feat(java): add support licenses and graph for gradle lock files

docs/docs/configuration/reporting.md

@@ -63,6 +63,7 @@ The following languages are currently supported:
 | Go       | [go.mod][go-mod]                           |
 | PHP      | [composer.lock][composer-lock]             |
 | Java     | [pom.xml][pom-xml]                         |
+|          | [*gradle.lockfile][gradle-lockfile]        |
 | Dart     | [pubspec.lock][pubspec-lock]               |
 
 This tree is the reverse of the dependency graph.
@@ -445,5 +446,6 @@ $ trivy convert --format table --severity CRITICAL result.json
 [go-mod]: ../coverage/language/golang.md#go-modules
 [composer-lock]: ../coverage/language/php.md#composer
 [pom-xml]: ../coverage/language/java.md#pomxml
+[gradle-lockfile]: ../coverage/language/java.md#gradlelock
 [pubspec-lock]: ../coverage/language/dart.md#dart
 [cargo-binaries]: ../coverage/language/rust.md#binaries

docs/docs/coverage/language/java.md

@@ -3,19 +3,19 @@ Trivy supports three types of Java scanning: `JAR/WAR/PAR/EAR`, `pom.xml` and `*
 
 Each artifact supports the following scanners:
 
-| Artifact         | SBOM  | Vulnerability | License |
-| ---------------- | :---: | :-----------: | :-----: |
-| JAR/WAR/PAR/EAR  |   ✓   |       ✓       |    -    |
-| pom.xml          |   ✓   |       ✓       |    ✓    |
-| *gradle.lockfile |   ✓   |       ✓       |    -    |
+| Artifact         | SBOM | Vulnerability | License |
+|------------------|:----:|:-------------:|:-------:|
+| JAR/WAR/PAR/EAR  |  ✓   |       ✓       |    -    |
+| pom.xml          |  ✓   |       ✓       |    ✓    |
+| *gradle.lockfile |  ✓   |       ✓       |    ✓    |
 
 The following table provides an outline of the features Trivy offers.
 
 | Artifact         |    Internet access    | Dev dependencies | [Dependency graph][dependency-graph] | Position |
 |------------------|:---------------------:|:----------------:|:------------------------------------:|:--------:|
 | JAR/WAR/PAR/EAR  |     Trivy Java DB     |     Include      |                  -                   |    -     |
 | pom.xml          | Maven repository [^1] |     Exclude      |                  ✓                   |  ✓[^7]   |
-| *gradle.lockfile |           -           |     Exclude      |                  -                   |    ✓     |
+| *gradle.lockfile |           -           |     Exclude      |                  ✓                   |    ✓     |
 
 These may be enabled or disabled depending on the target.
 See [here](./index.md) for the detail.
@@ -64,18 +64,32 @@ If you need to show them, use the `--include-dev-deps` flag.
 
 
 ## Gradle.lock
-`gradle.lock` files contain all necessary information about used dependencies.
-Trivy simply parses the file, extract dependencies, and finds vulnerabilities for them.
-It doesn't require the internet access.
+`gradle.lock` files only contain information about used dependencies.
+
+!!!note
+    All necessary files are checked locally. Gradle file scanning doesn't require internet access.
+
+### Dependency-tree
+!!! warning "EXPERIMENTAL"
+    This feature might change without preserving backwards compatibility.
+Trivy finds child dependencies from `*.pom` files in the cache[^8] directory.
+
+But there is no reliable way to determine direct dependencies (even using other files).
+Therefore, we mark all dependencies as indirect to use logic to guess direct dependencies and build a dependency tree.
+
+### Licenses
+Trity also can detect licenses for dependencies.
+
+Make sure that you have cache[^8] directory to find licenses from `*.pom` dependency files.
 
-[^1]: https://github.com/aquasecurity/trivy-java-db
 [^1]: Uses maven repository to get information about dependencies. Internet access required.
 [^2]: It means `*.jar`, `*.war`, `*.par` and `*.ear` file
 [^3]: `ArtifactID`, `GroupID` and `Version`
 [^4]: e.g. when parent pom.xml file has `../pom.xml` path
 [^5]: When you use dependency path in `relativePath` field in pom.xml file
 [^6]: `/Users/<username>/.m2/repository` (for Linux and Mac) and `C:/Users/<username>/.m2/repository` (for Windows) by default
 [^7]: To avoid confusion, Trivy only finds locations for direct dependencies from the base pom.xml file.
+[^8]: The supported directories are `$GRADLE_USER_HOME/caches` and `$HOME/.gradle/caches` (`%HOMEPATH%\.gradle\caches` for Windows).
 
 [dependency-graph]: ../../configuration/reporting.md#show-origins-of-vulnerable-dependencies
 [maven-invoker-plugin]: https://maven.apache.org/plugins/maven-invoker-plugin/usage.html

pkg/dependency/parser/gradle/lockfile/parse.go

@@ -46,6 +46,10 @@ func (Parser) Parse(r xio.ReadSeekerAt) ([]types.Library, []types.Dependency, er
 					EndLine:   lineNum,
 				},
 			},
+			// There is no reliable way to determine direct dependencies (even using other files).
+			// Therefore, we mark all dependencies as Indirect.
+			// This is necessary to try to guess direct dependencies and build a dependency tree.
+			Indirect: true,
 		})
 
 	}

pkg/dependency/parser/gradle/lockfile/parse_test.go

@@ -21,9 +21,10 @@ func TestParser_Parse(t *testing.T) {
 			inputFile: "testdata/happy.lockfile",
 			want: []types.Library{
 				{
-					ID:      "cglib:cglib-nodep:2.1.2",
-					Name:    "cglib:cglib-nodep",
-					Version: "2.1.2",
+					ID:       "cglib:cglib-nodep:2.1.2",
+					Name:     "cglib:cglib-nodep",
+					Version:  "2.1.2",
+					Indirect: true,
 					Locations: []types.Location{
 						{
 							StartLine: 4,
@@ -32,9 +33,10 @@ func TestParser_Parse(t *testing.T) {
 					},
 				},
 				{
-					ID:      "org.springframework:spring-asm:3.1.3.RELEASE",
-					Name:    "org.springframework:spring-asm",
-					Version: "3.1.3.RELEASE",
+					ID:       "org.springframework:spring-asm:3.1.3.RELEASE",
+					Name:     "org.springframework:spring-asm",
+					Version:  "3.1.3.RELEASE",
+					Indirect: true,
 					Locations: []types.Location{
 						{
 							StartLine: 5,
@@ -43,9 +45,10 @@ func TestParser_Parse(t *testing.T) {
 					},
 				},
 				{
-					ID:      "org.springframework:spring-beans:5.0.5.RELEASE",
-					Name:    "org.springframework:spring-beans",
-					Version: "5.0.5.RELEASE",
+					ID:       "org.springframework:spring-beans:5.0.5.RELEASE",
+					Name:     "org.springframework:spring-beans",
+					Version:  "5.0.5.RELEASE",
+					Indirect: true,
 					Locations: []types.Location{
 						{
 							StartLine: 6,

pkg/fanal/analyzer/language/java/gradle/lockfile.go

@@ -2,36 +2,104 @@ package gradle
 
 import (
 	"context"
+	"fmt"
+	"io"
+	"io/fs"
 	"os"
+	"sort"
 	"strings"
 
+	"github.com/samber/lo"
 	"golang.org/x/xerrors"
 
 	"github.com/aquasecurity/trivy/pkg/dependency/parser/gradle/lockfile"
+	godeptypes "github.com/aquasecurity/trivy/pkg/dependency/types"
 	"github.com/aquasecurity/trivy/pkg/fanal/analyzer"
 	"github.com/aquasecurity/trivy/pkg/fanal/analyzer/language"
 	"github.com/aquasecurity/trivy/pkg/fanal/types"
+	"github.com/aquasecurity/trivy/pkg/log"
+	"github.com/aquasecurity/trivy/pkg/utils/fsutils"
 )
 
 func init() {
-	analyzer.RegisterAnalyzer(&gradleLockAnalyzer{})
+	analyzer.RegisterPostAnalyzer(analyzer.TypeGradleLock, newGradleLockAnalyzer)
 }
 
 const (
-	version        = 1
+	version        = 2
 	fileNameSuffix = "gradle.lockfile"
 )
 
 // gradleLockAnalyzer analyzes '*gradle.lockfile'
-type gradleLockAnalyzer struct{}
+type gradleLockAnalyzer struct {
+	parser godeptypes.Parser
+}
+
+func newGradleLockAnalyzer(_ analyzer.AnalyzerOptions) (analyzer.PostAnalyzer, error) {
+	return &gradleLockAnalyzer{
+		parser: lockfile.NewParser(),
+	}, nil
+}
 
-func (a gradleLockAnalyzer) Analyze(_ context.Context, input analyzer.AnalysisInput) (*analyzer.AnalysisResult, error) {
-	p := lockfile.NewParser()
-	res, err := language.Analyze(types.Gradle, input.FilePath, input.Content, p)
+func (a gradleLockAnalyzer) PostAnalyze(_ context.Context, input analyzer.PostAnalysisInput) (*analyzer.AnalysisResult, error) {
+	poms, err := parsePoms()
 	if err != nil {
-		return nil, xerrors.Errorf("%s parse error: %w", input.FilePath, err)
+		log.Logger.Warnf("Unable to get licenses and dependsOn: %s", err)
+	}
+
+	required := func(path string, d fs.DirEntry) bool {
+		return a.Required(path, nil)
 	}
-	return res, nil
+
+	var apps []types.Application
+	err = fsutils.WalkDir(input.FS, ".", required, func(filePath string, _ fs.DirEntry, r io.Reader) error {
+		var app *types.Application
+		app, err = language.Parse(types.Gradle, filePath, r, a.parser)
+		if err != nil {
+			return xerrors.Errorf("%s parse error: %w", filePath, err)
+		}
+
+		if app == nil {
+			return nil
+		}
+
+		libs := lo.SliceToMap(app.Libraries, func(lib types.Package) (string, struct{}) {
+			return lib.ID, struct{}{}
+		})
+
+		for i, lib := range app.Libraries {
+			pom := poms[lib.ID]
+
+			// Fill licenses from pom file
+			if len(pom.Licenses.License) > 0 {
+				app.Libraries[i].Licenses = lo.Map(pom.Licenses.License, func(license License, _ int) string {
+					return license.Name
+				})
+			}
+
+			// File child deps from pom file
+			var deps []string
+			for _, dep := range pom.Dependencies.Dependency {
+				id := packageID(dep.GroupID, dep.ArtifactID, dep.Version)
+				if _, ok := libs[id]; ok {
+					deps = append(deps, id)
+				}
+			}
+			sort.Strings(deps)
+			app.Libraries[i].DependsOn = deps
+		}
+
+		sort.Sort(app.Libraries)
+		apps = append(apps, *app)
+		return nil
+	})
+	if err != nil {
+		return nil, xerrors.Errorf("walk error: %w", err)
+	}
+
+	return &analyzer.AnalysisResult{
+		Applications: apps,
+	}, nil
 }
 
 func (a gradleLockAnalyzer) Required(filePath string, _ os.FileInfo) bool {
@@ -45,3 +113,7 @@ func (a gradleLockAnalyzer) Type() analyzer.Type {
 func (a gradleLockAnalyzer) Version() int {
 	return version
 }
+
+func packageID(groupId, artifactId, ver string) string {
+	return fmt.Sprintf("%s:%s:%s", groupId, artifactId, ver)
+}

pkg/fanal/analyzer/language/java/gradle/lockfile_test.go

@@ -1,6 +1,7 @@
 package gradle
 
 import (
+	"context"
 	"os"
 	"testing"
 
@@ -13,54 +14,112 @@ import (
 
 func Test_gradleLockAnalyzer_Analyze(t *testing.T) {
 	tests := []struct {
-		name      string
-		inputFile string
-		want      *analyzer.AnalysisResult
+		name     string
+		dir      string
+		cacheDir string
+		want     *analyzer.AnalysisResult
 	}{
 		{
-			name:      "happy path",
-			inputFile: "testdata/happy.lockfile",
+			name:     "happy path",
+			dir:      "testdata/lockfiles/happy",
+			cacheDir: "testdata/cache",
+			want: &analyzer.AnalysisResult{
+				Applications: []types.Application{
+					{
+						Type:     types.Gradle,
+						FilePath: "gradle.lockfile",
+						Libraries: types.Packages{
+							{
+								ID:       "junit:junit:4.13",
+								Name:     "junit:junit",
+								Version:  "4.13",
+								Indirect: true,
+								Locations: []types.Location{
+									{
+										StartLine: 4,
+										EndLine:   4,
+									},
+								},
+								Licenses: []string{
+									"Eclipse Public License 1.0",
+								},
+								DependsOn: []string{
+									"org.hamcrest:hamcrest-core:1.3",
+								},
+							},
+							{
+								ID:       "org.hamcrest:hamcrest-core:1.3",
+								Name:     "org.hamcrest:hamcrest-core",
+								Version:  "1.3",
+								Indirect: true,
+								Locations: []types.Location{
+									{
+										StartLine: 5,
+										EndLine:   5,
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "happy path without cache",
+			dir:  "testdata/lockfiles/happy",
 			want: &analyzer.AnalysisResult{
 				Applications: []types.Application{
 					{
 						Type:     types.Gradle,
-						FilePath: "testdata/happy.lockfile",
+						FilePath: "gradle.lockfile",
 						Libraries: types.Packages{
 							{
-								ID:      "com.example:example:0.0.1",
-								Name:    "com.example:example",
-								Version: "0.0.1",
+								ID:       "junit:junit:4.13",
+								Name:     "junit:junit",
+								Version:  "4.13",
+								Indirect: true,
 								Locations: []types.Location{
 									{
 										StartLine: 4,
 										EndLine:   4,
 									},
 								},
 							},
+							{
+								ID:       "org.hamcrest:hamcrest-core:1.3",
+								Name:     "org.hamcrest:hamcrest-core",
+								Version:  "1.3",
+								Indirect: true,
+								Locations: []types.Location{
+									{
+										StartLine: 5,
+										EndLine:   5,
+									},
+								},
+							},
 						},
 					},
 				},
 			},
 		},
 		{
-			name:      "empty file",
-			inputFile: "testdata/empty.lockfile",
+			name: "empty file",
+			dir:  "testdata/lockfiles/empty",
+			want: &analyzer.AnalysisResult{},
 		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			f, err := os.Open(tt.inputFile)
+			if tt.cacheDir != "" {
+				t.Setenv("GRADLE_USER_HOME", tt.cacheDir)
+			}
+
+			a, err := newGradleLockAnalyzer(analyzer.AnalyzerOptions{})
 			require.NoError(t, err)
-			defer func() {
-				err = f.Close()
-				assert.NoError(t, err)
-			}()
 
-			a := gradleLockAnalyzer{}
-			got, err := a.Analyze(nil, analyzer.AnalysisInput{
-				FilePath: tt.inputFile,
-				Content:  f,
+			got, err := a.PostAnalyze(context.Background(), analyzer.PostAnalysisInput{
+				FS: os.DirFS(tt.dir),
 			})
 
 			assert.NoError(t, err)