JWT 实际上如何与 Spring MVC 一起创建令牌并验证令牌？

我实际上希望获得更多、更清晰的理解JWT概念及其运作方式Spring MVC。我找到了链接https://github.com/nielsutrecht/jwt-angular-spring https://github.com/nielsutrecht/jwt-angular-spring，其程序运行得非常好。但我想知道它如何创建令牌以及用户如何登录应用程序。我需要一些澄清/回答它是如何工作的？请做有需要的。

我的理解：在我看来，当您启动应用程序时，将调用 GenericFilterBean 实现类，它将生成 JWT 令牌并将其发送到本地存储中的 UI（但不确定），然后该令牌将随请求一起出现在标头中然后它将得到验证并授予用户访问权限？

我想放一些代码片段以供参考（甚至您可以从提到的链接中查找代码）

AuthenticationTokenProcessingFilter.java

public class AuthenticationTokenProcessingFilter extends GenericFilterBean {

    private final UserDetailsService userService;

    public AuthenticationTokenProcessingFilter(UserDetailsService userService){
        this.userService = userService;
    }


    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,ServletException{
        HttpServletRequest httpRequest = this.getAsHttpRequest(request);

        String authToken = this.extractAuthTokenFromRequest(httpRequest);
        String userName = TokenUtils.getUserNameFromToken(authToken);

        if (userName != null) {

            UserDetails userDetails = this.userService.loadUserByUsername(userName);

            if (TokenUtils.validateToken(authToken, userDetails)) {

                UsernamePasswordAuthenticationToken authentication =
                        new UsernamePasswordAuthenticationToken(userDetails, null, userDetails.getAuthorities());
                authentication.setDetails(new WebAuthenticationDetailsSource().buildDetails(httpRequest));
                SecurityContextHolder.getContext().setAuthentication(authentication);
            }
        }

        chain.doFilter(request, response);
    }


    private HttpServletRequest getAsHttpRequest(ServletRequest request){
        if (!(request instanceof HttpServletRequest)) {
            throw new RuntimeException("Expecting an HTTP request");
        }

        return (HttpServletRequest) request;
    }


    private String extractAuthTokenFromRequest(HttpServletRequest httpRequest){
        /* Get token from header */
        String authToken = httpRequest.getHeader("X-Auth-Token");
        System.out.println("AUTH TOKEN : "+authToken);

        /* If token not found get it from request parameter */
        if (authToken == null) {
            authToken = httpRequest.getParameter("token");
        }
        return authToken;
    }
}

TokenUtils.java

public class TokenUtils{
    public static final String MAGIC_KEY = "obfuscate";

    public static String createToken(UserDetails userDetails){
        System.out.println(" ----- Create Token ------");
        /* Expires in one hour */
        long expires = System.currentTimeMillis() + 1000L * 60 * 60;

        StringBuilder tokenBuilder = new StringBuilder();
        tokenBuilder.append(userDetails.getUsername());
        tokenBuilder.append(":");
        tokenBuilder.append(expires);
        tokenBuilder.append(":");
        tokenBuilder.append(TokenUtils.computeSignature(userDetails, expires));

        return tokenBuilder.toString();
    }


    public static String computeSignature(UserDetails userDetails, long expires){
        System.out.println("------ Compute Signature ------");
        StringBuilder signatureBuilder = new StringBuilder();
        signatureBuilder.append(userDetails.getUsername());
        signatureBuilder.append(":");
        signatureBuilder.append(expires);
        signatureBuilder.append(":");
        signatureBuilder.append(userDetails.getPassword());
        signatureBuilder.append(":");
        signatureBuilder.append(TokenUtils.MAGIC_KEY);

        MessageDigest digest;
        try {
            digest = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e) {
            throw new IllegalStateException("No MD5 algorithm available!");
        }
        System.out.println(new String(Hex.encode(digest.digest(signatureBuilder.toString().getBytes()))));
        return new String(Hex.encode(digest.digest(signatureBuilder.toString().getBytes())));
    }


    public static String getUserNameFromToken(String authToken){
        System.out.println("----- Get Username From TOken ----");
        if (null == authToken) {
            return null;
        }

        String[] parts = authToken.split(":");
        return parts[0];
    }


    public static boolean validateToken(String authToken, UserDetails userDetails)  {
        System.out.println("=== Validate Token ===");
        String[] parts = authToken.split(":");
        long expires = Long.parseLong(parts[1]);
        String signature = parts[2];

        if (expires < System.currentTimeMillis()) {
            return false;
        }
        System.out.println(signature.equals(TokenUtils.computeSignature(userDetails, expires)));
        return signature.equals(TokenUtils.computeSignature(userDetails, expires));
    }
}

上下文.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:jee="http://www.springframework.org/schema/jee"
    xmlns:util="http://www.springframework.org/schema/util"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:security="http://www.springframework.org/schema/security"
    xsi:schemaLocation="
            http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
            http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
            http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee.xsd
            http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd
            http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
            http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security.xsd">

    <context:annotation-config />

    <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations">
            <list>
                <value>classpath:database.properties</value>
            </list>
        </property>
    </bean>

    <!-- MySQL DataSource -->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="username" value="${jdbc.user}" />
        <property name="password" value="${jdbc.pass}" />
        <property name="driverClassName" value="${jdbc.driverClassName}" />
        <property name="url" value="${jdbc.url}" />
    </bean>

    <!-- Entity Manager Factory -->
    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="persistenceUnitName" value="examplePU" />
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
                <property name="generateDdl" value="true" />
                <property name="showSql" value="true" />
            </bean>
        </property>
    </bean>

    <!-- Transaction Manager -->
    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>


    <bean id="newsEntryDao" class="net.dontdrinkandroot.dao.newsentry.JpaNewsEntryDao" />

    <bean id="userDao" class="net.dontdrinkandroot.dao.user.JpaUserDao" />

    <bean id="dataBaseInitializer" class="net.dontdrinkandroot.dao.DataBaseInitializer" init-method="initDataBase">
        <constructor-arg ref="userDao" />
        <constructor-arg ref="newsEntryDao" />
        <constructor-arg ref="passwordEncoder" />
    </bean>

    <tx:annotation-driven transaction-manager="transactionManager" />

    <!-- =======================
        INIT REST COMPONENTS 
         ======================= -->

    <context:component-scan base-package="net.dontdrinkandroot.resources" />

    <bean id="objectMapper" class="org.codehaus.jackson.map.ObjectMapper" />



    <!-- ====================================== 
        SPRING SECURITY SETUP
         ====================================== -->

    <bean id="passwordEncoder" class="org.springframework.security.crypto.password.StandardPasswordEncoder">
        <constructor-arg value="ThisIsASecretSoChangeMe" />
    </bean>

    <security:authentication-manager id="authenticationManager">
        <security:authentication-provider user-service-ref="userDao">
            <security:password-encoder ref="passwordEncoder"></security:password-encoder>
        </security:authentication-provider>
    </security:authentication-manager>

    <security:http
            realm="Protected API"
            use-expressions="true"
            auto-config="false"
            create-session="stateless"
            entry-point-ref="unauthorizedEntryPoint"
            authentication-manager-ref="authenticationManager">
        <security:custom-filter ref="authenticationTokenProcessingFilter" position="FORM_LOGIN_FILTER" />
        <security:intercept-url pattern="/rest/user/authenticate" access="permitAll" />
        <security:intercept-url method="GET" pattern="/rest/news/**" access="hasRole('user')" />
        <security:intercept-url method="PUT" pattern="/rest/news/**" access="hasRole('admin')" />
        <security:intercept-url method="POST" pattern="/rest/news/**" access="hasRole('admin')" />
        <security:intercept-url method="DELETE" pattern="/rest/news/**" access="hasRole('admin')" />
    </security:http>

    <bean id="unauthorizedEntryPoint" class="net.dontdrinkandroot.rest.UnauthorizedEntryPoint" />

    <bean id="authenticationTokenProcessingFilter" class="net.dontdrinkandroot.rest.AuthenticationTokenProcessingFilter" >
        <constructor-arg ref="userDao" />
    </bean>

</beans>

EDIT-1:

AUTH TOKEN : null
----- Get Username From Token ----
Jan 01, 2016 2:35:01 AM com.sun.jersey.spi.container.servlet.WebComponent filterFormParameters
WARNING: A servlet request, to the URI http://localhost:8080/angular-rest-security/rest/user/authenticate, contains form parameters in the request body but the request body has been consumed by the servlet or a servlet filter accessing the request parameters. Only resource methods using @FormParam will work as expected. Resource methods consuming the request body by other means will not work as expected.
Hibernate: select user0_.id as id1_1_, user0_.name as name2_1_, user0_.password as password3_1_ from User user0_ where user0_.name=?
Hibernate: select roles0_.User_id as User_id1_1_0_, roles0_.roles as roles2_2_0_ from User_roles roles0_ where roles0_.User_id=?
Hibernate: select user0_.id as id1_1_, user0_.name as name2_1_, user0_.password as password3_1_ from User user0_ where user0_.name=?
Hibernate: select roles0_.User_id as User_id1_1_0_, roles0_.roles as roles2_2_0_ from User_roles roles0_ where roles0_.User_id=?
 ----- Create Token ------
------ Compute Signature ------
525b8e635bb234684d2a02b99f38d687
AUTH TOKEN : null
----- Get Username From Token ----
Jan 01, 2016 2:36:27 AM com.sun.jersey.spi.container.servlet.WebComponent filterFormParameters
WARNING: A servlet request, to the URI http://localhost:8080/angular-rest-security/rest/user/authenticate, contains form parameters in the request body but the request body has been consumed by the servlet or a servlet filter accessing the request parameters. Only resource methods using @FormParam will work as expected. Resource methods consuming the request body by other means will not work as expected.
AUTH TOKEN : admin:1451599569652:525b8e635bb234684d2a02b99f38d687
----- Get Username From Token ----
Hibernate: select user0_.id as id1_1_, user0_.name as name2_1_, user0_.password as password3_1_ from User user0_ where user0_.name=?
Hibernate: select roles0_.User_id as User_id1_1_0_, roles0_.roles as roles2_2_0_ from User_roles roles0_ where roles0_.User_id=?
Hibernate: select user0_.id as id1_1_, user0_.name as name2_1_, user0_.password as password3_1_ from User user0_ where user0_.name=?
Hibernate: select roles0_.User_id as User_id1_1_0_, roles0_.roles as roles2_2_0_ from User_roles roles0_ where roles0_.User_id=?
=== Validate Token ===
------ Compute Signature ------
525b8e635bb234684d2a02b99f38d687
true
------ Compute Signature ------
525b8e635bb234684d2a02b99f38d687
Hibernate: select user0_.id as id1_1_, user0_.name as name2_1_, user0_.password as password3_1_ from User user0_ where user0_.name=?
Hibernate: select roles0_.User_id as User_id1_1_0_, roles0_.roles as roles2_2_0_ from User_roles roles0_ where roles0_.User_id=?
 ----- Create Token ------
------ Compute Signature ------
b6238344022f3f4dd3787f0f8fa99b44
AUTH TOKEN : null
----- Get Username From Token ----
AUTH TOKEN : admin:1451599596826:b6238344022f3f4dd3787f0f8fa99b44
----- Get Username From Token ----
Hibernate: select user0_.id as id1_1_, user0_.name as name2_1_, user0_.password as password3_1_ from User user0_ where user0_.name=?
Hibernate: select roles0_.User_id as User_id1_1_0_, roles0_.roles as roles2_2_0_ from User_roles roles0_ where roles0_.User_id=?
=== Validate Token ===
------ Compute Signature ------
b6238344022f3f4dd3787f0f8fa99b44
true
------ Compute Signature ------
b6238344022f3f4dd3787f0f8fa99b44
AUTH TOKEN : admin:1451599596826:b6238344022f3f4dd3787f0f8fa99b44
----- Get Username From Token ----
Hibernate: select user0_.id as id1_1_, user0_.name as name2_1_, user0_.password as password3_1_ from User user0_ where user0_.name=?
Hibernate: select roles0_.User_id as User_id1_1_0_, roles0_.roles as roles2_2_0_ from User_roles roles0_ where roles0_.User_id=?
=== Validate Token ===
------ Compute Signature ------
b6238344022f3f4dd3787f0f8fa99b44
true
------ Compute Signature ------
b6238344022f3f4dd3787f0f8fa99b44
02:36:38,728 INFO NewsEntryResource.list():49 - list()
Hibernate: select newsentry0_.id as id1_0_, newsentry0_.content as content2_0_, newsentry0_.date as date3_0_ from NewsEntry newsentry0_ order by newsentry0_.date desc
AUTH TOKEN : null
----- Get Username From Token ----

我是链接的作者（https://github.com/nielsutrecht/jwt-angular-spring https://github.com/nielsutrecht/jwt-angular-spring） 你给了。

该示例应用程序使用 Jjwt 库来创建和解密 JSON Web 令牌。在我的示例应用程序中，当一个人成功登录时就会创建令牌。这发生在login()中的方法UserController.java。成功登录（为了简单起见，示例应用程序不处理诸如密码之类的愚蠢内容）返回LoginResponse有了这个令牌。然后，角度应用程序将其设置为随每个请求发送的默认标头。如果您不想让他们在按 F5 后再次登录，您可以将其存储在本地存储或 cookie 中。再次;这是一个让事情尽可能简单的例子；我故意遗漏了这些东西。

标头由JwtFilter类并存储在请求上下文中。这样，任何路径都可以访问此信息，而无需解密标头本身。

尽管所有内容都在相应的内容中进行了相当深入的解释博客文章 http://niels.nu/blog/2015/json-web-tokens.html: 如果有什么不明白的地方请告诉我。