JDBC批处理插入性能

我需要将几亿条记录插入mysql db。我要一次插入一百万个。请在下面查看我的代码。它似乎很慢。有什么方法可以优化它吗？

try { // Disable auto-commit connection.setAutoCommit(false);

    // Create a prepared statement
    String sql = "INSERT INTO mytable (xxx), VALUES(?)";
    PreparedStatement pstmt = connection.prepareStatement(sql);

    Object[] vals=set.toArray();
    for (int i=0; i<vals.length; i++) {
        pstmt.setString(1, vals[i].toString());
        pstmt.addBatch();
    }

    // Execute the batch
    int [] updateCounts = pstmt.executeBatch();
    System.out.append("inserted "+updateCounts.length);