在本教程中，我們將開發一個Spring Boot Application，它利用JWT身份驗證來保護公開的REST API。在此示例中，我們將使用用戶身份驗證的硬編碼用戶數據。任何用戶只有擁有有效的JSON Web令牌（JWT）才能使用此API。在 之前的教程中，我們已經了解了什么是JWT，何時以及如何使用它。

讓我們開始？

為了更好地理解，我們將分階段開發該項目

• 開發一個Spring Boot Application 簡單REST GET API 映射路徑 /hello 的
• 為JWT配置Spring Security。使用/authenticate的REST POST API，用戶將獲得有效的JSON Web令牌。然后，只有擁有有效令牌的用戶才允許用戶訪問api /hello
  
  Spring Boot JWT工作流程

開發Spring Boot Application GET REST API

Maven項目如下 -

Spring Boot REST

pom.xml如下 -

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.javainuse</groupId>
    <artifactId>spring-boot-jwt</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.1.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>

</project>

創建一個用于公開GET REST API的Controller類 -

package com.javainuse.controller;

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

@RestController
public class HelloWorldController {

    @RequestMapping({ "/hello" })
    public String firstPage() {
        return "Hello World";
    }

}

使用SpringBoot Annotation創建引導類

package com.javainuse;

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

@SpringBootApplication
public class SpringBootHelloWorldApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringBootHelloWorldApplication.class, args);
    }
}

編譯并將SpringBootHelloWorldApplication.java作為Java應用程序運行。
轉到localhost:8080/hello

Spring Boot REST輸出

Spring Security和JWT配置

我們將配置Spring Security和JWT以執行2個操作 -

• 生成JWT - 使用映射/authenticate訪問POST API 。在傳遞正確的用戶名和密碼時，它將生成一個JSON Web令牌（JWT）
• 驗證JWT - 如果用戶嘗試使用映射/hello訪問GET API 。僅當請求具有有效的JSON Web令牌（JWT）時才允許訪問

Maven項目如下

Spring Boot JWT REST

• 這些行動的順序流程如下─

生成JWT

Spring Boot JWT生成令牌

image.png

驗證JWT

Spring Boot JWT驗證令牌

添加Spring Security和JWT依賴項

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.javainuse</groupId>
    <artifactId>spring-boot-jwt</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.1.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.9.1</version>
        </dependency>
    </dependencies>

</project>

• 定義application.properties。正如之前的JWT教程中所述，我們指定了將用于散列算法的密鑰。 密鑰與標頭和有效負載組合以創建唯一的散列。如果您有密鑰，我們只能驗證此哈希。

jwt.secret=javainuse

• JwtTokenUtil

  JwtTokenUtil負責執行JWT操作，如創建和驗證。它使用io.jsonwebtoken.Jwts來實現這一點。

package com.javainuse.config;

import java.io.Serializable;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.function.Function;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.stereotype.Component;

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;

@Component
public class JwtTokenUtil implements Serializable {

 private static final long serialVersionUID = -2550185165626007488L;

 public static final long JWT_TOKEN_VALIDITY = 5 * 60 * 60;

 @Value("${jwt.secret}")
 private String secret;

 //retrieve username from jwt token
 public String getUsernameFromToken(String token) {
     return getClaimFromToken(token, Claims::getSubject);
 }

 //retrieve expiration date from jwt token
 public Date getExpirationDateFromToken(String token) {
     return getClaimFromToken(token, Claims::getExpiration);
 }

 public <T> T getClaimFromToken(String token, Function<Claims, T> claimsResolver) {
     final Claims claims = getAllClaimsFromToken(token);
     return claimsResolver.apply(claims);
 }
 //for retrieveing any information from token we will need the secret key
 private Claims getAllClaimsFromToken(String token) {
     return Jwts.parser().setSigningKey(secret).parseClaimsJws(token).getBody();
 }

 //check if the token has expired
 private Boolean isTokenExpired(String token) {
     final Date expiration = getExpirationDateFromToken(token);
     return expiration.before(new Date());
 }

 //generate token for user
 public String generateToken(UserDetails userDetails) {
     Map<String, Object> claims = new HashMap<>();
     return doGenerateToken(claims, userDetails.getUsername());
 }

 //while creating the token -
 //1. Define  claims of the token, like Issuer, Expiration, Subject, and the ID
 //2. Sign the JWT using the HS512 algorithm and secret key.
 //3. According to JWS Compact Serialization(https://tools.ietf.org/html/draft-ietf-jose-json-web-signature-41#section-3.1)
 //   compaction of the JWT to a URL-safe string 
 private String doGenerateToken(Map<String, Object> claims, String subject) {

     return Jwts.builder().setClaims(claims).setSubject(subject).setIssuedAt(new Date(System.currentTimeMillis()))
             .setExpiration(new Date(System.currentTimeMillis() + JWT_TOKEN_VALIDITY * 1000))
             .signWith(SignatureAlgorithm.HS512, secret).compact();
 }

 //validate token
 public Boolean validateToken(String token, UserDetails userDetails) {
     final String username = getUsernameFromToken(token);
     return (username.equals(userDetails.getUsername()) && !isTokenExpired(token));
 }
}

• JWTUserDetailsS??ervice

  JWTUserDetailsS??ervice實現Spring Security UserDetailsS??ervice接口。它會重載loadUserByUsername，以使用用戶名從數據庫中獲取用戶詳細信息。Spring Security Authentication Manager在驗證用戶提供的用戶詳細信息時，會調用此方法從數據庫中獲取用戶詳細信息。這里我們從硬編碼的用戶列表中獲取用戶詳細信息。用戶的密碼使用BCrypt以加密格式存儲。以前我們已經看到了 Spring Boot Security - 使用Bcrypt進行密碼編碼。 在這里使用在線Bcrypt Generator您可以生成密碼的Bcrypt。

package com.javainuse.service;

import java.util.ArrayList;

import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.stereotype.Service;

@Service
public class JwtUserDetailsService implements UserDetailsService {

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        if ("javainuse".equals(username)) {
            return new User("javainuse", "$2a$10$slYQmyNdGzTn7ZLBXBChFOC9f6kFjAqPhccnP6DxlWXx2lPk1C3G6",
                    new ArrayList<>());
        } else {
            throw new UsernameNotFoundException("User not found with username: " + username);
        }
    }
}

• JwtAuthenticationController

  加入JwtAuthenticationController POST API /authenticate。POST API獲取用戶名和密碼 - 使用Spring Authentication Manager我們驗證用戶名和密碼。如果憑據有效，則使用JWTTokenUtil創建JWT令牌并提供給客戶端。

package com.javainuse.controller;

import java.util.Objects;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.BadCredentialsException;
import org.springframework.security.authentication.DisabledException;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import com.javainuse.service.JwtUserDetailsService;


import com.javainuse.config.JwtTokenUtil;
import com.javainuse.model.JwtRequest;
import com.javainuse.model.JwtResponse;

@RestController
@CrossOrigin
public class JwtAuthenticationController {

    @Autowired
    private AuthenticationManager authenticationManager;

    @Autowired
    private JwtTokenUtil jwtTokenUtil;

    @Autowired
    private JwtUserDetailsService userDetailsService;

    @RequestMapping(value = "/authenticate", method = RequestMethod.POST)
    public ResponseEntity<?> createAuthenticationToken(@RequestBody JwtRequest authenticationRequest) throws Exception {

        authenticate(authenticationRequest.getUsername(), authenticationRequest.getPassword());

        final UserDetails userDetails = userDetailsService
                .loadUserByUsername(authenticationRequest.getUsername());

        final String token = jwtTokenUtil.generateToken(userDetails);

        return ResponseEntity.ok(new JwtResponse(token));
    }

    private void authenticate(String username, String password) throws Exception {
        try {
            authenticationManager.authenticate(new UsernamePasswordAuthenticationToken(username, password));
        } catch (DisabledException e) {
            throw new Exception("USER_DISABLED", e);
        } catch (BadCredentialsException e) {
            throw new Exception("INVALID_CREDENTIALS", e);
        }
    }
}

• JwtRequest

  存儲我們從客戶端收到的用戶名和密碼時需要此類。

package com.javainuse.model;

import java.io.Serializable;

public class JwtRequest implements Serializable {

    private static final long serialVersionUID = 5926468583005150707L;
    
    private String username;
    private String password;
    
    //need default constructor for JSON Parsing
    public JwtRequest()
    {
        
    }

    public JwtRequest(String username, String password) {
        this.setUsername(username);
        this.setPassword(password);
    }

    public String getUsername() {
        return this.username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return this.password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

• JwtResponse

  這是創建包含要返回給用戶的JWT的響應所必需的類。

package com.javainuse.model;

import java.io.Serializable;

public class JwtResponse implements Serializable {

    private static final long serialVersionUID = -8091879091924046844L;
    private final String jwttoken;

    public JwtResponse(String jwttoken) {
        this.jwttoken = jwttoken;
    }

    public String getToken() {
        return this.jwttoken;
    }
}

• JwtRequestFilter

  JwtRequestFilter擴展了Spring Web Filter OncePerRequestFilter類。對于任何傳入請求，此Filter類都會被執行。它檢查請求是否具有有效的JWT令牌。如果它具有有效的JWT令牌，則它在上下文中設置身份驗證，以指定當前用戶已通過身份驗證。

package com.javainuse.config;

import java.io.IOException;

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

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.web.authentication.WebAuthenticationDetailsSource;
import org.springframework.stereotype.Component;
import org.springframework.web.filter.OncePerRequestFilter;

import com.javainuse.service.JwtUserDetailsService;

import io.jsonwebtoken.ExpiredJwtException;

@Component
public class JwtRequestFilter extends OncePerRequestFilter {

    @Autowired
    private JwtUserDetailsService jwtUserDetailsService;

    @Autowired
    private JwtTokenUtil jwtTokenUtil;

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
            throws ServletException, IOException {

        final String requestTokenHeader = request.getHeader("Authorization");

        String username = null;
        String jwtToken = null;
        // JWT Token is in the form "Bearer token". Remove Bearer word and get
        // only the Token
        if (requestTokenHeader != null && requestTokenHeader.startsWith("Bearer ")) {
            jwtToken = requestTokenHeader.substring(7);
            try {
                username = jwtTokenUtil.getUsernameFromToken(jwtToken);
            } catch (IllegalArgumentException e) {
                System.out.println("Unable to get JWT Token");
            } catch (ExpiredJwtException e) {
                System.out.println("JWT Token has expired");
            }
        } else {
            logger.warn("JWT Token does not begin with Bearer String");
        }

        // Once we get the token validate it.
        if (username != null && SecurityContextHolder.getContext().getAuthentication() == null) {

            UserDetails userDetails = this.jwtUserDetailsService.loadUserByUsername(username);

            // if token is valid configure Spring Security to manually set
            // authentication
            if (jwtTokenUtil.validateToken(jwtToken, userDetails)) {

                UsernamePasswordAuthenticationToken usernamePasswordAuthenticationToken = new UsernamePasswordAuthenticationToken(
                        userDetails, null, userDetails.getAuthorities());
                usernamePasswordAuthenticationToken
                        .setDetails(new WebAuthenticationDetailsSource().buildDetails(request));
                // After setting the Authentication in the context, we specify
                // that the current user is authenticated. So it passes the
                // Spring Security Configurations successfully.
                SecurityContextHolder.getContext().setAuthentication(usernamePasswordAuthenticationToken);
            }
        }
        chain.doFilter(request, response);
    }

}

• JwtAuthenticationEntryPoint

  這個類將擴展Spring的AuthenticationEntryPoint類并重寫其方法。它拒絕每個未經身份驗證的請求并發送錯誤代碼401

package com.javainuse.config;

import java.io.IOException;
import java.io.Serializable;

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

import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.AuthenticationEntryPoint;
import org.springframework.stereotype.Component;

@Component
public class JwtAuthenticationEntryPoint implements AuthenticationEntryPoint, Serializable {

    private static final long serialVersionUID = -7858869558953243875L;

    @Override
    public void commence(HttpServletRequest request, HttpServletResponse response,
            AuthenticationException authException) throws IOException {

        response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Unauthorized");
    }
}

• WebSecurityConfig

  此類擴展了WebSecurityConfigurerAdapter，并自定義WebSecurity和HttpSecurity。

package com.javainuse.config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.authentication.AuthenticationManager;
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.config.http.SessionCreationPolicy;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private JwtAuthenticationEntryPoint jwtAuthenticationEntryPoint;

    @Autowired
    private UserDetailsService jwtUserDetailsService;

    @Autowired
    private JwtRequestFilter jwtRequestFilter;

    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        // configure AuthenticationManager so that it knows from where to load
        // user for matching credentials
        // Use BCryptPasswordEncoder
        auth.userDetailsService(jwtUserDetailsService).passwordEncoder(passwordEncoder());
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }

    @Bean
    @Override
    public AuthenticationManager authenticationManagerBean() throws Exception {
        return super.authenticationManagerBean();
    }

    @Override
    protected void configure(HttpSecurity httpSecurity) throws Exception {
        // We don't need CSRF for this example
        httpSecurity.csrf().disable()
                // dont authenticate this particular request
                .authorizeRequests().antMatchers("/authenticate").permitAll().
                // all other requests need to be authenticated
                anyRequest().authenticated().and().
                // make sure we use stateless session; session won't be used to
                // store user's state.
                exceptionHandling().authenticationEntryPoint(jwtAuthenticationEntryPoint).and().sessionManagement()
                .sessionCreationPolicy(SessionCreationPolicy.STATELESS);

        // Add a filter to validate the tokens with every request
        httpSecurity.addFilterBefore(jwtRequestFilter, UsernamePasswordAuthenticationFilter.class);
    }
}

啟動Spring Boot應用程序

• 生成JSON Web令牌 -

  使用localhost:8080/authenticate創建POST請求。正文應該有有效的用戶名和密碼。在我們的例子中，用戶名是javainuse，密碼是password。
  

  Spring Boot JWT教程

• 驗證JSON Web令牌

  • 嘗試使用標題中的上述生成標記訪問localhost:8080/hello，如下所示
    
    Spring Boot JSON Web令牌

轉：https://www.javainuse.com/spring/boot-jwt