org.supercsv.cellprocessor.Optional Java Examples

/**
 * Sets up the processors used for the examples. There are 10 CSV columns, so 10 processors are defined. All values
 * are converted to Strings before writing (there's no need to convert them), and null values will be written as
 * empty columns (no need to convert them to "").
 * 
 * @return the cell processors
 */
private static CellProcessor[] getProcessors() {
	
	final CellProcessor[] processors = new CellProcessor[] { new UniqueHashCode(), // customerNo (must be unique)
		new NotNull(), // firstName
		new NotNull(), // lastName
		new FmtDate("dd/MM/yyyy"), // birthDate
		new NotNull(), // mailingAddress
		new Optional(new FmtBool("Y", "N")), // married
		new Optional(), // numberOfKids
		new NotNull(), // favouriteQuote
		new NotNull(), // email
		new LMinMax(0L, LMinMax.MAX_LONG) // loyaltyPoints
	};
	
	return processors;
}
 

private static CellProcessor[] getProcessors4ClassifiedTweetIDSCCSV() {

		final CellProcessor[] processors = new CellProcessor[]{
				//new UniqueHashCode(), // tweetID (must be unique)
				new NotNull(),	// tweetID (must be unique): sometimes CAN be null!
				new NotNull(), 	// crisis name
				new Optional(),	// attribute name
				new Optional(), // attribute code
				new Optional(), // label name
				new Optional(), // label description
				new Optional(),	// label code
				new Optional(), // confidence
				new Optional(), // humanLabeled
		};
		return processors;
	}
 

private static CellProcessor[] getProcessors4ClassifiedCCSV() {

		final CellProcessor[] processors = new CellProcessor[]{
				//new UniqueHashCode(), // tweetID (must be unique)
				//new NotNull(),	// tweetID (must be unique)
				new Optional(),	// tweetID - data shows that sometimes tweetID CAN be null!
				new Optional(), // message
				new Optional(), // userID
				new Optional(), // userName
				new Optional(), // userURL
				new Optional(), // createdAt
				new NotNull(),	// crisis name
				new Optional(),	// attribute name
				new Optional(),	// attribute code
				new Optional(), // label name
				new Optional(), // label description
				new Optional(), // label code
				new Optional(), // confidence
				new Optional() // humanLabeled
		};
		return processors;
	}
 

private static CellProcessor[] getCollectorTweetsProcessors() {

		final CellProcessor[] processors = new CellProcessor[]{
				//new UniqueHashCode(), // tweetID (must be unique)
				//new NotNull(),	// tweetID (must be unique)
				new Optional(),		// data shows that sometimes tweetID CAN be null!
				new Optional(), // message
				//new FmtDate("dd/MM/yyyy"), // birthDate
				new Optional(), // userID
				new Optional(), // userName
				//new Optional(new FmtBool("Y", "N")), // isRT
				new Optional(), // userURL
				new Optional(), // createdAt
				new Optional() // tweet permanent URL
		};


		return processors;
	}
 

public void ReadTestCSVFile(Reader reader) throws IOException {
	ICsvBeanReader beanReader = new CsvBeanReader(reader, CsvPreference.STANDARD_PREFERENCE);
	final String[] header = beanReader.getHeader(true);
	assertEquals("customerNo", header[0]);
	CustomerBean customer = null;
	final String emailRegex = "[a-z0-9\\._]+@[a-z0-9\\.]+"; // just an example, not very robust!
	StrRegEx.registerMessage(emailRegex, "must be a valid email address");
	final CellProcessor[] processors = new CellProcessor[]{new UniqueHashCode(), // customerNo (must be unique)
			new NotNull(), // firstName
			new NotNull(), // lastName
			new ParseDate("dd/MM/yyyy"), // birthDate
			new ParseSqlTime("HH:mm:ss"), // birthTime
			new NotNull(), // mailingAddress
			new Optional(new ParseBool()), // married
			new Optional(new ParseInt()), // numberOfKids
			new NotNull(), // favouriteQuote
			new StrRegEx(emailRegex), // email
			new LMinMax(0L, LMinMax.MAX_LONG) // loyaltyPoints
	};
	customer = beanReader.read(CustomerBean.class, header, processors);
	assertEquals("1", customer.getCustomerNo());
	assertEquals("John", customer.getFirstName());
	assertEquals("[email protected]", customer.getEmail());
	assertEquals(0, customer.getLoyaltyPoints());
	beanReader.close();
}
 

/**
 * Sets up the processors used for the examples. There are 10 CSV columns, so 10 processors are defined. Empty
 * columns are read as null (hence the NotNull() for mandatory columns).
 * 
 * @return the cell processors
 */
private static CellProcessor[] getProcessors() {
	
	final String emailRegex = "[a-z0-9\\._]+@[a-z0-9\\.]+"; // just an example, not very robust!
	StrRegEx.registerMessage(emailRegex, "must be a valid email address");
	
	final CellProcessor[] processors = new CellProcessor[] { new UniqueHashCode(), // customerNo (must be unique)
		new NotNull(), // firstName
		new NotNull(), // lastName
		new ParseDate("dd/MM/yyyy"), // birthDate
		new ParseSqlTime("HH:mm:ss"),
		new NotNull(), // mailingAddress
		new Optional(new ParseBool()), // married
		new Optional(new ParseInt()), // numberOfKids
		new NotNull(), // favouriteQuote
		new StrRegEx(emailRegex), // email
		new LMinMax(0L, LMinMax.MAX_LONG) // loyaltyPoints
	};
	
	return processors;
}
 

/**
 * Returns array of cellprocessors, one for each field
 */
private CellProcessor[] getProcessor(List<Field> fields)
{
  CellProcessor[] processor = new CellProcessor[fields.size()];
  int fieldCount = 0;
  for (Field field : fields) {
    if (field.getType() == FieldType.DATE) {
      String format = field.getConstraints().get(DelimitedSchema.DATE_FORMAT) == null ? null
          : (String)field.getConstraints().get(DelimitedSchema.DATE_FORMAT);
      processor[fieldCount++] = new Optional(new FmtDate(format == null ? "dd/MM/yyyy" : format));
    } else {
      processor[fieldCount++] = new Optional();
    }
  }
  return processor;
}
 

private static CellProcessor[] getProcessors() {
	return new CellProcessor[]{
		new ParseDouble(), // price
		new ParseDouble(), // volRemaining
		new ParseInt(), // typeID
		new ParseInt(), // range
		new ParseLong(), // orderID
		new ParseInt(), // volEntered
		new ParseInt(), // minVolume
		new ParseBool(), // bid
		new ParseDate(), // issueDate
		new ParseInt(), // duration
		new ParseLong(), // stationID
		new ParseLong(), // regionID
		new ParseLong(), // solarSystemID
		new ParseInt(), // jumps
		new Optional()
	};
}
 

private CellProcessor[] getCellProcessors() {
    return new CellProcessor[]{
            //@formatter:off
            null,                                  // airport ID
            new Optional(),                        // name
            new Optional(),                        // city
            new Optional(),                        // country
            new Optional(new ParseAirportCode()),  // iataCode
            new Optional(new ParseAirportCode()),  // icaoCode
            new Optional(new ParseDouble()),       // latitude
            new Optional(new ParseDouble()),       // longitude
            null,                                  // altitude
            null,                                  // Timezone
            null,                                  // DST
            null,                                  // Tz database time zone
            null,                                  // Type
            null,                                  // Source
            //@formatter:on
    };

}
 

/**
 * Get Optional cellprocessor which means field is not mandatory.
 *
 * @param cellProcessor
 *          next processor in the chain.
 * @return CellProcessor
 */
private static CellProcessor addOptional(CellProcessor cellProcessor)
{
  if (cellProcessor == null) {
    return new Optional();
  }
  return new Optional(cellProcessor);
}
 

@Test
public void constructorsTest() throws Exception {
    new ParseDate("yyyyMMddHHmm");
    new ParseDate("yyyyMMddHHmm", true);
    new ParseDate("yyyyMMddHHmm", true, Locale.getDefault());
    new ParseDate("yyyyMMddHHmm", new Optional());
    new ParseDate("yyyyMMddHHmm", true, new Optional());
    new ParseDate("yyyyMMddHHmm", true, Locale.getDefault(), new Optional());
    //No exception means success.
}
 

@Test
public void constructorTests() throws Exception {
    new ParseBigDecimal(DecimalFormatSymbols.getInstance());
    new ParseBigDecimal(new Optional());
    new ParseBigDecimal(DecimalFormatSymbols.getInstance(), new Optional());
    //No exception means success.

}
 

public void initialise(String[] properties, CellProcessor[] processors)
{
  for (int i = 0; i < getFields().size(); i++) {
    FIELD_TYPE type = getFields().get(i).type;
    properties[i] = getFields().get(i).name;
    if (type == FIELD_TYPE.DOUBLE) {
      processors[i] = new Optional(new ParseDouble());
    } else if (type == FIELD_TYPE.INTEGER) {
      processors[i] = new Optional(new ParseInt());
    } else if (type == FIELD_TYPE.FLOAT) {
      processors[i] = new Optional(new ParseDouble());
    } else if (type == FIELD_TYPE.LONG) {
      processors[i] = new Optional(new ParseLong());
    } else if (type == FIELD_TYPE.SHORT) {
      processors[i] = new Optional(new ParseInt());
    } else if (type == FIELD_TYPE.STRING) {
      processors[i] = new Optional();
    } else if (type == FIELD_TYPE.CHARACTER) {
      processors[i] = new Optional(new ParseChar());
    } else if (type == FIELD_TYPE.BOOLEAN) {
      processors[i] = new Optional(new ParseChar());
    } else if (type == FIELD_TYPE.DATE) {
      processors[i] = new Optional(new ParseDate("dd/MM/yyyy"));
    }
  }

}
 

private CellProcessor[] getCellProcessors() {
    return new CellProcessor[]{
            //@formatter:off
            null,                           //airline ID
            new Optional(),                 //name
            new Optional(new ParseAlias()), //alias
            new Optional(),                 //iataCode
            new Optional(),                 //icaoCode
            new Optional(),                 //callsign
            new Optional(),                 //country
            null,                           //active
            //@formatter:on
    };

}
 

/**
 * An example of reading using CsvDozerBeanReader.
 */
private static void readWithCsvDozerBeanReader() throws Exception {
	
	final CellProcessor[] processors = new CellProcessor[] { 
		new Optional(new ParseInt()), // age
		new ParseBool(),              // consent
		new ParseInt(),               // questionNo 1
		new Optional(),               // answer 1
		new ParseInt(),               // questionNo 2
		new Optional(),               // answer 2
		new ParseInt(),               // questionNo 3
		new Optional()                // answer 3
	};
	
	ICsvDozerBeanReader beanReader = null;
	try {
		beanReader = new CsvDozerBeanReader(new FileReader(CSV_FILENAME), CsvPreference.STANDARD_PREFERENCE);
		
		beanReader.getHeader(true); // ignore the header
		beanReader.configureBeanMapping(SurveyResponse.class, FIELD_MAPPING);
		
		SurveyResponse surveyResponse;
		while( (surveyResponse = beanReader.read(SurveyResponse.class, processors)) != null ) {
			System.out.println(String.format("lineNo=%s, rowNo=%s, surveyResponse=%s", beanReader.getLineNumber(),
				beanReader.getRowNumber(), surveyResponse));
		}
		
	}
	finally {
		if( beanReader != null ) {
			beanReader.close();
		}
	}
}
 

/**
 * An example of partial reading using CsvDozerBeanReader.
 */
private static void partialReadWithCsvDozerBeanReader() throws Exception {
	
	// ignore age, and question/answer 3
	final String[] partialFieldMapping = new String[] { null, "consentGiven", "answers[0].questionNo",
		"answers[0].answer", "answers[1].questionNo", "answers[1].answer", null, null };
	
	// set processors for ignored columns to null for efficiency (could have used full array if we wanted them to execute anyway)
	final CellProcessor[] processors = new CellProcessor[] { null, new ParseBool(), new ParseInt(), new Optional(),
		new ParseInt(), new Optional(), null, null };
	
	ICsvDozerBeanReader beanReader = null;
	try {
		beanReader = new CsvDozerBeanReader(new FileReader(CSV_FILENAME), CsvPreference.STANDARD_PREFERENCE);
		
		beanReader.getHeader(true); // ignore the header
		beanReader.configureBeanMapping(SurveyResponse.class, partialFieldMapping);
		
		SurveyResponse surveyResponse;
		while( (surveyResponse = beanReader.read(SurveyResponse.class, processors)) != null ) {
			System.out.println(String.format("lineNo=%s, rowNo=%s, surveyResponse=%s", beanReader.getLineNumber(),
				beanReader.getRowNumber(), surveyResponse));
		}
		
	}
	finally {
		if( beanReader != null ) {
			beanReader.close();
		}
	}
}
 

private static CellProcessor[] getProcessors() {
	
	final CellProcessor[] processors = new CellProcessor[] { 
               new UniqueHashCode(), // ID (must be unique)
               new NotNull(), // Name
               new Optional(), // Role
               new NotNull() // Salary
       };
	return processors;
}
 

private static CellProcessor[] getClassifiedTweetVariableProcessors(final int count) {
	CellProcessor[] processors = new CellProcessor[count];
	for (int i = 0;i < count;i++) {
		processors[i] = new Optional();
	}
	return processors;
}
 

private CellProcessor[] getCellProcessors() {
    return new CellProcessor[]{
            //@formatter:off
            new Optional(new ParseAirlinesIataCode()), //airline
            null,                                      //airline ID
            new Optional(new ParseAirportIataCode()),  //source airport
            null,                                      //source airport ID
            new Optional(new ParseAirportIataCode()),  //destination airport
            null,                                      //destination airport ID
            new Optional(new ParseCodeShare()),        //codeShare
            new Optional(new ParseInt()),              //stops
            null,                                      //equipment
             //@formatter:on
    };
}
 

/**
 * An example of reading using CsvDozerBeanReader that uses indexed mapping and a cell processor
 * to read into a List of Answer beans (this requires a hint).
 */
private static void readWithCsvDozerBeanReaderUsingIndexMappingAndHints() throws Exception {
	
	// simple cell processor that creates an Answer with a value
	final CellProcessor parseAnswer = new CellProcessorAdaptor() {
		public Object execute(Object value, CsvContext context) {
			return new Answer(null, (String) value);
		}
	};
	
	final CellProcessor[] processors = new CellProcessor[] { 
		new Optional(new ParseInt()), // age
		null,                         // consent
		null,                         // questionNo 1
		new Optional(parseAnswer),    // answer 1
		null,                         // questionNo 2
		new Optional(parseAnswer),    // answer 2
		null,                         // questionNo 3
		new Optional(parseAnswer)     // answer 3
	};
	
	// no deep mapping (answers[0].answer) required as we're using a cell processor to create the bean
	final String[] fieldMapping = {"age", null, null, "answers[0]", null, "answers[1]", null, "answers[2]"};
	
	// the indexed mappings need a hint for Dozer to work
	final Class<?>[] hintTypes = {null, null, null, Answer.class, null, Answer.class, null, Answer.class};
	
	ICsvDozerBeanReader beanReader = null;
	try {
		beanReader = new CsvDozerBeanReader(new FileReader(CSV_FILENAME), CsvPreference.STANDARD_PREFERENCE);
		
		beanReader.getHeader(true); // ignore the header
		beanReader.configureBeanMapping(SurveyResponse.class, fieldMapping, hintTypes);
		
		SurveyResponse surveyResponse;
		while( (surveyResponse = beanReader.read(SurveyResponse.class, processors)) != null ) {
			System.out.println(String.format("lineNo=%s, rowNo=%s, surveyResponse=%s", beanReader.getLineNumber(),
				beanReader.getRowNumber(), surveyResponse));
		}
		
	}
	finally {
		if( beanReader != null ) {
			beanReader.close();
		}
	}
}
 

/**
 * An example of writing using CsvDozerBeanWriter.
 */
private static void writeWithDozerCsvBeanWriter() throws Exception {
	
	final CellProcessor[] processors = new CellProcessor[] { 
		new Token(0, null),     // age
		new FmtBool("Y", "N"),  // consent
		new NotNull(),          // questionNo 1
		new Optional(),         // answer 1
		new NotNull(),          // questionNo 2
		new Optional(),         // answer 2
		new NotNull(),          // questionNo 3
		new Optional() };       // answer 3
	
	// create the survey responses to write
	SurveyResponse response1 = new SurveyResponse(18, true, Arrays.asList(new Answer(1, "Twelve"), new Answer(2,
		"Albert Einstein"), new Answer(3, "Big Bang Theory")));
	SurveyResponse response2 = new SurveyResponse(0, true, Arrays.asList(new Answer(1, "Thirteen"), new Answer(2,
		"Nikola Tesla"), new Answer(3, "Stargate")));
	SurveyResponse response3 = new SurveyResponse(42, false, Arrays.asList(new Answer(1, null), new Answer(2,
		"Carl Sagan"), new Answer(3, "Star Wars")));
	final List<SurveyResponse> surveyResponses = Arrays.asList(response1, response2, response3);
	
	ICsvDozerBeanWriter beanWriter = null;
	try {
		beanWriter = new CsvDozerBeanWriter(new FileWriter("target/writeWithCsvDozerBeanWriter.csv"),
			CsvPreference.STANDARD_PREFERENCE);
		
		// configure the mapping from the fields to the CSV columns
		beanWriter.configureBeanMapping(SurveyResponse.class, FIELD_MAPPING);
		
		// write the header
		beanWriter.writeHeader("age", "consentGiven", "questionNo1", "answer1", "questionNo2", "answer2",
			"questionNo3", "answer3");
		
		// write the beans
		for( final SurveyResponse surveyResponse : surveyResponses ) {
			beanWriter.write(surveyResponse, processors);
		}
		
	}
	finally {
		if( beanWriter != null ) {
			beanWriter.close();
		}
	}
}
 

/**
 * An example of appending writing using CsvDozerBeanWriter
 */
public static void appendingWriteWithCsvDozerBeanWriter() throws Exception {
	
	final CellProcessor[] processors = new CellProcessor[] {
			new Token(0, null),     // age
			new FmtBool("Y", "N"),  // consent
			new NotNull(),          // questionNo 1
			new Optional(),         // answer 1
			new NotNull(),          // questionNo 2
			new Optional(),         // answer 2
			new NotNull(),          // questionNo 3
			new Optional() };       // answer 3
	
	// create the survey responses to write
	SurveyResponse response1 = new SurveyResponse(18, true, Arrays.asList(new Answer(1, "Twelve"), new Answer(2,
			"Albert Einstein"), new Answer(3, "Big Bang Theory")));
	SurveyResponse response2 = new SurveyResponse(0, true, Arrays.asList(new Answer(1, "Thirteen"), new Answer(2,
			"Nikola Tesla"), new Answer(3, "Stargate")));
	SurveyResponse response3 = new SurveyResponse(42, false, Arrays.asList(new Answer(1, null), new Answer(2,
			"Carl Sagan"), new Answer(3, "Star Wars")));

	ICsvDozerBeanWriter beanWriter = null;
	try {
		beanWriter = new CsvDozerBeanWriter(new FileWriter("target/appendingWriteWithCsvDozerBeanWriter.csv"),
				CsvPreference.STANDARD_PREFERENCE);

		// configure the mapping from the fields to the CSV columns
		beanWriter.configureBeanMapping(SurveyResponse.class, FIELD_MAPPING);

		// write the header
		beanWriter.writeHeader("age", "consentGiven", "questionNo1", "answer1", "questionNo2", "answer2",
				"questionNo3", "answer3");

		// write the beans
		beanWriter.write(response1, processors);
	}
	finally {
		if( beanWriter != null ) {
			beanWriter.close();
		}
	}
	
	// appending write
	try {
		beanWriter = new CsvDozerBeanWriter(
				new FileWriter("target/appendingWriteWithCsvDozerBeanWriter.csv", true),
				CsvPreference.STANDARD_PREFERENCE);
		beanWriter.configureBeanMapping(SurveyResponse.class, FIELD_MAPPING);
		beanWriter.write(response2, processors);
		beanWriter.write(response3, processors);
	}
	finally {
		if( beanWriter != null ){
			beanWriter.close();
		}
	}
}
 

/**
 * Tests mapping columns to indexed list elements (with no deep mapping). Dozer requires a hint in this situation.
 */
@Test
public void testReadToListElement() throws IOException {
	final String csv = "age,answer1,answer2,answer3\n"
		+ "23,Nikola Tesla,\"\"\"A brief history of time\"\" by Steven Hawking\",Theoretical physicist\n"
		+ ",Genghis Kahn,\"\"\"Monsoon\"\" by Wilbur Smith\",\n"
		+ "44,,,\"I hate surveys, thanks for wasting my time!\"";
	reader = new StringReader(csv);
	beanReader = new CsvDozerBeanReader(reader, PREFS);
	
	beanReader.getHeader(true); // skip header
	
	final String[] fieldMapping = new String[] { "age", "answers[0]", "answers[1]", "answers[2]" };
	final Class<?>[] hintTypes = new Class<?>[] { null, Answer.class, Answer.class, Answer.class };
	beanReader.configureBeanMapping(SurveyResponse.class, fieldMapping, hintTypes);
	
	final CellProcessor parseAnswer = new CellProcessor() {
		public Object execute(Object value, CsvContext context) {
			return value == null ? null : new Answer(0, (String) value);
		}
	};
	final CellProcessor[] processors = new CellProcessor[] { new Optional(new ParseInt()), parseAnswer,
		parseAnswer, parseAnswer };
	
	SurveyResponse response1 = beanReader.read(SurveyResponse.class, processors);
	assertEquals(23, response1.getAge());
	assertEquals(3, response1.getAnswers().size());
	assertEquals("Nikola Tesla", response1.getAnswers().get(0).getAnswer());
	assertEquals("\"A brief history of time\" by Steven Hawking", response1.getAnswers().get(1).getAnswer());
	assertEquals("Theoretical physicist", response1.getAnswers().get(2).getAnswer());
	
	SurveyResponse response2 = beanReader.read(SurveyResponse.class, processors);
	assertEquals(0, response2.getAge());
	assertEquals(3, response2.getAnswers().size());
	assertEquals("Genghis Kahn", response2.getAnswers().get(0).getAnswer());
	assertEquals("\"Monsoon\" by Wilbur Smith", response2.getAnswers().get(1).getAnswer());
	assertNull(response2.getAnswers().get(2));
	
	SurveyResponse response3 = beanReader.read(SurveyResponse.class, processors);
	assertEquals(44, response3.getAge());
	assertEquals(3, response3.getAnswers().size());
	assertNull(response3.getAnswers().get(0));
	assertNull(response3.getAnswers().get(1));
	assertEquals("I hate surveys, thanks for wasting my time!", response3.getAnswers().get(2).getAnswer());
	
	assertNull(beanReader.read(SurveyResponse.class, processors));
	
}