Spring配置CharacterEncodingFilter

在web.xml中配置：

	<filter>
		<filter-name>CharacterFilter</filter-name>
		<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
			<init-param>
				<param-name>encoding</param-name>
				<param-value>utf-8</param-value>
			</init-param>
	</filter>
	<filter-mapping>
		<filter-name>CharacterFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>

这个类的源码实现方法如下：

	@Override
	protected void doFilterInternal(
			HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
			throws ServletException, IOException {

		if (this.encoding != null && (this.forceEncoding ||               request.getCharacterEncoding() == null)) {
                      //当请求没有包含字符码类型的时候，就会被设置为utf-8
			request.setCharacterEncoding(this.encoding);
			if (this.forceEncoding) {
				response.setCharacterEncoding(this.encoding);
			}
		}
		filterChain.doFilter(request, response);
	}