add support for spring boot 4, with a fallback to 3

Author: zakerf

src/java/frameworks/java_cf_env.go

@@ -2,11 +2,12 @@ package frameworks
 
 import (
 	"fmt"
-	"github.com/cloudfoundry/java-buildpack/src/java/common"
 	"os"
 	"path/filepath"
 	"strings"
 
+	"github.com/cloudfoundry/java-buildpack/src/java/common"
+
 	"github.com/cloudfoundry/libbuildpack"
 )
 
@@ -30,14 +31,14 @@ func (j *JavaCfEnvFramework) Detect() (string, error) {
 		return "", nil
 	}
 
-	// Check if Spring Boot 3.x is present
-	if !j.isSpringBoot3() {
+	// Check if Spring Boot 3.x/4.x is present
+	if !j.isSpringBootMajor(4) && !j.isSpringBootMajor(3) {
 		return "", nil
 	}
 
 	// Don't enable if java-cfenv is already in the application
 	if j.hasJavaCfEnv() {
-		j.context.Log.Debug("java-cfenv already present in application")
+		j.context.Log.Info("java-cfenv already present in application")
 		return "", nil
 	}
 
@@ -48,14 +49,27 @@ func (j *JavaCfEnvFramework) Detect() (string, error) {
 func (j *JavaCfEnvFramework) Supply() error {
 	j.context.Log.Debug("Installing Java CF Env")
 
-	// Get java-cfenv dependency from manifest
-	dep, err := j.context.Manifest.DefaultVersion("java-cfenv")
+	dependency := "java-cfenv"
+	defaultVersion := "4.0.0"
+	versionPattern := "4.x.x"
+
+	if j.isSpringBootMajor(3) {
+		defaultVersion = "3.5.1"
+		versionPattern = "3.x.x"
+	}
+
+	allVersions := j.context.Manifest.AllDependencyVersions(dependency)
+	resolvedVersion, err := libbuildpack.FindMatchingVersion(versionPattern, allVersions)
+
+	dep := libbuildpack.Dependency{Name: dependency, Version: resolvedVersion}
 	if err != nil {
-		j.context.Log.Warning("Unable to determine Java CF Env version, using default")
+		j.context.Log.Warning("Unable to determine Java CF Env version for pattern %s, using default", versionPattern)
 		dep = libbuildpack.Dependency{
-			Name:    "java-cfenv",
-			Version: "3.1.0", // Fallback version
+			Name:    dependency,
+			Version: defaultVersion,
 		}
+	} else {
+		j.context.Log.Debug("Resolved Java CF Env version pattern '%s' to %s", versionPattern, resolvedVersion)
 	}
 
 	// Install java-cfenv JAR
@@ -139,15 +153,14 @@ func (j *JavaCfEnvFramework) isEnabled() bool {
 	return true
 }
 
-// isSpringBoot3 checks if the application is Spring Boot 3.x
-func (j *JavaCfEnvFramework) isSpringBoot3() bool {
-	// Look for Spring Boot 3.x JARs
-	// Spring Boot 3.x uses spring-boot-3.*.jar
+// isSpringBootMajor checks if the application is Spring Boot <major>.x
+func (j *JavaCfEnvFramework) isSpringBootMajor(major int) bool {
+	jarGlob := fmt.Sprintf("spring-boot-%d.*.jar", major)
 	patterns := []string{
-		filepath.Join(j.context.Stager.BuildDir(), "**", "spring-boot-3.*.jar"),
-		filepath.Join(j.context.Stager.BuildDir(), "WEB-INF", "lib", "spring-boot-3.*.jar"),
-		filepath.Join(j.context.Stager.BuildDir(), "BOOT-INF", "lib", "spring-boot-3.*.jar"),
-		filepath.Join(j.context.Stager.BuildDir(), "lib", "spring-boot-3.*.jar"),
+		filepath.Join(j.context.Stager.BuildDir(), "**", jarGlob),
+		filepath.Join(j.context.Stager.BuildDir(), "WEB-INF", "lib", jarGlob),
+		filepath.Join(j.context.Stager.BuildDir(), "BOOT-INF", "lib", jarGlob),
+		filepath.Join(j.context.Stager.BuildDir(), "lib", jarGlob),
 	}
 
 	for _, pattern := range patterns {
@@ -161,7 +174,7 @@ func (j *JavaCfEnvFramework) isSpringBoot3() bool {
 	manifestPath := filepath.Join(j.context.Stager.BuildDir(), "META-INF", "MANIFEST.MF")
 	if content, err := os.ReadFile(manifestPath); err == nil {
 		manifest := string(content)
-		if strings.Contains(manifest, "Spring-Boot-Version: 3.") {
+		if strings.Contains(manifest, fmt.Sprintf("Spring-Boot-Version: %d.", major)) {
 			return true
 		}
 	}

src/java/supply/supply_test.go

@@ -1,12 +1,13 @@
 package supply_test
 
 import (
-	"github.com/cloudfoundry/java-buildpack/src/internal/mocks"
-	"github.com/golang/mock/gomock"
 	"os"
 	"path/filepath"
 	"time"
 
+	"github.com/cloudfoundry/java-buildpack/src/internal/mocks"
+	"github.com/golang/mock/gomock"
+
 	"github.com/cloudfoundry/java-buildpack/src/java/supply"
 	"github.com/cloudfoundry/libbuildpack"
 	. "github.com/onsi/ginkgo/v2"
@@ -177,7 +178,33 @@ dependencies: []
 			})
 		})
 
-		Context("When a Spring-boot application is present", func() {
+		Context("When a Spring-boot 4 application is present", func() {
+			BeforeEach(func() {
+				// Create a Spring Boot JAR with BOOT-INF
+				bootInfDir := filepath.Join(buildDir, "BOOT-INF")
+				Expect(os.MkdirAll(bootInfDir, 0755)).To(Succeed())
+				Expect(os.MkdirAll(filepath.Join(buildDir, "META-INF"), 0755)).To(Succeed())
+
+				// Create META-INF/MANIFEST.MF with corresponding content of a Spring Boot app
+				manifestFile := filepath.Join(buildDir, "META-INF", "MANIFEST.MF")
+				Expect(os.WriteFile(manifestFile, []byte("Spring-Boot-Version: 4.x.x"), 0644)).To(Succeed())
+
+				//Create install dir and mock for the java cf env spring boot related dependency
+				javaCfEnvInstallDir := filepath.Join(depsDir, depsIdx, "java_cf_env")
+				Expect(os.MkdirAll(filepath.Join(javaCfEnvInstallDir), 0755)).To(Succeed())
+
+				depJavaCfEnv := libbuildpack.Dependency{Name: "java-cfenv", Version: "4.999.0"}
+				mockManifest.EXPECT().DefaultVersion("java-cfenv").Return(depJavaCfEnv, nil)
+				mockManifest.EXPECT().AllDependencyVersions("java-cfenv").Return([]string{"4.999.0", "3.999.0"})
+				mockInstaller.EXPECT().InstallDependency(depJavaCfEnv, javaCfEnvInstallDir).Return(nil)
+			})
+
+			It("Supply passes successfully", func() {
+				Expect(supply.Run(supplier)).To(Succeed())
+			})
+		})
+
+		Context("When a Spring-boot 3 application is present", func() {
 			BeforeEach(func() {
 				// Create a Spring Boot JAR with BOOT-INF
 				bootInfDir := filepath.Join(buildDir, "BOOT-INF")
@@ -192,8 +219,9 @@ dependencies: []
 				javaCfEnvInstallDir := filepath.Join(depsDir, depsIdx, "java_cf_env")
 				Expect(os.MkdirAll(filepath.Join(javaCfEnvInstallDir), 0755)).To(Succeed())
 
-				depJavaCfEnv := libbuildpack.Dependency{Name: "java-cfenv", Version: "3.5.0"}
-				mockManifest.EXPECT().DefaultVersion("java-cfenv").Return(depJavaCfEnv, nil).Times(2)
+				depJavaCfEnv := libbuildpack.Dependency{Name: "java-cfenv", Version: "3.999.0"}
+				mockManifest.EXPECT().DefaultVersion("java-cfenv").Return(depJavaCfEnv, nil)
+				mockManifest.EXPECT().AllDependencyVersions("java-cfenv").Return([]string{"4.999.0", "3.999.0"})
 				mockInstaller.EXPECT().InstallDependency(depJavaCfEnv, javaCfEnvInstallDir).Return(nil)
 			})