diff --git a/build-android.gradle b/build-android.gradle
index e7b046b..a7901ec 100644
--- a/build-android.gradle
+++ b/build-android.gradle
@@ -9,7 +9,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.6.0'
+        classpath 'com.android.tools.build:gradle:4.2.0'
     }
 }
 // This Gradle script is used only when we are running tests in an Android environment to verify
@@ -60,6 +60,14 @@ android {
 }
 
 dependencies {
+    // See note in build-shared.gradle on the purpose of "privateImplementation". The
+    // Android Gradle plugin doesn't seem to have a good way to customize the classpath
+    // of the compile and test tasks, but since we're not actually publishing any
+    // Android artifacts from this project (we use this build only for CI testing), we
+    // can simply copy the dependencies from "privateImplementation" into the standard
+    // "implementation" for the Android build.
+    implementation configurations.privateImplementation
+
     androidTestImplementation "junit:junit:4.12"
     androidTestImplementation "org.hamcrest:hamcrest-library:1.3"
     androidTestImplementation "com.android.support.test:runner:1.0.2"
diff --git a/build-shared.gradle b/build-shared.gradle
index a6ec4eb..085dd5f 100644
--- a/build-shared.gradle
+++ b/build-shared.gradle
@@ -17,17 +17,36 @@ ext {
 
 ext.versions = [
     "gson": "2.7",
-    "jackson": "2.10.0"
+    "jacksonCore": "2.10.5",
+    "jacksonDatabind": "2.10.5.1"
 ]
 
 ext.libraries = [:]
 
+configurations {
+    privateImplementation
+}
+
 dependencies {
-    // Dependencies will not be exposed in the pom - see below in pom.withXml block
-    implementation "com.google.code.gson:gson:${versions.gson}"
-    implementation "com.fasterxml.jackson.core:jackson-core:${versions.jackson}"
-    implementation "com.fasterxml.jackson.core:jackson-databind:${versions.jackson}"
+    // The Gson and Jackson dependencies go into a custom configuration here, instead of
+    // the regular "implementation" configuration. We don't want them to be visible at
+    // all in the module's published dependencies - not even in "runtime" scope - because:
+    //
+    // 1. For Gson: While java-sdk-common does need Gson in order to work, the
+    // LaunchDarkly SDKs that use java-sdk-common have different strategies for packaging
+    // Gson. The Android SDK exposes it as a regular dependency; the Java server-side SDK
+    // embeds and shades Gson and does not expose it as a dependency. So we are leaving
+    // it up to the SDK to provide Gson in some way.
+    //
+    // 2. For Jackson: The SDKs do not use, require, or embed Jackson; we provide the
+    // LDJackson class as a convenience for applications that do use Jackson, and it is
+    // only usable if the application already has Jackson in its classpath. So we do not
+    // want Jackson to show up as a transitive  dependency.
+    privateImplementation "com.google.code.gson:gson:${versions.gson}"
+    privateImplementation "com.fasterxml.jackson.core:jackson-core:${versions.jacksonCore}"
+    privateImplementation "com.fasterxml.jackson.core:jackson-databind:${versions.jacksonDatabind}"
 
+    testImplementation configurations.privateImplementation
     testImplementation "org.hamcrest:hamcrest-library:1.3"
     testImplementation "junit:junit:4.12"
 }
diff --git a/build.gradle b/build.gradle
deleted file mode 100644
index 470f688..0000000
--- a/build.gradle
+++ /dev/null
@@ -1,217 +0,0 @@
-
-buildscript {
-    repositories {
-        mavenCentral()
-        mavenLocal()
-    }
-}
-
-plugins {
-    id "java"
-    id "java-library"
-    id "checkstyle"
-    id "jacoco"
-    id "signing"
-    id "maven-publish"
-    id "de.marcphilipp.nexus-publish" version "0.3.0"
-    id "io.codearte.nexus-staging" version "0.21.2"
-    id "org.ajoberstar.git-publish" version "2.1.3"
-    id "idea"
-}
-
-repositories {
-    mavenLocal()
-    // Before LaunchDarkly release artifacts get synced to Maven Central they are here along with snapshots:
-    maven { url "https://oss.sonatype.org/content/groups/public/" }
-    mavenCentral()
-}
-
-configurations.all {
-    // check for updates every build for dependencies with: 'changing: true'
-    resolutionStrategy.cacheChangingModulesFor 0, 'seconds'
-}
-
-apply from: 'build-shared.gradle'
-
-checkstyle {
-    configFile file("${project.rootDir}/checkstyle.xml")
-}
-
-// custom tasks for creating source/javadoc jars
-task sourcesJar(type: Jar, dependsOn: classes) {
-    classifier = 'sources'
-    from sourceSets.main.allSource
-}
-
-task javadocJar(type: Jar, dependsOn: javadoc) {
-    classifier = 'javadoc'
-    from javadoc.destinationDir
-}
-
-javadoc {
-    // Force the Javadoc build to fail if there are any Javadoc warnings. See: https://discuss.gradle.org/t/javadoc-fail-on-warning/18141/3
-    // The '-quiet' as second argument is actually a hack,
-    // since the one parameter addStringOption doesn't seem to
-    // work, we extra add '-quiet', which is added anyway by
-    // gradle. See https://github.com/gradle/gradle/issues/2354
-    // See JDK-8200363 (https://bugs.openjdk.java.net/browse/JDK-8200363)
-    // for information about the -Xwerror option.
-    options.addStringOption('Xwerror', '-quiet')
-}
-
-artifacts {
-    archives jar, sourcesJar, javadocJar
-}
-
-test {
-    testLogging {
-        events "passed", "skipped", "failed", "standardOut", "standardError"
-        showStandardStreams = true
-        exceptionFormat = 'full'
-    }
-}
-
-jacocoTestReport { // code coverage report
-	reports {
-		xml.enabled
-		csv.enabled true
-		html.enabled true
-	}
-}
-
-jacocoTestCoverageVerification {
-	// See notes in CONTRIBUTING.md on code coverage. Unfortunately we can't configure line-by-line code
-	// coverage overrides within the source code itself, because Jacoco operates on bytecode.
-	violationRules { rules ->
-		def knownMissedLinesForMethods = [
-			// The key for each of these items is the complete method signature minus the "com.launchdarkly.sdk." prefix.
-			"EvaluationReason.error(com.launchdarkly.sdk.EvaluationReason.ErrorKind)": 1,
-			"EvaluationReasonTypeAdapter.parse(com.google.gson.stream.JsonReader)": 1,
-			"LDValue.equals(java.lang.Object)": 1,
-			"LDValueTypeAdapter.read(com.google.gson.stream.JsonReader)": 1,
-			"json.JsonSerialization.getDeserializableClasses()": -1,
-			"json.LDGson.LDTypeAdapter.write(com.google.gson.stream.JsonWriter, java.lang.Object)": 1,
-			"json.LDJackson.GsonReaderToJacksonParserAdapter.peekInternal()": 3
-		]
-		
-		knownMissedLinesForMethods.each { partialSignature, maxMissedLines ->
-			if (maxMissedLines > 0) {  // < 0 means skip entire method
-				rules.rule {
-					element = "METHOD"
-					includes = [ "com.launchdarkly.sdk." + partialSignature ]
-					limit {
-						counter = "LINE"
-						value = "MISSEDCOUNT"
-						maximum = maxMissedLines
-					}
-				}
-			}
-		}
-		
-		// General rule that we should expect 100% test coverage; exclude any methods that have overrides above
-		rule {
-			element = "METHOD"
-			limit {
-				counter = "LINE"
-				value = "MISSEDCOUNT"
-				maximum = 0
-			}
-			excludes = knownMissedLinesForMethods.collect { partialSignature, maxMissedLines ->
-				"com.launchdarkly.sdk." + partialSignature
-			}
-		}
-	}
-}
-
-idea {
-    module {
-        downloadJavadoc = true
-        downloadSources = true
-    }
-}
-
-nexusStaging {
-    packageGroup = "com.launchdarkly"
-    numberOfRetries = 40 // we've seen extremely long delays in closing repositories
-}
-
-publishing {
-    publications {
-        mavenJava(MavenPublication) {
-            from components.java
-
-            groupId = 'com.launchdarkly'
-            artifactId = 'launchdarkly-java-sdk-common'
-
-            artifact sourcesJar
-            artifact javadocJar
-            
-            pom {
-                name = 'launchdarkly-java-sdk-common'
-                description = 'LaunchDarkly SDK Java Common Classes'
-                url = 'https://github.com/launchdarkly/java-sdk-common'
-                licenses {
-                    license {
-                        name = 'The Apache License, Version 2.0'
-                        url = 'http://www.apache.org/licenses/LICENSE-2.0.txt'
-                    }
-                }
-                developers {
-                    developer {
-                        name = 'LaunchDarkly'
-                        email = 'team@launchdarkly.com'
-                    }
-                }
-                scm {
-                    connection = 'scm:git:git://github.com/launchdarkly/java-sdk-common.git'
-                    developerConnection = 'scm:git:ssh:git@github.com:launchdarkly/java-sdk-common.git'
-                    url = 'https://github.com/launchdarkly/java-sdk-common'
-                }
-            }   
-                     
-                // We are deliberately hiding our dependencies in the pom, for the following reasons:
-                //
-                // 1. Gson: While java-sdk-common does need Gson in order to work, the LaunchDarkly SDKs that use
-                // java-sdk-common have different strategies for packaging Gson. The Android SDK exposes it as a
-                // regular dependency; the Java server-side SDK embeds and shades Gson and does not expose it as
-                // a dependency. So we are leaving it up to the SDK to provide Gson in some way.
-                //
-                // 2. Jackson: The SDKs do not use, require, or embed Jackson; we provide the LDJackson class as
-                // a convenience for applications that do use Jackson. So we do not want it to be a transitive
-                // dependency.
-            pom.withXml {
-                asNode().dependencies.forEach { it.value = "" }
-            }
-        }
-    }
-    repositories {
-        mavenLocal()
-    }
-}
-
-nexusPublishing {
-    clientTimeout = java.time.Duration.ofMinutes(2) // we've seen extremely long delays in creating repositories
-    repositories {
-        sonatype {
-            username = ossrhUsername
-            password = ossrhPassword            
-        }
-    }
-}
-
-signing {
-    sign publishing.publications.mavenJava
-}
-
-tasks.withType(Sign) {
-    onlyIf { !"1".equals(project.findProperty("LD_SKIP_SIGNING")) } // so we can build jars for testing in CI
-}
-
-gitPublish {
-    repoUri = 'git@github.com:launchdarkly/java-sdk-common.git'
-    branch = 'gh-pages'
-    contents {
-        from javadoc
-    }
-    commitMessage = 'publishing javadocs'
-}
diff --git a/build.gradle.kts b/build.gradle.kts
new file mode 100644
index 0000000..04f37af
--- /dev/null
+++ b/build.gradle.kts
@@ -0,0 +1,180 @@
+import java.time.Duration
+import org.gradle.api.tasks.testing.logging.TestExceptionFormat
+import org.gradle.external.javadoc.CoreJavadocOptions
+
+// These values come from gradle.properties
+val ossrhUsername: String by project
+val ossrhPassword: String by project
+
+buildscript {
+    repositories {
+        mavenCentral()
+        mavenLocal()
+    }
+}
+
+plugins {
+    java
+    "java-library"
+    checkstyle
+    signing
+    "maven-publish"
+    idea
+    jacoco
+    id("de.marcphilipp.nexus-publish") version "0.3.0"
+    id("io.codearte.nexus-staging") version "0.30.0"
+}
+
+repositories {
+    mavenLocal()
+    // Before LaunchDarkly release artifacts get synced to Maven Central they are here along with snapshots:
+    maven { url = uri("https://oss.sonatype.org/content/groups/public/") }
+    mavenCentral()
+}
+
+apply { from("build-shared.gradle") }
+
+java {
+    withJavadocJar()
+    withSourcesJar()
+}
+
+checkstyle {
+    configFile = file("${project.rootDir}/checkstyle.xml")
+}
+
+tasks.compileJava {
+    // See note in build-shared.gradle on the purpose of "privateImplementation"
+    classpath = configurations["privateImplementation"]
+}
+
+tasks.javadoc.configure {
+    // Force the Javadoc build to fail if there are any Javadoc warnings. See: https://discuss.gradle.org/t/javadoc-fail-on-warning/18141/3
+    // See JDK-8200363 (https://bugs.openjdk.java.net/browse/JDK-8200363)
+    // for information about the -Xwerror option.
+    (options as CoreJavadocOptions).addStringOption("Xwerror")
+
+    // See note in build-shared.gradle on the purpose of "privateImplementation"
+    classpath = configurations["privateImplementation"]
+}
+
+tasks.test.configure {
+    testLogging {
+        events("passed", "skipped", "failed", "standardOut", "standardError")
+        showStandardStreams = true
+        exceptionFormat = TestExceptionFormat.FULL
+    }
+}
+
+tasks.jacocoTestReport.configure {
+    reports {
+        xml.isEnabled = true
+        csv.isEnabled = true
+        html.isEnabled = true
+    }
+}
+
+tasks.jacocoTestCoverageVerification.configure {
+    // See notes in CONTRIBUTING.md on code coverage. Unfortunately we can't configure line-by-line code
+    // coverage overrides within the source code itself, because Jacoco operates on bytecode.
+    violationRules {
+        val knownMissedLinesForMethods = mapOf(
+            "EvaluationReason.error(com.launchdarkly.sdk.EvaluationReason.ErrorKind)" to 1,
+            "EvaluationReasonTypeAdapter.parse(com.google.gson.stream.JsonReader)" to 1,
+            "LDValue.equals(java.lang.Object)" to 1,
+            "LDValueTypeAdapter.read(com.google.gson.stream.JsonReader)" to 1,
+            "json.JsonSerialization.getDeserializableClasses()" to -1,
+            "json.LDGson.LDTypeAdapter.write(com.google.gson.stream.JsonWriter, java.lang.Object)" to 1,
+            "json.LDJackson.GsonReaderToJacksonParserAdapter.peekInternal()" to 3
+        )
+
+        knownMissedLinesForMethods.forEach { (signature, maxMissedLines) ->
+            if (maxMissedLines > 0) {  // < 0 means skip entire method
+                rule {
+                    element = "METHOD"
+                    includes = listOf("com.launchdarkly.sdk." + signature)
+                    limit {
+                        counter = "LINE"
+                        value = "MISSEDCOUNT"
+                        maximum = maxMissedLines.toBigDecimal()
+                    }
+                }
+            }
+        }
+        
+        // General rule that we should expect 100% test coverage; exclude any methods that have overrides above
+        rule {
+            element = "METHOD"
+            limit {
+                counter = "LINE"
+                value = "MISSEDCOUNT"
+                maximum = 0.toBigDecimal()
+            }
+            excludes = knownMissedLinesForMethods.map { (signature, maxMissedLines) ->
+                "com.launchdarkly.sdk." + signature }
+        }
+    }
+}
+
+idea {
+    module {
+        isDownloadJavadoc = true
+        isDownloadSources = true
+    }
+}
+
+nexusStaging {
+    packageGroup = "com.launchdarkly"
+    numberOfRetries = 40 // we've seen extremely long delays in closing repositories
+}
+
+publishing {
+    publications {
+        create<MavenPublication>("mavenJava") {
+            from(components["java"])
+
+            groupId = "com.launchdarkly"
+            artifactId = "launchdarkly-java-sdk-common"
+
+            pom {
+                name.set("launchdarkly-java-sdk-common")
+                description.set("LaunchDarkly SDK Java Common Classes")
+                url.set("https://github.com/launchdarkly/java-sdk-common")
+                licenses {
+                    license {
+                        name.set("The Apache License, Version 2.0")
+                        url.set("http://www.apache.org/licenses/LICENSE-2.0.txt")
+                    }
+                }
+                developers {
+                    developer {
+                        name.set("LaunchDarkly")
+                        email.set("team@launchdarkly.com")
+                    }
+                }
+                scm {
+                    connection.set("scm:git:git://github.com/launchdarkly/java-sdk-common.git")
+                    developerConnection.set("scm:git:ssh:git@github.com:launchdarkly/java-sdk-common.git")
+                    url.set("https://github.com/launchdarkly/java-sdk-common")
+                }
+            }
+        }
+    }
+    repositories {
+        mavenLocal()
+    }
+}
+
+nexusPublishing {
+    clientTimeout.set(Duration.ofMinutes(2)) // we've seen extremely long delays in creating repositories
+    repositories {
+        sonatype {
+            username.set(ossrhUsername)
+            password.set(ossrhPassword)
+        }
+    }
+}
+
+signing {
+    sign(publishing.publications["mavenJava"])
+}
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 5c2d1cf..f3d88b1 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index a2bf131..442d913 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.2.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.8.3-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
index 83f2acf..2fe81a7 100755
--- a/gradlew
+++ b/gradlew
@@ -154,19 +154,19 @@ if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
         else
             eval `echo args$i`="\"$arg\""
         fi
-        i=$((i+1))
+        i=`expr $i + 1`
     done
     case $i in
-        (0) set -- ;;
-        (1) set -- "$args0" ;;
-        (2) set -- "$args0" "$args1" ;;
-        (3) set -- "$args0" "$args1" "$args2" ;;
-        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
-        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
-        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
-        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
-        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
-        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
     esac
 fi
 
@@ -175,14 +175,9 @@ save () {
     for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
     echo " "
 }
-APP_ARGS=$(save "$@")
+APP_ARGS=`save "$@"`
 
 # Collect all arguments for the java command, following the shell quoting and substitution rules
 eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
 
-# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
-if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
-  cd "$(dirname "$0")"
-fi
-
 exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
index 24467a1..9109989 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -29,6 +29,9 @@ if "%DIRNAME%" == "" set DIRNAME=.
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
 @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
 set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"