优化读写逻辑

src/main/java/com/alibaba/excel/converters/inputstream/InputStreamImageConverter.java

@@ -8,7 +8,7 @@ import com.alibaba.excel.enums.CellDataTypeEnum;
 import com.alibaba.excel.metadata.CellData;
 import com.alibaba.excel.metadata.GlobalConfiguration;
 import com.alibaba.excel.metadata.property.ExcelContentProperty;
-import com.alibaba.excel.util.IOUtils;
+import com.alibaba.excel.util.IoUtils;
 
 /**
  * File and image converter
@@ -35,7 +35,7 @@ public class InputStreamImageConverter implements Converter<InputStream> {
     @Override
     public CellData convertToExcelData(InputStream value, ExcelContentProperty contentProperty,
         GlobalConfiguration globalConfiguration) throws IOException {
-        return new CellData(IOUtils.toByteArray(value));
+        return new CellData(IoUtils.toByteArray(value));
     }
 
 }

src/main/java/com/alibaba/excel/util/FileUtils.java

@@ -36,7 +36,7 @@ public class FileUtils {
         InputStream in = openInputStream(file);
         try {
             final long fileLength = file.length();
-            return fileLength > 0 ? IOUtils.toByteArray(in, (int)fileLength) : IOUtils.toByteArray(in);
+            return fileLength > 0 ? IoUtils.toByteArray(in, (int)fileLength) : IoUtils.toByteArray(in);
         } finally {
             in.close();
         }

src/main/java/com/alibaba/excel/util/IoUtils.java

@@ -10,7 +10,7 @@ import java.io.OutputStream;
  *
  * @author Jiaju Zhuang
  */
-public class IOUtils {
+public class IoUtils {
     public static final int EOF = -1;
     /**
      * The default buffer size ({@value}) to use for