java屏蔽非法字符

<div class="iteye-blog-content-contain" style="font-size: 14px;">
<p> </p>
<pre name="code" class="java">package com.bingyang.model;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class WordFilter implements Filter
{
private List&lt;String&gt; unString;
/**
* 过滤器初始化,将要屏蔽的字符串都加载到list集合中.
*/
public void init(FilterConfig filterConfig) throws ServletException
{
    unString = new ArrayList&lt;String&gt;();
    String aa="日,tmd,TMD,滚蛋,系统";
    StringTokenizer st = new StringTokenizer(aa, ",");
    while(st.hasMoreElements()){
    unString.add(st.nextElement().toString());
    }
}

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
    throws IOException, ServletException
{
request.setCharacterEncoding("utf-8");
    String content = request.getParameter("content");//需要过滤的参数
    if(content!=null){
        for (int i = 0; i < unString.size(); i++)
        {
            String strIllegal = unString.get(i);
            if (content.indexOf(strIllegal) >= 0)
            {
                content = content.replaceAll(strIllegal, "*");//非法字符替换成*
            }
            request.setAttribute("content", content);//为request设置属性保存修改后的值
        }
    }
    chain.doFilter(request, response);
}
public void destroy()
{
    //System.out.println("过滤器销毁");
}
}
</pre>
<p> </p>
</div>