build: config spotless plugin and reformat code

build.gradle

@@ -1,9 +1,3 @@
-buildscript {
-    dependencies {
-        classpath "com.diffplug.spotless:spotless-plugin-gradle:4.5.1"
-    }
-}
-
 plugins {
     id 'java'
     id 'java-library'
@@ -12,18 +6,7 @@ plugins {
     id 'com.github.johnrengelman.shadow' version '4.0.2'
 }
 
-apply plugin: "com.diffplug.gradle.spotless"
-
-spotless {
-    java {
-        removeUnusedImports()
-        eclipse().configFile('shardingsphere_eclipse_formatter.xml')
-        target fileTree('.') {
-            include '**/*.java'
-        }
-    }
-}
-//tasks.compileJava.dependsOn(spotlessJavaApply)
+apply from: '../spotless.gradle'
 
 shadowJar {
     classifier = "jar"