序言：几乎所有项目都需要拦截器，所以小伙伴们必须要掌握这门技术哦，不然只会mybaits增删改查那是实习生干的活呀。
1、创建拦截器类，implements HandlerInterceptor
public class MyIncerteptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println("进入拦截器");
HttpSession session = request.getSession();
Admin user = (Admin) request.getSession().getAttribute("ADMIN_ACCOUNT");
if (user == null) {
//用户为空，重新登录
response.sendRedirect(request.getContextPath() + "/login.html");
return false;
}
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
}
}
2、配置文件，注册拦截器 implements
@Configuration
public class InterceptorConfig implements WebMvcConfigurer {
@Override
public void addInterceptors(InterceptorRegistry registry) {
String[] addPathPatterns ={
"/dtb/**"
};
String[] excludePathPatterns ={
"/test/**"
};
InterceptorRegistration interceptorRegistration = registry.addInterceptor(new MyIncerteptor());
interceptorRegistration.addPathPatterns(addPathPatterns);
interceptorRegistration.excludePathPatterns(excludePathPatterns);
}
}
addPathPatterns是拦截的那些目录，excludePathPatterns不拦截的路径，上面我们可以换一种常用的写法，只不过上面看上去更明白，interceptorRegistration获取的注册对象添加拦截器，并设置拦截路径
@Configuration
public class InterceptorConfig implements WebMvcConfigurer {
@Override
public void addInterceptors(InterceptorRegistry registry) {
String[] addPathPatterns ={
"/dtb/**"
};
String[] excludePathPatterns ={
"/test/**"
};
registry.addInterceptor(new MyIncerteptor()).addPathPatterns(addPathPatterns).excludePathPatterns(excludePathPatterns);
}
}
在优化一下，可以写成：
@Configuration
public class InterceptorConfig implements WebMvcConfigurer {
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new MyIncerteptor()).addPathPatterns("/dtb/**").excludePathPatterns("/test/**");
}
}
成功！其实就两个类就可以了。
3、注意点：
springboot2.0以后：使用spring5，废弃了WebMvcConfigurerAdapter,解决方案 implements WebMvcConfigurer
springboot2.0之前，1.X版本，使用spring4，使用拦截器需要 extends WebMvcConfigurerAdapter
转载于:https://my.oschina.net/mdxlcj/blog/1858710