Beispielhafte Einführung zur Implementierung eines komplexen relationalen Ausdrucksfilters auf Basis von Java

 @Data
 @AllArgsConstructor
 @NoArgsConstructor
 @Accessors(chain = true)
 public class ExpressDto {
     /**
      * 序号
      */
     private Integer seq;
     /**
      * 深度（运算优先级）
      */
     private Integer deep;
     /**
      * 关系运算符
      */
     private String relation;
     /**
      * 类型
      */
     private String type;
     /**
      * 运算条件
      */
     private String field;
     /**
      * 逻辑运算符
      */
     private String operator;
     /**
      * 运算值
      */
     private String values;
     /**
      * 运算结果
      */
     private Boolean result;
 }

 //关系 栈
 Deque<String> relationStack=new LinkedList();
 //结果栈
 Deque<Boolean> resultStack=new LinkedList();
 // 当前深度
 Integer nowDeep=1;

 for (ExpressDto expressDto:list) {
             if(!StringUtils.equals(expressDto.getType(),"GROUP")){
                 //TODO 进行具体单个表达式计算并获取结果
                 resultStack.push(expressDto.getResult());
                 // 将关系放入栈中
                 relationStack.push(expressDto.getRelation());
                 if(deep==0 && resultStack.size()>1){ //由于已处理小于0的deep，当前deep理论上是>=0的，0表示同等级，需要立即运算
                     relationOperator(relationStack, resultStack);
                 }
             }else{
                 // 将关系放入栈中
                 relationStack.push(expressDto.getRelation());
             }
         } 
 
 private void relationOperator(Deque<String> relationStack, Deque<Boolean> resultStack) {
         Boolean lastResult= resultStack.pop();
         Boolean firstResult= resultStack.pop();
         String relation=relationStack.pop();
         if(StringUtils.equals(relation,"AND")){
             resultStack.push(firstResult&& lastResult) ;
             return;
         }
         if(StringUtils.equals(relation,"OR")){
             resultStack.push( firstResult|| lastResult);
             return;
         }else{
             throw new RuntimeException("表达式解析异常：关系表达式错误");
         }
     }

   /**
      * 处理层级遗留元素
      *
      * @param relationStack
      * @param resultStack
      */
     private void computeBeforeEndGroup(Deque<String> relationStack, Deque<Boolean> resultStack) {
         boolean isBeginSymbol=StringUtils.equals(relationStack.peek(),"BEGIN");//防止group中仅有一个判断条件
         while(!isBeginSymbol){//上一个运算符非BEGIN，说明该group中还有运算需要优先处理，正常这里应该仅循环一次
             relationOperator(relationStack, resultStack);
             isBeginSymbol=StringUtils.equals(relationStack.peek(),"BEGIN");
         }
         if(isBeginSymbol){
             relationStack.pop();//该优先级处理完毕，将BEGIN运算符弹出
         }
     }

     /**
      * 表达式解析器
      * 表达式规则：
      * 关系relation属性有：BEGIN、AND、OR 三种
      * 表达式类型 Type 属性有：GROUP、CONDITION 两种
      * 深度 deep 属性 根节点为 1，每增加一个括号（GROUP）deep+1，括号结束deep-1
      * 序号req：初始值为1，往后依次递增，用于防止表达式解析顺序错误
      * exp1：表达式：A &&(( B || C )|| (D && E)) && F
      * 分解对象：
      * [
      * {"seq":1,"deep":1,relation:"BEGIN","type":"CONDITION","field"="A"...},
      * {"seq":2,"deep":1,relation:"AND","type":"GROUP","field":""...},
      * {"seq":3,"deep":2,relation:"BEGIN","type":"GROUP","field":""...},
      * {"seq":4,"deep":3,relation:"BEGIN","type":"CONDITION","field":"B"...},
      * {"seq":5,"deep":3,relation:"OR","type":"CONDITION","field":"C"...},
      * {"seq":6,"deep":2,relation:"OR","type":"GROUP","field":""...},
      * {"seq":7,"deep":3,relation:"BEGIN","type":"CONDITION","field":"D"...},
      * {"seq":8,"deep":3,relation:"AND","type":"CONDITION","field":"E"...},
      * {"seq":9,"deep":1,relation:"AND","type":"CONDITION","field":"F"...}
      * ]
      *
      * exp2:(A || B && C)||(D && E && F)
      * [
      * {"seq":1,"deep":1,relation:"BEGIN","type":"GROUP","field":""...},
      * {"seq":2,"deep":2,relation:"BEGIN","type":"CONDITION","field":"A"...},
      * {"seq":3,"deep":2,relation:"OR","type":"CONDITION","field":"B"...},
      * {"seq":4,"deep":2,relation:"AND","type":"CONDITION","field":"C"...},
      * {"seq":5,"deep":1,relation:"OR","type":"GROUP","field":""...},
      * {"seq":6,"deep":2,relation:"BEGIN","type":"CONDITION","field":"D"...},
      * {"seq":7,"deep":2,relation:"AND","type":"CONDITION","field":"E"...},
      * {"seq":8,"deep":2,relation:"AND","type":"CONDITION","field":"F"...}
      * ]
      *
      *
      * @param list
      * @return
      */
     public boolean expressProcessor(Listlist){
         //关系 栈
         Deque relationStack=new LinkedList();
         //结果栈
         Deque resultStack=new LinkedList();
         // 当前深度
         Integer nowDeep=1;
         Integer seq=0;
         for (ExpressDto expressDto:list) {
             // 顺序检测，防止顺序错误
             int checkReq=expressDto.getSeq()-seq;
             if(checkReq!=1){
                 throw new RuntimeException("表达式异常：解析顺序异常");
             }
             seq=expressDto.getSeq();
             //计算深度（计算优先级），判断当前逻辑是否需要处理括号
             int deep=expressDto.getDeep()-nowDeep;
             // 赋予当前深度
             nowDeep=expressDto.getDeep();
             //deep 减小，说明有括号结束，需要处理括号到对应的层级，deep减少数量等于组（"）"）结束的数量
             while(deep++ < 0){
                 computeBeforeEndGroup(relationStack, resultStack);
             }
 
             if(!StringUtils.equals(expressDto.getType(),"GROUP")){
                 //TODO 进行具体单个表达式计算并获取结果
                 resultStack.push(expressDto.getResult());
                 // 将关系放入栈中
                 relationStack.push(expressDto.getRelation());
                 if(deep==0 && resultStack.size()>1){ //由于已处理小于0的deep，当前deep理论上是>=0的，0表示同等级，需要立即运算
                     relationOperator(relationStack, resultStack);
                 }
             }else{
                 // 将关系放入栈中
                 relationStack.push(expressDto.getRelation());
             }
         }
         //遍历完毕，处理栈中未进行运算的节点
         while(nowDeep-- > 0){ // 这里使用 nowdeep>0 的原因是最后deep=1的关系表达式也需要进行处理
             computeBeforeEndGroup(relationStack, resultStack);
         }
         if(resultStack.size()!=1){
             throw new RuntimeException("表达式解析异常:解析结果数量异常解析数量:"+resultStack.size());
         }
         return resultStack.pop();
     }
 
     /**
      * 处理层级遗留元素
      *
      * @param relationStack
      * @param resultStack
      */
     private void computeBeforeEndGroup(Deque<String> relationStack, Deque<Boolean> resultStack) {
         boolean isBeginSymbol=StringUtils.equals(relationStack.peek(),"BEGIN");//防止group中仅有一个判断条件
         while(!isBeginSymbol){//上一个运算符非BEGIN，说明该group中还有运算需要优先处理，正常这里应该仅循环一次
             relationOperator(relationStack, resultStack);
             isBeginSymbol=StringUtils.equals(relationStack.peek(),"BEGIN");
         }
         if(isBeginSymbol){
             relationStack.pop();//该优先级处理完毕，将BEGIN运算符弹出
         }
     }
 
 
     /**
      * 关系运算处理
      * @param relationStack
      * @param resultStack
      */
     private void relationOperator(Deque relationStack, Deque resultStack) {
         Boolean lastResult= resultStack.pop();
         Boolean firstResult= resultStack.pop();
         String relation=relationStack.pop();
         if(StringUtils.equals(relation,"AND")){
             resultStack.push(firstResult&& lastResult) ;
             return;
         }
         if(StringUtils.equals(relation,"OR")){
             resultStack.push( firstResult|| lastResult);
             return;
         }else{
             throw new RuntimeException("表达式解析异常：关系表达式错误");
         }
     }

 /**
      * 表达式：A
      */
     @Test
     public void expTest0(){
         ExpressDto E1=new ExpressDto().setDeep(1).setResult(false).setSeq(1).setType("CONDITION").setField("A").setRelation("BEGIN");
         List<ExpressDto> list = new ArrayList();
         list.add(E1);
         boolean re=expressProcessor(list);
         Assertions.assertFalse(re);
     }
     /**
      * 表达式：(A && B)||(C || D)
      */
     @Test
     public void expTest1(){
         ExpressDto E1=new ExpressDto().setDeep(1).setSeq(1).setType("GROUP").setRelation("BEGIN");
         ExpressDto E2=new ExpressDto().setDeep(2).setResult(true).setSeq(2).setType("Condition").setField("A").setRelation("BEGIN");
         ExpressDto E3=new ExpressDto().setDeep(2).setResult(false).setSeq(3).setType("Condition").setField("B").setRelation("AND");
         ExpressDto E4=new ExpressDto().setDeep(1).setSeq(4).setType("GROUP").setRelation("OR");
         ExpressDto E5=new ExpressDto().setDeep(2).setResult(true).setSeq(5).setType("Condition").setField("C").setRelation("BEGIN");
         ExpressDto E6=new ExpressDto().setDeep(2).setResult(false).setSeq(6).setType("Condition").setField("D").setRelation("OR");
 
         List<ExpressDto> list = new ArrayList();
         list.add(E1);
         list.add(E2);
         list.add(E3);
         list.add(E4);
         list.add(E5);
         list.add(E6);
         boolean re=expressProcessor(list);
         Assertions.assertTrue(re);
     }
 
     /**
      * 表达式：A && (B || C && D)
      */
     @Test
     public void expTest2(){
         ExpressDto E1=new ExpressDto().setDeep(1).setResult(true).setSeq(1).setType("Condition").setField("A").setRelation("BEGIN");
         ExpressDto E2=new ExpressDto().setDeep(1).setSeq(2).setType("GROUP").setRelation("AND");
         ExpressDto E3=new ExpressDto().setDeep(2).setResult(false).setSeq(3).setType("Condition").setField("B").setRelation("BEGIN");
         ExpressDto E4=new ExpressDto().setDeep(2).setResult(false).setSeq(4).setType("Condition").setField("C").setRelation("OR");
         ExpressDto E5=new ExpressDto().setDeep(2).setResult(true).setSeq(5).setType("Condition").setField("D").setRelation("AND");
         List<ExpressDto> list = new ArrayList();
         list.add(E1);
         list.add(E2);
         list.add(E3);
         list.add(E4);
         list.add(E5);
         boolean re=expressProcessor(list);
         Assertions.assertFalse(re);
         E4.setResult(true);
         list.set(3,E4);
         re=expressProcessor(list);
         Assertions.assertTrue(re);
         E1.setResult(false);
         list.set(0,E1);
         re=expressProcessor(list);
         Assertions.assertFalse(re);
     }
 
     @Test
     public void expTest3(){
         ExpressDto E1=new ExpressDto().setDeep(1).setResult(true).setSeq(1).setType("Condition").setField("A").setRelation("BEGIN");
         ExpressDto E2=new ExpressDto().setDeep(1).setSeq(2).setType("GROUP").setRelation("OR");
         ExpressDto E3=new ExpressDto().setDeep(2).setResult(true).setSeq(3).setType("Condition").setField("B").setRelation("BEGIN");
         ExpressDto E4=new ExpressDto().setDeep(2).setSeq(4).setType("GROUP").setRelation("AND");
         ExpressDto E5=new ExpressDto().setDeep(3).setResult(true).setSeq(5).setType("Condition").setField("C").setRelation("BEGIN");
         ExpressDto E6=new ExpressDto().setDeep(3).setResult(false).setSeq(6).setType("Condition").setField("D").setRelation("OR");
 
         List<ExpressDto> list = new ArrayList();
         list.add(E1);
         list.add(E2);
         list.add(E3);
         list.add(E4);
         list.add(E5);
         list.add(E6);
         boolean re=expressProcessor(list);
         Assertions.assertTrue(re);
     }
 
     /**
      * 表达式：A &&(( B || C )|| (D && E))
      */
     @Test
     public void expTest4(){
         ExpressDto E1=new ExpressDto().setDeep(1).setSeq(1).setType("CONDITION").setResult(true).setField("A").setRelation("BEGIN");
         ExpressDto E2=new ExpressDto().setDeep(1).setSeq(2).setType("GROUP").setRelation("AND");
         ExpressDto E3=new ExpressDto().setDeep(2).setSeq(3).setType("GROUP").setRelation("BEGIN");
         ExpressDto E4=new ExpressDto().setDeep(3).setSeq(4).setType("CONDITION").setResult(true).setField("B").setRelation("BEGIN");
         ExpressDto E5=new ExpressDto().setDeep(3).setSeq(5).setType("CONDITION").setResult(true).setField("C").setRelation("OR");
         ExpressDto E6=new ExpressDto().setDeep(2).setSeq(6).setType("GROUP").setRelation("OR");
         ExpressDto E7=new ExpressDto().setDeep(3).setSeq(7).setType("CONDITION").setResult(false).setField("D").setRelation("BEGIN");
         ExpressDto E8=new ExpressDto().setDeep(3).setSeq(8).setType("CONDITION").setResult(false).setField("E").setRelation("AND");
         List<ExpressDto> list = new ArrayList();
         list.add(E1);
         list.add(E2);
         list.add(E3);
         list.add(E4);
         list.add(E5);
         list.add(E6);
         list.add(E7);
         list.add(E8);
         boolean re=expressProcessor(list);
         Assertions.assertTrue(re);
     }
 
 
     /**
      * 表达式：(A)
      */
     @Test
     public void expTest5(){
         ExpressDto E1=new ExpressDto().setDeep(1).setSeq(1).setType("GROUP").setRelation("BEGIN");
         ExpressDto E2=new ExpressDto().setDeep(2).setResult(true).setSeq(2).setType("Condition").setField("A").setRelation("BEGIN");
         List<ExpressDto> list = new ArrayList();
         list.add(E1);
         list.add(E2);
         boolean re=expressProcessor(list);
         Assertions.assertTrue(re);
         E2.setResult(false);
         list.set(1,E2);
         Assertions.assertFalse(expressProcessor(list));
     }