(commons-compress) 01/03: Use BigInteger.longValueExact() instead of a magic number (Java 8 API)

[ggregory]

This is an automated email from the ASF dual-hosted git repository.

ggregory pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/commons-compress.git

commit a795aa9662aac989e2b3ab913d56b6f01711d23d
Author: Gary Gregory <garydgreg...@gmail.com>
AuthorDate: Sat Dec 7 16:08:51 2024 -0500

    Use BigInteger.longValueExact() instead of a magic number (Java 8 API)
    
    - Avoids computing the bit length on every call when  usually not needed
    - Better method name
    - Better Javadoc
---
 .../compress/archivers/zip/X7875_NewUnix.java      |  4 ++--
 .../commons/compress/archivers/zip/ZipUtil.java    | 27 +++++++++++-----------
 .../compress/archivers/zip/ZipUtilTest.java        | 10 ++++----
 3 files changed, 21 insertions(+), 20 deletions(-)

diff --git 
a/src/main/java/org/apache/commons/compress/archivers/zip/X7875_NewUnix.java 
b/src/main/java/org/apache/commons/compress/archivers/zip/X7875_NewUnix.java
index 43a02ab3a..567af5116 100644
--- a/src/main/java/org/apache/commons/compress/archivers/zip/X7875_NewUnix.java
+++ b/src/main/java/org/apache/commons/compress/archivers/zip/X7875_NewUnix.java
@@ -174,7 +174,7 @@ public class X7875_NewUnix implements ZipExtraField, 
Cloneable, Serializable {
      * @return the GID value.
      */
     public long getGID() {
-        return ZipUtil.bigToLong(gid);
+        return ZipUtil.toLong(gid);
     }
 
     /**
@@ -257,7 +257,7 @@ public class X7875_NewUnix implements ZipExtraField, 
Cloneable, Serializable {
      * @return the UID value.
      */
     public long getUID() {
-        return ZipUtil.bigToLong(uid);
+        return ZipUtil.toLong(uid);
     }
 
     @Override
diff --git 
a/src/main/java/org/apache/commons/compress/archivers/zip/ZipUtil.java 
b/src/main/java/org/apache/commons/compress/archivers/zip/ZipUtil.java
index cc141e96d..1658e7862 100644
--- a/src/main/java/org/apache/commons/compress/archivers/zip/ZipUtil.java
+++ b/src/main/java/org/apache/commons/compress/archivers/zip/ZipUtil.java
@@ -112,19 +112,6 @@ public abstract class ZipUtil {
         return i;
     }
 
-    /**
-     * Converts a BigInteger into a long, and blows up (NumberFormatException) 
if the BigInteger is too big.
-     *
-     * @param big BigInteger to convert.
-     * @return long representation of the BigInteger.
-     */
-    static long bigToLong(final BigInteger big) {
-        if (big.bitLength() <= 63) { // bitLength() doesn't count the sign bit.
-            return big.longValue();
-        }
-        throw new NumberFormatException("The BigInteger cannot fit inside a 64 
bit java long: [" + big + "]");
-    }
-
     /**
      * Tests if this library is able to read or write the given entry.
      */
@@ -389,6 +376,20 @@ public abstract class ZipUtil {
         ZipLong.putLong(javaToDosTime(t), buf, offset);
     }
 
+    /**
+     * Converts a BigInteger to a long, and throws a NumberFormatException if 
the BigInteger is too big.
+     *
+     * @param big BigInteger to convert.
+     * @return {@code BigInteger} converted to a {@code long}.
+     */
+    static long toLong(final BigInteger big) {
+        try {
+            return big.longValueExact();
+        } catch (final ArithmeticException e) {
+            throw new NumberFormatException("The BigInteger cannot fit inside 
a 64 bit java long: [" + big + "]");
+        }
+    }
+
     /**
      * Converts an unsigned integer to a signed byte (e.g., 255 becomes -1).
      *
diff --git 
a/src/test/java/org/apache/commons/compress/archivers/zip/ZipUtilTest.java 
b/src/test/java/org/apache/commons/compress/archivers/zip/ZipUtilTest.java
index 8d4961575..b4fa80de3 100644
--- a/src/test/java/org/apache/commons/compress/archivers/zip/ZipUtilTest.java
+++ b/src/test/java/org/apache/commons/compress/archivers/zip/ZipUtilTest.java
@@ -91,15 +91,15 @@ public class ZipUtilTest {
         final BigInteger big2 = BigInteger.valueOf(Long.MAX_VALUE);
         final BigInteger big3 = BigInteger.valueOf(Long.MIN_VALUE);
 
-        assertEquals(1L, ZipUtil.bigToLong(big1));
-        assertEquals(Long.MAX_VALUE, ZipUtil.bigToLong(big2));
-        assertEquals(Long.MIN_VALUE, ZipUtil.bigToLong(big3));
+        assertEquals(1L, ZipUtil.toLong(big1));
+        assertEquals(Long.MAX_VALUE, ZipUtil.toLong(big2));
+        assertEquals(Long.MIN_VALUE, ZipUtil.toLong(big3));
 
         final BigInteger big4 = big2.add(big1);
-        assertThrows(IllegalArgumentException.class, () -> 
ZipUtil.bigToLong(big4), "Should have thrown IllegalArgumentException");
+        assertThrows(IllegalArgumentException.class, () -> 
ZipUtil.toLong(big4), "Should have thrown IllegalArgumentException");
 
         final BigInteger big5 = big3.subtract(big1);
-        assertThrows(IllegalArgumentException.class, () -> 
ZipUtil.bigToLong(big5),
+        assertThrows(IllegalArgumentException.class, () -> 
ZipUtil.toLong(big5),
                 "ZipUtil.bigToLong(BigInteger) should have thrown 
IllegalArgumentException");
     }