java版括号匹配检测

做一个空栈,读入字符直到结尾.如果读入一个封闭符号,空栈时报错;非空时弹出栈尾字符,如果不匹配则报错.否则读入为开放字符,压入栈中.最后如果栈空,返回true.

其中用到MyStack类,详情请见

 public class KuohaoJiancha {
     private char [] item = {'(',')','[',']','{','}'};
     private MyStack stack = new MyStack();
     private char[] str;
     private int currentNum;
     public KuohaoJiancha(String str){
         this.str = str.toCharArray();;
     }

     public boolean display(){
         for(int i = 0; i < str.length; i++){
             currentNum = charNumber(str[i]);
             if(misByStackIsEmpty(str[i]))
                 return false;

             if(currentNum % 2 == 1) {
                 if (currentNum - charNumber((char) stack.pop()) != 1)
                     return false;
             }
             else stack.push(str[i]);
         }
         return true;
     }

     private int charNumber(char c){
         int i = 0;
         for(; i < 6; i++){
             if(c == item[i])
                 break;
         }
         return i;
     }

     private boolean misByStackIsEmpty(char c){//如果读入一个封闭符号,空栈时报错
         if(stack.isEmpty())
             if(currentNum % 2 == 1)
                 return true;
         return false;
     }

 }