Use toUnsignedString() to convert uint32 and uint64 to strings.

This method has existed since Java 8, released in 2014.

Also adjust the tests so that they verify unsigned integer values that are too big for the signed counterpart (for example, 4294967295 which fits in `uint32` but not `int32`).

We don't use the parallel `Long.parseUnsignedLong` because the existing code handles inputs like `"1.0"`.

PiperOrigin-RevId: 723945649

java/util/src/main/java/com/google/protobuf/util/JsonFormat.java

@@ -1258,15 +1258,15 @@ private void printSingleFieldValue(
           if (alwaysWithQuotes) {
             generator.print("\"");
           }
-          generator.print(unsignedToString((Integer) value));
+          generator.print(Integer.toUnsignedString((int) value));
           if (alwaysWithQuotes) {
             generator.print("\"");
           }
           break;
 
         case UINT64:
         case FIXED64:
-          generator.print("\"" + unsignedToString((Long) value) + "\"");
+          generator.print("\"" + Long.toUnsignedString((long) value) + "\"");
           break;
 
         case STRING:
@@ -1307,26 +1307,6 @@ private void printSingleFieldValue(
     }
   }
 
-  /** Convert an unsigned 32-bit integer to a string. */
-  private static String unsignedToString(final int value) {
-    if (value >= 0) {
-      return Integer.toString(value);
-    } else {
-      return Long.toString(value & 0x00000000FFFFFFFFL);
-    }
-  }
-
-  /** Convert an unsigned 64-bit integer to a string. */
-  private static String unsignedToString(final long value) {
-    if (value >= 0) {
-      return Long.toString(value);
-    } else {
-      // Pull off the most-significant bit so that BigInteger doesn't think
-      // the number is negative, then set it again using setBit().
-      return BigInteger.valueOf(value & Long.MAX_VALUE).setBit(Long.SIZE - 1).toString();
-    }
-  }
-
   private static String getTypeName(String typeUrl) throws InvalidProtocolBufferException {
     String[] parts = typeUrl.split("/");
     if (parts.length == 1) {

java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java

@@ -84,8 +84,8 @@ public static void resetLocale() {
   private void setAllFields(TestAllTypes.Builder builder) {
     builder.setOptionalInt32(1234);
     builder.setOptionalInt64(1234567890123456789L);
-    builder.setOptionalUint32(5678);
-    builder.setOptionalUint64(2345678901234567890L);
+    builder.setOptionalUint32(-1);
+    builder.setOptionalUint64(-1L);
     builder.setOptionalSint32(9012);
     builder.setOptionalSint64(3456789012345678901L);
     builder.setOptionalFixed32(3456);
@@ -190,8 +190,8 @@ public void testAllFields() throws Exception {
             "{\n"
                 + "  \"optionalInt32\": 1234,\n"
                 + "  \"optionalInt64\": \"1234567890123456789\",\n"
-                + "  \"optionalUint32\": 5678,\n"
-                + "  \"optionalUint64\": \"2345678901234567890\",\n"
+                + "  \"optionalUint32\": 4294967295,\n"
+                + "  \"optionalUint64\": \"18446744073709551615\",\n"
                 + "  \"optionalSint32\": 9012,\n"
                 + "  \"optionalSint64\": \"3456789012345678901\",\n"
                 + "  \"optionalFixed32\": 3456,\n"
@@ -1611,8 +1611,8 @@ public void testOmittingInsignificantWhiteSpace() throws Exception {
             "{"
                 + "\"optionalInt32\":1234,"
                 + "\"optionalInt64\":\"1234567890123456789\","
-                + "\"optionalUint32\":5678,"
-                + "\"optionalUint64\":\"2345678901234567890\","
+                + "\"optionalUint32\":4294967295,"
+                + "\"optionalUint64\":\"18446744073709551615\","
                 + "\"optionalSint32\":9012,"
                 + "\"optionalSint64\":\"3456789012345678901\","
                 + "\"optionalFixed32\":3456,"