一、升级框架依赖

无论如何，安全是第一，所以先把框架升级再说。（具体是选择哪个版本升级，建议按照安全厂商的要求）

 1     <parent>
 2         <groupId>org.springframework.boot</groupId>
 3         <artifactId>spring-boot-starter-parent</artifactId>
 4         <version>2.6.5</version>
 5     </parent>
 8     <properties>
 9         <spring-framework.version>5.3.18</spring-framework.version>
10         <spring-boot.version>2.6.5</spring-boot.version>
11         <spring-data.version>2.6.3</spring-data.version>
12        ......
13     </properties>

JDK使用corretto-1.8.0_322

框架依赖升级了之后，开始编译调试，也就是升级框架带来的兼容性问题，通常最令人抓狂的也就是这部分。

二、调试基础框的兼容性问题

不断地发现报错有各种问题，网上找类似的情况，再分析、筛选、尝试，将搜罗的解决方法记录下来。

1.RedisCacheWriter错误

先把升级后接口新加的3个方法添加上，后续有问题再调试。

 1     @Override
 2     public void clearStatistics(String name) {
 3         statistics.reset(name) ;
 6     @Override
 7     public RedisCacheWriter withStatisticsCollector(CacheStatisticsCollector cacheStatisticsCollector){
 8         return this;
11     @Override
12     public CacheStatistics getCacheStatistics(String cacheName) {
13         return statistics.getCacheStatistics(cacheName);
在该类头部，添加定义：
1     private final CacheStatisticsCollector statistics = CacheStatisticsCollector.create();
2.RedisUtil错误
 （1）替换报错的方法
 1     private Set<String> keys(String keyPrefix) {
 2         String realKey = keyPrefix + "*";
 4         try {
 5             return redisTemplate.execute((RedisCallback<Set<String>>) connection -> {
 6                 Set<String> binaryKeys = new HashSet<>();
 8                 Cursor<byte[]> cursor = connection.scan(ScanOptions.scanOptions().match(realKey).count(Integer.MAX_VALUE).build());
 9                 while (cursor.hasNext()) {
10                     binaryKeys.add(new String(cursor.next()));
11                 }
13                 return binaryKeys;
14             });
15         } catch (Throwable e) {
16             e.printStackTrace();
17         }
19         return null;
（2）报错语句加上类型转换
 1     @SuppressWarnings("unchecked")
 2     public void del(String... key) {
 3         if (key != null && key.length > 0) {
 4             if (key.length == 1) {
 5                 redisTemplate.delete(key[0]);
 6             } else {
 7                 redisTemplate.delete((Collection<String>) CollectionUtils.arrayToList(key));
3.无法访问okhttp3.HttpUrl 
 1 private static MinioClient initMinio(String minioUrl, String minioName,String minioPass) {
 2     if (minioClient == null) {
 3         try {
 4             minioClient = MinioClient.builder()
 5                     .endpoint(minioUrl)
 6                     .credentials(minioName, minioPass)
 7                     .build();
 8         } catch (Exception e) {
 9             e.printStackTrace();
10         }
11     }
12     return minioClient;
分析原因：项目里的依赖包版本冲突，修改pom.xml
 1     <properties>
 2         <minio.version>8.3.7</minio.version>
 3         <okhttp.version>4.8.1</okhttp.version>
 4     </properties>
 7     <dependencies>
 8 ......
 9         <dependency>
10             <groupId>io.minio</groupId>
11             <artifactId>minio</artifactId>
12             <version>${minio.version}</version>
13             <scope>compile</scope>
14         </dependency>
16         <dependency>
17             <groupId>com.squareup.okhttp3</groupId>
18             <artifactId>okhttp</artifactId>
19             <version>${okhttp.version}</version>
20             <scope>compile</scope>
21         </dependency>
22 ......
23     </dependencies>
4.程序包feign.hystrix不存在
 添加依赖引用：
 1     <dependencies>
 2         <!-- feign -->
 3         <dependency>
 4             <groupId>org.springframework.cloud</groupId>
 5             <artifactId>spring-cloud-starter-openfeign</artifactId>
 6         </dependency>
 7        ......
 8         <dependency>
 9             <groupId>io.github.openfeign</groupId>
10             <artifactId>feign-hystrix</artifactId>
11         </dependency>
12     </dependencies>
5.程序包org.springframework.cloud.netflix.ribbon不存在
1         <dependency>
2             <groupId>org.springframework.cloud</groupId>
3             <artifactId>spring-cloud-openfeign-core</artifactId>
4             <version>3.1.1</version>
5             <scope>compile</scope>
6         </dependency>
检查项目里的依赖包版本冲突问题
6.程序包org.junit不存在
1         <dependency>
2             <groupId>junit</groupId>
3             <artifactId>junit</artifactId>
4             <version>4.13.2</version>
5             <scope>test</scope>
6         </dependency>
 7.对RemoteApplicationEvent的引用不明确
1     public JeecgRemoteApplicationEvent(EventObj source, String originService) {
2         super(source, originService, (String) null);
3         this.eventObj = source;
8.dependencies.dependency.version
 1 [INFO] Scanning for projects...
 2 [ERROR] [ERROR] Some problems were encountered while processing the POMs:
 3 [ERROR] 'dependencies.dependency.version' for org.springframework.cloud:spring-cloud-starter-netflix-hystrix:jar is missing. @ line 51, column 21
 5 [ERROR] The build could not read 1 project -> [Help 1]
 注明依赖包的版本号：
1         <dependency>
2             <groupId>org.springframework.cloud</groupId>
3             <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
4             <version>2.2.10.RELEASE</version>
5             <scope>compile</scope>
6         </dependency>
9.解决其他一些依赖包的引用与版本冲突问题，在此就不一一列举
Cannot resolve io.github.openfeign:feign-hystrix:11.8
Cannot resolve org.springframework.boot:spring-boot-configuration-processor:2.6.5
Cannot resolve org.springframework.cloud:spring-cloud-starter-openfeign:3.1.1
Cannot resolve io.netty:netty-all:4.1.75.Final
Cannot resolve org.codehaus.groovy:groovy:3.0.10
10.项目编译通过，检查框架是否升级成功，并且不存在其他版本冲突
（1）如图：Spring Framework == 5.3.18
（2）如图：Spring Boot== 2.6.5
 注：看到以上2个图中的版本与预期一致，说明框架升级编译已没问题，后续再对业务代码进行调试、试运行。
 项目框架升级：Spring Boot 升级到2.6.5， Spring Framework升级到5.3.18 【续】 - 圆觉悟禅道 - 博客园 (cnblogs.com)