过滤器（Filter）的注册方法和 Servlet 一样，有两种方式：代码注册或者注解注册
1.代码注册方式
通过代码方式注入过滤器
@Bean
public FilterRegistrationBean indexFilterRegistration() {
FilterRegistrationBean registration = new FilterRegistrationBean(new IndexFilter());
registration.addUrlPatterns("/");
return registration;
}
IndexFilter.Java类：
package com.example.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
public class IndexFilter implements Filter{
@Override
public void destroy() {
System.out.println("filter destroy method");
}
@Override
public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
throws IOException, ServletException {
System.out.println("filter doFilter method");
}
@Override
public void init(FilterConfig arg0) throws ServletException {
System.out.println("filter init method");
}
}
2.注解方式
通过注解方式注入过滤器
IndexFilter2.java类
package com.example.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
@WebFilter(urlPatterns = "/*", filterName = "indexFilter2")
public class IndexFilter2 implements Filter{
@Override
public void destroy() {
System.out.println("filter2 destroy method");
}
@Override
public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
throws IOException, ServletException {
System.out.println("filter2 doFilter method");
}
@Override
public void init(FilterConfig arg0) throws ServletException {
System.out.println("filter2 init method");
}
}
把注解加到入口处启动即可
@SpringBootApplication
@ServletComponentScan
public class SpringBootSimpleApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBootSimpleApplication.class, args);
}
}