过滤器

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 CharacterEncodingFilter implements Filter {
private FilterConfig config;
private String encoding = "ISO8859_1";

public void destroy() {
config = null;
}

public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
request.setCharacterEncoding(encoding);
chain.doFilter(request, response);
}

public void init(FilterConfig config) throws ServletException {
this.config = config;
String s = config.getInitParameter("encoding");
if (s != null) {
encoding = s;
}
}
}

然后在web-inf里面配置

<filter>
<filter-name>EncodingFilter</filter-name>
<filter-class>CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>

<filter-mapping>
<filter-name>EncodingFilter </filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>