        System.out.println("age = " + age);
        System.out.println("phone = " + phone);
        System.out.println("idCard = " + idCard);
        System.out.println("date = " + date);
        return HttpResult.success();
    }
}

annotation

单个规则注解

package com.et.annotation;

import java.lang.annotation.*;


@Target({ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
//add more on a method
@Repeatable(CheckContainer.class)
public @interface Check {

   String ex() default "";

   String msg() default "";

}

多个规则注解

package com.et.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;


@Target({ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
public @interface CheckContainer {

   Check[] value();
}

AOP拦截注解

package com.et.annotation;

import com.et.exception.UserFriendlyException;
import com.googlecode.aviator.AviatorEvaluator;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.LocalVariableTableParameterNameDiscoverer;
import org.springframework.util.StringUtils;

import java.lang.reflect.Method;
import java.util.*;


@Aspect
@Configuration
public class AopConfig {

   /**
    * Aspects monitor multiple annotations, because one annotation is Check and multiple annotations are compiled to CheckContainer
    */
   @Pointcut("@annotation(com.et.annotation.CheckContainer) || @annotation(com.et.annotation.Check)")
   public void pointcut() {
   }

   @Before("pointcut()")
   public Object before(JoinPoint point) {
      //get params
      Object[] args = point.getArgs();
      //get param name
      Method method = ((MethodSignature) point.getSignature()).getMethod();
      LocalVariableTableParameterNameDiscoverer u = new LocalVariableTableParameterNameDiscoverer();
      String[] paramNames = u.getParameterNames(method);

      CheckContainer checkContainer = method.getDeclaredAnnotation(CheckContainer.class);
      List<Check> value = new ArrayList<>();

      if (checkContainer != null) {
         value.addAll(Arrays.asList(checkContainer.value()));
      } else {
         Check check = method.getDeclaredAnnotation(Check.class);
         value.add(check);
      }
      for (int i = 0; i < value.size(); i++) {
         Check check = value.get(i);
         String ex = check.ex();
         //In the rule engine, null is represented by nil
         ex = ex.replaceAll("null", "nil");
         String msg = check.msg();
         if (StringUtils.isEmpty(msg)) {
            msg = "server exception...";
         }

         Map<String, Object> map = new HashMap<>(16);
         for (int j = 0; j < paramNames.length; j++) {
            //Prevent index out of bounds
            if (j > args.length) {
               continue;
            }
            map.put(paramNames[j], args[j]);
         }
         Boolean result = (Boolean) AviatorEvaluator.execute(ex, map);
         if (!result) {
            throw new UserFriendlyException(msg);
         }
      }
      return null;
   }
}

全局异常拦截

package com.et.exception;

import com.alibaba.fastjson.JSON;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.lang.Nullable;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;

import javax.servlet.http.HttpServletRequest;


@Configuration
@ControllerAdvice
public class DefaultGlobalExceptionHandler extends ResponseEntityExceptionHandler {
   private static final Logger LOGGER = LoggerFactory.getLogger(DefaultGlobalExceptionHandler.class);

   @Override
   protected ResponseEntity<Object> handleExceptionInternal(Exception ex, @Nullable Object body, HttpHeaders headers, HttpStatus status, WebRequest request) {
      HttpResult httpResult = HttpResult.failure(status.is5xxServerError() ? ErrorCode.serverError.getDesc() : ErrorCode.paramError.getDesc());
      LOGGER.error("handleException, ex caught, contextPath={}, httpResult={}, ex.msg={}", request.getContextPath(), JSON.toJSONString(httpResult), ex.getMessage());
      return super.handleExceptionInternal(ex, httpResult, headers, status, request);
   }

   @ExceptionHandler(Exception.class)
   protected ResponseEntity handleException(HttpServletRequest request, Exception ex) {
      boolean is5xxServerError;
      HttpStatus httpStatus;
      HttpResult httpResult;
      if (ex instanceof UserFriendlyException) {
         UserFriendlyException userFriendlyException = (UserFriendlyException) ex;
         is5xxServerError = userFriendlyException.getHttpStatusCode() >= 500;
         httpStatus = HttpStatus.valueOf(userFriendlyException.getHttpStatusCode());
         httpResult = HttpResult.failure(userFriendlyException.getErrorCode(), userFriendlyException.getMessage());
      } else if (ex instanceof IllegalArgumentException) {
         // Spring assertions are used in parameter judgment. requireTrue will throw an IllegalArgumentException. The client cannot handle 5xx exceptions, so 200 is still returned.
         httpStatus = HttpStatus.OK;
         is5xxServerError = false;
         httpResult = HttpResult.failure("Parameter verification error or data abnormality!");
      } else {
         httpStatus = HttpStatus.INTERNAL_SERVER_ERROR;
         is5xxServerError = true;
         httpResult = HttpResult.failure(ErrorCode.serverError.getDesc());
      }
      if (is5xxServerError) {
         LOGGER.error("handleException, ex caught, uri={}, httpResult={}", request.getRequestURI(), JSON.toJSONString(httpResult), ex);
      } else {
         LOGGER.error("handleException, ex caught, uri={}, httpResult={}, ex.msg={}", request.getRequestURI(), JSON.toJSONString(httpResult), ex.getMessage());
      }
      return new ResponseEntity<>(httpResult, httpStatus);
   }

}

以上只是一些关键代码，所有代码请参见下面代码仓库

代码仓库

https://github.com/Harries/springboot-demo(aviator)

3.测试

启动Spring Boot应用
访问 http://127.0.0.1:8088/simple?name=jack&age=12
返回校验信息{"status":false,"code":4,"message":"Age must be over 18 years old","entry":null}