diff --git a/client/src/main/java/org/mvndaemon/mvnd/client/DaemonParameters.java b/client/src/main/java/org/mvndaemon/mvnd/client/DaemonParameters.java index 858975e5..e81335e7 100644 --- a/client/src/main/java/org/mvndaemon/mvnd/client/DaemonParameters.java +++ b/client/src/main/java/org/mvndaemon/mvnd/client/DaemonParameters.java @@ -139,7 +139,8 @@ public class DaemonParameters { .orLocalProperty(provider, globalPropertiesPath()) .orSystemProperty() .orEnvironmentVariable() - .or(new ValueSource(description -> description.append("java command"), this::javaHomeFromPath)) + .or(new ValueSource( + description -> description.append("java command"), DaemonParameters::javaHomeFromPath)) .orFail() .asPath(); try { @@ -149,8 +150,12 @@ public class DaemonParameters { } } - private String javaHomeFromPath() { - final String jHome = OsUtils.findJavaHomeFromPath(); + private static String javaHomeFromPath() { + LOG.warn( + "Falling back to finding JAVA_HOME by running java executable available in PATH." + + " You may want to avoid this time consumig task by setting JAVA_HOME environment variable" + + " or by passing java.home system property through command line or in one of mvnd configuration files."); + final String jHome = OsUtils.findJavaHomeFromJavaExecutable("java"); if (null != jHome) { System.setProperty(Environment.JAVA_HOME.getProperty(), jHome); } diff --git a/common/src/main/java/org/mvndaemon/mvnd/common/OsUtils.java b/common/src/main/java/org/mvndaemon/mvnd/common/OsUtils.java index eb0569db..45ae8826 100644 --- a/common/src/main/java/org/mvndaemon/mvnd/common/OsUtils.java +++ b/common/src/main/java/org/mvndaemon/mvnd/common/OsUtils.java @@ -111,16 +111,23 @@ public class OsUtils { } } - public static String findJavaHomeFromPath() { - String[] cmd = {"java", "-XshowSettings:properties", "-version"}; - final List output = new ArrayList(1); + /** + * Executes the given {@code javaExecutable} with {@code -XshowSettings:properties -version} parameters and extracts + * the value of {@code java.home} from the output. + * + * @param javaExecutable pass {@code "java"} to get {@code java} binary available in {@code PATH} environment + * variable or pass an absolute path to a {@code "java"} executable + * @return a {@code java.home} value or null + */ + public static String findJavaHomeFromJavaExecutable(String javaExecutable) { + String[] cmd = {javaExecutable, "-XshowSettings:properties", "-version"}; + final List output = new ArrayList(); exec(cmd, output); - List javaHomeLines = - output.stream().filter(l -> l.contains(" java.home = ")).collect(Collectors.toList()); - if (javaHomeLines.size() == 1) { - return javaHomeLines.get(0).trim().replaceFirst("java.home = ", ""); - } - return null; + return output.stream() + .filter(l -> l.contains(" java.home = ")) + .map(l -> l.substring(l.indexOf('=') + 1).trim()) + .findFirst() + .orElse(null); } private static void exec(String[] cmd, final List output) { diff --git a/common/src/test/java/org/mvndaemon/mvnd/common/OsUtilsTest.java b/common/src/test/java/org/mvndaemon/mvnd/common/OsUtilsTest.java index 41cb71bd..dd8eac32 100644 --- a/common/src/test/java/org/mvndaemon/mvnd/common/OsUtilsTest.java +++ b/common/src/test/java/org/mvndaemon/mvnd/common/OsUtilsTest.java @@ -31,4 +31,11 @@ public class OsUtilsTest { Assertions.assertEquals("1g", OsUtils.kbTohumanReadable(1024 * 1024)); Assertions.assertEquals("1t", OsUtils.kbTohumanReadable(1024 * 1024 * 1024)); } + + @Test + void findJavaHomeFromPath() { + final String expectedJavaHome = System.getProperty("java.home"); + Assertions.assertEquals( + expectedJavaHome, OsUtils.findJavaHomeFromJavaExecutable(expectedJavaHome + "/bin/java")); + } }