diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index f75b22832e..3816a2b06f 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -6,8 +6,8 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        # test against latest 8, 11, 17 of zulu and temurin java
-        java-version: [8, 11, 17]
+        # test against latest 8, 11, 17, 21 of zulu and temurin java
+        java-version: [8, 11, 17, 21]
         java-vendor: ['zulu', 'temurin', 'corretto']
     steps:
       - uses: actions/checkout@v4
diff --git a/build.gradle b/build.gradle
index 52bc7a43ee..3bc9ba2463 100644
--- a/build.gradle
+++ b/build.gradle
@@ -84,13 +84,13 @@ gradle.projectsEvaluated {
 
 tasks.named('wrapper') {
   distributionType = Wrapper.DistributionType.ALL
-  gradleVersion = '6.9.1'
+  gradleVersion = '8.13'
 }
 
 // Set up properties needed for all testing, adds "testAll" task to root
 apply from: "$rootDir/gradle/root/testing.gradle"
 // Generates coverage report for testAll
-apply from: "$rootDir/gradle/root/coverage.gradle"
+//apply from: "$rootDir/gradle/root/coverage.gradle"
 // Attaches fatJar tasks to root project (makes toolsUI, ncIdv, etc.)
 apply from: "$rootDir/gradle/root/fatJars.gradle"
 // Creates pubs for artifacts created in fatJars.gradle
diff --git a/cdm-test-utils/src/main/java/ucar/unidata/util/test/UtilsTestStructureArray.java b/cdm-test-utils/src/main/java/ucar/unidata/util/test/UtilsTestStructureArray.java
index 8d35a0f261..22525eb5cc 100644
--- a/cdm-test-utils/src/main/java/ucar/unidata/util/test/UtilsTestStructureArray.java
+++ b/cdm-test-utils/src/main/java/ucar/unidata/util/test/UtilsTestStructureArray.java
@@ -75,8 +75,8 @@ private void testArrayStructureByRecno(ArrayStructure as) {
       List<StructureMembers.Member> members = sdata.getMembers();
       for (StructureMembers.Member m : members) {
         Array sdataArray = sdata.getArray(m);
-        assert (sdataArray.getElementType() == m.getDataType().getPrimitiveClassType()) : sdataArray.getElementType()
-            + " != " + m.getDataType().getPrimitiveClassType();
+        assert (sdataArray.getElementType() == m.getDataType().getPrimitiveClassType())
+            : sdataArray.getElementType() + " != " + m.getDataType().getPrimitiveClassType();
 
         Array sdataArray2 = sdata.getArray(m.getName());
         UtilsMa2Test.testEquals(sdataArray, sdataArray2);
diff --git a/cdm-test/src/test/java/ucar/nc2/dataset/TestTransforms.java b/cdm-test/src/test/java/ucar/nc2/dataset/TestTransforms.java
index 598f1960b0..e83e1a2f10 100644
--- a/cdm-test/src/test/java/ucar/nc2/dataset/TestTransforms.java
+++ b/cdm-test/src/test/java/ucar/nc2/dataset/TestTransforms.java
@@ -309,8 +309,8 @@ private VerticalTransform test(NetcdfDataset ncd, String levName, String varName
     // should be compatible with vunit
     if (vunit != null) {
       String vertCoordUnit = vt.getUnitString();
-      assert vunit.isCompatible(vertCoordUnit) : vertCoordUnit + " not udunits compatible with "
-          + vunit.getUnitString();
+      assert vunit.isCompatible(vertCoordUnit)
+          : vertCoordUnit + " not udunits compatible with " + vunit.getUnitString();
     }
 
     return vt;
diff --git a/cdm-test/src/test/java/ucar/nc2/ncml/TestNcMLStrides.java b/cdm-test/src/test/java/ucar/nc2/ncml/TestNcMLStrides.java
index 01e63f77ab..1466ee0b6b 100644
--- a/cdm-test/src/test/java/ucar/nc2/ncml/TestNcMLStrides.java
+++ b/cdm-test/src/test/java/ucar/nc2/ncml/TestNcMLStrides.java
@@ -100,8 +100,8 @@ public void testStride(String stride) throws IOException, InvalidRangeException
     Index ci = correct.getIndex();
     Index di = data.getIndex();
     for (int i = 0; i < data.getSize(); i++)
-      assert (data.getInt(di.set(i)) == correct.getInt(ci.set(i))) : stride + " index " + i + " = "
-          + data.getInt(di.set(i)) + " != " + correct.getInt(ci.set(i));
+      assert (data.getInt(di.set(i)) == correct.getInt(ci.set(i)))
+          : stride + " index " + i + " = " + data.getInt(di.set(i)) + " != " + correct.getInt(ci.set(i));
   }
 
 }
diff --git a/cdm/core/src/main/java/ucar/ma2/ArrayStructureMA.java b/cdm/core/src/main/java/ucar/ma2/ArrayStructureMA.java
index 275e9d0939..e0c45c7ca0 100644
--- a/cdm/core/src/main/java/ucar/ma2/ArrayStructureMA.java
+++ b/cdm/core/src/main/java/ucar/ma2/ArrayStructureMA.java
@@ -228,9 +228,9 @@ public static ArrayStructureMA factoryMA(ArrayStructure from) throws IOException
       if (numRecords == -1) {
         numRecords = firstDimLen;
       } else {
-        assert numRecords == firstDimLen : String.format(
-            "Expected all structure members to have the same first" + "dimension length, but %d != %d.", numRecords,
-            firstDimLen);
+        assert numRecords == firstDimLen
+            : String.format("Expected all structure members to have the same first" + "dimension length, but %d != %d.",
+                numRecords, firstDimLen);
       }
 
       memberArrayMap.put(m.getName(), array);
diff --git a/cdm/core/src/main/java/ucar/nc2/ft/point/standard/plug/CFpointObs.java b/cdm/core/src/main/java/ucar/nc2/ft/point/standard/plug/CFpointObs.java
index 1ec8ec8793..e862da03fa 100644
--- a/cdm/core/src/main/java/ucar/nc2/ft/point/standard/plug/CFpointObs.java
+++ b/cdm/core/src/main/java/ucar/nc2/ft/point/standard/plug/CFpointObs.java
@@ -420,8 +420,8 @@ protected TableConfig getTimeSeriesProfileConfig(NetcdfDataset ds, EncodingInfo
             // zDim = z.getDimension(0);
           }
         } else { // 1d time
-          assert z.getRank() != 1
-              || !time.getDimension(0).equals(z.getDimension(0)) : "time and z dimensions must be different";
+          assert z.getRank() != 1 || !time.getDimension(0).equals(z.getDimension(0))
+              : "time and z dimensions must be different";
         }
 
         TableConfig profileTable = makeMultidimInner(ds, stationTable, info.childDim, info, errlog);
diff --git a/cdm/core/src/main/java/ucar/nc2/ft2/coverage/HorizCoordSys.java b/cdm/core/src/main/java/ucar/nc2/ft2/coverage/HorizCoordSys.java
index e8c15b86cb..efd3ee8b9e 100644
--- a/cdm/core/src/main/java/ucar/nc2/ft2/coverage/HorizCoordSys.java
+++ b/cdm/core/src/main/java/ucar/nc2/ft2/coverage/HorizCoordSys.java
@@ -756,8 +756,8 @@ private static int calcStride(int numTotal, int maxToInclude) {
     int stride = Math.max(1, (int) Math.ceil(numTotal / (double) maxToInclude));
     int numIncluded = (int) Math.ceil(numTotal / (double) stride);
 
-    assert numIncluded <= maxToInclude : String.format("We're set to include %d points, but we wanted a max of %d.",
-        numIncluded, maxToInclude);
+    assert numIncluded <= maxToInclude
+        : String.format("We're set to include %d points, but we wanted a max of %d.", numIncluded, maxToInclude);
     return stride;
   }
 
@@ -766,9 +766,9 @@ private static void assertNotExceedingMaxBoundaryPoints(int numBoundaryPoints, i
     // Widen to long to avoid possible overflow, because last two arguments will often be Integer.MAX_VALUE.
     long maxBoundaryPoints = 2 * (long) maxPointsInYEdge + 2 * (long) maxPointsInXEdge;
 
-    assert numBoundaryPoints <= maxBoundaryPoints : String.format(
-        "We should be returning a maximum of %d boundary points, but we're returning %d instead.", maxBoundaryPoints,
-        numBoundaryPoints);
+    assert numBoundaryPoints <= maxBoundaryPoints
+        : String.format("We should be returning a maximum of %d boundary points, but we're returning %d instead.",
+            maxBoundaryPoints, numBoundaryPoints);
   }
 
   /**
diff --git a/cdm/core/src/test/java/thredds/client/catalog/TestResolve.java b/cdm/core/src/test/java/thredds/client/catalog/TestResolve.java
index 1d97a4f856..f3a7201c38 100644
--- a/cdm/core/src/test/java/thredds/client/catalog/TestResolve.java
+++ b/cdm/core/src/test/java/thredds/client/catalog/TestResolve.java
@@ -28,8 +28,8 @@ public void testResolve() throws IOException {
     logger.debug("ACD service= {}", s);
 
     assert getAccessURL(cat, "nest11").equals("http://www.acd.ucar.edu/dods/testServer/flux/CO2.nc");
-    assert getAccessURL(cat, "nest12").equals(base + "netcdf/data/flux/NO2.nc") : getAccessURL(cat, "nest12") + " != "
-        + ClientCatalogUtil.makeFilepath() + "netcdf/data/flux/NO2.nc";
+    assert getAccessURL(cat, "nest12").equals(base + "netcdf/data/flux/NO2.nc")
+        : getAccessURL(cat, "nest12") + " != " + ClientCatalogUtil.makeFilepath() + "netcdf/data/flux/NO2.nc";
 
     assert getMetadataURL(cat, "nest1", "NETCDF").equals("any.xml");
     assert getMetadataURL(cat, "nest1", "ADN").equals("http://you/corrupt.xml");
diff --git a/cdm/gcdm/build.gradle b/cdm/gcdm/build.gradle
index 770f5a53c4..58a2aca191 100644
--- a/cdm/gcdm/build.gradle
+++ b/cdm/gcdm/build.gradle
@@ -82,6 +82,7 @@ task startDaemon(type: JavaExecFork) {
   stopAfter = test
   waitForPort = 16111
   waitForOutput = 'Server started, listening on 16111'
+  dependsOn testClasses
 }
 
 test.dependsOn(startDaemon)
diff --git a/docs/build.gradle b/docs/build.gradle
index ca17864f08..c3fd43dee1 100644
--- a/docs/build.gradle
+++ b/docs/build.gradle
@@ -189,7 +189,7 @@ tasks.withType(JavaCompile).configureEach {
   options.compilerArgs = ['-Xlint:deprecation']
 }
 
-apply plugin: 'com.diffplug.gradle.spotless'
+apply plugin: 'com.diffplug.spotless'
 spotless {
   java {
     // target java files in the test directory
diff --git a/gradle/any/coverage.gradle b/gradle/any/coverage.gradle
index 141cb5e034..91a0df2680 100644
--- a/gradle/any/coverage.gradle
+++ b/gradle/any/coverage.gradle
@@ -44,12 +44,6 @@ tasks.withType(JacocoReport).all {  // Will apply to ":<subproject>:jacocoTestRe
   group = 'Reports'
   dependsOn tasks.withType(Test)
 
-  reports {
-    xml.enabled = false
-    html.enabled = true
-    csv.enabled = false
-  }
-
   // By default, JacocoReport runs onlyIf ALL of the executionData exist. We want it to run if ANY exists.
   setOnlyIf {
     executionData.any {
diff --git a/gradle/any/dependencies.gradle b/gradle/any/dependencies.gradle
index f0e59f4817..4bd2093935 100644
--- a/gradle/any/dependencies.gradle
+++ b/gradle/any/dependencies.gradle
@@ -56,6 +56,6 @@ configurations.all {
     //    +--- org.apache.httpcomponents:httpclient:4.5.12
     //    |    ...
     //
-    substitute module('commons-logging:commons-logging') because 'we want to control JCL logging with slf4j' with module("org.slf4j:jcl-over-slf4j:${depVersion.slf4j}")
+    substitute module('commons-logging:commons-logging') because 'we want to control JCL logging with slf4j' using module("org.slf4j:jcl-over-slf4j:${depVersion.slf4j}")
   }
 }
diff --git a/gradle/any/java-library.gradle b/gradle/any/java-library.gradle
index c7c70f0ff9..8d231cdb3f 100644
--- a/gradle/any/java-library.gradle
+++ b/gradle/any/java-library.gradle
@@ -9,13 +9,13 @@ apply from: "$rootDir/gradle/any/spotless.gradle"
 apply plugin: 'maven-publish'
 
 def sourceJar = tasks.register('sourceJar', Jar) {
-  classifier 'sources'
+  setArchiveClassifier('sources')
   from sourceSets.main.allJava
 }
 
 def javadocJar = tasks.register('javadocJar', Jar) {
   dependsOn javadoc
-  classifier 'javadoc'
+  setArchiveClassifier('javadoc')
   from files(javadoc.destinationDir)
 }
 
diff --git a/gradle/any/shared-mvn-coords.gradle b/gradle/any/shared-mvn-coords.gradle
index 5a0282fb7d..eef9b96e82 100644
--- a/gradle/any/shared-mvn-coords.gradle
+++ b/gradle/any/shared-mvn-coords.gradle
@@ -7,9 +7,9 @@ ext {
 
   // plugin version management
   buildPlugins = [:]
-  buildPlugins.shadow = 'gradle.plugin.com.github.johnrengelman:shadow:7.1.2'
+  buildPlugins.shadow = 'com.gradleup.shadow:com.gradleup.shadow.gradle.plugin:8.3.5'
   buildPlugins.sonarqube = 'org.sonarsource.scanner.gradle:sonarqube-gradle-plugin:3.0'
-  buildPlugins.spotless = 'com.diffplug.spotless:spotless-plugin-gradle:4.5.1'
+  buildPlugins.spotless = 'com.diffplug.spotless:spotless-plugin-gradle:5.17.1'
   buildPlugins.protobuf = 'com.google.protobuf:protobuf-gradle-plugin:0.8.18'
   buildPlugins.depcheck = 'org.owasp:dependency-check-gradle:8.2.1'
 
diff --git a/gradle/any/spotless.gradle b/gradle/any/spotless.gradle
index d25cd7927f..9fa45e9c42 100644
--- a/gradle/any/spotless.gradle
+++ b/gradle/any/spotless.gradle
@@ -1,5 +1,5 @@
 apply plugin: 'java'
-apply plugin: 'com.diffplug.gradle.spotless'
+apply plugin: 'com.diffplug.spotless'
 
 spotless {
   java {
diff --git a/gradle/root/fatJars.gradle b/gradle/root/fatJars.gradle
index 4e4e5bb10a..bf36cd01da 100644
--- a/gradle/root/fatJars.gradle
+++ b/gradle/root/fatJars.gradle
@@ -20,7 +20,7 @@ if (!name.equals(rootProject.name)) {
 
 // need this to resolve dependencies defined through the netcdf-java-platform project
 apply from: "$rootDir/gradle/any/dependencies.gradle"
-apply plugin: 'com.github.johnrengelman.shadow'
+apply plugin: 'com.gradleup.shadow'
 
 // todo: this indicates we need have too much logic in our script plugin
 // This script plugin is a candidate for moving into buildSrc.
diff --git a/gradle/root/spotless.gradle b/gradle/root/spotless.gradle
index a03206319f..ffdedaaeaa 100644
--- a/gradle/root/spotless.gradle
+++ b/gradle/root/spotless.gradle
@@ -2,7 +2,7 @@ if (!name.equals(rootProject.name)) {
   throw new GradleException("This script plugin should only be applied to the root project, not '$name'.")
 }
 
-apply plugin: 'com.diffplug.gradle.spotless'
+apply plugin: 'com.diffplug.spotless'
 
 spotless {
   format 'misc', {
diff --git a/gradle/root/testing.gradle b/gradle/root/testing.gradle
index a60a11144c..b56b73cdf6 100644
--- a/gradle/root/testing.gradle
+++ b/gradle/root/testing.gradle
@@ -121,7 +121,7 @@ gradle.projectsEvaluated {
     description = 'Runs all subproject Test tasks'
     dependsOn subprojectTestTasks
     // If we run testAll, generate coverage report after all of the tests run
-    finalizedBy jacocoRootReport
+    //finalizedBy jacocoRootReport
   }
 
   task rootTestReport(type: TestReport, group: 'Reports') {
@@ -137,7 +137,7 @@ gradle.projectsEvaluated {
     //     ":grib:test" --finalizedBy--> ":rootTestReport" --dependsOn--> "all_subproject_Tests"
     // In other words, all subproject tests would get run, no matter what.
     // Passing File arguments to reportOn() instead doesn't create that dependency.
-    reportOn subprojectTestTasks*.binResultsDir
+    reportOn subprojectTestTasks*.binaryResultsDirectory
 
     // Wait until all Test tasks have run. This creates a task *ordering*, not a dependency.
     mustRunAfter subprojectTestTasks
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index e708b1c023..9bbc975c74 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 763217c50f..ed4c299adb 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.6.4-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.13-all.zip
+networkTimeout=10000
+validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
index 4f906e0c81..faf93008b7 100755
--- a/gradlew
+++ b/gradlew
@@ -1,7 +1,7 @@
-#!/usr/bin/env sh
+#!/bin/sh
 
 #
-# Copyright 2015 the original author or authors.
+# Copyright © 2015-2021 the original authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -15,69 +15,103 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 
 ##############################################################################
-##
-##  Gradle start up script for UN*X
-##
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
 ##############################################################################
 
 # Attempt to set APP_HOME
+
 # Resolve links: $0 may be a link
-PRG="$0"
-# Need this for relative symlinks.
-while [ -h "$PRG" ] ; do
-    ls=`ls -ld "$PRG"`
-    link=`expr "$ls" : '.*-> \(.*\)$'`
-    if expr "$link" : '/.*' > /dev/null; then
-        PRG="$link"
-    else
-        PRG=`dirname "$PRG"`"/$link"
-    fi
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
 done
-SAVED="`pwd`"
-cd "`dirname \"$PRG\"`/" >/dev/null
-APP_HOME="`pwd -P`"
-cd "$SAVED" >/dev/null
 
-APP_NAME="Gradle"
-APP_BASE_NAME=`basename "$0"`
-
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
-MAX_FD="maximum"
+MAX_FD=maximum
 
 warn () {
     echo "$*"
-}
+} >&2
 
 die () {
     echo
     echo "$*"
     echo
     exit 1
-}
+} >&2
 
 # OS specific support (must be 'true' or 'false').
 cygwin=false
 msys=false
 darwin=false
 nonstop=false
-case "`uname`" in
-  CYGWIN* )
-    cygwin=true
-    ;;
-  Darwin* )
-    darwin=true
-    ;;
-  MINGW* )
-    msys=true
-    ;;
-  NONSTOP* )
-    nonstop=true
-    ;;
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
 esac
 
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
@@ -87,9 +121,9 @@ CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 if [ -n "$JAVA_HOME" ] ; then
     if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
         # IBM's JDK on AIX uses strange locations for the executables
-        JAVACMD="$JAVA_HOME/jre/sh/java"
+        JAVACMD=$JAVA_HOME/jre/sh/java
     else
-        JAVACMD="$JAVA_HOME/bin/java"
+        JAVACMD=$JAVA_HOME/bin/java
     fi
     if [ ! -x "$JAVACMD" ] ; then
         die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
@@ -98,88 +132,120 @@ Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
     fi
 else
-    JAVACMD="java"
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
+    fi
 fi
 
 # Increase the maximum file descriptors if we can.
-if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
-    MAX_FD_LIMIT=`ulimit -H -n`
-    if [ $? -eq 0 ] ; then
-        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
-            MAX_FD="$MAX_FD_LIMIT"
-        fi
-        ulimit -n $MAX_FD
-        if [ $? -ne 0 ] ; then
-            warn "Could not set maximum file descriptor limit: $MAX_FD"
-        fi
-    else
-        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
-    fi
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
 fi
 
-# For Darwin, add options to specify how the application appears in the dock
-if $darwin; then
-    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
-fi
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
 
 # For Cygwin or MSYS, switch paths to Windows format before running java
-if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
-    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
-    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
-
-    JAVACMD=`cygpath --unix "$JAVACMD"`
-
-    # We build the pattern for arguments to be converted via cygpath
-    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
-    SEP=""
-    for dir in $ROOTDIRSRAW ; do
-        ROOTDIRS="$ROOTDIRS$SEP$dir"
-        SEP="|"
-    done
-    OURCYGPATTERN="(^($ROOTDIRS))"
-    # Add a user-defined pattern to the cygpath arguments
-    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
-        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
-    fi
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
     # Now convert the arguments - kludge to limit ourselves to /bin/sh
-    i=0
-    for arg in "$@" ; do
-        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
-        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
-
-        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
-            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
-        else
-            eval `echo args$i`="\"$arg\""
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
         fi
-        i=`expr $i + 1`
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
     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" ;;
-    esac
 fi
 
-# Escape application args
-save () {
-    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
-    echo " "
-}
-APP_ARGS=`save "$@"`
 
-# 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"
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
 
 exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
index 107acd32c4..9d21a21834 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -13,8 +13,10 @@
 @rem See the License for the specific language governing permissions and
 @rem limitations under the License.
 @rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
 
-@if "%DEBUG%" == "" @echo off
+@if "%DEBUG%"=="" @echo off
 @rem ##########################################################################
 @rem
 @rem  Gradle startup script for Windows
@@ -25,7 +27,8 @@
 if "%OS%"=="Windows_NT" setlocal
 
 set DIRNAME=%~dp0
-if "%DIRNAME%" == "" set DIRNAME=.
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
@@ -40,13 +43,13 @@ if defined JAVA_HOME goto findJavaFromJavaHome
 
 set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto execute
+if %ERRORLEVEL% equ 0 goto execute
 
-echo.
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 goto fail
 
@@ -56,11 +59,11 @@ set JAVA_EXE=%JAVA_HOME%/bin/java.exe
 
 if exist "%JAVA_EXE%" goto execute
 
-echo.
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 goto fail
 
@@ -75,13 +78,15 @@ set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
 :end
 @rem End local scope for the variables with windows NT shell
-if "%ERRORLEVEL%"=="0" goto mainEnd
+if %ERRORLEVEL% equ 0 goto mainEnd
 
 :fail
 rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
 rem the _cmd.exe /c_ return code!
-if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
-exit /b 1
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
 
 :mainEnd
 if "%OS%"=="Windows_NT" endlocal
diff --git a/netcdf4/build.gradle b/netcdf4/build.gradle
index 7f9578aed9..662c8f82a8 100644
--- a/netcdf4/build.gradle
+++ b/netcdf4/build.gradle
@@ -75,13 +75,6 @@ jacocoFullTestReport.configure {
       it.exists()
     }
   }
-
-  // just the html here, as it's only for devs and not something that gets submitted elsewhere
-  reports {
-    xml.enabled = false
-    html.destination file("${buildDir}/reports/allTests")
-    csv.enabled = false
-  }
 }
 
 check.configure {
diff --git a/netcdf4/src/main/java/ucar/nc2/jni/netcdf/Nc4Iosp.java b/netcdf4/src/main/java/ucar/nc2/jni/netcdf/Nc4Iosp.java
index 91d45f12e6..a6a5e6f8d1 100755
--- a/netcdf4/src/main/java/ucar/nc2/jni/netcdf/Nc4Iosp.java
+++ b/netcdf4/src/main/java/ucar/nc2/jni/netcdf/Nc4Iosp.java
@@ -331,9 +331,9 @@ private void makeDimensions(Group4 g4) throws IOException {
     if (ret != 0)
       throw new IOException(ret + ": " + nc4.nc_strerror(ret));
 
-    assert numDimsInGoup_p.getValue() == numDimidsInGroup_p.getValue() : String.format(
-        "Number of dimensions in group (%s) differed from number of dimension IDs in group (%s).",
-        numDimsInGoup_p.getValue(), numDimidsInGroup_p.getValue());
+    assert numDimsInGoup_p.getValue() == numDimidsInGroup_p.getValue()
+        : String.format("Number of dimensions in group (%s) differed from number of dimension IDs in group (%s).",
+            numDimsInGoup_p.getValue(), numDimidsInGroup_p.getValue());
 
     // We need this in order to allocate the correct length for unlimitedDimIdsInGroup.
     IntByReference numUnlimitedDimsInGroup_p = new IntByReference();
diff --git a/waterml/src/main/java/ucar/nc2/ogc/waterml/NcMeasureType.java b/waterml/src/main/java/ucar/nc2/ogc/waterml/NcMeasureType.java
index a3dadb81d3..f9f041e033 100644
--- a/waterml/src/main/java/ucar/nc2/ogc/waterml/NcMeasureType.java
+++ b/waterml/src/main/java/ucar/nc2/ogc/waterml/NcMeasureType.java
@@ -22,8 +22,8 @@ public static MeasureType initValue(MeasureType value, PointFeature pointFeat, V
         .format("%s appeared in the list of data variables but not in the StructureData.", dataVar.getShortName());
 
     Array dataArray = pointFeat.getDataAll().getArray(firstDataMember);
-    assert dataArray.getSize() == 1 : String.format("Expected array to be scalar, but its shape was %s.",
-        Arrays.toString(dataArray.getShape()));
+    assert dataArray.getSize() == 1
+        : String.format("Expected array to be scalar, but its shape was %s.", Arrays.toString(dataArray.getShape()));
 
     double dataVal = dataArray.getDouble(0);
     value.setDoubleValue(dataVal);