Loader.java :  » UML » xuml-compiler » au » com » southsky » cashbooks » admin » Java Open Source

package au.com.southsky.cashbooks.admin;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.List;

import javax.persistence.EntityManagerFactory;

import au.com.southsky.cashbooks.CashbooksInjectorModule;
import au.com.southsky.cashbooks.utils.CSVutil;

import com.google.inject.Guice;
import com.google.inject.Inject;
import com.google.inject.Injector;

public abstract class Loader {

  protected static Injector injector = Guice
      .createInjector(new CashbooksInjectorModule());

  protected EntityManagerFactory entityManagerFactory;

  protected EntityManagerFactory getEntityManagerFactory() {
    return entityManagerFactory;
  }

  protected BufferedReader in;
  protected int count;

  protected void prepareReader(File f) throws LoaderException {
    try {
      this.in = new BufferedReader(new InputStreamReader(
          new FileInputStream(f)));

      // check that column headings are what we expect

      checkCsvColumnNames(in.readLine());
      count = 1;
    } catch (IOException e) {
      throw new LoaderException(e);
    }
  }

  @Inject
  public void setEntityManagerFactory(
      EntityManagerFactory entityManagerFactory) {
    this.entityManagerFactory = entityManagerFactory;
  }

  abstract protected String[] getCsvFieldNames();

  protected void checkCsvColumnNames(String rec) throws LoaderException {
    List<String> fileFieldNames = CSVutil.parse(rec);
    String[] csvFieldNames = getCsvFieldNames();

    if (csvFieldNames.length > fileFieldNames.size()) {
      throw new LoaderException("Insufficient fields in file");
    }

    if (csvFieldNames.length < fileFieldNames.size()) {
      throw new LoaderException("Too many fields in file");
    }

    for (int i = 0; i < csvFieldNames.length; i++) {
      if (!(csvFieldNames[i].equals(fileFieldNames.get(i)))) {
        throw new LoaderException(String.format(
            "In field %d, was expection '%s' but got '%s'", i,
            csvFieldNames[i], fileFieldNames.get(i)));

      }
    }
  }
  
  

  protected List<String> getNextRecord() throws LoaderException {
    String rec = null;
    try {
      rec = in.readLine();

      if (rec == null) {
        in.close();
        return null;
      }
    } catch (IOException e) {
      throw new LoaderException(e);
    }

    count++;

    // parse the line into fields

    List<String> fields = CSVutil.parse(rec);

    if (fields.size() < getCsvFieldNames().length) {
      throw new LoaderException(
          "Insuffient fields to construct event at line " + count);
    }
    return fields;
  }

}