字符编码过滤器

public class CharacterEncodingFilter implements Filter{
	private String encoding;
	private Boolean forceEncoding=false;

	@Override
	public void init(FilterConfig config) throws ServletException {
		this.encoding=config.getInitParameter("encoding");
		forceEncoding=Boolean.valueOf(config.getInitParameter("force"));	
		System.out.println("字符编码过滤器初始化");
	}
	

	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
			throws IOException, ServletException {
		//类型转换
		HttpServletRequest req=(HttpServletRequest) request;
		HttpServletResponse resp=(HttpServletResponse) response;
		//设置编码
		//1.应用中没有编码并且我自己设置了编码
		//2.应用中已经有编码了，但是依然要使用我自己的编码；强制使用
		if(hasLength(encoding)&&(req.getCharacterEncoding()==null||forceEncoding)) {
			req.setCharacterEncoding(encoding);
		}
		//放行
		chain.doFilter(req, resp);
	}

	
   private boolean hasLength(String str) {
		return str!=null&&!"".equals(str.trim());
	}


public void destroy() {
		
	}

}

 

<filter>
   <filter-name>CharacterEncodingFilter</filter-name>
   <filter-class>web.filter.CharacterEncodingFilter</filter-class>
   <!-- 设置编码 -->
   <init-param>
      <param-name>encoding</param-name>
      <param-value>utf-8</param-value>
   </init-param>
   <!-- 是否强制使用改编码 -->
   <init-param>
      <param-name>force</param-name>
      <param-value>true</param-value>
   </init-param>
 </filter>
 <filter-mapping>
   <filter-name>CharacterEncodingFilter</filter-name>
   <url-pattern>/*</url-pattern>
 </filter-mapping>

如果在是否强制使用编码那里设置false，那人家还是会用自己的编码