--- old/src/java.base/share/classes/java/math/BigInteger.java	2019-08-20 11:49:24.000000000 -0700
+++ new/src/java.base/share/classes/java/math/BigInteger.java	2019-08-20 11:49:24.000000000 -0700
@@ -4001,9 +4001,9 @@
         for (int i=numGroups-2; i >= 0; i--) {
             // Prepend (any) leading zeros for this digit group
             s = Long.toString(digitGroups[i], radix);
-            int numLeadingZeros = digitsPerLong[radix]-s.length();
+            int numLeadingZeros = digitsPerLong[radix] - s.length();
             if (numLeadingZeros != 0) {
-                buf.append(zeros[numLeadingZeros]);
+                buf.append(zeros, 0, numLeadingZeros);
                 count += numLeadingZeros;
             }
             buf.append(s);
@@ -4045,14 +4045,13 @@
             // Don't pad if we're at the beginning of the string.
             if (!atBeginning && len < digits) {
                 int m = digits - len;
-                int zl1 = zeros.length - 1;
-                while (m >= zl1) {
-                    sb.insert(pos, zeros[zl1]);
-                    pos += zl1;
-                    m -= zl1;
+                while (m >= NUM_ZEROS) {
+                    sb.insert(pos, zeros, 0, NUM_ZEROS);
+                    pos += NUM_ZEROS;
+                    m -= NUM_ZEROS;
                 }
                 if (m > 0) {
-                    sb.insert(pos, zeros[m]);
+                    sb.insert(pos, zeros, 0, m);
                 }
             }
 
@@ -4105,14 +4104,11 @@
         return cacheLine[exponent];
     }
 
-    /* zero[i] is a string of i consecutive zeros. */
-    private static String[] zeros = new String[64];
-    static {
-        zeros[63] =
-            "000000000000000000000000000000000000000000000000000000000000000";
-        for (int i=0; i < 63; i++)
-            zeros[i] = zeros[63].substring(0, i);
-    }
+    /* Size of zeros string. */
+    private static int NUM_ZEROS = 63;
+
+    /* zero is a string of NUM_ZEROS consecutive zeros. */
+    private static final String zeros = "0".repeat(NUM_ZEROS);
 
     /**
      * Returns the decimal String representation of this BigInteger.