Getting Where condition string for filtering specific object records

//Returns wherecondition for soql based on SearchFieldWrapper class list which can be used on visual force page for filter functionality.
public String getWhereCondition (List searchFieldWrapperList) {
 String whereCondition = '';
 for (WrapperClass f : searchFieldWrapperList) {
  String fieldValue = f.fieldValue;                    
  String fieldName = f.fieldName;
  if(f.fieldName != null && f.ObjectName != null) {                    
   Schema.DisplayType fieldDisplayType = SchemaCache.getFieldDescribe(obj, fieldName).getType();
   if(fieldDisplayType == Schema.DisplayType.Reference) {
    if(f.fieldName.contains('__c')) {
     fieldName = f.fieldName.replace('__c', '__r') + '.Name';
    } else if(f.fieldName.endswith('id')){
     fieldName = f.fieldName.substring(0, f.fieldName.length()-2)+'.Name';
    } 
   }     
   if(!String.isBlank(fieldValue) && f.customFieldType == 'str') {                        
    if(f.selectedCondition == ReadConstantClass.CONTAINS) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' LIKE \'' + '%' + fieldValue + '%\' ';
    } else if(f.selectedCondition == ReadConstantClass.STARTS_WITH) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' LIKE \'' + fieldValue + '%\' ';
    } else if(f.selectedCondition == ReadConstantClass.ENDS_WITH) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' LIKE \'' + '%' + fieldValue + '\' ';
    } else if(f.selectedCondition == ReadConstantClass.EQUALS) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' = \'' + fieldValue + '\' ';
    } 
   } else if(f.customFieldType == 'num') {
    if(String.isBlank(fieldValue)) {
     fieldValue = '0';
    }
    if(fieldValue.isNumeric()) {
     if(f.selectedCondition == ReadConstantClass.EQUALS) {
      whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' = ' + fieldValue + ' ';
     } else if(f.selectedCondition == ReadConstantClass.NOT_EQUALS) {
      whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' != ' + fieldValue + ' ';
     } else if(f.selectedCondition == ReadConstantClass.LESS_THAN) {
      whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' < ' + fieldValue + ' ';
     } else if(f.selectedCondition == ReadConstantClass.GREATER_THAN) {
      whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' > ' + fieldValue + ' ';
     } else if(f.selectedCondition == ReadConstantClass.LESS_OR_EQUALS) {
      whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' <= ' + fieldValue + ' ';
     } else if(f.selectedCondition == ReadConstantClass.GREATER_OR_EQUALS) {
      whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' >= ' + fieldValue + ' ';
     }  
    } else {
     returnBlankList = true;
    }
   } else if(f.customFieldType == 'bool') {
    if(f.selectedCondition == ReadConstantClass.EQUALS) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' = ' + f.boolValue + ' ';
    }
   } else if(f.dateValue != null && f.customFieldType == 'dateType') {
    String dateValue = String.valueOf(f.dateValue).substring(0, 10);
    if(f.selectedCondition == ReadConstantClass.EQUALS) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' = ' + dateValue + ' ';                        
    } else if(f.selectedCondition == ReadConstantClass.NOT_EQUALS) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' != ' + dateValue  + ' ';
    } else if(f.selectedCondition == ReadConstantClass.LESS_THAN) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' < ' + dateValue  + ' ';
    } else if(f.selectedCondition == ReadConstantClass.GREATER_THAN) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' > ' + dateValue  + ' ';
    } else if(f.selectedCondition == ReadConstantClass.LESS_OR_EQUALS) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' <= ' + dateValue  + ' ';
    } else if(f.selectedCondition == ReadConstantClass.GREATER_OR_EQUALS) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' >= ' + dateValue  + ' ';
    }     
   } else if(f.dateTimeValue != null && f.customFieldType == 'dateTimeType') {
    String dateTimeValue = f.dateTimeValue.format('yyyy-MM-dd\'T\'hh:mm:ss\'z\''); 
    if(f.selectedCondition == ReadConstantClass.EQUALS) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' = ' + dateTimeValue + ' ';
    } else if(f.selectedCondition == ReadConstantClass.NOT_EQUALS) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' != ' + dateTimeValue + ' ';
    } else if(f.selectedCondition == ReadConstantClass.LESS_THAN) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' < ' + dateTimeValue + ' ';
    } else if(f.selectedCondition == ReadConstantClass.GREATER_THAN) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' > ' + dateTimeValue + ' ';
    } else if(f.selectedCondition == ReadConstantClass.LESS_OR_EQUALS) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' <= ' + dateTimeValue + ' ';
    } else if(f.selectedCondition == ReadConstantClass.GREATER_OR_EQUALS) {
     whereCondition += ReadConstantClass.AND_OPERATOR + fieldName + ' >= ' + dateTimeValue + ' ';
    }     
   } 
  }
 }
 return whereCondition;
}

//Wrapper Class
public class SearchFieldWrapper {
 public String fieldName {get;set;}
 public String fieldValue{get;set;}
 public Boolean boolValue {get;set;} //In case of boolean type, use this value rather than fieldValue
 public Date dateValue {get;set;} //In case of date type, use this value
 public DateTime dateTimeValue {get;set;} //In case of date time type, use this value
 public String selectedCondition {get;set;} 
 public String customFieldType{get;set;} // str, num, bool, dateType, dateTimeType
}

ReadConstantClass class

public class ReadConstantClass{
    public static final string EQUALS = 'equals';
    public static final string NOT_EQUALS= 'not equal to';
    public static final string LESS_THAN = 'less than';
    public static final string GREATER_THAN = 'greater than';
    public static final string LESS_OR_EQUALS= 'less or equal';
    public static final string GREATER_OR_EQUALS = 'greater or equal';
    public static final string CONTAINS = 'contains';
    public static final string STARTS_WITH = 'starts with';
    public static final string ENDS_WITH = 'ends with'; 
    public static final string ORDER_BY = ' order by ';  
    public static final string WHERE_CLAUSE = ' where ';   
    public static final string IN_CLAUSE = ' in ';  
    public static final string NOT_OPERATOR = ' not '; 
    public static final string AND_OPERATOR = ' and '; 
    public static final string LIMIT_ROWS = ' not ';  
}

Feel free to contact me regarding full implementation.