MySQL，从已解析文件加载数据的最有效方法

Question

My File has the following format:

Table1; Info
rec_x11;rec_x21;rec_x31;rec_x41
rec_x12;rec_x22;rec_x32;rec_x42
...
\n
Table2; Info
rec_x11;rec_x21;rec_x31;rec_x41
rec_x12;rec_x22;rec_x32;rec_x42
...
\n
Table3; Info
rec_x11;rec_x21;rec_x31;rec_x41
rec_x12;rec_x22;rec_x32;rec_x42
...

Each batch of records starting from the next line after TableX header and ending by an empty line delimiter is about 700-800 lines size.

Each such batch of lines ( rec_xyz ...) need to be imported into the relevant MyISAM table name indicated in the header of the batch ( TableX )

I am familiar with the option to pipeline the stream using shell comands into LOAD DATA command.

I am interested in simple java snipet code which will parse this file and execute LOAD DATA for a single batch of records each time (in a for loop and maybe using seek command).

for now i am trying to use IGNORE LINES to jump over processed records, but i am not familiar if there is an option to ignore lines from BELOW?

is there a more efficient way to parse and load this type of file into DB?

EDIT

I have read that JDBC supports input stream to LOAD DATA starting from 5.1.3, can i use it to iterate over the file with an input stream and change the LOAD DATA statement each time?

Answer 1

I am attaching my code as a solution,

This solution is based on the additional functionality ( setLocalInfileInputStream ) added by MySQL Connector/J 5.1.3 and later.

I am pipe-lining input-stream into LOAD DATA INTO statement, instead of using direct file URL.

Additional info: I am using BoneCP as a connection pool

public final void readFile(final String path)
        throws IOException, SQLException, InterruptedException {
    File file = new File(path);

    final Connection connection = getSqlDataSource().getConnection();
    Statement statement = SqlDataSource.getInternalStatement(connection.createStatement());

    try{
        Scanner fileScanner = new Scanner(file);
        fileScanner.useDelimiter(Pattern.compile("^$", Pattern.MULTILINE));

        while(fileScanner.hasNext()){
            String line;
            while ((line = fileScanner.nextLine()).isEmpty());

            InputStream is = new ByteArrayInputStream(fileScanner.next().getBytes("UTF-8"));
            String [] tableName = line.split(getSeparator());
            setTable((tableName[0]+"_"+tableName[1]).replace('-', '_'));

            String sql = "LOAD DATA LOCAL INFILE '" + SingleCsvImportBean.getOsDependantFileName(file) + "' " 
                    + "INTO TABLE " + SqlUtils.escape(getTable()) 
                    + "FIELDS TERMINATED BY '" + getSeparator() 
                    + "' ESCAPED BY '' LINES TERMINATED BY '" + getLinefeed() + "' ";
            sql += "(" + implodeStringArray(getFields(), ", ") + ")";       
            sql += getSetClause();

            ((com.mysql.jdbc.Statement) statement).setLocalInfileInputStream(is);
            statement.execute(sql);         
        }
    }finally{
        statement.close();
        connection.close();
    }   
}