revert change in classes that maintain jdk 1.4 compatibility

Author: doom369

src/demo/share/java2d/J2DBench/src/j2dbench/tests/iio/InputImageTests.java

@@ -184,7 +184,7 @@ private static void initIIOReadFormats() {
             String klass = spi.getClass().getName();
             String format = spi.getFormatNames()[0].toLowerCase();
             String suffix = spi.getFileSuffixes()[0].toLowerCase();
-            if (suffix == null || suffix.isEmpty()) {
+            if (suffix == null || suffix.equals("")) {
                 suffix = format;
             }
             String shortName;

src/demo/share/java2d/J2DBench/src/j2dbench/tests/iio/OutputImageTests.java

@@ -143,7 +143,7 @@ private static void initIIOWriteFormats() {
             String klass = spi.getClass().getName();
             String format = spi.getFormatNames()[0].toLowerCase();
             String suffix = spi.getFileSuffixes()[0].toLowerCase();
-            if (suffix == null || suffix.isEmpty()) {
+            if (suffix == null || suffix.equals("")) {
                 suffix = format;
             }
             String shortName;