如何在Spring Boot中启用HTTP响应缓存

Question

@Controller
public class MyRestController {
    @RequestMapping(value = "/someUrl", method = RequestMethod.GET)
    public @ResponseBody ResponseEntity<String> myMethod(
            HttpServletResponse httpResponse) throws SQLException {
        return new ResponseEntity<String>("{}", HttpStatus.OK);
    }
}

Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Expires: 0
Pragma: no-cache

null

Answer 1

事实证明，无缓存HTTP头是由Spring Security设置的。在http://docs.spring.io/spring-security/site/docs/current/reference/htmlsingle/#headers中讨论了这一点。

下面的命令禁用HTTP响应标头杂注：no-cache，但不能解决问题：

import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.config.annotation.web.servlet.configuration.EnableWebMvcSecurity;

@Configuration
@EnableWebMvcSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        // Prevent the HTTP response header of "Pragma: no-cache".
        http.headers().cacheControl().disable();
    }
}

我最终完全禁用了公共静态资源的Spring Security性，如下所示（在与上面相同的类中）：

@Override
public void configure(WebSecurity web) throws Exception {
    web.ignoring().antMatchers("/static/public/**");
}

@Configuration
public class MvcConfigurer extends WebMvcConfigurerAdapter
        implements EmbeddedServletContainerCustomizer {
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        // Resources without Spring Security. No cache control response headers.
        registry.addResourceHandler("/static/public/**")
            .addResourceLocations("classpath:/static/public/");

        // Resources controlled by Spring Security, which
        // adds "Cache-Control: must-revalidate".
        registry.addResourceHandler("/static/**")
            .addResourceLocations("classpath:/static/")
            .setCachePeriod(3600*24);
    }
}