面向切面编程
什么叫面向切面编程呢，就是说监听一切相关的类或者方法，这个被监听者就是切面
常见的切面
- 方法的切面
- interceptor拦截器
- filter过滤器
在ssm文件夹下创建一个叫aop的文件夹
方法的切面
可以在被监听的方法的前后或者环绕进行拦截，下面是环绕的示例代码
// aop/aop.java
@Component
@Aspect
public class aop {
// Pointcut定义切点函数
@Pointcut("execution(* com.pdt.ssm.service.*.*(..))")
private void myPointcut() { }
@Around("myPointcut()")
public Object aroundAdvice(ProceedingJoinPoint jp) throws Throwable {
System.out.println("--->BindingResultAop start...");
String className = jp.getTarget().getClass().getName();
String methodName = jp.getSignature().getName();
System.out.println("before " + className + "." + methodName + "() invoking!");
// 执行目标方法
return jp.proceed();
}
}
interceptor拦截器
这个最常用在对未登陆用户的监听
// aop/interceptor.java
public class interceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest req, HttpServletResponse res,
Object arg2) throws Exception {
// 在这个可以判断访问路径，
// 常用于 判断req是不是有指定的token或者session表示登录状态
// 也可以用来判断访问路径存不存在，没有返回404页面
// 返回true是放行，false就是
// 如果不放行，先用req.getRequestDispatcher(路径).forword(req,res)，再return false
return true;
}
}
filter过滤器
我设定了3个过滤器
- whiteList，白名单过滤器
// config.java 添加白名单
public class config {
public static final ArrayList whiteList = new ArrayList();
static {
whiteList.add("127.0.0.1:80");
whiteList.add("127.0.0.1:3000");
whiteList.add("127.0.0.1:8080");
whiteList.add("127.0.0.1:8848");
whiteList.add("127.0.0.1:9528");
whiteList.add("localhost:9528");
}
public static boolean isWhiteList(String ip) {
if(whiteList.indexOf(ip)==-1){
return false;
}
return true;
}
}
// WebFilter注解就不需要去web.xml里配置filter标签
@WebFilter(filterName = "whiteListFilter",
urlPatterns = "/*",/*通配符（*）表示对所有的web资源进行拦截*/
initParams = {
@WebInitParam(name = "charset", value = "utf-8")/*这里可以放一些初始化的参数*/
})
public class whiteListFilter implements Filter {
private String filterName;
public void destroy() {
/*销毁时调用*/
System.out.println(filterName + "销毁");
}
public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
HttpServletRequest httpreq = (HttpServletRequest)req;
String Origin = httpreq.getHeader("Origin");
System.out.println(Origin);
// String Referer = httpreq.getHeader("Referer");
if(StringUtils.isEmpty(Origin)){
chain.doFilter(req,resp); //放行
}else{
Origin = Origin.split("//")[1];
System.out.println(Origin);
if(config.isWhiteList(Origin)){
chain.doFilter(req,resp); //放行
}else{
System.out.println("不在白名单之内");
}
}
}
public void init(FilterConfig config) throws ServletException {
/*初始化方法 接收一个FilterConfig类型的参数 该参数是对Filter的一些配置*/
filterName = config.getFilterName();
System.out.println("过滤器：" + filterName + "启动");
}
}
- 日记过滤器
// WebFilter注解就不需要去web.xml里配置filter标签
@WebFilter(filterName = "loggerFilter",
urlPatterns = "/*",/*通配符（*）表示对所有的web资源进行拦截*/
initParams = {
@WebInitParam(name = "charset", value = "utf-8")/*这里可以放一些初始化的参数*/
})
public class loggerFilter implements Filter {
private String filterName;
final Logger log = Logger.getLogger(loggerFilter.class);
public void destroy() {
/*销毁时调用*/
System.out.println(filterName + "销毁");
}
public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
HttpServletRequest httpreq = (HttpServletRequest)req;
System.out.println(new Date().getTime()+"---"+httpreq.getMethod()+"---"+httpreq.getRequestURL());
/*过滤方法 主要是对request和response进行一些处理，然后交给下一个过滤器或Servlet处理*/
log.info("这是日志")
chain.doFilter(req,resp); //放行
}
public void init(FilterConfig config) throws ServletException {
/*初始化方法 接收一个FilterConfig类型的参数 该参数是对Filter的一些配置*/
filterName = config.getFilterName();
System.out.println("过滤器：" + filterName + "启动");
}
}
- 跨域过滤器
// WebFilter注解就不需要去web.xml里配置filter标签
@WebFilter(filterName = "crosFilter",
urlPatterns = "/*",/*通配符（*）表示对所有的web资源进行拦截*/
initParams = {
@WebInitParam(name = "charset", value = "utf-8")/*这里可以放一些初始化的参数*/
})
public class crosFilter implements Filter {
private String filterName;
public void destroy() {
/*销毁时调用*/
System.out.println(filterName + "销毁");
}
public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
System.out.println(filterName);
/*过滤方法 主要是对request和response进行一些处理，然后交给下一个过滤器或Servlet处理*/
HttpServletResponse httpResponse = (HttpServletResponse)resp;
httpResponse.setHeader("Access-Control-Allow-Origin", "*");
httpResponse.setHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE");
httpResponse.setHeader("Access-Control-Max-Age", "1800");
httpResponse.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With,Content-Type,Accept,accept,Access-Control-Request-Method,Access-Control-Request-Headers,token,x-token");
httpResponse.setHeader("Access-Control-Allow-Credentials", "true");
chain.doFilter(req,resp); //放行
}
public void init(FilterConfig config) throws ServletException {
/*初始化方法 接收一个FilterConfig类型的参数 该参数是对Filter的一些配置*/
filterName = config.getFilterName();
System.out.println("过滤器：" + filterName + "启动");
}
}