新增计算公式

pom.xml

@@ -42,6 +42,7 @@
         <lombok.version>1.18.10</lombok.version>
         <zhyd.oauth.version>1.15.6</zhyd.oauth.version>
         <jsqlparser.version>1.4</jsqlparser.version>
+        <googlecode.aviator.version>2.3.3</googlecode.aviator.version>
     </properties>
 
     <!-- 依赖声明 -->
@@ -329,6 +330,13 @@
                 <artifactId>flowable-json-converter</artifactId>
                 <version>${flowable.version}</version>
             </dependency>
+
+            <!--Aviator是一个轻量级、高性能的Java表达式执行引擎，它动态地将表达式编译成字节码并运行。可被用于动态的公式计算、规则执行和过滤等场景-->
+            <dependency>
+                <groupId>com.googlecode.aviator</groupId>
+                <artifactId>aviator</artifactId>
+                <version>${googlecode.aviator.version}</version>
+            </dependency>
         </dependencies>
     </dependencyManagement>
 

snow-common/pom.xml

@@ -151,6 +151,11 @@
             <groupId>com.alipay.sdk</groupId>
             <artifactId>alipay-sdk-java</artifactId>
         </dependency>
+
+        <dependency>
+            <groupId>com.googlecode.aviator</groupId>
+            <artifactId>aviator</artifactId>
+        </dependency>
     </dependencies>
 
 </project>

snow-common/src/main/java/com/snow/common/annotation/FormulaChinese.java

@@ -0,0 +1,20 @@
+package com.snow.common.annotation;
+
+import java.lang.annotation.*;
+
+/**
+ * @author qimingjin
+ * @Title:
+ * @Description:
+ * @date 2021/9/30 10:50
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.TYPE,ElementType.METHOD,ElementType.FIELD})
+@Documented
+public @interface FormulaChinese {
+    /**
+     * 计算汉化名称
+     * @return
+     */
+    String name() default "";
+}

snow-common/src/main/java/com/snow/common/utils/formula/MathEnv.java

@@ -0,0 +1,41 @@
+package com.snow.common.utils.formula;
+
+import com.snow.common.annotation.FormulaChinese;
+import lombok.extern.slf4j.Slf4j;
+
+import java.lang.reflect.Field;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * 表达式计算引擎
+ */
+@Slf4j
+public class MathEnv {
+
+    /**
+     * 根据对象获取变量和值
+     * @param o
+     * @return
+     */
+    public Map<String, Object> getEnv(Object o) {
+        Map<String, Object> env = new HashMap<>(30);
+        Field[] fields = o.getClass().getDeclaredFields();
+        for (Field f : fields) {
+            FormulaChinese annotation = f.getAnnotation(FormulaChinese.class);
+            if (null != annotation) {
+                String name = annotation.name();
+                f.setAccessible(true);
+                Object fieldVal = null;
+                try {
+                    fieldVal = f.get(o);
+                } catch (IllegalAccessException e) {
+                    log.info("exception:{}", e);
+                    throw new RuntimeException(e);
+                }
+                env.put(name, fieldVal);
+            }
+        }
+        return env;
+    }
+}

snow-common/src/main/java/com/snow/common/utils/formula/MathFormula.java

@@ -0,0 +1,48 @@
+package com.snow.common.utils.formula;
+
+import com.googlecode.aviator.AviatorEvaluator;
+import com.googlecode.aviator.Expression;
+import lombok.extern.slf4j.Slf4j;
+
+import java.math.BigDecimal;
+import java.util.Map;
+
+/**
+ * 表达式计算引擎
+ */
+@Slf4j
+public class MathFormula {
+
+    /**
+     * 通过对象执行公式
+     * @param mathformula
+     * @param o
+     * @return
+     */
+    public static BigDecimal executeFormula(String mathformula, Object o) {
+        MathEnv mathEnv = new MathEnv();
+        Map<String, Object> env = mathEnv.getEnv(o);
+        return compileAndExecute(mathformula, env);
+    }
+
+    /**
+     * 通过Map执行公式
+     * @param mathFormula
+     * @param env
+     * @return
+     */
+    private static BigDecimal compileAndExecute(String mathFormula, Map<String, Object> env) {
+        // 打印计算公式
+        log.info("**************************************************");
+        log.info("@@传入的计算公式 => {}", mathFormula);
+        Expression compiledExp = AviatorEvaluator.compile(mathFormula);
+        // 打印变量和值
+        env.entrySet().forEach(e ->log.info("{} => {}", e.getKey(), e.getValue()));
+        // 打印结果
+        BigDecimal result = (BigDecimal) compiledExp.execute(env);
+        log.info("@@根据公式计算结果 => {}", result);
+        log.info("**************************************************");
+        return result;
+    }
+
+}