小试ThreadLocal想到“隐式参数”模式

1 定义一个类读写threadlocal变量

public class ThreadAttributes {

        private static ThreadLocal<Map<String, Object>> threadAttribues = new ThreadLocal<Map<String, Object>>() {

                protected synchronized Map<String, Object> initialValue() {
                        return new HashMap<String, Object>();
                }
        };

        public static Object getThreadAttribute(String name) {

                return threadAttribues.get().get(name);

        }

        public static Object setThreadAttribute(String name, Object value) {

                return threadAttribues.get().put(name, value);

        }

}

2 在一个filter里写入request
public void doFilter(ServletRequest req, ServletResponse resp,
                        FilterChain chain) throws IOException, ServletException {
                HttpServletRequest request = (HttpServletRequest) req;
                HttpServletResponse response = (HttpServletResponse) resp;

                
                ThreadAttributes.setThreadAttribute("request", req);
        .....
}

3 读取request
HttpServletRequest request = (HttpServletRequest)ThreadAttributes.getThreadAttribute("request");