cn.novelweb.tool.upload.fastdfs.utils.MetadataMapperUtils Maven / Gradle / Ivy
package cn.novelweb.tool.upload.fastdfs.utils;
import cn.novelweb.tool.upload.fastdfs.constant.OtherConstants;
import cn.novelweb.tool.upload.fastdfs.model.MateData;
import java.nio.charset.Charset;
import java.util.HashSet;
import java.util.Set;
/**
* 文件标签（元数据）映射对象
* 2020-02-03 15:36
*
* @author LiZW
**/
public class MetadataMapperUtils {
private MetadataMapperUtils() {
}
/**
* 将元数据映射为byte
*/
public static byte[] toByte(Set metadataSet, Charset charset) {
if (null == metadataSet || metadataSet.isEmpty()) {
return new byte[0];
}
StringBuilder sb = new StringBuilder(32 * metadataSet.size());
for (MateData md : metadataSet) {
sb.append(md.getName()).append(OtherConstants.DFS_FIELD_SEPARATOR).append(md.getValue());
sb.append(OtherConstants.DFS_RECORD_SEPARATOR);
}
// 去除最后一个分隔符
sb.delete(sb.length() - OtherConstants.DFS_RECORD_SEPARATOR.length(), sb.length());
return sb.toString().getBytes(charset);
}
/**
* 将byte映射为对象
*/
public static Set fromByte(byte[] content, Charset charset) {
Set mdSet = new HashSet<>();
if (null == content) {
return mdSet;
}
String metaBuff = new String(content, charset);
String[] rows = metaBuff.split(OtherConstants.DFS_RECORD_SEPARATOR);
for (String row : rows) {
String[] cols = row.split(OtherConstants.DFS_FIELD_SEPARATOR, 2);
MateData md = new MateData(cols[0]);
if (cols.length == 2) {
md.setValue(cols[1]);
}
mdSet.add(md);
}
return mdSet;
}
}