读取tar中CSV文件的内容。广州档案馆

Question

我想在数据库表中保存table档案的内容。

该存档包含CSV格式的txt文件。

想法是在数据库中为txt文件中的每一行插入一行。

问题是我无法单独读取文件的内容，然后转到下一个文件。

EntryTable和EntryTableLine下面是Hibernate实体。

EntryTable与EntryTableLine处于OneTo很多关系（一个文件-EntryTable-可以有很多行-EntryTableLine-）。

public static final int TAB = 9;

FileInputStream fileInputStream = new FileInputStream(fileLocation);
GZIPInputStream gzipInputStream = new GZIPInputStream(fileInputStream);
TarArchiveInputStream tar = new TarArchiveInputStream(gzipInputStream);

BufferedReader reader = new BufferedReader(new InputStreamReader(tar));
// Columns are delimited with TAB
CSVFormat csvFormat = CSVFormat.TDF.withHeader().withDelimeter((char) TAB);
CSVParser parser = new CSVParser(reader, csvFormat);

TarArchiveEntry tarEntry = tar.getNextTarEntry();

while(tarEntry != null){
  EntryTable entryTable = new EntryTable();
  entryTable.setFilename(tarEntry.getName());

  if(reader != null){

     // Here is the problem
     for(CSVRecord record : parser){
        //this could have been a StringBuffer
        String line;
        int i = 1;
        for(String val : record){
           line = "<column" + i + ">" + val + "</column" + i + ">";
        }

        EntryTableLine entryTableLine = new EntryTableLine();
        entryTableLine.setContent(line);
        entryDao.saveLine(entryTableLine);
      }
  }
  tarEntry = tar.getNextTarEntry();
}

我尝试将tarEntry.getFile()转换为InputStream，但不幸的是tarEntry.getFile()为null。

假设我在存档中有4个文件。每个文件内部有 3 行。但是，在数据库中，某些条目有 5 行，而其他条目没有。

谢谢！

Answer 1

做类似的事情解决了这个问题:

TarArchiveEntry entry = tarInput.getNextTarEntry();
byte[] content = new byte[entry.getSize()];
LOOP UNTIL entry.getSize() HAS BEEN READ {
    tarInput.read(content, offset, content.length - offset);
}

评论中提到的参考资料

Answer 2

尝试直接从inputstream读取：

        BufferedReader br = null;
        while(tarEntry != null){
            br = new BufferedReader(new InputStreamReader(tarEntry));

Answer 3

您可以使用Apache Commons Compress的TarArchiveInputStream，如下所示（参考）：

TarArchiveInputStream input = new TarArchiveInputStream(new GzipCompressorInputStream(new FileInputStream("C:\\Users\\User\\Desktop\\Books\\test\\CoverLetter-Version2.gz")));
TarArchiveEntry entry = input.getNextTarEntry();
System.out.println(entry.getName()); // prints the name of file inside the tar
BufferedReader br = null;
StringBuilder sb = new StringBuilder();
while (entry != null) {
    br = new BufferedReader(new InputStreamReader(input)); // Read directly from tarInput
    System.out.println("For File = " + currentEntry.getName());
    String line;
    while ((line = br.readLine()) != null) {
          System.out.println("line="+line);
    }
     entry = input.getNextTarEntry(); 
}