在 Controller 中注入 SessionScope bean 不起作用

Question

我在设置属性值时遇到问题，即。 shortname 到 Spring Boot.

中的 SessionScope bean

这是我的 class:

    import java.util.Map;

    public class LdapUser {
        private String shortname = "";
        private Map<String,String> token = null;
        private String id = "";
    
    public LdapUser() {
           
        }
    
        public String getshortname() {
            return shortname;
        }
    
        public void setshortname(String shortname) {
            this.shortname = shortname;
        }
... remaining geters and setters

我的 Bean 定义在这里：

import xxx.controllers.SwitchController;
import xxx.isim.LdapUser;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;
import org.springframework.context.annotation.ScopedProxyMode;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.context.WebApplicationContext;

@Configuration
public class RestTemplateClient {

    Logger logger = LoggerFactory.getLogger(SwitchController.class);

    @Bean
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }

    @Bean
    @Scope(value = WebApplicationContext.SCOPE_SESSION, proxyMode = ScopedProxyMode.TARGET_CLASS)
    public LdapUser sessionScopedLdapUser() {
        logger.info("LdapUser bean instance created");
        return new LdapUser();
    }
}

我在控制器中使用 Bean：

import xxx.errors.IsimConnectionException;
import xxx.isim.IsimConnection;
import xxx.isim.LdapUser;
import xxx.services.IsimRestApiService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.core.Authentication;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.annotation.Resource;
import java.security.Principal;

@Controller
public class HomeController {

    private static final Logger log = LoggerFactory.getLogger(HomeController.class);

    @Autowired
    IsimRestApiService isimConn;

    @Resource(name = "sessionScopedLdapUser")
    LdapUser sessionScopedLdapUser;

    @RequestMapping("/")
    public String index(Principal principal) throws IsimConnectionException {
        Authentication authentication = (Authentication) principal;

        /

        if ((authentication.getPrincipal() != null) && (authentication.isAuthenticated())) {
            // set the shortname for the session
            String shortname = (String)authentication.getPrincipal();
            sessionScopedLdapUser.setshortname(shortname); //<-----

我的 Bean 的 shortname 值在带有箭头的行之后仍然为空，即使我正确地获得了 shortname 字符串值并且该值不为空。你能指出我在设置 bean 属性值时做错了什么吗？我按照示例 here for SessionScope Beans

更新： 我还尝试使用 autowired 而不是 @Resource(name = "sessionScopedLdapUser") 但执行后该值仍然为 null sessionScopedLdapUser.setshortname(shortname);

 @Autowired
 LdapUser sessionScopedLdapUser

我还在日志中看到 LdapUser bean 实例被创建了三次。这怎么可能？

2021-09-21 10:55:55,469 INFO  [http-nio-8080-exec-4] xxx.config.RestTemplateClient: LdapUser bean instance created
2021-09-21 10:57:05,247 INFO  [http-nio-8080-exec-4] xxx.config.RestTemplateClient: LdapUser bean instance created
2021-09-21 10:58:08,401 INFO  [http-nio-8080-exec-4] xxx.config.RestTemplateClient: LdapUser bean instance created

想法是每个 HTTP 会话有一个 bean。我真的很困惑，希望得到一些提示。我正在阅读这篇文章 article，也许那是因为我正在尝试将会话范围 bean 注入到 Singletone bean。

我的文件结构是：

xxx
---auth
---config
   --- RestRemplateClient
---controllers
   --- HomeController
---errors
---isim
   --- LdapUser
---services
Mainapp

Answer 1

您可以指定您的配置如下：-

import org.springframework.context.annotation.Scope;
import java.time.LocalDateTime;
import org.springframework.context.annotation.ScopedProxyMode;
import org.springframework.stereotype.Component;

@Component
@Scope(value = "session", proxyMode = ScopedProxyMode.TARGET_CLASS)
public class LdapUser {

    private String shortName = "LdapUser Session Scope";
// other properties
    
    public LdapUser() {
        System.out.println("LdapUser SessionScope Constructor Called at "+LocalDateTime.now());
    }

    public String getShortName() {
        return shortName;
    }

    public void setShortName(String shortName) {
        this.shortName = shortName;
    }
}

配置中：

@Configuration
public class RestTemplateClient {

    Logger logger = LoggerFactory.getLogger(SwitchController.class);

    @Autowired
    private LdapUser ldapUser;

    @Bean
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }

    public void setLdapUser(LdapUser ldapUser) {
    this.ldapUser = ldapUser;
    }

    public LdapUser getLdapUser() {
    return ldapUser;
    }
}

并进入您的控制器：-

@Controller
public class HomeController {
// Other Codes

@Autowired
private RestTemplateClient restTemplateClient;

private static final Logger log = LoggerFactory.getLogger(HomeController.class);

    @Autowired
    IsimRestApiService isimConn;

@RequestMapping("/")
    public String index(Principal principal) throws IsimConnectionException {
        Authentication authentication = (Authentication) principal;

        /

        if ((authentication.getPrincipal() != null) && (authentication.isAuthenticated())) {
            // set the shortname for the session
            String shortname = (String)authentication.getPrincipal();
restTemplateClient.getLdapUser().setShortName("LdapUser Session Scope Updated");
// .... Other codes
}
}
}

Answer 2

感谢@M。 Deinum 我能够弄清楚。我正在查看调试器中的字段值，并且那个字段值始终为空，因为我正在查看代理而不是真实对象。

这是在@Controller class 中注入 session 作用域 bean 的代码。它也可以在@Service class.

中以相同的方式正常工作

public class LdapUser {
    private String shortname = "";
    private Map<String,String> token = new HashMap<>();
    private String id = "";

    public LdapUser() {
        this.shortname = shortname;
        this.token = token;
        this.id = id;
    }


    public String getshortname() {
        return shortname;
    }

    public void setshortname(String shortname) {
        this.shortname = shortname;
    }
 ... other getters and setters

我的 bean 配置 class:

@Configuration
public class RestTemplateClient {

Logger logger = LoggerFactory.getLogger(SwitchController.class);

@Bean
public RestTemplate restTemplate() {
    return new RestTemplate();
}

@Bean
@SessionScope
public LdapUser sessionScopedLdapUser() {
    logger.info("LdapUser bean instance created at "+ LocalDateTime.now());
    return new LdapUser();
}

}

我的控制器class:

@Controller
public class HomeController {
private static final Logger log = LoggerFactory.getLogger(HomeController.class);

@Autowired
IsimRestApiService isimConn;

@Autowired
LdapUser sessionScopedLdapUser;

@RequestMapping("/")
public String index(Principal principal) throws IsimConnectionException {
    Authentication authentication = (Authentication) principal;

    //System.out.println("******* USER IS " + authentication.getPrincipal());

    if ((authentication.getPrincipal() != null) && (authentication.isAuthenticated())) {
        // set the shortname for the session
        String shortname = (String)authentication.getPrincipal();

        sessionScopedLdapUser.setshortname(shortname);

在 Controller 中注入 SessionScope bean 不起作用

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