JWT快速入门

太过爱你忘了你带给我的痛 2024-03-30 11:26 73阅读 0赞

## JWT快速入门 ##

### 简介 ###

**JWT**：JSON Web Token，是一个开放标准(RFC 7519)，它定义了一种紧凑的、自包含的方式，用于作为JSON对象在各方之间**安全地传输信息**。该信息可以被验证和信任，因为它是**数字签名**的。

**作用**：JWT最常见的场景的授权认证，一旦用户登录之后，后续每个请求都会包含JWT，系统处理每次用户请求之前，都会先进行JWT安全校验，通过之后再进行处理。

**组成**：  
`JSON Web Token`由三部分组成，它们之间用圆点(.)连接。这三部分分别是：

*  Header(首标)

{
        
        'alg': "HS256", # 使用的算法
        'typ': "JWT"
    }

*  Payload(负载)

{
        
        "sub": '1234567890',
        "name": 'john',
        "admin":true
    }

*  Signature(签名)

// 首先是使用base64UrlEncode方法把header与payload拼接起来
    var encodedstring = base64UrlEncode(header) + '.' + base64UrlEncode(payload);
    
    // 然后在使用算法对上面拼接的字符串进行加密 使用的算法就是上面header中的那个alg
    var signature = HMACSHA256(encodedString, 'secret');

### 代码展示 ###

**创建一个Java项目**  
![在这里插入图片描述][a01a17cd0e324e7dba5622320864fd84.png]  
![在这里插入图片描述][b2ad468572d14573a8a307b6548dd78f.png]  
![在这里插入图片描述][e9b35c67e6a44f8a8b5ba307c6148e30.png]

**pom.xml**

<?xml version="1.0" encoding="UTF-8"?>
    <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>org.example</groupId>
        <artifactId>JWT</artifactId>
        <version>1.0-SNAPSHOT</version>
    
        <properties>
            <maven.compiler.source>8</maven.compiler.source>
            <maven.compiler.target>8</maven.compiler.target>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        </properties>
        <dependencies>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>3.8.1</version>
            </dependency>
            <dependency>
                <groupId>io.jsonwebtoken</groupId>
                <artifactId>jjwt</artifactId>
                <version>0.9.1</version>
            </dependency>
            <dependency>
                <groupId>javax.xml.bind</groupId>
                <artifactId>jaxb-api</artifactId>
                <version>2.3.0</version>
            </dependency>
            <dependency>
                <groupId>com.sun.xml.bind</groupId>
                <artifactId>jaxb-impl</artifactId>
                <version>2.3.0</version>
            </dependency>
            <dependency>
                <groupId>com.sun.xml.bind</groupId>
                <artifactId>jaxb-core</artifactId>
                <version>2.3.0</version>
            </dependency>
            <dependency>
                <groupId>javax.activation</groupId>
                <artifactId>activation</artifactId>
                <version>1.1.1</version>
            </dependency>
        </dependencies>
    
    </project>

![在这里插入图片描述][472e9588f7d54bcd8502f500fd7cc359.png]

**测试代码**

*  加密过程

import io.jsonwebtoken.JwtBuilder;
    import io.jsonwebtoken.Jwts;
    import io.jsonwebtoken.SignatureAlgorithm;
    
    import java.util.Date;
    import java.util.UUID;
    
    public class Test {
        
        // 持续的时间
        private long time = 1000 * 60 * 60 * 24; // 一天的毫秒数
        // 数字签名
        private String signature = "admin";
        @org.junit.Test
        public void jwtTest(){
        
            JwtBuilder jwtBuilder = Jwts.builder();
            // 采用链式编程传参
            String jwtToken = jwtBuilder
                                  // header->设置类型
                                  .setHeaderParam("typ","JWT")
                                  // header->这是算法
                                  .setHeaderParam("alg","HS256")
                                  // payload 设置用户情况
                                  .claim("username", "lihua")
                                  .claim("role", "admain")
                                  // 设置主题
                                .setSubject("admin-test")
                                // 设置持续的有效时间
                                .setExpiration(new Date(System.currentTimeMillis() + time))
                                // 设置随机id
                                .setId(UUID.randomUUID().toString())
                                // signature 设置数字签名加密
                                .signWith(SignatureAlgorithm.HS256, signature)
                                // 将这几部分拼接起来
                                .compact();
            // 打印结果
            System.out.println(jwtToken);
        }
    }

**运行结果**  
结果由三部分构成

eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9
    .eyJ1c2VybmFtZSI6ImxpaHVhIiwicm9sZSI6ImFkbWFpbiIsInN1YiI6ImFkbWluLXRlc3QiLCJleHAiOjE2NzE3NzkzOTMsImp0aSI6IjA5M2Y2NWYwLTg2M2YtNDAzZS1iMjQzLTlkNTY0NmQzZThhMCJ9
    .8uN_E9Dd5HxEd43A4GUi12pMKNEQ95_6LerPnoiWuCY

*  解密过程

@org.junit.Test
        public void parse(){
        
            // 密文
            String token = "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1c2VybmFtZSI6ImxpaHVhIiwicm9sZSI6ImFkbWFpbiIsInN1YiI6ImFkbWluLXRlc3QiLCJleHAiOjE2NzE3NzkzOTMsImp0aSI6IjA5M2Y2NWYwLTg2M2YtNDAzZS1iMjQzLTlkNTY0NmQzZThhMCJ9.8uN_E9Dd5HxEd43A4GUi12pMKNEQ95_6LerPnoiWuCY";
            JwtParser jwtParser = Jwts.parser();
            // 使用数字签名解密
            Jws<Claims> claimsJws = jwtParser.setSigningKey(signature).parseClaimsJws(token);
            // 获取存储体payload
            Claims claims = claimsJws.getBody();
            // 输出加密结果
            System.out.println(claims.get("username"));
            System.out.println(claims.get("role"));
            System.out.println(claims.getId());
            System.out.println(claims.getSubject());
            System.out.println(claims.getExpiration());
        }

**运行结果**  
![在这里插入图片描述][321a591c02c640e79a2a872c00097b32.png]

**完整代码**

import io.jsonwebtoken.*;
    
    import java.util.Date;
    import java.util.UUID;
    
    public class Test {
        
        // 持续的时间
        private long time = 1000 * 60 * 60 * 24; // 一天的毫秒数
        // 数字签名
        private String signature = "admin";
        @org.junit.Test
        public void jwtTest(){
        
            JwtBuilder jwtBuilder = Jwts.builder();
            // 采用链式编程传参
            String jwtToken = jwtBuilder
                                  // header->设置类型
                                  .setHeaderParam("typ","JWT")
                                  // header->这是算法
                                  .setHeaderParam("alg","HS256")
                                  // payload 设置用户情况
                                  .claim("username", "lihua")
                                  .claim("role", "admain")
                                  // 设置主题
                                .setSubject("admin-test")
                                // 设置持续的有效时间
                                .setExpiration(new Date(System.currentTimeMillis() + time))
                                // 设置随机id
                                .setId(UUID.randomUUID().toString())
                                // signature 设置数字签名加密
                                .signWith(SignatureAlgorithm.HS256, signature)
                                // 将这几部分拼接起来
                                .compact();
            // 打印结果
            System.out.println(jwtToken);
        }
        @org.junit.Test
        public void parse(){
        
            // 密文
            String token = "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1c2VybmFtZSI6ImxpaHVhIiwicm9sZSI6ImFkbWFpbiIsInN1YiI6ImFkbWluLXRlc3QiLCJleHAiOjE2NzE3NzkzOTMsImp0aSI6IjA5M2Y2NWYwLTg2M2YtNDAzZS1iMjQzLTlkNTY0NmQzZThhMCJ9.8uN_E9Dd5HxEd43A4GUi12pMKNEQ95_6LerPnoiWuCY";
            JwtParser jwtParser = Jwts.parser();
            // 使用数字签名解密
            Jws<Claims> claimsJws = jwtParser.setSigningKey(signature).parseClaimsJws(token);
            // 获取存储体payload
            Claims claims = claimsJws.getBody();
            // 输出加密结果
            System.out.println(claims.get("username"));
            System.out.println(claims.get("role"));
            System.out.println(claims.getId());
            System.out.println(claims.getSubject());
            System.out.println(claims.getExpiration());
        }
    }

[a01a17cd0e324e7dba5622320864fd84.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/c05fcc3016ef4d17b9c4c420efbf70d3.png
[b2ad468572d14573a8a307b6548dd78f.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/87bd8b82ff09466e996c84e33056d50b.png
[e9b35c67e6a44f8a8b5ba307c6148e30.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/22b17144e5714481b3868c6e27f21b91.png
[472e9588f7d54bcd8502f500fd7cc359.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/43eda76026d94592ac7166d11b1de1ee.png
[321a591c02c640e79a2a872c00097b32.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/2ec3fd612e3d4367b1da287a94ce3d2a.png