JabRef · halirutan · Nov 9, 2017 · Nov 9, 2017 · Nov 10, 2017 · lenhard
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -31,6 +31,7 @@ We refer to [GitHub issues](https://github.com/JabRef/jabref/issues) by using `#
 - Integrity check "Abbreviation Detection" detects abbreviated names for journals and booktitles based on the internal list instead of only looking for "." signs. Fixes [#3144](https://github.com/JabRef/jabref/issues/3144).
 - We added a dialog to show that JabRef is working on checking integrity. [#3358](https://github.com/JabRef/jabref/issues/3358)
 - We added an option to mass append to fields via the Quality -> set/clear/append/rename fields dialog. [#2721](https://github.com/JabRef/jabref/issues/2721)
+- We added a check on startup to ensure JabRef is run with an adequate Java version. [3310](https://github.com/JabRef/jabref/issues/3310)
 
 ### Fixed
  - We fixed the translation of \textendash in the entry preview [#3307](https://github.com/JabRef/jabref/issues/3307)

diff --git a/build.gradle b/build.gradle
@@ -38,6 +38,10 @@ sourceCompatibility = 1.8
 targetCompatibility = 1.8
 mainClassName = "org.jabref.JabRefMain"
 
+// These are the Java version requirements we will check on each start of JabRef
+ext.minRequiredJavaVersion = "1.8.0_144"
+ext.allowJava9 = false
+
 install4j {
     installDir = file(project.ext.install4jDir)
 }
@@ -160,7 +164,11 @@ processResources {
                 "year": String.valueOf(Calendar.getInstance().get(Calendar.YEAR)),
                 "authors": new File('AUTHORS').readLines().findAll { !it.startsWith("#") }.join(", "),
                 "developers": new File('DEVELOPERS').readLines().findAll { !it.startsWith("#") }.join(", "),
-                "azureInstrumentationKey": System.getenv('AzureInstrumentationKey'))
+                "azureInstrumentationKey": System.getenv('AzureInstrumentationKey'),
+                "minRequiredJavaVersion": minRequiredJavaVersion,
+                "allowJava9": allowJava9
+
+        )
         filteringCharset = 'UTF-8'
     }
 

diff --git a/src/main/java/org/jabref/JabRefMain.java b/src/main/java/org/jabref/JabRefMain.java
@@ -3,6 +3,8 @@
 import java.net.Authenticator;
 import java.util.Map;
 
+import javax.swing.JFrame;
+import javax.swing.JOptionPane;
 import javax.swing.SwingUtilities;
 
 import javafx.application.Application;
@@ -24,6 +26,8 @@
 import org.jabref.logic.protectedterms.ProtectedTermsLoader;
 import org.jabref.logic.remote.RemotePreferences;
 import org.jabref.logic.remote.client.RemoteListenerClient;
+import org.jabref.logic.util.BuildInfo;
+import org.jabref.logic.util.JavaVersion;
 import org.jabref.logic.util.OS;
 import org.jabref.migrations.PreferencesMigrations;
 import org.jabref.model.EntryTypes;
@@ -53,11 +57,52 @@ public void start(Stage mainStage) throws Exception {
         SwingUtilities.invokeLater(() -> start(arguments));
     }
 
+    /**
+     * Tests if we are running an acceptable Java and terminates JabRef when we are sure the version is not supported.
+     * This test uses the requirements for the Java version as specified in <code>gradle.build</code>. It is possible to
+     * define a minimum version including the built number and to indicate whether Java 9 can be use (which it currently
+     * can't). It tries to compare this version number to the version of the currently running JVM. The check is
+     * optimistic and will rather return true even if we could not exactly determine the version.
+     * <p>
+     * Note: Users with an very old version like 1.6 will not profit from this since class versions are incompatible and
+     * JabRef won't even start.
+     */
+    private static void ensureCorrectJavaVersion() {
+        // Check if we are running an acceptable version of Java
+        final BuildInfo buildInfo = Globals.BUILD_INFO;
+        JavaVersion checker = new JavaVersion();
+        final boolean java9Fail = !buildInfo.isAllowJava9() && checker.isJava9();
+        final boolean versionFail = !checker.isAtLeast(buildInfo.getMinRequiredJavaVersion());
+
+        if (java9Fail || versionFail) {
+            StringBuilder versionError = new StringBuilder(
+                    Localization.lang("Your current Java version (%0) is not supported. Please install version %1 or higher.",
+                            checker.getJavaVersion(),
+                            buildInfo.getMinRequiredJavaVersion()
+                    )
+            );
+            if (!buildInfo.isAllowJava9()) {
+                versionError.append("\n");
+                versionError.append(Localization.lang("Note that currently, JabRef does not run with Java 9."));
+            }
+            final JFrame frame = new JFrame();
+            JOptionPane.showMessageDialog(frame, versionError, Localization.lang("Error"), JOptionPane.ERROR_MESSAGE);
+            frame.dispose();
+
+            // We exit on Java 9 error since this will definitely not work
+            if (java9Fail) {
+                System.exit(0);
+            }
+        }
+    }
+
     private static void start(String[] args) {
         FallbackExceptionHandler.installExceptionHandler();
 
         JabRefPreferences preferences = JabRefPreferences.getInstance();
 
+        ensureCorrectJavaVersion();
+
         ProxyPreferences proxyPreferences = preferences.getProxyPreferences();
         ProxyRegisterer.register(proxyPreferences);
         if (proxyPreferences.isUseProxy() && proxyPreferences.isUseAuthentication()) {

diff --git a/src/main/java/org/jabref/logic/util/BuildInfo.java b/src/main/java/org/jabref/logic/util/BuildInfo.java
@@ -21,6 +21,8 @@ public class BuildInfo {
     private final String developers;
     private final String year;
     private final String azureInstrumentationKey;
+    private final String minRequiredJavaVersion;
+    private final boolean allowJava9;
 
 
     public BuildInfo() {
@@ -45,6 +47,8 @@ public BuildInfo(String path) {
         year = properties.getProperty("year", "");
         developers = properties.getProperty("developers", "");
         azureInstrumentationKey = properties.getProperty("azureInstrumentationKey", "");
+        minRequiredJavaVersion = properties.getProperty("minRequiredJavaVersion", "1.8");
+        allowJava9 = "true".equals(properties.getProperty("allowJava9", ""));
     }
 
     public Version getVersion() {
@@ -66,4 +70,12 @@ public String getYear() {
     public String getAzureInstrumentationKey() {
         return azureInstrumentationKey;
     }
+
+    public String getMinRequiredJavaVersion() {
+        return minRequiredJavaVersion;
+    }
+
+    public boolean isAllowJava9() {
+        return allowJava9;
+    }
 }
diff --git a/src/main/java/org/jabref/logic/util/JavaVersion.java b/src/main/java/org/jabref/logic/util/JavaVersion.java
@@ -0,0 +1,76 @@
+package org.jabref.logic.util;
+
+import java.util.Scanner;
+import java.util.regex.Pattern;
+
+/**
+ * Provides simple checks to ensure the correct version for JabRef is available. Currently, we need to make sure that we
+ * have Java 1.8 but not Java 9. The functions here are not intended for direct use. Instead, they are called inside
+ * {@link BuildInfo}, which has the required java version string (e.g. 1.8.0_144) available through the build system.
+ * The version check should always happen through the <code>Globals#BUILD_INFO</code> instance which is available at a
+ * very early stage in the JabRef startup.
+ */
+public class JavaVersion {
+
+    // See http://openjdk.java.net/jeps/223
+    private static final Pattern DELIMITER = Pattern.compile("[._\\-+]");
+    private final String JAVA_VERSION;
+
+    public JavaVersion() {
+        // Be adventurous and assume that we can always access this property!
+        JAVA_VERSION = System.getProperty("java.version");
+    }
+
+    public JavaVersion(final String version) {
+        JAVA_VERSION = version;
+    }
+
+    /**
+     * Tries to determine if we are running on Java 9. This test should return false, when we cannot extract the correct
+     * Java version. Note that Java 9 has a different version scheme like "9-internal".
+     *
+     * @return true if Java 9 is used
+     */
+    public boolean isJava9() {
+        if (JAVA_VERSION != null) {
+            // Since isAtLeast is very optimistic, we first need to check if we have a "number" in the version string
+            // at all. Otherwise we would get false-positives.
+            final Scanner scanner = new Scanner(JAVA_VERSION);
+            scanner.useDelimiter(DELIMITER);
+            if (scanner.hasNextInt()) {
+                return isAtLeast("1.9");
+            }
+        }
+        return false;
+    }
+
+    /**
+     * A very optimistic test for ensuring we at least have a minimal required Java version. It will not fail when we
+     * cannot determine the result. In essence, this method splits a version string using {@link
+     * JavaVersion#DELIMITER} and compares two version number by number.
+     *
+     * @param version Should be in the form X.X.X_XXX where X are integers.
+     * @return true if the numbers in version available for comparison are all greater-equals the currently running Java
+     * version.
+     */
+    public boolean isAtLeast(final String version) {
+        if (JAVA_VERSION == null || version == null) {
+            return true;
+        }
+        final Scanner scannerRunningVersion = new Scanner(JAVA_VERSION);
+        final Scanner scannerRequiredVersion = new Scanner(version);
+        scannerRunningVersion.useDelimiter(DELIMITER);
+        scannerRequiredVersion.useDelimiter(DELIMITER);
+        while (scannerRunningVersion.hasNextInt() && scannerRequiredVersion.hasNextInt()) {
+            final int running = scannerRunningVersion.nextInt();
+            final int required = scannerRequiredVersion.nextInt();
+            if (running == required) continue;
+            return running >= required;
+        }
+        return true;
+    }
+
+    public String getJavaVersion() {
+        return JAVA_VERSION;
+    }
+}
diff --git a/src/main/resources/build.properties b/src/main/resources/build.properties
@@ -3,3 +3,5 @@ year=${year}
 authors=${authors}
 developers=${developers}
 azureInstrumentationKey=${azureInstrumentationKey}
+minRequiredJavaVersion = ${minRequiredJavaVersion}
+allowJava9 = ${allowJava9}
diff --git a/src/main/resources/l10n/JabRef_da.properties b/src/main/resources/l10n/JabRef_da.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_de.properties b/src/main/resources/l10n/JabRef_de.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=Anzeigen_der_Kons
 Remove_line_breaks=Entfernen_der_Zeilenumbrüche
 Removes_all_line_breaks_in_the_field_content.=Entfernen_aller_Zeilenumbrüche_im_Inhalt_des_Feldes.
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=JabRef_kann_nicht_mit_Java_9_verwendet_werden.
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=Die_verwendete_Java_Installation_(%0)_wird_nicht_unterstützt._Bitte_installieren_Sie_Version_%1_oder_neuer.
diff --git a/src/main/resources/l10n/JabRef_el.properties b/src/main/resources/l10n/JabRef_el.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_en.properties b/src/main/resources/l10n/JabRef_en.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=Show_console_outp
 Remove_line_breaks=Remove_line_breaks
 Removes_all_line_breaks_in_the_field_content.=Removes_all_line_breaks_in_the_field_content.
 Checking_integrity...=Checking_integrity...
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=Note_that_currently,_JabRef_does_not_run_with_Java_9.
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.
diff --git a/src/main/resources/l10n/JabRef_es.properties b/src/main/resources/l10n/JabRef_es.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_fa.properties b/src/main/resources/l10n/JabRef_fa.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_fr.properties b/src/main/resources/l10n/JabRef_fr.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=Afficher_la_sorti
 Remove_line_breaks=Supprimer_les_sauts_de_ligne
 Removes_all_line_breaks_in_the_field_content.=Supprime_tous_les_sauts_de_ligne_du_contenu_d'un_champ
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_in.properties b/src/main/resources/l10n/JabRef_in.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_it.properties b/src/main/resources/l10n/JabRef_it.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_ja.properties b/src/main/resources/l10n/JabRef_ja.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_nl.properties b/src/main/resources/l10n/JabRef_nl.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_no.properties b/src/main/resources/l10n/JabRef_no.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_pt_BR.properties b/src/main/resources/l10n/JabRef_pt_BR.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_ru.properties b/src/main/resources/l10n/JabRef_ru.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_sv.properties b/src/main/resources/l10n/JabRef_sv.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_tr.properties b/src/main/resources/l10n/JabRef_tr.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=Consol_çıktıs
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_vi.properties b/src/main/resources/l10n/JabRef_vi.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=
diff --git a/src/main/resources/l10n/JabRef_zh.properties b/src/main/resources/l10n/JabRef_zh.properties
@@ -2350,3 +2350,6 @@ Show_console_output_(only_necessary_when_the_launcher_is_used)=
 Remove_line_breaks=
 Removes_all_line_breaks_in_the_field_content.=
 Checking_integrity...=
+
+Note_that_currently,_JabRef_does_not_run_with_Java_9.=
+Your_current_Java_version_(%0)_is_not_supported._Please_install_version_%1_or_higher.=