[WIP] Add Maven integration tests for Toolchain class

rockcraft-maven/src/it/toolchain-jdk11-test/foo/Foo.java

@@ -0,0 +1,7 @@
+package foo;
+
+public class Foo {
+    public static void main(String[] args) {
+        System.out.println("Hello from JDK 11!");
+    }
+}

rockcraft-maven/src/it/toolchain-jdk11-test/invoker.properties

@@ -0,0 +1 @@
+invoker.goals=--no-transfer-progress install -X

rockcraft-maven/src/it/toolchain-jdk11-test/pom.xml

@@ -0,0 +1,47 @@
+<project>
+    <groupId>foo</groupId>
+    <artifactId>toolchain-jdk11-test</artifactId>
+    <version>1</version>
+    <modelVersion>4.0.0</modelVersion>
+    <properties>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
+    </properties>
+    <build>
+        <directory>${project.basedir}/target</directory>
+        <outputDirectory>${project.basedir}/target/classes</outputDirectory>
+        <testOutputDirectory>${project.basedir}/target/test-classes</testOutputDirectory>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-toolchains-plugin</artifactId>
+                <version>3.2.0</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>toolchain</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <toolchains>
+                        <jdk>
+                            <version>11</version>
+                        </jdk>
+                    </toolchains>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>io.github.rockcrafters</groupId>
+                <artifactId>rockcraft-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>create-rock</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+</project>

rockcraft-maven/src/it/toolchain-jdk11-test/prebuild.bsh

@@ -0,0 +1,21 @@
+import java.io.*;
+
+// Copy the toolchains.xml file to ~/.m2/ for this test
+File toolchainsSource = new File(basedir, "toolchains.xml");
+File toolchainsTarget = new File(System.getProperty("user.home") + "/.m2/toolchains.xml");
+
+// Ensure the directory exists
+toolchainsTarget.getParentFile().mkdirs();
+
+// Copy the file using streams
+FileInputStream fis = new FileInputStream(toolchainsSource);
+FileOutputStream fos = new FileOutputStream(toolchainsTarget);
+byte[] buffer = new byte[1024];
+int length;
+while ((length = fis.read(buffer)) > 0) {
+    fos.write(buffer, 0, length);
+}
+fis.close();
+fos.close();
+
+System.out.println("Copied toolchains.xml to " + toolchainsTarget);

rockcraft-maven/src/it/toolchain-jdk11-test/toolchains.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF8"?>
+<toolchains>
+    <toolchain>
+        <type>jdk</type>
+        <provides>
+            <version>11</version>
+            <vendor>temurin</vendor>
+        </provides>
+        <configuration>
+            <jdkHome>/usr/lib/jvm/temurin-11-jdk-amd64</jdkHome>
+        </configuration>
+    </toolchain>
+</toolchains>

rockcraft-maven/src/it/toolchain-jdk11-test/verify.bsh

@@ -0,0 +1,33 @@
+import java.io.*;
+
+// Check that the rockcraft.yaml file was created
+File target = new File(basedir, "target");
+
+File[] files = target.listFiles(new FilenameFilter(){
+    public boolean accept(File dir, String name) {
+        return name.equals("rockcraft.yaml");
+    }
+});
+
+if (files == null || files.length == 0) {
+    throw new FileNotFoundException("Could not find generated rockcraft.yaml file in " + target);
+}
+
+// Read the file and check for openjdk-11-jdk
+File rockcraftYaml = files[0];
+BufferedReader reader = new BufferedReader(new FileReader(rockcraftYaml));
+String line;
+boolean foundJdk11 = false;
+while ((line = reader.readLine()) != null) {
+    if (line.contains("openjdk-11-jdk")) {
+        foundJdk11 = true;
+        break;
+    }
+}
+reader.close();
+
+if (!foundJdk11) {
+    throw new RuntimeException("Expected to find openjdk-11-jdk in rockcraft.yaml, but it was not found.");
+}
+
+System.out.println("SUCCESS: Toolchain correctly detected JDK 11 and set build-packages to openjdk-11-jdk");

rockcraft-maven/src/it/toolchain-jdk17-test/foo/Foo.java

@@ -0,0 +1,7 @@
+package foo;
+
+public class Foo {
+    public static void main(String[] args) {
+        System.out.println("Hello from JDK 17!");
+    }
+}

rockcraft-maven/src/it/toolchain-jdk17-test/invoker.properties

@@ -0,0 +1 @@
+invoker.goals=--no-transfer-progress install -X

rockcraft-maven/src/it/toolchain-jdk17-test/pom.xml

@@ -0,0 +1,47 @@
+<project>
+    <groupId>foo</groupId>
+    <artifactId>toolchain-jdk17-test</artifactId>
+    <version>1</version>
+    <modelVersion>4.0.0</modelVersion>
+    <properties>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+    </properties>
+    <build>
+        <directory>${project.basedir}/target</directory>
+        <outputDirectory>${project.basedir}/target/classes</outputDirectory>
+        <testOutputDirectory>${project.basedir}/target/test-classes</testOutputDirectory>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-toolchains-plugin</artifactId>
+                <version>3.2.0</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>toolchain</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <toolchains>
+                        <jdk>
+                            <version>17</version>
+                        </jdk>
+                    </toolchains>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>io.github.rockcrafters</groupId>
+                <artifactId>rockcraft-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>create-rock</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+</project>

rockcraft-maven/src/it/toolchain-jdk17-test/prebuild.bsh

@@ -0,0 +1,21 @@
+import java.io.*;
+
+// Copy the toolchains.xml file to ~/.m2/ for this test
+File toolchainsSource = new File(basedir, "toolchains.xml");
+File toolchainsTarget = new File(System.getProperty("user.home") + "/.m2/toolchains.xml");
+
+// Ensure the directory exists
+toolchainsTarget.getParentFile().mkdirs();
+
+// Copy the file using streams
+FileInputStream fis = new FileInputStream(toolchainsSource);
+FileOutputStream fos = new FileOutputStream(toolchainsTarget);
+byte[] buffer = new byte[1024];
+int length;
+while ((length = fis.read(buffer)) > 0) {
+    fos.write(buffer, 0, length);
+}
+fis.close();
+fos.close();
+
+System.out.println("Copied toolchains.xml to " + toolchainsTarget);

rockcraft-maven/src/it/toolchain-jdk17-test/toolchains.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF8"?>
+<toolchains>
+    <toolchain>
+        <type>jdk</type>
+        <provides>
+            <version>17</version>
+            <vendor>temurin</vendor>
+        </provides>
+        <configuration>
+            <jdkHome>/usr/lib/jvm/temurin-17-jdk-amd64</jdkHome>
+        </configuration>
+    </toolchain>
+</toolchains>

rockcraft-maven/src/it/toolchain-jdk17-test/verify.bsh

@@ -0,0 +1,33 @@
+import java.io.*;
+
+// Check that the rockcraft.yaml file was created
+File target = new File(basedir, "target");
+
+File[] files = target.listFiles(new FilenameFilter(){
+    public boolean accept(File dir, String name) {
+        return name.equals("rockcraft.yaml");
+    }
+});
+
+if (files == null || files.length == 0) {
+    throw new FileNotFoundException("Could not find generated rockcraft.yaml file in " + target);
+}
+
+// Read the file and check for openjdk-17-jdk
+File rockcraftYaml = files[0];
+BufferedReader reader = new BufferedReader(new FileReader(rockcraftYaml));
+String line;
+boolean foundJdk17 = false;
+while ((line = reader.readLine()) != null) {
+    if (line.contains("openjdk-17-jdk")) {
+        foundJdk17 = true;
+        break;
+    }
+}
+reader.close();
+
+if (!foundJdk17) {
+    throw new RuntimeException("Expected to find openjdk-17-jdk in rockcraft.yaml, but it was not found.");
+}
+
+System.out.println("SUCCESS: Toolchain correctly detected JDK 17 and set build-packages to openjdk-17-jdk");

rockcraft-maven/src/main/java/com/canonical/rockcraft/maven/Toolchain.java

@@ -10,6 +10,9 @@
 import java.io.InputStreamReader;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.HashSet;
 import java.util.Arrays;
 
@@ -21,6 +24,39 @@ public final class Toolchain {
     private Toolchain() {
     }
 
+    private static String getToolchainJavacPath(ToolchainManager toolchainManager, MavenSession session) {
+        if (toolchainManager == null) {
+            return null;
+        }
+        org.apache.maven.toolchain.Toolchain jdkToolchain = toolchainManager.getToolchainFromBuildContext("jdk", session);
+        if (jdkToolchain == null) {
+            return null;
+        }
+        return jdkToolchain.findTool("javac");
+    }
+
+    private static String getJavacPath(ToolchainManager toolchainManager, MavenSession session, Log log) {
+        String where = getToolchainJavacPath(toolchainManager, session);
+        if (where != null) {
+            return where;
+        }
+        String javaHome = System.getProperty("java.home");
+        if (javaHome == null || javaHome.isEmpty()) {
+            log.warn("java-rockcraft-plugin: please configure Maven toolchain or provide a valid Java Home.");
+            return null;
+        }
+        Path java9Path = Paths.get(javaHome, "bin", "javac");
+        Path java8Path = Paths.get(Paths.get(javaHome).getParent().toString(), "bin", "javac");
+
+        if (Files.isExecutable(java9Path)) {
+            return java9Path.toString();
+        } else if (Files.isExecutable(java8Path)) {
+            return java8Path.toString();
+        }
+        log.warn("java-rockcraft-plugin: please configure Maven toolchain or provide a valid Java Home: "+ javaHome);
+        return null;
+    }
+
     /**
      * Gets the toolchain settings for the project
      *
@@ -31,31 +67,21 @@ private Toolchain() {
      */
     public static String getToolchainPackage(MavenSession session, ToolchainManager toolchainManager, Log log) {
         try {
-            if (toolchainManager == null) {
-                log.warn("java-rockcraft-plugin: Maven Toolchain manager is not present.");
-                return ToolchainHelper.DEFAULT_JDK;
-            }
-            System.err.println("---- has toolchain manager --- ");
-            org.apache.maven.toolchain.Toolchain jdkToolchain = toolchainManager.getToolchainFromBuildContext("jdk", session);
-            if (jdkToolchain == null) {
-                log.warn("java-rockcraft-plugin: Maven Toolchain is not configured. Please configure toolchain or use buildPackage configuration");
-                return ToolchainHelper.DEFAULT_JDK;
-            }
-            String tool = jdkToolchain.findTool("javac");
+            String tool = getJavacPath(toolchainManager, session, log);
             if (tool == null) {
-                log.warn("java-rockcraft-plugin: Maven Toolchain - javac tool is not found.");
                 return ToolchainHelper.DEFAULT_JDK;
             }
+
             ToolchainHelper.ToolchainPackage p = ToolchainHelper.getBuildPackage(tool);
             switch (p.getReason()) {
                 case JAVAC_ERROR:
-                    log.warn("java-rockcraft-plugin: Maven Toolchain - javac error {}, please set buildPackage configuration option: {}", tool, p.getRawOutput());
+                    log.warn("java-rockcraft-plugin: Maven Toolchain - javac error " + tool + ", please set buildPackage configuration option: " + p.getRawOutput());
                     break;
                 case JAVAC_VERSION_STRING:
-                    log.warn("java-rockcraft-plugin: Maven Toolchain - unable to parse javac version string, please set buildPackage configuration option: {}", p.getRawOutput());
+                    log.warn("java-rockcraft-plugin: Maven Toolchain - unable to parse javac version string, please set buildPackage configuration option: " + p.getRawOutput());
                     break;
                 case JAVAC_UNSUPPORTED_VERSION_STRING:
-                    log.warn("java-rockcraft-plugin: Maven Toolchain - unsupported version string, please set buildPackage configuration option. {}", p.getRawOutput());
+                    log.warn("java-rockcraft-plugin: Maven Toolchain - unsupported version string, please set buildPackage configuration option. " + p.getRawOutput());
                     break;
             }
             return p.getName();