fix: use profile.d to append CLASSPATH instead of WriteEnvFile

src/java/frameworks/client_certificate_mapper.go

@@ -2,9 +2,10 @@ package frameworks
 
 import (
 	"fmt"
-	"github.com/cloudfoundry/java-buildpack/src/java/common"
 	"os"
 	"path/filepath"
+
+	"github.com/cloudfoundry/java-buildpack/src/java/common"
 )
 
 // ClientCertificateMapperFramework implements mTLS client certificate mapper support
@@ -69,17 +70,15 @@ func (c *ClientCertificateMapperFramework) Finalize() error {
 		return nil
 	}
 
-	// Add to classpath via CLASSPATH environment variable
-	classpath := os.Getenv("CLASSPATH")
-	if classpath != "" {
-		classpath += ":"
-	}
-	classpath += matches[0]
+	depsIdx := c.context.Stager.DepsIdx()
+	runtimePath := fmt.Sprintf("$DEPS_DIR/%s/client_certificate_mapper/%s", depsIdx, filepath.Base(matches[0]))
 
-	if err := c.context.Stager.WriteEnvFile("CLASSPATH", classpath); err != nil {
-		return fmt.Errorf("failed to set CLASSPATH for Client Certificate Mapper: %w", err)
+	profileScript := fmt.Sprintf("export CLASSPATH=\"%s:${CLASSPATH:-}\"\n", runtimePath)
+	if err := c.context.Stager.WriteProfileD("client_certificate_mapper.sh", profileScript); err != nil {
+		return fmt.Errorf("failed to write client_certificate_mapper.sh profile.d script: %w", err)
 	}
 
+	c.context.Log.Debug("Client Certificate Mapper JAR will be added to classpath at runtime: %s", runtimePath)
 	return nil
 }
 

src/java/frameworks/java_cf_env.go

@@ -1,12 +1,12 @@
 package frameworks
 
 import (
-	"github.com/cloudfoundry/java-buildpack/src/java/common"
 	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
 
+	"github.com/cloudfoundry/java-buildpack/src/java/common"
 	"github.com/cloudfoundry/libbuildpack"
 	"gopkg.in/yaml.v2"
 )
@@ -81,17 +81,15 @@ func (j *JavaCfEnvFramework) Finalize() error {
 		return nil
 	}
 
-	// Add to classpath via CLASSPATH environment variable
-	classpath := os.Getenv("CLASSPATH")
-	if classpath != "" {
-		classpath += ":"
-	}
-	classpath += matches[0]
+	depsIdx := j.context.Stager.DepsIdx()
+	runtimePath := fmt.Sprintf("$DEPS_DIR/%s/java_cf_env/%s", depsIdx, filepath.Base(matches[0]))
 
-	if err := j.context.Stager.WriteEnvFile("CLASSPATH", classpath); err != nil {
-		return fmt.Errorf("failed to set CLASSPATH for Java CF Env: %w", err)
+	profileScript := fmt.Sprintf("export CLASSPATH=\"%s:${CLASSPATH:-}\"\n", runtimePath)
+	if err := j.context.Stager.WriteProfileD("java_cf_env.sh", profileScript); err != nil {
+		return fmt.Errorf("failed to write java_cf_env.sh profile.d script: %w", err)
 	}
 
+	j.context.Log.Debug("Java CF Env JAR will be added to classpath at runtime: %s", runtimePath)
 	return nil
 }
 

src/java/frameworks/maria_db_jdbc.go

@@ -88,8 +88,11 @@ func (f *MariaDBJDBCFramework) Finalize() error {
 
 	f.context.Log.BeginStep("Configuring MariaDB JDBC driver")
 
-	// Add to CLASSPATH environment variable
-	if err := f.context.Stager.WriteEnvFile("CLASSPATH", f.jarPath); err != nil {
+	depsIdx := f.context.Stager.DepsIdx()
+	runtimePath := fmt.Sprintf("$DEPS_DIR/%s/mariadb_jdbc/%s", depsIdx, filepath.Base(f.jarPath))
+
+	profileScript := fmt.Sprintf("export CLASSPATH=\"%s:${CLASSPATH:-}\"\n", runtimePath)
+	if err := f.context.Stager.WriteProfileD("mariadb_jdbc.sh", profileScript); err != nil {
 		f.context.Log.Warning("Failed to add MariaDB JDBC to CLASSPATH: %s", err)
 		return nil // Non-blocking
 	}

src/java/frameworks/postgresql_jdbc.go

@@ -2,11 +2,10 @@ 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"
 )
 
@@ -73,17 +72,15 @@ func (p *PostgresqlJdbcFramework) Finalize() error {
 		return nil
 	}
 
-	// Add to classpath via CLASSPATH environment variable
-	classpath := os.Getenv("CLASSPATH")
-	if classpath != "" {
-		classpath += ":"
-	}
-	classpath += matches[0]
+	depsIdx := p.context.Stager.DepsIdx()
+	runtimePath := fmt.Sprintf("$DEPS_DIR/%s/postgresql_jdbc/%s", depsIdx, filepath.Base(matches[0]))
 
-	if err := p.context.Stager.WriteEnvFile("CLASSPATH", classpath); err != nil {
-		return fmt.Errorf("failed to set CLASSPATH for PostgreSQL JDBC: %w", err)
+	profileScript := fmt.Sprintf("export CLASSPATH=\"%s:${CLASSPATH:-}\"\n", runtimePath)
+	if err := p.context.Stager.WriteProfileD("postgresql_jdbc.sh", profileScript); err != nil {
+		return fmt.Errorf("failed to write postgresql_jdbc.sh profile.d script: %w", err)
 	}
 
+	p.context.Log.Debug("PostgreSQL JDBC JAR will be added to classpath at runtime: %s", runtimePath)
 	return nil
 }
 

src/java/frameworks/spring_auto_reconfiguration.go

@@ -101,17 +101,15 @@ func (s *SpringAutoReconfigurationFramework) Finalize() error {
 		return nil
 	}
 
-	// Add to classpath via CLASSPATH environment variable
-	classpath := os.Getenv("CLASSPATH")
-	if classpath != "" {
-		classpath += ":"
-	}
-	classpath += matches[0]
+	depsIdx := s.context.Stager.DepsIdx()
+	runtimePath := fmt.Sprintf("$DEPS_DIR/%s/spring_auto_reconfiguration/%s", depsIdx, filepath.Base(matches[0]))
 
-	if err := s.context.Stager.WriteEnvFile("CLASSPATH", classpath); err != nil {
-		return fmt.Errorf("failed to set CLASSPATH for Spring Auto-reconfiguration: %w", err)
+	profileScript := fmt.Sprintf("export CLASSPATH=\"%s:${CLASSPATH:-}\"\n", runtimePath)
+	if err := s.context.Stager.WriteProfileD("spring_auto_reconfiguration.sh", profileScript); err != nil {
+		return fmt.Errorf("failed to write spring_auto_reconfiguration.sh profile.d script: %w", err)
 	}
 
+	s.context.Log.Debug("Spring Auto-reconfiguration JAR will be added to classpath at runtime: %s", runtimePath)
 	return nil
 }