code: public static void main(String... args) throws Exception {
  
          Map<String, Object> map = new HashMap<String, Object>();
  
          map.put("current", new Date());
          map.put("numbers", new Integer[] { 1, 2, 3, 5, 8, 13, 21, 34 });
          map.put("index", 5);
          map.put(":2", 2);
          map.put("map", map);
  
          ExprResolver exprResolver = new ExprResolverImpl(map, map);
          
  
          System.out.println("map['index']=" +  // NL
                  exprResolver.executeExpr(":map[index]"));
          System.out.println("numbers[5]=" +  // NL
                  exprResolver.executeExpr(":map[numbers][5]"));
  
          System.out.println( // NL
                  exprResolver.executeExpr( // NL
                          "$numbers[:index] + :2"));
          System.out.println( // NL
                  exprResolver.executeExpr( // NL
                          ":current.year - ($current.month + $current.day) - :2"));
          System.out.println( // NL
                  exprResolver.executeExpr( // NL
                          ":current.year - ($current.month + $current.day) + $numbers[:index] + :2"));
      }
docs: 进行简单测试