QuickOCM

QuickOCM - Parse and convert your CSV files to your models in your java application.

Features

1. Significance of header in CSV.
2. Annotation based, annotate your models with header-name, datatype, nested model structure.
3. Supports nested object compositions in the models.
4. Treats each record of the CSV as a model and will invoke user designated handler for each row i.e. model.
5. Validation of the data-types in CSV automatically handled.

Getting Started

Maven dependency

	<dependency>
		<groupId>io.github.mkhanal</groupId>
		<artifactId>quickocm</artifactId>
		<version>1.0</version>
	</dependency<

Assume your CSV, (first line are headers)

user name 		, age 		, Date Of JOiNinG 	, Referrer Code 	, Street Name  	, House No , City
phillips  		, 23  		, 19/09/1999	  	, referrer1     	, south street 	, 12       	 , Timbak 1
sri krishna 		, 25  		, 20/12/2012      	, referrer2     	, north street 	, 24       	 , Timbak 2
Jaquiline 		, 44  		,	  	          	, referrer3     	, east street  	, 36       	 , Timbak 3
Who so ever 	, 20000 	, 22/02/2010  		, referrer4     	, west street  	, 48       	 , Timbak 4

To parse this, you need :

• An equivalent Model
• Annotations @ImportField and @ImportFields over corresponding fileds.
  1. Default constructor.
  2. Setters for fields to be set.
  If your model User is composed of Address, you can see how nested values are being resolved.

  public class User {
    //Getter, Setter, Default Constructor
    @ImportField(mandatory = true, name = "User Name", type = "String")
    private String name;
  
    @ImportField(mandatory = true, type = "int") //default -> header name = field name
    private Integer age;
  
    @ImportField(type = "Date", name = "date of joining") //case insensitive headers
    private Date joiningDate;
  
    @ImportField(type = "String", name = "Referrer Code", nested = "code")
    private Referrer referrer;
  
    @ImportFields(importFields = {
      @ImportField(type = "String", name = "Street Name", nested = "streetName"),
      @ImportField(type = "int", name = "House No", nested = "houseNo"),
      @ImportField(type = "String", name = "City", nested = "city")})
    private Address completeAddress;
  
    private String createdBy; //logged in user not present in csv file, can be pulled from session
  }
  
  public class Referrer {
      //Getter, Setter, Default Constructor
      private String code;
  }
  
  public class Address {
      //Getter, Setter, Default Constructor
      private Integer houseNo;
      private String streetName;
      private String city;
  }
  
  

  For each row in CSV, your handler will be invoked. So create a handler

  public class UserRecordHandler implements RecordHandler<User> {
    //Getter
    private List<User> uploadedUsers = new ArrayList<User>();
  
    @Override
    public void execute(User user, int i, Map map) {
      user.setCreatedBy((String) map.get("loggedInUser"));
      uploadedUsers.add(user);
    }
  }
  

  This is it. The below code shows a simple test

  
  public class UserRecordHandlerTest {
  
    private CsvParser<User> csvParser;
  
    @Before
    public void setUp() throws Exception {
      Map<String, String> supplementaryInfo = new HashMap<String, String>() {{
        put("loggedInUser", "User123");
      }};
  
      csvParser = new CsvParser<User>(supplementaryInfo);
    }
  
    @Test
    public void shouldParseCsvFileAndGetAllUsers() throws Exception {
      String csvContent =
          "User Name  , Age  , Date Of JOiNinG, Referrer Code, Street Name , House No, City\n" +
          "phillips   , 23   , 19/09/1999     , referrer1    , south street, 12      , Timbak 1\n" +
          "sri krishna, 25   , 20/12/2012     , referrer2    , north street, 24      , Timbak 2\n" +
          "Jaquiline  , 44   ,                , referrer3    , east street , 36      , Timbak 3\n" +
          "Who so ever, 20000, 22/02/2010     , referrer4    , west street , 48      , Timbak 4";
  
      InputStream inputStream = new ByteInputStream(csvContent.getBytes(), csvContent.length());
      UserRecordHandler userRecordHandler = new UserRecordHandler();
  
      csvParser.process(inputStream, User.class, userRecordHandler);
  
      SimpleDateFormat format = new SimpleDateFormat("dd/MM/yyyy");
  
      List<User> uploadedUsers = userRecordHandler.getUploadedUsers();
      assertEquals(4, uploadedUsers.size());
  
      assertThat(uploadedUsers.get(0), isSameUser(new User(
      "phillips", 23, format.parse("19/09/1999"), "referrer1", "south street", 12, "Timbak 1", "User123")));
  
      assertThat(uploadedUsers.get(1), isSameUser(new User(
      "sri krishna", 25, format.parse("20/12/2012"), "referrer2", "north street", 24, "Timbak 2", "User123")));
  
      assertThat(uploadedUsers.get(2), isSameUser(new User(
      "Jaquiline", 44, null, "referrer3", "east street", 36, "Timbak 3", "User123")));
  
      assertThat(uploadedUsers.get(3), isSameUser(new User(
      "Who so ever", 20000, format.parse("22/02/2010"), "referrer4", "west street", 48, "Timbak 4", "User123")));
  
    }
  }
  
  

  The code shows that for each record, how the record handler was executed with the Object in question. Also note how extra information like audit info was passed through supplementaryInfo map