如何在弹簧靴中设置过滤链？

Question

I have come across spring-boot and intend to add a filter chain for incoming request.

Here is the Application:

package example.hello;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        ApplicationContext ctx = SpringApplication.run(Application.class, args);
    }

}

Here is the Controller:

package example.hello;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.concurrent.atomic.AtomicLong;

@RestController
public class GreetingController {

    private static final String template = "Hello, %s!";
    private final AtomicLong counter = new AtomicLong();

    @RequestMapping("/greeting")
    public Greeting greeting(@RequestParam(value="name", defaultValue="World") String name) {
        return new Greeting(counter.incrementAndGet(),
                String.format(template, name));
    }
}

Here is the Filter Config:

package example.hello;

import org.springframework.boot.context.embedded.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class WebConfig {

    @Bean
    public FilterRegistrationBean greetingFilterRegistrationBean() {
        FilterRegistrationBean registrationBean = new FilterRegistrationBean();
        registrationBean.setName("greeting");
        GreetingFilter greetingFilter = new GreetingFilter();
        registrationBean.setFilter(greetingFilter);
        registrationBean.setOrder(1);
        return registrationBean;
    }

    @Bean
    public FilterRegistrationBean helloFilterRegistrationBean() {
        FilterRegistrationBean registrationBean = new FilterRegistrationBean();
        registrationBean.setName("hello");
        HelloFilter helloFilter = new HelloFilter();
        registrationBean.setFilter(helloFilter);
        registrationBean.setOrder(2);
        return registrationBean;
    }

}

Here is the HelloFilter and Greeting Filter:

package example.hello;

import javax.servlet.*;
import java.io.IOException;

public class HelloFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("HelloFilter!");
    }

    @Override
    public void destroy() {

    }
}

package example.hello;

import javax.servlet.*;
import java.io.IOException;

public class GreetingFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("Greetings from filter!");
    }

    @Override
    public void destroy() {

    }
}

When I start the application and run curl localhost:8080/greeting , Only "Greetings from filter" is received and the HelloFilter is not invoked.

Besides there is no response from Greeting Controller . It seems that the GreetingFilter blocks the procedure.

So how to set the filter chain in Spring boot. Are there any bugs in the code above?

Answer 1

在GreetingFilter中添加以下代码行

filterChain.doFilter(servletRequest, servletResponse);

Answer 2

I would just like to clarify a little more on what Gangadhar suggested. You can try adding :

filterChain.doFilter(servletRequest, servletResponse);

in doFilter method of your filter classes.This will create chaining of the filters.