全站乱码解决过滤器

java web乱码的产生:

1. get提交乱码:get中如果出现了中文,预览器会以utf-8的方式转成url格式发送出去.服务器收到后,默认转成iso-8859-1.造成乱码.这种方式没有什么好的办法,只能用反编码再解码解决.

2.post提交乱码:内容乱码可以用一下的两行来解决,告诉服务器内容部分要用什么编码解决.

<span style="white-space:pre">	</span>response.setCharacterEncoding("UTF-8");
	response.setContentType("text/html;charset=UTF-8 ");

使用全站过滤器解决乱码:

1. 创建一个自己的request类,覆盖掉获取get提交的三个方法并处理.
2. 在web.xml中配置过滤器.

<filter>
    <filter-name>webFilter</filter-name>
    <filter-class>filter.webFilter</filter-class>
 </filter>

<filter-mapping>
    <filter-name>webFilter</filter-name>
    <servlet-name>*</servlet-name>
 </filter-mapping>

</pre><pre name="code" class="java">package filter;

import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLEncoder;
import java.net.URLPermission;
import java.security.URIParameter;
import java.util.Enumeration;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

import com.sun.accessibility.internal.resources.accessibility;
import com.sun.corba.se.impl.encoding.OSFCodeSetRegistry.Entry;
import com.sun.corba.se.spi.orb.StringPair;
import com.sun.org.apache.xml.internal.security.keys.content.RetrievalMethod;

public class myHttpRequest extends HttpServletRequestWrapper
{
    private HttpServletRequest request = null;

    public myHttpRequest(HttpServletRequest request)
    {
	super(request);
	this.request = request;
    }

    @Override
    public String getParameter(String name)
    {
	if(request.getParameter(name) != null)
	{
	    return request.getParameterValues(name)[0];
	}
	return null;
    }

    boolean isEncode = false;

    @Override
    public Map getParameterMap()
    {
	try
	{
	    if(request.getMethod().equalsIgnoreCase("POST"))
	    {
		request.setCharacterEncoding("UTF-8");
		return request.getParameterMap();
	    }
	    else if(request.getMethod().equalsIgnoreCase("GET"))
	    {
		Map<String, String[]> map = request.getParameterMap();
		if(isEncode)
		{
		    return map;
		}
		else
		{
		    for (Map.Entry<String, String[]> entry : map.entrySet())
		    {
			String[] vs = entry.getValue();
			for (int i = 0; i < vs.length; i++)
			{
			    vs[i] = new String(vs[i].getBytes("iso-8859-1"),
				    "utf-8");
			}
		    }
		    isEncode = true;
		    return map;
		}
	    }
	    else
	    {
		return super.getParameterMap();
	    }
	}
	catch (UnsupportedEncodingException e)
	{
	    e.printStackTrace();
	}
	return null;
    }

    @Override
    public String[] getParameterValues(String name)
    {
	return (String[])this.request.getParameterMap().get(name);
    }
}

package filter;

import java.io.IOException;

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

public class webFilter implements Filter
{
    @Override
    public void init(FilterConfig filterConfig) throws ServletException
    {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
	    FilterChain chain) throws IOException, ServletException
    {
	response.setCharacterEncoding("UTF-8");
	response.setContentType("text/html;charset=UTF-8 ");
	chain.doFilter(new myHttpRequest((HttpServletRequest)request), response);
    }

    @Override
    public void destroy()
    {
    }
}