更新 spring-boot 到最新的 v2.4.2 版本

server/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>1.5.8.RELEASE</version>
+        <version>2.4.2</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
     <modelVersion>4.0.0</modelVersion>
@@ -14,12 +14,6 @@
     <artifactId>kkFileView</artifactId>
     <version>3.3.1</version>
 
-    <properties>
-        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
-        <java.version>1.8</java.version>
-    </properties>
-
     <repositories>
         <repository>
             <!-- required for org.hyperic:sigar -->
@@ -27,6 +21,7 @@
             <url>https://repository.jboss.org/nexus/content/groups/public-jboss/</url>
         </repository>
     </repositories>
+
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
@@ -197,6 +192,7 @@
             <version>0.2.1</version>
         </dependency>
     </dependencies>
+
     <build>
         <resources>
             <resource>