过滤器解决乱码问题

package cn.itcast.estore.web.filter;import java.io.IOException;import java.io.UnsupportedEncodingException;import java.util.Map;import java.util.Set;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;import javax.servlet.http.HttpServletRequestWrapper;/** * 解决乱码通用的过滤器程序 *  * @author seawind */public class EncodingFilter implements Filter {@Overridepublic void destroy() {}@Overridepublic void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException {// 解决postrequest.setCharacterEncoding("utf-8");// 解决getEncodingRequest encodingRequest = new EncodingRequest((HttpServletRequest) request);// 解决响应response.setContentType("text/html;charset=utf-8");chain.doFilter(encodingRequest, response);}@Overridepublic void init(FilterConfig filterConfig) throws ServletException {}}class EncodingRequest extends HttpServletRequestWrapper {private HttpServletRequest request;private boolean hasEncode = false;public EncodingRequest(HttpServletRequest request) {super(request);this.request = request;}@Overridepublic String getParameter(String name) {// 通过getParameterMap方法完成String[] values = getParameterValues(name);if (values == null) {return null;}return values[0];}@Overridepublic String[] getParameterValues(String name) {// 通过getParameterMap方法完成Map<String, String[]> parameterMap = getParameterMap();String[] values = parameterMap.get(name);return values;}@Overridepublic Map getParameterMap() {Map<String, String[]> parameterMap = request.getParameterMap();String method = request.getMethod();if (method.equalsIgnoreCase("post")) {return parameterMap;}// get提交方式 手动转码 , 这里的转码只进行一次 所以通过 hasEncode 布尔类型变量控制if (!hasEncode) {Set<String> keys = parameterMap.keySet();for (String key : keys) {String[] values = parameterMap.get(key);if (values == null) {continue;}for (int i = 0; i < values.length; i++) {String value = values[i];// 解决gettry {value = new String(value.getBytes("ISO-8859-1"),"utf-8");// values是一个地址values[i] = value;} catch (UnsupportedEncodingException e) {e.printStackTrace();}}// 一次转码完成后，设置转码状态为truehasEncode = true;}}return parameterMap;}}

</pre><pre name="code" class="java">在工程web.xml文件中添加如下代码：

<pre name="code" class="html"> <filter>  <filter-name>EncodingFilter</filter-name>  <filter-class>cn.itcast.estore.web.filter.EncodingFilter</filter-class>  </filter>  <filter-mapping>  <filter-name>EncodingFilter</filter-name>  <url-pattern>/*</url-pattern>  </filter-mapping>