com.luhuiguo.fastdfs.proto.mapper.MetadataMapper Maven / Gradle / Ivy
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package com.luhuiguo.fastdfs.proto.mapper;
import java.nio.charset.Charset;
import java.util.HashSet;
import java.util.Set;
import com.luhuiguo.fastdfs.domain.MetaData;
import com.luhuiguo.fastdfs.proto.OtherConstants;
/**
* 文件标签（元数据）映射对象
*
* @author tobato
*
*/
public class MetadataMapper {
private MetadataMapper() {
// hide for utils
}
/**
* 将元数据映射为byte
*
* @param list
* @param charset
* @return
*/
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 (MetaData md : metadataSet) {
sb.append(md.getName()).append(OtherConstants.FDFS_FIELD_SEPERATOR).append(md.getValue());
sb.append(OtherConstants.FDFS_RECORD_SEPERATOR);
}
// 去除最后一个分隔符
sb.delete(sb.length() - OtherConstants.FDFS_RECORD_SEPERATOR.length(), sb.length());
return sb.toString().getBytes(charset);
}
/**
* 将byte映射为对象
*
* @param content
* @param charset
* @return
*/
public static Set fromByte(byte[] content, Charset charset) {
Set mdSet = new HashSet();
if (null == content) {
return mdSet;
}
String meta_buff = new String(content, charset);
String[] rows = meta_buff.split(OtherConstants.FDFS_RECORD_SEPERATOR);
for (int i = 0; i < rows.length; i++) {
String[] cols = rows[i].split(OtherConstants.FDFS_FIELD_SEPERATOR, 2);
MetaData md = new MetaData(cols[0]);
if (cols.length == 2) {
md.setValue(cols[1]);
}
mdSet.add(md);
}
return mdSet;
}
}