Java 8 is minimum.

xstream/src/java/com/thoughtworks/xstream/converters/extended/ISO8601GregorianCalendarConverter.java

@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2005 Joe Walnes.
- * Copyright (C) 2006, 2007, 2011, 2013, 2014, 2015, 2016, 2017, 2018 XStream Committers.
+ * Copyright (C) 2006, 2007, 2011, 2013, 2014, 2015, 2016, 2017, 2018, 2021 XStream Committers.
  * All rights reserved.
  *
  * The software in this package is published under the terms of the BSD
@@ -11,12 +11,11 @@
  */
 package com.thoughtworks.xstream.converters.extended;
 
-import java.lang.reflect.InvocationTargetException;
 import java.util.GregorianCalendar;
 
 import com.thoughtworks.xstream.converters.SingleValueConverter;
 import com.thoughtworks.xstream.converters.basic.AbstractSingleValueConverter;
-import com.thoughtworks.xstream.core.JVM;
+import com.thoughtworks.xstream.core.util.ISO8601JavaTimeConverter;
 
 
 /**
@@ -35,22 +34,7 @@ public class ISO8601GregorianCalendarConverter extends AbstractSingleValueConver
     private final SingleValueConverter converter;
 
     public ISO8601GregorianCalendarConverter() {
-        SingleValueConverter svConverter = null;
-        final Class<? extends SingleValueConverter> type = JVM.<SingleValueConverter>loadClassForName(JVM.isVersion(8)
-            ? "com.thoughtworks.xstream.core.util.ISO8601JavaTimeConverter"
-            : "com.thoughtworks.xstream.core.util.ISO8601JodaTimeConverter");
-        try {
-            svConverter = type.getDeclaredConstructor().newInstance();
-        } catch (final
-                InstantiationException
-                | IllegalAccessException
-                | IllegalArgumentException
-                | InvocationTargetException
-                | NoSuchMethodException
-                | SecurityException e) {
-            // ignore
-        }
-        converter = svConverter;
+        converter = new ISO8601JavaTimeConverter();
     }
 
     @Override

xstream/src/java/com/thoughtworks/xstream/core/JVM.java

@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2004, 2005, 2006 Joe Walnes.
- * Copyright (C) 2006, 2007, 2008, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 XStream Committers.
+ * Copyright (C) 2006, 2007, 2008, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 XStream Committers.
  * All rights reserved.
  *
  * The software in this package is published under the terms of the BSD
@@ -55,7 +55,7 @@ public class JVM implements Caching {
 
     private static final String vendor = System.getProperty("java.vm.vendor");
     private static final float majorJavaVersion = getMajorJavaVersion();
-    private static final float DEFAULT_JAVA_VERSION = 1.7f;
+    private static final float DEFAULT_JAVA_VERSION = 1.8f;
     private static final boolean reverseFieldOrder = false;
     private static final Class<? extends ReflectionProvider> reflectionProviderType;
     @Deprecated
@@ -207,31 +207,31 @@ public JVM() {
      */
     private static final float getMajorJavaVersion() {
         try {
-            return isAndroid() ? 1.7f : Float.parseFloat(System.getProperty("java.specification.version"));
+            return isAndroid() ? 8f : Float.parseFloat(System.getProperty("java.specification.version"));
         } catch (final NumberFormatException e) {
             // Some JVMs may not conform to the x.y.z java.version format
             return DEFAULT_JAVA_VERSION;
         }
     }
 
     /**
-     * @deprecated As of 1.4.4, minimal JDK version is 1.4 already
+     * @deprecated As of 1.4.4, minimal JDK version is 1.8 already
      */
     @Deprecated
     public static boolean is14() {
         return isVersion(4);
     }
 
     /**
-     * @deprecated As of 1.4.4, minimal JDK version will be 1.7 for next major release
+     * @deprecated As of 1.4.4, minimal JDK version is 1.8 already
      */
     @Deprecated
     public static boolean is15() {
         return isVersion(5);
     }
 
     /**
-     * @deprecated As of 1.4.4, minimal JDK version will be 1.7 for next major release
+     * @deprecated As of 1.4.4, minimal JDK version is 1.8 already
      */
     @Deprecated
     public static boolean is16() {
@@ -240,7 +240,7 @@ public static boolean is16() {
 
     /**
      * @since 1.4
-     * @deprecated As of 1.4.10, minimal JDK version will be 1.7 for next major release
+     * @deprecated As of 1.4.10, minimal JDK version is 1.8 already
      */
     @Deprecated
     public static boolean is17() {
@@ -333,8 +333,8 @@ public <T> Class<? extends T> loadClass(final String name) {
     public static <T> Class<? extends T> loadClassForName(final String name, final boolean initialize) {
         try {
             @SuppressWarnings("unchecked")
-            final Class<? extends T> clazz = (Class<? extends T>)Class
-                .forName(name, initialize, JVM.class.getClassLoader());
+            final Class<? extends T> clazz = (Class<? extends T>)Class.forName(name, initialize, JVM.class
+                .getClassLoader());
             return clazz;
         } catch (final LinkageError | ClassNotFoundException e) {
             return null;
@@ -623,7 +623,7 @@ public static void main(final String... args) {
         System.out.println("Can parse UTC date format: " + canParseUTCDateFormat());
         System.out.println("Can create derive ObjectOutputStream: " + canCreateDerivedObjectOutputStream());
         System.out.println("Reverse field order detected for JDK: " + reverseJDK);
-        System.out
-            .println("Reverse field order detected (only if JVM class itself has been compiled): " + reverseLocal);
+        System.out.println("Reverse field order detected (only if JVM class itself has been compiled): "
+            + reverseLocal);
     }
 }

xstream/src/java/com/thoughtworks/xstream/core/util/ISO8601JodaTimeConverter.java

@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2005 Joe Walnes.
- * Copyright (C) 2006, 2007, 2011, 2013, 2014, 2015, 2016, 2017 XStream Committers.
+ * Copyright (C) 2006, 2007, 2011, 2013, 2014, 2015, 2016, 2017, 2021 XStream Committers.
  * All rights reserved.
  *
  * The software in this package is published under the terms of the BSD
@@ -35,7 +35,9 @@
  * @author Jörg Schaible
  * @see <a href="http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=40874">ISO 8601</a>
  * @since 1.4.10
+ * @deprecated As of upcoming, no longer required since Java 8, use {@link ISO8601JavaTimeConverter} instead
  */
+@Deprecated
 public class ISO8601JodaTimeConverter extends AbstractSingleValueConverter {
     private static final DateTimeFormatter[] formattersUTC = { //
         ISODateTimeFormat.dateTime(), //

xstream/src/test/com/thoughtworks/acceptance/ConcurrentTypesTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012, 2015, 2017, 2018 XStream Committers.
+ * Copyright (C) 2012, 2015, 2017, 2018, 2021 XStream Committers.
  * All rights reserved.
  *
  * The software in this package is published under the terms of the BSD
@@ -14,7 +14,6 @@
 import java.util.concurrent.ConcurrentHashMap;
 
 import com.thoughtworks.xstream.converters.collections.MapConverter;
-import com.thoughtworks.xstream.core.JVM;
 
 
 public class ConcurrentTypesTest extends AbstractAcceptanceTest {
@@ -40,22 +39,20 @@ public static class DerivedConcurrentHashMap extends ConcurrentHashMap<Object, O
     }
 
     public void testDerivedConcurrentHashMap() {
-        if (JVM.isVersion(8)) {
-            xstream.alias("derived-map", DerivedConcurrentHashMap.class);
-            xstream.registerConverter(new MapConverter(xstream.getMapper(), DerivedConcurrentHashMap.class));
-
-            final Map<Object, Object> map = new DerivedConcurrentHashMap();
-            map.put("test", "JUnit");
-
-            final String xml = ""
-                + "<derived-map>\n"
-                + "  <entry>\n"
-                + "    <string>test</string>\n"
-                + "    <string>JUnit</string>\n"
-                + "  </entry>\n"
-                + "</derived-map>";
-
-            assertBothWays(map, xml);
-        }
+        xstream.alias("derived-map", DerivedConcurrentHashMap.class);
+        xstream.registerConverter(new MapConverter(xstream.getMapper(), DerivedConcurrentHashMap.class));
+
+        final Map<Object, Object> map = new DerivedConcurrentHashMap();
+        map.put("test", "JUnit");
+
+        final String xml = ""
+            + "<derived-map>\n"
+            + "  <entry>\n"
+            + "    <string>test</string>\n"
+            + "    <string>JUnit</string>\n"
+            + "  </entry>\n"
+            + "</derived-map>";
+
+        assertBothWays(map, xml);
     }
 }

xstream/src/test/com/thoughtworks/xstream/converters/extended/ISO8601GregorianCalendarConverterTest.java

@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2005 Joe Walnes.
- * Copyright (C) 2006, 2007, 2011, 2017, 2018 XStream Committers.
+ * Copyright (C) 2006, 2007, 2011, 2017, 2018, 2021 XStream Committers.
  * All rights reserved.
  *
  * The software in this package is published under the terms of the BSD
@@ -293,17 +293,15 @@ public void testParsesStandardDateFragment() {
         expected.set(Calendar.YEAR, 2017);
         Calendar out = (Calendar)converter.fromString("2017");
         assertEquals(expected.getTime(), out.getTime());
-        if (JVM.isVersion(8)) { // Java 8 passes, Joda-Time fails
-            expected.set(Calendar.MONTH, 3);
-            out = (Calendar)converter.fromString("2017-04");
-            assertEquals(expected.getTime(), out.getTime());
-        }
+        expected.set(Calendar.MONTH, 3);
+        out = (Calendar)converter.fromString("2017-04");
+        assertEquals(expected.getTime(), out.getTime());
     }
 
     public void testParsesStandardWeekDateFragment() {
         final Calendar expected = Calendar.getInstance();
         expected.clear();
-        if (!JVM.isVersion(8)) { // TODO: Java 8 fails here, Joda-Time passes
+        if (!JVM.isVersion(8)) { // TODO: Java fails here, Joda-Time passes
             expected.set(2017, 3, 17);
             final Calendar out = (Calendar)converter.fromString("2017-W16");
             assertEquals(expected.getTime(), out.getTime());