【Kotlin Spring Boot 服务端开发： 问题集锦】 Spring Security : 自定义AccessDeniedHandler 处理 Ajax 请求

AccessDeniedHandler 接口定义：

package org.springframework.security.web.access;

import org.springframework.security.access.AccessDeniedException;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Used by {@link ExceptionTranslationFilter} to handle an
 * <code>AccessDeniedException</code>.
 *
 * @author Ben Alex
 */
public interface AccessDeniedHandler {
    // ~ Methods
    // ========================================================================================================

    /**
     * Handles an access denied failure.
     *
     * @param request that resulted in an <code>AccessDeniedException</code>
     * @param response so that the user agent can be advised of the failure
     * @param accessDeniedException that caused the invocation
     *
     * @throws IOException in the event of an IOException
     * @throws ServletException in the event of a ServletException
     */
    void handle(HttpServletRequest request, HttpServletResponse response,
            AccessDeniedException accessDeniedException) throws IOException,
            ServletException;
}

Spring 的默认实现是 AccessDeniedHandlerImpl ：

package org.springframework.security.web.access;

import java.io.IOException;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.http.HttpStatus;
import org.springframework.security.access.AccessDeniedException;
import org.springframework.security.web.WebAttributes;

/**
 * Base implementation of {@link AccessDeniedHandler}.
 * <p>
 * This implementation sends a 403 (SC_FORBIDDEN) HTTP error code. In addition, if an
 * {@link #errorPage} is defined, the implementation will perform a request dispatcher
 * "forward" to the specified error page view. Being a "forward", the
 * <code>SecurityContextHolder</code> will remain populated. This is of benefit if the
 * view (or a tag library or macro) wishes to access the
 * <code>SecurityContextHolder</code>. The request scope will also be populated with the
 * exception itself, available from the key {@link WebAttributes#ACCESS_DENIED_403}.
 *
 * @author Ben Alex
 */
public class AccessDeniedHandlerImpl implements AccessDeniedHandler {
    // ~ Static fields/initializers
    // =====================================================================================

    protected static final Log logger = LogFactory.getLog(AccessDeniedHandlerImpl.class);

    // ~ Instance fields
    // ================================================================================================

    private String errorPage;

    // ~ Methods
    // ========================================================================================================

    public void handle(HttpServletRequest request, HttpServletResponse response,
            AccessDeniedException accessDeniedException) throws IOException,
            ServletException {
        if (!response.isCommitted()) {
            if (errorPage != null) {
                // Put exception into request scope (perhaps of use to a view)
                request.setAttribute(WebAttributes.ACCESS_DENIED_403,
                        accessDeniedException);

                // Set the 403 status code.
                response.setStatus(HttpStatus.FORBIDDEN.value());

                // forward to error page.
                RequestDispatcher dispatcher = request.getRequestDispatcher(errorPage);
                dispatcher.forward(request, response);
            }
            else {
                response.sendError(HttpStatus.FORBIDDEN.value(),
                    HttpStatus.FORBIDDEN.getReasonPhrase());
            }
        }
    }

    /**
     * The error page to use. Must begin with a "/" and is interpreted relative to the
     * current context root.
     *
     * @param errorPage the dispatcher path to display
     *
     * @throws IllegalArgumentException if the argument doesn't comply with the above
     * limitations
     */
    public void setErrorPage(String errorPage) {
        if ((errorPage != null) && !errorPage.startsWith("/")) {
            throw new IllegalArgumentException("errorPage must begin with '/'");
        }

        this.errorPage = errorPage;
    }
}

自定义实现 MyAccessDeniedHandler

package com.ksb.ksb_with_security.handler

import org.slf4j.LoggerFactory
import org.springframework.http.HttpStatus
import org.springframework.security.access.AccessDeniedException
import org.springframework.security.web.WebAttributes
import org.springframework.security.web.access.AccessDeniedHandler
import javax.servlet.http.HttpServletRequest
import javax.servlet.http.HttpServletResponse


class MyAccessDeniedHandler : AccessDeniedHandler {
    val logger = LoggerFactory.getLogger(MyAccessDeniedHandler::class.java)

    var errorPage: String? = null

    constructor(errorPage: String?) {
        this.errorPage = errorPage
    }

    override fun handle(request: HttpServletRequest, response: HttpServletResponse, accessDeniedException: AccessDeniedException) {
        val isAjax = ControllerTools.isAjaxRequest(request)

        if (!response.isCommitted) {
            if (isAjax) {
                val msg = accessDeniedException.message
                logger.info("accessDeniedException.message = $msg")
                val accessDenyMsg = """
                    {
                    "code":"403",
                    "msg": "没有权限"
                    }
                """.trimIndent()

                ControllerTools.print(response, accessDenyMsg)
            } else if (errorPage != null) {
                // Put exception into request scope (perhaps of use to a view)
                request.setAttribute(WebAttributes.ACCESS_DENIED_403,
                        accessDeniedException)

                // Set the 403 status code.
                response.status = HttpStatus.FORBIDDEN.value()

                // forward to error page.
                val dispatcher = request.getRequestDispatcher(errorPage)
                dispatcher.forward(request, response)
            }
        }
    }
}


object ControllerTools {
    fun isAjaxRequest(request: HttpServletRequest): Boolean {
        return "XMLHttpRequest".equals(request.getHeader("X-Requested-With"), true)
    }

    fun print(response: HttpServletResponse, msg: String) {
        response.characterEncoding = "UTF-8"
        response.contentType = "application/json; charset=utf-8"
        val out = response.writer
        out.append(msg)
        out.flush()
    }
}

然后，在自定义的继承 WebSecurityConfigurerAdapter的配置类WebSecurityConfig 中这样使用上面自定义的MyAccessDeniedHandler

package com.ksb.ksb_with_security.security

import com.ksb.ksb_with_security.handler.MyAccessDeniedHandler
import com.ksb.ksb_with_security.service.MyUserDetailService
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder
import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity
import org.springframework.security.config.annotation.web.builders.HttpSecurity
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter
import org.springframework.security.core.userdetails.UserDetailsService
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder
import org.springframework.security.web.access.AccessDeniedHandler

/**
prePostEnabled :决定Spring Security的前注解是否可用 [@PreAuthorize,@PostAuthorize,..]
secureEnabled : 决定是否Spring Security的保障注解 [@Secured] 是否可用
jsr250Enabled ：决定 JSR-250 annotations 注解[@RolesAllowed..] 是否可用.
 */

@Configuration
@EnableWebSecurity
// 开启 Spring Security 方法级安全
@EnableGlobalMethodSecurity(prePostEnabled = true, securedEnabled = true, jsr250Enabled = true)
class WebSecurityConfig : WebSecurityConfigurerAdapter() {

    @Bean
    fun myAccessDeniedHandler(): AccessDeniedHandler {
        return MyAccessDeniedHandler("/403")
    }

    @Bean
    override fun userDetailsService(): UserDetailsService {
        return MyUserDetailService()
    }

    @Throws(Exception::class)
    override fun configure(http: HttpSecurity) {
        http.csrf().disable()
        http.authorizeRequests()
            .antMatchers("/", // 首页不拦截
                    "/css/**",
                    "/fonts/**",
                    "/js/**",
                    "/images/**" // 不拦截静态资源
            ).permitAll()
            .anyRequest().authenticated()
            .and()
            .formLogin().loginPage("/login")// url 请求路径，对应 LoginController 里面的 @GetMapping("/login")
            .usernameParameter("username")
            .passwordParameter("password")
            .defaultSuccessUrl("/main").permitAll()
            .and()
            .exceptionHandling().accessDeniedHandler(myAccessDeniedHandler())
//            .exceptionHandling().accessDeniedPage("/403")
            .and()
            .logout().permitAll()

        http.logout().logoutSuccessUrl("/")

    }

    @Throws(Exception::class)
    override fun configure(auth: AuthenticationManagerBuilder) {
        //AuthenticationManager 使用我们的 lightSwordUserDetailService 来获取用户信息
        auth.userDetailsService(userDetailsService())
            .passwordEncoder(passwordEncoder())
    }

    /**
     * 密码加密算法
     *
     * @return
     */
    @Bean
    fun passwordEncoder(): BCryptPasswordEncoder {
        return BCryptPasswordEncoder();
    }
}