Index: lucene/src/java/org/apache/lucene/util/Constants.java
===================================================================
--- lucene/src/java/org/apache/lucene/util/Constants.java	(revision 1201662)
+++ lucene/src/java/org/apache/lucene/util/Constants.java	(working copy)
@@ -28,13 +28,20 @@
 
   /** The value of <tt>System.getProperty("java.version")<tt>. **/
   public static final String JAVA_VERSION = System.getProperty("java.version");
-  /** True iff this is Java version 1.1. */
+ 
+  /** True iff this is Java version 1.1.
+   * @deprecated This constant is useless since Lucene is on Java 5 */
+  @Deprecated
   public static final boolean JAVA_1_1 = JAVA_VERSION.startsWith("1.1.");
-  /** True iff this is Java version 1.2. */
+  /** True iff this is Java version 1.2.
+   * @deprecated This constant is useless since Lucene is on Java 5 */
+  @Deprecated
   public static final boolean JAVA_1_2 = JAVA_VERSION.startsWith("1.2.");
-  /** True iff this is Java version 1.3. */
+  /** True iff this is Java version 1.3.
+   * @deprecated This constant is useless since Lucene is on Java 5 */
+  @Deprecated
   public static final boolean JAVA_1_3 = JAVA_VERSION.startsWith("1.3.");
- 
+
   /** The value of <tt>System.getProperty("os.name")<tt>. **/
   public static final String OS_NAME = System.getProperty("os.name");
   /** True iff running on Linux. */
@@ -50,11 +57,13 @@
   public static final String OS_VERSION = System.getProperty("os.version");
   public static final String JAVA_VENDOR = System.getProperty("java.vendor");
 
-  // NOTE: this logic may not be correct; if you know of a
-  // more reliable approach please raise it on java-dev!
   public static final boolean JRE_IS_64BIT;
+  public static final boolean JRE_IS_MINIMUM_JAVA6;
+  public static final boolean JRE_IS_MINIMUM_JAVA7;
   static {
-    String x = System.getProperty("sun.arch.data.model");
+    // NOTE: this logic may not be correct; if you know of a
+    // more reliable approach please raise it on java-dev!
+    final String x = System.getProperty("sun.arch.data.model");
     if (x != null) {
       JRE_IS_64BIT = x.indexOf("64") != -1;
     } else {
@@ -64,6 +73,24 @@
         JRE_IS_64BIT = false;
       }
     }
+
+    // this method only exists in Java 6:
+    boolean v6 = true;
+    try {
+      String.class.getMethod("isEmpty");
+    } catch (NoSuchMethodException nsme) {
+      v6 = false;
+    }
+    JRE_IS_MINIMUM_JAVA6 = v6;
+    
+    // this method only exists in Java 7:
+    boolean v7 = true;
+    try {
+      Throwable.class.getMethod("getSuppressed");
+    } catch (NoSuchMethodException nsme) {
+      v7 = false;
+    }
+    JRE_IS_MINIMUM_JAVA7 = v7;
   }
 
   // this method prevents inlining the final version constant in compiled classes,
Index: lucene/src/test/org/apache/lucene/util/TestIOUtils.java
===================================================================
--- lucene/src/test/org/apache/lucene/util/TestIOUtils.java	(revision 1201662)
+++ lucene/src/test/org/apache/lucene/util/TestIOUtils.java	(working copy)
@@ -44,15 +44,7 @@
   }
 
   public void testSuppressedExceptions() {
-    boolean isJava7 = true;
-    try {
-      // this class only exists in Java 7:
-      Class.forName("java.lang.AutoCloseable");
-    } catch (ClassNotFoundException cnfe) {
-      isJava7 = false;
-    }
-    
-    if (!isJava7) {
+    if (!Constants.JRE_IS_MINIMUM_JAVA7) {
       System.err.println("WARNING: TestIOUtils.testSuppressedExceptions: Full test coverage only with Java 7, as suppressed exception recording is not supported before.");
     }
     
@@ -71,7 +63,7 @@
         System.out.println("TestIOUtils.testSuppressedExceptions: Thrown Exception stack trace:");
         System.out.println(trace);
       }
-      if (isJava7) {
+      if (Constants.JRE_IS_MINIMUM_JAVA7) {
         assertTrue("Stack trace does not contain first suppressed Exception: " + trace,
           trace.contains("java.io.IOException: TEST-IO-EXCEPTION-1"));
         assertTrue("Stack trace does not contain second suppressed Exception: " + trace,
@@ -97,7 +89,7 @@
         System.out.println("TestIOUtils.testSuppressedExceptions: Thrown Exception stack trace:");
         System.out.println(trace);
       }
-      if (isJava7) {
+      if (Constants.JRE_IS_MINIMUM_JAVA7) {
         assertTrue("Stack trace does not contain suppressed Exception: " + trace,
           trace.contains("java.io.IOException: TEST-IO-EXCEPTION-2"));
       }