numberlenghtlimiteddmt.java

accp s1毕业项目 考试管理系统

package com.exam.ui.utils;

import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.PlainDocument;

public class NumberLenghtLimitedDmt extends PlainDocument {
	private static final long serialVersionUID = 1L;
	private int limit; 
	   public NumberLenghtLimitedDmt(int limit) {
	    super();
	       this.limit = limit;
	    }  
	   public void insertString
	     (int offset, String  str, AttributeSet attr)
	                                   throws BadLocationException {   
	       if (str == null){
	        return;
	       }
	       if ((getLength() + str.length()) <= limit) {
	       
	       char[] upper = str.toCharArray();
	       int length=0;
	       for (int i = 0; i < upper.length; i++) {       
	           if (upper[i]>='0'&&upper[i]<='9'){           
	              upper[length++] = upper[i];
	           }
	       }
	         super.insertString(offset, new String(upper,0,length), attr);
	      }
	    }


}