密码学【java】初探究之springboo集成mybatis,swagger,数字签名

Myth丶恋晨 2024-03-22 13:21 50阅读 0赞

#### 文章目录 ####

*  项目环境
 *  一 swagger技术的补充
 *   *  1.1 \[swagger\](（https://github.com/OAI/OpenAPI-Specification）)介绍
     *  1.2 swagger的基础注解
     *  1.3 controller添加swagger注解
 *  二 项目搭建
 *   *  2.1 创建数据库
     *  2.2 引入项目依赖
     *  2.3 配置数据库的连接
     *  2.4 配置swagger的配置信息
     *  2.5 编写实体类
     *  2.6 编写业务接口和查询实现
     *  2.7 启动项目
 *  三 项目完成之数字签名
 *   *  3.1 编写工具类
     *   *  3.1.1 RsaDemo
         *  3.1.2 SignatureDemo
     *  3.2 添加controller接口
     *  3.3 运行程序

![在这里插入图片描述][d89777d662964535bc97af394c90cdd9.jpeg_pic_center]

## 项目环境 ##

*  JDK19
 *  springboot 2.7.6
 *  swagger 2.9.2
 *  lombok
 *  commons-io 2.11.0
 *  mysql 8.0.32

## 一 swagger技术的补充 ##

### 1.1 swagger介绍 ###

*  OpenAPI规范（OpenAPI Specification 简称OAS）是Linux基金会的一个项目，试图通过定义一种用来描述API格式或API定义的语言，来规范RESTful服务开发过程，目前版本是V3.0，并且已经发布并开源在github上。
 *  [Swagger][]是全球最大的OpenAPI规范（OAS）API开发工具框架，支持从设计和文档到测试和部署的整个API生命周期的开发。
 *  Spring Boot 可以集成Swagger，生成Swagger接口，Spring Boot是Java领域的神器，它是Spring项目下快速构建项目的框架

### 1.2 swagger的基础注解 ###

*  swagger通过注解生成接口文档，包括接口名、请求方法、参数、返回信息的等

<table> 
 <thead> 
  <tr> 
   <th>注释</th> 
   <th>说明</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>@Api</td> 
   <td>修饰整个类，描述Controller的作用</td> 
  </tr> 
  <tr> 
   <td>@ApiOperation</td> 
   <td>描述一个类的一个方法，或者说一个接口</td> 
  </tr> 
  <tr> 
   <td>@ApiParam</td> 
   <td>单个参数描述</td> 
  </tr> 
  <tr> 
   <td>@ApiModel</td> 
   <td>用对象实体来作为入参</td> 
  </tr> 
  <tr> 
   <td>@ApiProperty</td> 
   <td>用对象接实体收参数时，描述对象的一个字段</td> 
  </tr> 
  <tr> 
   <td>@ApiResponse</td> 
   <td>HTTP响应其中1个描述</td> 
  </tr> 
  <tr> 
   <td>@ApiResponses</td> 
   <td>HTTP响应整体描述</td> 
  </tr> 
  <tr> 
   <td>@ApiIgnore</td> 
   <td>使用该注解忽略这个API</td> 
  </tr> 
  <tr> 
   <td>@ApiError</td> 
   <td>发生错误返回的信息</td> 
  </tr> 
  <tr> 
   <td>@ApiImplicitParam</td> 
   <td>一个请求参数</td> 
  </tr> 
  <tr> 
   <td>@ApiImplicitParams</td> 
   <td>多个请求参数</td> 
  </tr> 
 </tbody> 
</table>

--------------------

*  @Api
    
     *  修饰整个类，描述Controller的作用
    
        @Controller
        @RequestMapping("/queryAll")
        @Api(value = "查询所有记录")
        public class queryAll {
              
            //...
        }

--------------------

*  @ApiOperation
    
     *  用于描述一个方法或者接口,可以添加的参数形式：
    
        @ApiOperation(value = “接口说明”, httpMethod = “接口请求方式”, response = “接口返回参数类型”, notes = “接口发布说明”）
    
        @RequestMapping("/swagger")
        @ResponseBody
        @ApiOperation(value = "根据用户名获取用户的信息",notes = "查询数据库中的记录",httpMethod = "POST",response = String.class)
            public String getUserInfo(String userName) {
              
                return "1234";
            }
        }

--------------------

*  @ApiImplicitParam 一个请求参数
    
        @ApiImplicitParam(required = “是否必须参数”, name = “参数名称”, value = “参数具体描述”,dateType=“变量类型”,paramType=”请求方式”）

@ApiImplicitParam(name = "userName",value = "用户名",required = true,dataType = "String",paramType = "query")
        public String getUserInfo(String userName) {
        
            return "1234";
        }
    }

--------------------

*  @ApiImplicitParams 多个请求参数
    
     *  参数和@ApiImplicitParam一致，只是这个注解可以添加多个参数而已
    
        @ApiImplicitParams({
              
            @ApiImplicitParam(name = "nickName",value = "用户的昵称",paramType = "query",dataType = "String",required = true),
            @ApiImplicitParam(name = "id",value = "用户的ID",paramType = "query",dataType = "Integer",required = true)
        })
        public String getUserInfoByNickName(String nickName, Integer id) {
              
            return "1234";
        }

### 1.3 controller添加swagger注解 ###

import com.yang.mapper.UserMapper;
    import com.yang.pojo.User;
    import com.yang.utils.RsaDemo;
    import com.yang.utils.SignatureDemo;
    import io.swagger.annotations.Api;
    import io.swagger.annotations.ApiImplicitParam;
    import io.swagger.annotations.ApiImplicitParams;
    import io.swagger.annotations.ApiOperation;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.*;
    
    import java.security.PublicKey;
    import java.util.List;
    
    /**
     * @author 缘友一世
     * date 2023/1/22-13:00
     */
    @Api(tags = "提供用户的增删改查的功能")
    @RestController
    //@RestController为开发提供了方便☺，在提供json接口时需要的配置操作再也不需要自己配置了
    //@RestController注解相当于@ResponseBody和@Controller的结合
    public class UserController {
        
        @Autowired
        UserMapper userMapper;
        @ApiOperation(value = "查询用户")
        @RequestMapping(value = "/findAll", method = RequestMethod.GET)
        public List<User> queryUserList() {
        
            List<User> userList = userMapper.queryUserList();
            for(User user:userList ) {
        
                System.out.println(user);
            }
            return userList;
        }
        @ApiOperation(value = "根据id查询用户")
        @RequestMapping(value = "/queryUserById",method = RequestMethod.GET)
        @ApiImplicitParams({
        
                //@ApiImplicitParam(name = "userName",value = "用户的昵称",paramType = "query",dataType = "String",required = true),
                @ApiImplicitParam(name = "id",value = "用户的id",paramType = "query",dataType = "int",required = true)
        })
        public User queryUserById(@RequestParam("id") int Id) {
        
            return userMapper.queryUserById(Id);
        }
    
        @ApiOperation(value = "添加用户")
        @RequestMapping(value = "/addUser", method = RequestMethod.POST)
        public String addUser() {
        
            userMapper.addUser(new User(6, "三毛", "123456"));
            return "finish addUser";
        }
        @ApiOperation(value = "更新用户")
        @RequestMapping(value = "/updateUser", method = RequestMethod.PUT)
        public String updateUser() {
        
            userMapper.updateUser(new User(6, "阿毛", "5211314"));
            return "finish UpdateUser";
        }
        @ApiOperation(value = "删除用户")
        @RequestMapping(value = "/addUser", method = RequestMethod.DELETE)
        public String deleteUer() {
        
            userMapper.deleteUser(6);
            return "finish DeleteUser";
        }
    
        @ApiOperation(value = "购物")
        @RequestMapping(value = "/buy", method = RequestMethod.GET)
        public String buy(String price, String num, String signature) {
        
            try {
        
                // 获取公钥
                PublicKey publicKey = RsaDemo.loadPublicKeyFromFile("RSA", "a.pub");
                // 第一个参数：原文
                // 第二个参数：算法
                // 第三个参数：公钥
                // 第四个参数：签名
                boolean result = SignatureDemo.verifySignature(price + num, "SHA256withRSA", publicKey, signature);
                System.out.println(result);
                if (result) {
        
                    return "购物成功";
                }
            } catch (Exception e) {
        
                e.printStackTrace();
            }
    
            return "购物失败";
        }
    }

## 二 项目搭建 ##

*  创建项目的过程，就不再赘述！

### 2.1 创建数据库 ###

CREATE DATABASE USER;
    USE USER;
    CREATE TABLE USER(
      id INT PRIMARY KEY AUTO_INCREMENT,
      username VARCHAR(20),
      password VARCHAR(50),
    )

*  然后自己随便插入一条数据！

### 2.2 引入项目依赖 ###

<dependencies>
      <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-jdbc</artifactId>
      </dependency>
      <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-web</artifactId>
      </dependency>
    
      <dependency>
          <groupId>com.mysql</groupId>
          <artifactId>mysql-connector-j</artifactId>
          <scope>runtime</scope>
      </dependency>
      <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-test</artifactId>
          <scope>test</scope>
      </dependency>
    
      <dependency>
          <groupId>org.mybatis.spring.boot</groupId>
          <artifactId>mybatis-spring-boot-starter</artifactId>
          <version>3.0.1</version>
      </dependency>
    
      <dependency>
          <groupId>org.projectlombok</groupId>
          <artifactId>lombok</artifactId>
      </dependency>
    
      
      <dependency>
          <groupId>io.springfox</groupId>
          <artifactId>springfox-swagger2</artifactId>
          <version>2.9.2</version>
      </dependency>
      <dependency>
          <groupId>io.springfox</groupId>
          <artifactId>springfox-swagger-ui</artifactId>
          <version>2.9.2</version>
      </dependency>
    
      <dependency>
          <groupId>commons-io</groupId>
          <artifactId>commons-io</artifactId>
          <version>2.11.0</version>
      </dependency>
      <dependency>
          <groupId>commons-codec</groupId>
          <artifactId>commons-codec</artifactId>
          <version>1.15</version>
      </dependency>
    </dependencies>

### 2.3 配置数据库的连接 ###

spring:
      mvc:
        pathmatch:
          matching-strategy: ant_path_matcher
      datasource:
        username: root
        password: yqk.20021027
        url: jdbc:mysql://localhost:3306/user?useSSL=true&useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
        driver-class-name: com.mysql.cj.jdbc.Driver
    #整合mybatis
    mybatis:
      type-aliases-package: com.yang.pojo
      mapper-locations: classpath:mybatis/mapper/*.xml

### 2.4 配置swagger的配置信息 ###

import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import springfox.documentation.builders.RequestHandlerSelectors;
    import springfox.documentation.service.ApiInfo;
    import springfox.documentation.service.Contact;
    import springfox.documentation.spi.DocumentationType;
    import springfox.documentation.spring.web.plugins.Docket;
    import springfox.documentation.swagger2.annotations.EnableSwagger2;
    
    import java.util.ArrayList;
    
    @Configuration //配置类
    @EnableSwagger2// 开启Swagger2的自动配置
    public class SwaggerConfig {
        
        //配置docket以配置Swagger具体参数
        @Bean
        public Docket docket() {
        
            return new Docket(DocumentationType.SWAGGER_2)
                    .enable(true)
                    .apiInfo(apiInfo())
                    .select()
                    .apis(RequestHandlerSelectors.basePackage("com.yang.controller"))
                    .build();
        }
    
        //配置swagger文档信息apiInfo
        private ApiInfo apiInfo() {
        
            //作者信息
            Contact contact = new Contact("缘友一世", "https://www.csdn.net/", "xxxxxxxxx@qq.com");
            return new ApiInfo(
                    "Spring Boot集成Swagger和加密解密",//标题
                    "学习Swagger",//描述
                    "1.0",//版本
                    "http://localhost",//组织连接
                    contact,//联系人信息
                    "Apache 2.0",//许可
                    "http://www.apache.org/licenses/LICENSE-2.0",//许可连接
                    new ArrayList());//拓展
        }
    
    
    }

### 2.5 编写实体类 ###

*  根据数据库表的结果，进行编写实体类
 *  可以使用lombok工具快速生成get，set方法和有参、无参构造器

import lombok.AllArgsConstructor;
    import lombok.Data;
    import lombok.NoArgsConstructor;
    import org.apache.ibatis.type.Alias;
    
    /**
     * @author 缘友一世
     * date 2023/1/22-12:55
     */
    @Data
    @AllArgsConstructor
    @NoArgsConstructor
    @Alias("User")
    public class User {
        
        private int id;
        private String username;
        private String password;
    }

### 2.6 编写业务接口和查询实现 ###

![在这里插入图片描述][853998dfbd4348279bde4128a1566413.png]

1.  编写controller接口
    
        import com.yang.mapper.UserMapper;
        import com.yang.pojo.User;
        import com.yang.utils.RsaDemo;
        import com.yang.utils.SignatureDemo;
        import io.swagger.annotations.Api;
        import io.swagger.annotations.ApiImplicitParam;
        import io.swagger.annotations.ApiImplicitParams;
        import io.swagger.annotations.ApiOperation;
        import org.springframework.beans.factory.annotation.Autowired;
        import org.springframework.web.bind.annotation.*;
        
        import java.security.PublicKey;
        import java.util.List;
        
        /**
         * @author 缘友一世
         * date 2023/1/22-13:00
         */
        @Api(tags = "提供用户的增删改查的功能")
        @RestController
        //@RestController为开发提供了方便☺，在提供json接口时需要的配置操作再也不需要自己配置了
        //@RestController注解相当于@ResponseBody和@Controller的结合
        public class UserController {
              
            @Autowired
            UserMapper userMapper;
            @ApiOperation(value = "查询用户")
            @RequestMapping(value = "/findAll", method = RequestMethod.GET)
            public List<User> queryUserList() {
              
                List<User> userList = userMapper.queryUserList();
                for(User user:userList ) {
              
                    System.out.println(user);
                }
                return userList;
            }
            @ApiOperation(value = "根据id查询用户")
            @RequestMapping(value = "/queryUserById",method = RequestMethod.GET)
            @ApiImplicitParams({
              
                    //@ApiImplicitParam(name = "userName",value = "用户的昵称",paramType = "query",dataType = "String",required = true),
                    @ApiImplicitParam(name = "id",value = "用户的id",paramType = "query",dataType = "int",required = true)
            })
            public User queryUserById(@RequestParam("id") int Id) {
              
                return userMapper.queryUserById(Id);
            }
        
            @ApiOperation(value = "添加用户")
            @RequestMapping(value = "/addUser", method = RequestMethod.POST)
            public String addUser() {
              
                userMapper.addUser(new User(6, "三毛", "123456"));
                return "finish addUser";
            }
            @ApiOperation(value = "更新用户")
            @RequestMapping(value = "/updateUser", method = RequestMethod.PUT)
            public String updateUser() {
              
                userMapper.updateUser(new User(6, "阿毛", "5211314"));
                return "finish UpdateUser";
            }
            @ApiOperation(value = "删除用户")
            @RequestMapping(value = "/addUser", method = RequestMethod.DELETE)
            public String deleteUer() {
              
                userMapper.deleteUser(6);
                return "finish DeleteUser";
            }
        
        }
2.  编写mapper接口
    
        @Mapper//这个注释表名这是一个mybatis的mapper的类
        @Repository
        public interface UserMapper {
              
        
            List<User> queryUserList();
        
            User queryUserById(int id);
        
            int addUser(User user);
        
            int updateUser(User user);
        
            int deleteUser(int id);
        }
3.  编写mapeer的实现

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper
            PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
            "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="com.yang.mapper.UserMapper">
        <select id="queryUserList" resultType="User">
            select * from user;
        </select>
        <select id="queryUserById" resultType="User" parameterType="int">
            select * from user where id = #{id};
        </select>
    
        <insert id="addUser" parameterType="User">
            insert into user(id,name,pwd) values (#{id},#{name},#{pwd});
        </insert>
    
        <update id="updateUser" parameterType="User">
            update user set name=#{name},pwd=#{pwd} where id=#{id};
        </update>
    
        <delete id="deleteUser" parameterType="int">
            delete from user where id=#{id};
        </delete>
    </mapper>

### 2.7 启动项目 ###

*  swagger的访问地址:`http://localhost:8080/swagger-ui.html`  
    ![在这里插入图片描述][2bd48ee502a444e0980da5c592e6a65c.png]  
    ![在这里插入图片描述][997b6834803643c0b611d8a0c2ed36ff.png]
 *  点击try it out 输入姓名， Execute执行，返回如下图效果  
    ![在这里插入图片描述][3d7447cc5e524d9cb79c65cd04e9551a.png]

## 三 项目完成之数字签名 ##

*  模拟购物场景，用户点击购物的时候，在前端生成签名信息，传递给后台服务器进行校验，如果价格，数量，签名都正确，购物成功，如果参数被人修改，则购物失败  
    ![在这里插入图片描述][be036989cb9449c896fe464bddc05297.png]

### 3.1 编写工具类 ###

*  两个代码 RsaDemo.java 和 SignatureDemo.java
    
     *  RsaDemo：生成并保存公钥和私钥文件
     *  SignatureDemo：生成数字签名  
        ![在这里插入图片描述][d3a94a0420b142f8935addac89e3d697.png]

#### 3.1.1 RsaDemo ####

package com.yang.utils;
    
    import java.io.ByteArrayOutputStream;
    import java.io.File;
    import java.nio.charset.Charset;
    import java.security.*;
    import java.security.spec.PKCS8EncodedKeySpec;
    import java.security.spec.X509EncodedKeySpec;
    
    import org.apache.commons.codec.binary.Base64;
    import org.apache.commons.io.FileUtils;
    
    import javax.crypto.Cipher;
    
    public class RsaDemo {
        
        public static void main(String[] args) throws Exception {
        
    
            generateKeyToFile("RSA", "a.pub", "a.pri");
        }
    
        /**
         * 生成密钥对并保存在本地文件中
         *
         * @param algorithm : 算法
         * @param pubPath   : 公钥保存路径
         * @param priPath   : 私钥保存路径
         */
        public static void generateKeyToFile(String algorithm, String pubPath, String priPath) throws Exception {
        
            // 获取密钥对生成器
            KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(algorithm);
            // 获取密钥对
            KeyPair keyPair = keyPairGenerator.generateKeyPair();
            // 获取公钥
            PublicKey publicKey = keyPair.getPublic();
            // 获取私钥
            PrivateKey privateKey = keyPair.getPrivate();
            // 获取byte数组
            byte[] publicKeyEncoded = publicKey.getEncoded();
            byte[] privateKeyEncoded = privateKey.getEncoded();
            // 进行Base64编码
            String publicKeyString = Base64.encodeBase64String(publicKeyEncoded);
            String privateKeyString = Base64.encodeBase64String(privateKeyEncoded);
            // 保存文件
            FileUtils.writeStringToFile(new File(pubPath), publicKeyString,Charset.forName("UTF-8"));
            FileUtils.writeStringToFile(new File(priPath), privateKeyString,Charset.forName("UTF-8"));
    
        }
    
        /**
         * 从文件中加载公钥
         *
         * @param algorithm : 算法
         * @param filePath  : 文件路径
         * @return : 公钥
         */
        public static PublicKey loadPublicKeyFromFile(String algorithm, String filePath) throws Exception {
        
            // 将文件内容转为字符串
            String keyString = FileUtils.readFileToString(new File(filePath), Charset.forName("UTF-8"));
    
            return loadPublicKeyFromString(algorithm, keyString);
    
        }
    
        /**
         * 从字符串中加载公钥
         *
         * @param algorithm : 算法
         * @param keyString : 公钥字符串
         * @return : 公钥
         */
        public static PublicKey loadPublicKeyFromString(String algorithm, String keyString) throws Exception {
        
            // 进行Base64解码
            byte[] decode = Base64.decodeBase64(keyString);
            // 获取密钥工厂
            KeyFactory keyFactory = KeyFactory.getInstance(algorithm);
            // 构建密钥规范
            X509EncodedKeySpec keyspec = new X509EncodedKeySpec(decode);
            // 获取公钥
            return keyFactory.generatePublic(keyspec);
    
        }
    
        /**
         * 从文件中加载私钥
         *
         * @param algorithm : 算法
         * @param filePath  : 文件路径
         * @return : 私钥
         */
        public static PrivateKey loadPrivateKeyFromFile(String algorithm, String filePath) throws Exception {
        
            // 将文件内容转为字符串
            String keyString = FileUtils.readFileToString(new File(filePath),Charset.forName("UTF-8"));
            return loadPrivateKeyFromString(algorithm, keyString);
    
        }
    
        /**
         * 从字符串中加载私钥
         *
         * @param algorithm : 算法
         * @param keyString : 私钥字符串
         * @return : 私钥
         */
        public static PrivateKey loadPrivateKeyFromString(String algorithm, String keyString) throws Exception {
        
            // 进行Base64解码
            byte[] decode = Base64.decodeBase64(keyString);
            // 获取密钥工厂
            KeyFactory keyFactory = KeyFactory.getInstance(algorithm);
            // 构建密钥规范
            PKCS8EncodedKeySpec keyspec = new PKCS8EncodedKeySpec(decode);
            // 生成私钥
            return keyFactory.generatePrivate(keyspec);
    
        }
    
        /**
         * 使用密钥加密数据
         *
         * @param algorithm      : 算法
         * @param input          : 原文
         * @param key            : 密钥
         * @param maxEncryptSize : 最大加密长度(需要根据实际情况进行调整)
         * @return : 密文
         */
        public static String encrypt(String algorithm, String input, Key key, int maxEncryptSize) throws Exception {
        
            // 获取Cipher对象
            Cipher cipher = Cipher.getInstance(algorithm);
            // 初始化模式(加密)和密钥
            cipher.init(Cipher.ENCRYPT_MODE, key);
            // 将原文转为byte数组
            byte[] data = input.getBytes();
            // 总数据长度
            int total = data.length;
            // 输出流
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            decodeByte(maxEncryptSize, cipher, data, total, baos);
            // 对密文进行Base64编码
            return Base64.encodeBase64String(baos.toByteArray());
    
        }
    
    
    
        /**
         * 分段处理数据
         *
         * @param maxSize : 最大处理能力
         * @param cipher  : Cipher对象
         * @param data    : 要处理的byte数组
         * @param total   : 总数据长度
         * @param baos    : 输出流
         * @throws Exception
         */
        public static void decodeByte(int maxSize, Cipher cipher, byte[] data, int total, ByteArrayOutputStream baos) throws Exception {
        
            // 偏移量
            int offset = 0;
            // 缓冲区
            byte[] buffer;
            // 如果数据没有处理完, 就一直继续
            while (total - offset > 0) {
        
                // 如果剩余的数据 >= 最大处理能力, 就按照最大处理能力来加密数据
                if (total - offset >= maxSize) {
        
                    // 加密数据
                    buffer = cipher.doFinal(data, offset, maxSize);
                    // 偏移量向右侧偏移最大数据能力个
                    offset += maxSize;
                } else {
        
                    // 如果剩余的数据 < 最大处理能力, 就按照剩余的个数来加密数据
                    buffer = cipher.doFinal(data, offset, total - offset);
                    // 偏移量设置为总数据长度, 这样可以跳出循环
                    offset = total;
                }
                // 向输出流写入数据
                baos.write(buffer);
            }
        }
    
    }

*  运行 RsaDemo.java 生成 公钥和私钥  
    ![在这里插入图片描述][abb48bacb3ce4ea1b877a6be50a24809.png]

#### 3.1.2 SignatureDemo ####

package com.yang.utils;
    
    import org.apache.commons.codec.binary.Base64;
    
    import java.security.PrivateKey;
    import java.security.PublicKey;
    import java.security.Signature;
    
    public class SignatureDemo {
        
        public static void main(String[] args) throws Exception {
        
            // 10:表示购物的价格
            // 10:表示购物的数量
            String a = "10" + "10";
    
            PublicKey publicKey = RsaDemo.loadPublicKeyFromFile("RSA", "a.pub");
            PrivateKey privateKey = RsaDemo.loadPrivateKeyFromFile("RSA", "a.pri");
    
            String signaturedData = getSignature(a, "sha256withrsa", privateKey);
            System.out.println(signaturedData);
        }
    
        /**
         * 生成签名
         *
         * @param input      : 原文
         * @param algorithm  : 算法
         * @param privateKey : 私钥
         * @return : 签名
         * @throws Exception
         */
        public static String getSignature(String input, String algorithm, PrivateKey privateKey) throws Exception {
        
            // 获取签名对象
            Signature signature = Signature.getInstance(algorithm);
            // 初始化签名
            signature.initSign(privateKey);
            // 传入原文
            signature.update(input.getBytes());
            // 开始签名
            byte[] sign = signature.sign();
            // 对签名数据进行Base64编码
            return Base64.encodeBase64String(sign);
        }
    
        /**
         * 校验签名
         *
         * @param input          : 原文
         * @param algorithm      : 算法
         * @param publicKey      : 公钥
         * @param signaturedData : 签名
         * @return : 数据是否被篡改
         * @throws Exception
         */
        public static boolean verifySignature(String input, String algorithm, PublicKey publicKey, String signaturedData) throws Exception {
        
            // 获取签名对象
            Signature signature = Signature.getInstance(algorithm);
            // 初始化签名
            signature.initVerify(publicKey);
            // 传入原文
            signature.update(input.getBytes());
            // 校验数据
            return signature.verify(Base64.decodeBase64(signaturedData));
    
        }
    
    }

*  运行 SignatureDemo.java 生成 签名信息
    
        iMWjY/L17jMT8nippbtnWjkztU1l9DOH6I31cBwpVRNR7wD3qYRKJGTS+eFNrC+ygFlGmOLqON14vGxBxp7KKAauSuWMmWlbfynKeMsDveIo8ttssYHT+InNf
        0WLgwOnvUnKVK/CZF3rOdYTWYAZAqinJ/SikniPUfE1ZRknwksEFfXqEMUOAWeuHRdeVE+JdhGxv9yT5kV6agBccwili3fPaCQR5nfalPLRccrKlEV5RDwOjO
        YzQk3q64NHXNP1qsK9CpRbVsQPQjNFgU+GwgwI1E8HQJpdDKsbZYgLcBoCFqaoiARDjSsFnlmjpB/uUmF9YJdPkIkTEr3fSiteO3mNeu/WeZXp749MZF3IjRj
        zJYg9bF2s/iuR42zszvlmmWkBLzv9FD8kmg2u8UxhcsarSHirjl7MHF20kbM6h9t51v8DR2cz8ci6ciphiMI6ZE7/rVTfnzq9SdZRaoM+rMKn08ZFHWYXO3MX
        XZmlDQtd0WSF5hVwAgyU9zXMAHi2

### 3.2 添加controller接口 ###

@ApiOperation(value = "购物")
    @RequestMapping(value = "/buy", method = RequestMethod.GET)
    public String buy(String price, String num, String signature) {
        
        try {
        
            // 获取公钥
            PublicKey publicKey = RsaDemo.loadPublicKeyFromFile("RSA", "a.pub");
            // 第一个参数：原文
            // 第二个参数：算法
            // 第三个参数：公钥
            // 第四个参数：签名
            boolean result = SignatureDemo.verifySignature(price + num, "SHA256withRSA", publicKey, signature);
            System.out.println(result);
            if (result) {
        
                return "购物成功";
            }
        } catch (Exception e) {
        
            e.printStackTrace();
        }
    
        return "购物失败";
    }

### 3.3 运行程序 ###

*  swagger访问的地址:`http://localhost:8080/swagger-ui.html`
    
    ![在这里插入图片描述][df2a245e53644b188b6f7cd29ebb43f1.png]  
    ![在这里插入图片描述][57a9c8dced4649b58c94197a1b64fd46.png]
 *  如果在请求服务器的时候，程序被人篡改，如价格改成100元，运行就会购物失败  
    ![在这里插入图片描述][0cfa15b9dc63403e849ac10257872c4d.png]

[d89777d662964535bc97af394c90cdd9.jpeg_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/22/54eb6debaf494b28ac8be3cb797519c2.png
[Swagger]: https://swagger.io/
[853998dfbd4348279bde4128a1566413.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/22/38798238cab847d69f000d9087c5ad29.png
[2bd48ee502a444e0980da5c592e6a65c.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/22/d42263e576374de8add7ee4a584ee2ed.png
[997b6834803643c0b611d8a0c2ed36ff.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/22/6eb203529d8b40d598de60673e8e3d7b.png
[3d7447cc5e524d9cb79c65cd04e9551a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/22/61664136cc294d9eb421e0cb4d73378e.png
[be036989cb9449c896fe464bddc05297.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/22/296da9d2bd4f4b24839338e776e6da9c.png
[d3a94a0420b142f8935addac89e3d697.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/22/78ad9a212e4d406f9bcd45ac664a6ba1.png
[abb48bacb3ce4ea1b877a6be50a24809.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/22/516f17077dd2460c937cb00ce13ec997.png
[df2a245e53644b188b6f7cd29ebb43f1.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/22/afcf2fc50f774f03abc9f4b12d166263.png
[57a9c8dced4649b58c94197a1b64fd46.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/22/4d8eb4c8439c4089aae63083b63e5c6f.png
[0cfa15b9dc63403e849ac10257872c4d.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/22/27ba96ae06b04819acb1ad88f691edd4.png