fel基本使用

fel 我猜 是  function expression language 的缩写，函数表达式语言

 

使用：引入maven依赖（据说有0.9支持大整数 但是 maven 仓库没有 ）

?

1 2 3 4 5 6 7

<!-- fel -->  <dependency>     <groupId>org.eweb4j</groupId>     <artifactId>fel</artifactId>     <version>0.8</version> </dependency>

　　

 

测试和使用说明：

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426

package com.lomi.fel;   import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map;   import org.junit.Test;   import com.alibaba.fastjson.JSONObject; import com.greenpineyu.fel.Expression; import com.greenpineyu.fel.FelEngine; import com.greenpineyu.fel.FelEngineImpl; import com.greenpineyu.fel.common.ObjectUtils; import com.greenpineyu.fel.context.AbstractContext; import com.greenpineyu.fel.context.ContextChain; import com.greenpineyu.fel.context.FelContext; import com.greenpineyu.fel.context.MapContext; import com.greenpineyu.fel.function.CommonFunction; import com.greenpineyu.fel.function.Function; import com.greenpineyu.fel.parser.FelNode; import com.lomi.entity.Goods;   public class FelTest {             /**      * 使用常量      */     @Test     public void test0() {         FelEngine felEngine = new FelEngineImpl();         Object result = felEngine.eval("2*3");         System.out.println(result);     }             /**      * 使用变量      */     @Test     public void test2() {         FelEngine felEngine = new FelEngineImpl();         FelContext ctx = felEngine.getContext();         ctx.set("count", 10);         ctx.set("price", 100);         Object result = felEngine.eval("count*price");         System.out.println(result);     }       /**      * 使用变量的方法和属性      */     @Test     public void test3() {         FelEngine felEngine = new FelEngineImpl();         FelContext ctx = felEngine.getContext();         Goods good = Goods.randomGoods();         ctx.set("good", good);                   Map<String, String> map = new HashMap<String, String>();         map.put("key1", "value1");         ctx.set("map", map);           //取不存在的方法属性,返回null         Object result = felEngine.eval("good.size");         System.out.println("result:" + result);           //调用good的toString         result = felEngine.eval("good.toString");         System.out.println("result:" + result);           //获取name（分别调用  name() 方法 和  getName() 方法，name(优先) ，不会取直接获取私有字段）         result = felEngine.eval("good.name");         System.out.println("result:" + result);                   //调用有参方法  name(int  i)         result = felEngine.eval("good.name(1)");         System.out.println("result:" + result);                     //获取 map 的 value         result = felEngine.eval("map.key1");         System.out.println("result:" + result);     }       /**      * 使用集合，直接用下标获取 集合元素      */     @Test     public void test4() {         FelEngine felEngine = new FelEngineImpl();         FelContext ctx = felEngine.getContext();           // 数组         int[] intArray = { 1, 2, 3 };         ctx.set("intArray", intArray);         String exp = "intArray[0]";         System.out.println(exp + "->" + felEngine.eval(exp));           // List         List<Integer> list = Arrays.asList(1, 2, 3);         ctx.set("list", list);         exp = "list[0]";         System.out.println(exp + "->" + felEngine.eval(exp));           // 集合         Collection<String> coll = Arrays.asList("a", "b", "c");         ctx.set("coll", coll);         // 获取集合最前面的元素。执行结果为"a"         exp = "coll[0]";         System.out.println(exp + "->" + felEngine.eval(exp));           // 迭代器         Iterator<String> iterator = coll.iterator();         ctx.set("iterator", iterator);         // 获取迭代器最前面的元素。执行结果为"a"         exp = "iterator[0]";         System.out.println(exp + "->" + felEngine.eval(exp));           //Map         Map<String, String> m = new HashMap<String, String>();         m.put("name", "HashMap");         ctx.set("map", m);         exp = "map.name";         System.out.println(exp + "->" + felEngine.eval(exp));           // 多维数组         int[][] intArrays = { { 11, 12 }, { 21, 22 } };         ctx.set("intArrays", intArrays);         exp = "intArrays[0][0]";         System.out.println(exp + "->" + felEngine.eval(exp));           // 多维综合体，支持数组、集合的任意组合。         List<int[]> listArray = new ArrayList<int[]>();         listArray.add(new int[] { 1, 2, 3 });         listArray.add(new int[] { 4, 5, 6 });         ctx.set("listArray", listArray);         exp = "listArray[0][0]";         System.out.println(exp + "->" + felEngine.eval(exp));     }       /**      * 使用类的静态方法和new      */     @Test     public void test5() {         FelEngine fel = new FelEngineImpl();         FelContext ctx = fel.getContext();         ctx.set("json", JSONObject.class);         ctx.set("goods", Goods.randomGoods());           System.out.println(fel.eval("json.toJSONString( goods )"));                                       // 调用Math.min(1,2),java.lang包下面的都可简写         System.out.println(FelEngine.instance.eval("$('Math').min(1,2)"));                   // 调用new Goods().randomGoods();         System.out.println(FelEngine.instance.eval("$('com.lomi.entity.Goods.new').randomGoods()"));                   //感觉这玩意可以用链式编程动态编程(如果不考虑效率的话)         ctx.set("name1", "张三");         System.out.println(FelEngine.instance.eval("$('com.lomi.entity.Goods.new').setName(name1)",ctx));                         }       /**      * 使用上下文的参数      */     @Test     public void test6() {         // 负责提供气象服务的上下文环境         FelContext ctx = new AbstractContext() {             public Object get(String name) {                 if ("天气".equals(name)) {                     return "晴";                 }                 if ("温度".equals(name)) {                     return 25;                 }                 return null;             }         };                                       FelEngine felEngine = new FelEngineImpl(ctx);         Object eval = felEngine.eval("'天气:'+天气+';温度:'+温度");         System.out.println(eval);     }       /**      * 多层上下文（有继承关系，新的覆盖老的重复值）      */     @Test     public void test7() {         FelEngine felEngine = new FelEngineImpl();                   FelContext ctx1 = felEngine.getContext();         ctx1.set("a", 10);         ctx1.set("b", 100);                             FelContext ctx2 = new ContextChain(ctx1, new MapContext());         ctx2.set("a", 20);                             String exp = "b" + "-" + "a";                             //使用上下文2         Object rt2 = felEngine.eval(exp, ctx2);         System.out.println("b-a=" + rt2);                             //使用上下文1         Object rt = felEngine.eval(exp);         System.out.println("b-a=" + rt);       }       /**      * 编译以后在执行效率会高很多(先编译后执行，前提是公式固定)      */     @Test     public void test8() {         FelEngine fel = new FelEngineImpl();         FelContext ctx = fel.getContext();         ctx.set("单价", 5000);         ctx.set("数量", 12);         ctx.set("运费", 7500);         Expression exp = fel.compile("单价*数量+运费", ctx);         Object result = exp.eval(ctx);         System.out.println(result);     }       /**      * 大值（不知道哪里有0.9的版本）      */     @Test     public void test9() {         /*          * FelEngine fel = FelBuilder.bigNumberEngine(); String input =          * "111111111111111111111111111111+22222222222222222222222222222222"; Object          * value = fel.eval(input); Object compileValue = fel.compile(input,          * fel.getContext()).eval(fel.getContext()); System.out.println("大数值计算（解释执行）:" +          * value); System.out.println("大数值计算（编译执行）:" + compileValue);          */     }           /**      * 子定义函数      */     @Test     public void test11() {         Function fun = new CommonFunction() {               public String getName() {                   return "hello";               }               @Override               public Object call(Object[] arguments) {                   Object msg = null;                   if(arguments!= null && arguments.length>0){                       msg = arguments[0];                   }                                     System.out.println( msg );                                   return "say:" + ObjectUtils.toString(msg);               }           };                              Function addFun = new CommonFunction() {               public String getName() {                   return "add";               }               @Override               public Object call(Object[] arguments) {                   if(arguments== null || arguments.length != 2){                     throw new RuntimeException("参数异常");                 }                                     int a = (int)arguments[0];                 int b = (int)arguments[1];                 return a+b;               }           };                                        FelEngine felEngine = new FelEngineImpl();           //添加函数到引擎中。           felEngine.addFun(fun);           felEngine.addFun(addFun);                             String exp = "hello('你好')";           //解释执行           Object eval = felEngine.eval(exp);           System.out.println("hello "+eval);                               //编译执行(编译的过程会直接执行一边，如果这时候 修改了 上下文的变量，就要注意了)         Expression compile = felEngine.compile(exp, null);           eval = compile.eval(null);           System.out.println("hello "+eval);                             //函数里面可以套函数( CommonFunction.call.(Object[] arguments) 方法里面拿到的都是已经吧内嵌函数计算好了，详情见父类的 CommonFunction.call(FelNode node, FelContext context) )         System.out.println( felEngine.eval("hello( add(3,2) )") );     }                             /**      * 效率比较，正常简单相加20亿次，5秒      */     @Test     public void test12() {                   Long start = System.currentTimeMillis();         Integer a = 0;         Add add = new Add();         for(int i = 0;i<2000000000;i++) {             a= (Integer) add.call( new Integer[] {a,1} );         }         Long end = System.currentTimeMillis();         System.out.println( a );         System.out.println( end-start );     }           /**      * 解释执行也就差5000 倍，10W次6 秒。      */     @Test     public void test13() {                   Long start = System.currentTimeMillis();         FelEngine felEngine = new FelEngineImpl();           felEngine.addFun( new Add() );         Integer a = 0;         for(int i = 0;i<1000000;i++) {             a = (Integer) felEngine.eval("add("+ a +",1)");         }         Long end = System.currentTimeMillis();         System.out.println( a );         System.out.println( end-start );     }                 /**      * 解释执行也就差10多20 倍，2亿次9 秒      */     @Test     public void test14() {                   Long start = System.currentTimeMillis();         FelEngine felEngine = new FelEngineImpl();           felEngine.addFun( new Add2() );         Object a = 0;         FelContext felContext = felEngine.getContext();         felContext.set("a", 0 );                   //不知道为啥编译会把int类型改成double。         Expression expression  = felEngine.compile("add(a,1)",felContext);                   for(int i = 0;i<200000000;i++) {             a =  expression.eval(felContext);         }                   Long end = System.currentTimeMillis();         System.out.println( a );         System.out.println( end-start );     }<br><br><br><br>　　　　             class Add extends CommonFunction{         @Override         public String getName() {             return "add";         }           @Override         public Object call(Object[] arguments) {             return (Integer)arguments[0] + (Integer)arguments[1];         }     }           class Add2 extends CommonFunction{         FelContext context;                   public Object call(FelNode node, FelContext context) {             Object[] children = evalArgs(node, context);             this.context = context;             return call(children);         }                             @Override         public String getName() {             return "add";         }           @Override         public Integer call(Object[] arguments) {             Integer a = (Integer)arguments[0] + (Integer)arguments[1];             context.set("a", a);             return a;         }     }                                             }

　　　　　　/**
　　　　　　* 覆盖 com.greenpineyu.fel.function.operator 下面的 +，-，*，/,=,等可以从定义这些符号，比如让 1==2 返回true
　　　　　　*/
　　　　　　@Test
　　　　　　　　public void testEqual() {
　　　　　　　　FelEngine felEngine = new FelEngineImpl();

　　　　　　　　Object evalRt = felEngine.eval("1==2");
　　　　　　　　System.out.println( evalRt );

　　　　　　}

　　

附Goods类:

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93

package com.lomi.entity;   import com.lomi.utils.CodeUtil;   import cn.hutool.core.util.IdUtil;   public class Goods {     private Long id;       private String name;       private Integer stock;       private String des;       private String data;           public Goods( String name ) {         this.name = name;     }     public Goods() {}       public Long getId() {         return id;     }       public void setId(Long id) {         this.id = id;     }       public String getName() {         return name;     }           public String name(int  i) {         return "name方法" + i;     }       public Goods setName(String name) {         this.name = name == null ? null : name.trim();         return this;     }       public Integer getStock() {         return stock;     }       public void setStock(Integer stock) {         this.stock = stock;     }       public String getDes() {         return des;     }       public void setDes(String des) {         this.des = des == null ? null : des.trim();     }       public String getData() {         return data;     }       public void setData(String data) {         this.data = data == null ? null : data.trim();     }                                     @Override     public String toString() {         return "Goods [id=" + id + ", name=" + name + ", stock=" + stock + ", des=" + des + ", data=" + data + "]";     }                 public static Goods randomGoods() {         Goods goods = new Goods();         goods.setId(IdUtil.getSnowflakeNextId());         goods.setData(  CodeUtil.getRandomNum18() );         goods.setDes( CodeUtil.randomCode(6) );         goods.setName( CodeUtil.randomCode(3) );         goods.setStock( Integer.valueOf( CodeUtil.randomNumCode(4) ) );                   return goods;     }           public static void main(String[] args) {          System.out.println( Long.MAX_VALUE );     }       }

　　

例子地址代码：https://github.com/hualiuwuxin/TestExample.git