hardcode required checksum and add comments

Author: joshua2519

gradlew

@@ -201,7 +201,7 @@ fi
 
 
 # Loop in case we encounter an error.
-REQUIRED_WRAPPER_JAR_CHECKSUM=$(curl -sSL "https://services.gradle.org/distributions/gradle-9.1.0-wrapper.jar.sha256")
+REQUIRED_WRAPPER_JAR_CHECKSUM="76805e32c009c0cf0dd5d206bddc9fb22ea42e84db904b764f3047de095493f3"
 for attempt in 1 2 3; do
   if [ ! -e "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" ]; then
     if ! curl -s -S --retry 3 -L -o "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" "https://raw.githubusercontent.com/gradle/gradle/v9.1.0/gradle/wrapper/gradle-wrapper.jar"; then
@@ -211,7 +211,8 @@ for attempt in 1 2 3; do
       continue
     fi
   else
-    # Verify checksum of existing wrapper JAR.
+    # Verify checksum of existing wrapper JAR. 
+    # This prevents developers from running into incompatibility issues when using an outdated wrapper JAR after a Gradle upgrade.
     # Use sha256sum or shasum, whichever is available.
     if command -v sha256sum >/dev/null 2>&1; then
       LOCAL_WRAPPER_JAR_CHECKSUM=$(sha256sum "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" | awk '{print $1}')

wrapper.gradle

@@ -42,11 +42,12 @@ task bootstrapWrapper() {
         // fetch the jar.
         def wrapperBaseUrl = "https://raw.githubusercontent.com/gradle/gradle/v$versions.gradle/gradle/wrapper"
         def wrapperJarUrl = wrapperBaseUrl + "/gradle-wrapper.jar"
-        def wrapperJarChecksumUrl = "https://services.gradle.org/distributions/gradle-$versions.gradle-wrapper.jar.sha256"
+        // IMPORTANT: This checksum **must** be updated whenever the Gradle version changes.
+        String wrapperChecksum = "76805e32c009c0cf0dd5d206bddc9fb22ea42e84db904b764f3047de095493f3"
 
         def bootstrapString = """
       # Loop in case we encounter an error.
-      REQUIRED_WRAPPER_JAR_CHECKSUM=\$(curl -sSL "$wrapperJarChecksumUrl")
+      REQUIRED_WRAPPER_JAR_CHECKSUM="$wrapperChecksum"
       for attempt in 1 2 3; do
         if [ ! -e "$wrapperJarPath" ]; then
           if ! curl -s -S --retry 3 -L -o "$wrapperJarPath" "$wrapperJarUrl"; then
@@ -56,7 +57,8 @@ task bootstrapWrapper() {
             continue
           fi
         else
-          # Verify checksum of existing wrapper JAR.
+          # Verify checksum of existing wrapper JAR. 
+          # This prevents developers from running into incompatibility issues when using an outdated wrapper JAR after a Gradle upgrade.
           # Use sha256sum or shasum, whichever is available.
           if command -v sha256sum >/dev/null 2>&1; then
             LOCAL_WRAPPER_JAR_CHECKSUM=\$(sha256sum "$wrapperJarPath" | awk '{print \$1}')