中缀式转后缀式工具类实现 - JAVA

*
*/
public static boolean isLowerOfPriority(char ch1, char ch2)
{
int priority1 = getPriority(ch1);
int priority2 = getPriority(ch2);

return priority1 <= priority2;
}

/**
*
*

      * 是否字母
      * @param ch
      * @return
      */ 
     private static boolean isCharacter(char ch) 
     { 
         return (ch >= Operators.LOWER_CASE_A && ch <= Operators.LOWER_CASE_Z) 
             || (ch >= Operators.UPPER_CASE_A && ch <= Operators.UPPER_CASE_Z); 
     } 
      
     /**
      * 
      * 
      * 字符是否数字
      * 
      * @param ch
      * @return
      */ 
     private static boolean isNumber(char ch) 
     { 
         return ch <= Operators.NINE && ch >= Operators.ZERO; 
     } 
      
     /**
      * 
      * 
      * 获取操作符的优先级
      * 
      * @param ch
      * @return
      */ 
     private static int getPriority(char ch) 
     { 
         if (getPriorities().containsKey(ch)) 
         { 
             return getPriorities().get(ch); 
         } 
         return Operators.ERROR_PRIORITY; 
     } 
      
     /**
      * 获取 priorities
      * 
      * @return 返回 priorities
      */ 
     private static Map getPriorities() 
     { 
         return priorities; 
     } 
 }  
 import java.util.HashMap;
 import java.util.Map; 
 /**
  * 

  * 操作符处理工具类
  *
  * @author  dobuy
  * 修改时间:  2013-5-22
  * 

  */
 public final class OperatorUtils
 {
     /**
      * 保存所有操作符(Key)及优先级(Value)
      */
     private static final Map priorities;
    
     private OperatorUtils()
     {
     }
    
     /**
      * 类加载时初始化
      */
     static
     {
         priorities = new HashMap();
        
         getPriorities().put(Operators.OPEN_BRACKET, Operators.HIGH_PRIORITY);
         getPriorities().put(Operators.MULTIPLITICATION, Operators.MIDIUM_PRIORITY);
         getPriorities().put(Operators.DIVISION, Operators.MIDIUM_PRIORITY);
         getPriorities().put(Operators.COMPLIMENT, Operators.MIDIUM_PRIORITY);
         getPriorities().put(Operators.ADD, Operators.LOW_PRIORITY);
         getPriorities().put(Operators.SUBRACTION, Operators.LOW_PRIORITY);
     }
    
     /**
      * 
      * 字符是否是操作符(除了字母和数字都是操作符)
      *
      * @param ch
      * @return
      * @author  dobuy
      * 修改时间:  2013-5-22
      */
     public static boolean isOperator(char ch)
     {
         return !isCharacter(ch) && !isNumber(ch);
     }
    
     /**
      *
      * 
      * ch1的优先级是否不高于ch2
      *
      * @param ch1
      * @param ch2
      * @return
      * 

      */
     public static boolean isLowerOfPriority(char ch1, char ch2)
     {
         int priority1 = getPriority(ch1);
         int priority2 = getPriority(ch2);
        
         return priority1 <= priority2;
     }
    
     /**
      *
      * 
      * 是否字母
      * @param ch
      * @return
      */
     private static boolean isCharacter(char ch)
     {
         return (ch >= Operators.LOWER_CASE_A && ch <= Operators.LOWER_CASE_Z)
             || (ch >= Operators.UPPER_CASE_A && ch <= Operators.UPPER_CASE_Z);
     }
    
     /**
      *
      * 
      * 字符是否数字
      *
      * @param ch
      * @return
      */
     private static boolean isNumber(char ch)
     {
         return ch <= Operators.NINE && ch >= Operators.ZERO;
     }
    
     /**
      *
      * 
      * 获取操作符的优先级
      *
      * @param ch
      * @return
      */
     private static int getPriority(char ch)
     {
         if (getPriorities().containsKey(ch))
         {
             return getPriorities().get(ch);
         }
         return Operators.ERROR_PRIORITY;
     }
    
     /**
      * 获取 priorities
      *
      * @return 返回 priorities
      */
     private static Map getPriorities()
     {
         return priorities;
     }
 }





 
 表达式处理工具类： 
   
 [java]  import java.util.Stack; 
  
 /**
  * 

  * 中缀表达式变后缀表达式工具类
  * 
  * @author  dobuy
  * 修改时间:  2013-5-22
中缀式转后缀式工具类实现 (二)
