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BAEL-3462 Univosity Parsers (#9222)

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* BAEL-3462 CSV Univosity Example

* Added a row processor example
This commit is contained in:
Amy DeGregorio
2020-05-17 14:17:51 -04:00
committed by GitHub
parent 688b71721d
commit 4c3beb7ac7
10 changed files with 374 additions and 0 deletions
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80
libraries-data-2/src/main/java/com/baeldung/univocity/OutputService.java Normal file
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package com.baeldung.univocity;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.baeldung.univocity.model.Product;
import com.univocity.parsers.common.processor.BeanWriterProcessor;
import com.univocity.parsers.csv.CsvWriter;
import com.univocity.parsers.csv.CsvWriterSettings;
import com.univocity.parsers.fixed.FixedWidthFields;
import com.univocity.parsers.fixed.FixedWidthWriter;
import com.univocity.parsers.fixed.FixedWidthWriterSettings;
import com.univocity.parsers.tsv.TsvWriter;
import com.univocity.parsers.tsv.TsvWriterSettings;
public class OutputService {
private Logger logger = LoggerFactory.getLogger(ParsingService.class);
public enum OutputType {
CSV, TSV, FIXED_WIDTH
};
public boolean writeData(List<Object[]> products, OutputType outputType, String outputPath) {
try (Writer outputWriter = new OutputStreamWriter(new FileOutputStream(new File(outputPath)), "UTF-8")) {
switch (outputType) {
case CSV: {
CsvWriter writer = new CsvWriter(outputWriter, new CsvWriterSettings());
writer.writeRowsAndClose(products);
}
break;
case TSV: {
TsvWriter writer = new TsvWriter(outputWriter, new TsvWriterSettings());
writer.writeRowsAndClose(products);
}
break;
case FIXED_WIDTH: {
FixedWidthFields fieldLengths = new FixedWidthFields(8, 30, 10);
FixedWidthWriterSettings settings = new FixedWidthWriterSettings(fieldLengths);
FixedWidthWriter writer = new FixedWidthWriter(outputWriter, settings);
writer.writeRowsAndClose(products);
}
break;
default:
logger.warn("Invalid OutputType: " + outputType);
return false;
}
return true;
} catch (IOException e) {
logger.error(e.getMessage());
return false;
}
}
public boolean writeBeanToFixedWidthFile(List<Product> products, String outputPath) {
try (Writer outputWriter = new OutputStreamWriter(new FileOutputStream(new File(outputPath)), "UTF-8")) {
BeanWriterProcessor<Product> rowProcessor = new BeanWriterProcessor<Product>(Product.class);
FixedWidthFields fieldLengths = new FixedWidthFields(8, 30, 10);
FixedWidthWriterSettings settings = new FixedWidthWriterSettings(fieldLengths);
settings.setHeaders("product_no", "description", "unit_price");
settings.setRowWriterProcessor(rowProcessor);
FixedWidthWriter writer = new FixedWidthWriter(outputWriter, settings);
writer.writeHeaders();
for (Product product : products) {
writer.processRecord(product);
}
writer.close();
return true;
} catch (IOException e) {
logger.error(e.getMessage());
return false;
}
}
}

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libraries-data-2/src/main/java/com/baeldung/univocity/ParsingService.java Normal file
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package com.baeldung.univocity;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.baeldung.univocity.model.Product;
import com.univocity.parsers.common.processor.BatchedColumnProcessor;
import com.univocity.parsers.common.processor.BeanListProcessor;
import com.univocity.parsers.csv.CsvParser;
import com.univocity.parsers.csv.CsvParserSettings;
import com.univocity.parsers.fixed.FixedWidthFields;
import com.univocity.parsers.fixed.FixedWidthParser;
import com.univocity.parsers.fixed.FixedWidthParserSettings;
public class ParsingService {
private Logger logger = LoggerFactory.getLogger(ParsingService.class);
public List<String[]> parseCsvFile(String relativePath) {
try (Reader inputReader = new InputStreamReader(new FileInputStream(new File(relativePath)), "UTF-8")) {
CsvParserSettings settings = new CsvParserSettings();
settings.setMaxCharsPerColumn(100);
settings.setMaxColumns(50);
CsvParser parser = new CsvParser(settings);
List<String[]> parsedRows = parser.parseAll(inputReader);
return parsedRows;
} catch (IOException e) {
logger.error("IOException opening file: " + relativePath + " " + e.getMessage());
return new ArrayList<String[]>();
}
}
public List<String[]> parseFixedWidthFile(String relativePath) {
try (Reader inputReader = new InputStreamReader(new FileInputStream(new File(relativePath)), "UTF-8")) {
FixedWidthFields fieldLengths = new FixedWidthFields(8, 30, 10);
FixedWidthParserSettings settings = new FixedWidthParserSettings(fieldLengths);
FixedWidthParser parser = new FixedWidthParser(settings);
List<String[]> parsedRows = parser.parseAll(inputReader);
return parsedRows;
} catch (IOException e) {
logger.error("IOException opening file: " + relativePath + " " + e.getMessage());
return new ArrayList<String[]>();
}
}
public List<Product> parseCsvFileIntoBeans(String relativePath) {
try (Reader inputReader = new InputStreamReader(new FileInputStream(new File(relativePath)), "UTF-8")) {
BeanListProcessor<Product> rowProcessor = new BeanListProcessor<Product>(Product.class);
CsvParserSettings settings = new CsvParserSettings();
settings.setHeaderExtractionEnabled(true);
settings.setProcessor(rowProcessor);
CsvParser parser = new CsvParser(settings);
parser.parse(inputReader);
return rowProcessor.getBeans();
} catch (IOException e) {
logger.error("IOException opening file: " + relativePath + " " + e.getMessage());
return new ArrayList<Product>();
}
}
public List<String[]> parseCsvFileInBatches(String relativePath) {
try (Reader inputReader = new InputStreamReader(new FileInputStream(new File(relativePath)), "UTF-8")) {
CsvParserSettings settings = new CsvParserSettings();
settings.setProcessor(new BatchedColumnProcessor(5) {
@Override
public void batchProcessed(int rowsInThisBatch) {
}
});
CsvParser parser = new CsvParser(settings);
List<String[]> parsedRows = parser.parseAll(inputReader);
return parsedRows;
} catch (IOException e) {
logger.error("IOException opening file: " + relativePath + " " + e.getMessage());
return new ArrayList<String[]>();
}
}
}

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libraries-data-2/src/main/java/com/baeldung/univocity/model/Product.java Normal file
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package com.baeldung.univocity.model;
import com.univocity.parsers.annotations.Parsed;
public class Product {
@Parsed(field = "product_no")
private String productNumber;
@Parsed
private String description;
@Parsed(field = "unit_price")
private float unitPrice;
public String getProductNumber() {
return productNumber;
}
public void setProductNumber(String productNumber) {
this.productNumber = productNumber;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public float getUnitPrice() {
return unitPrice;
}
public void setUnitPrice(float unitPrice) {
this.unitPrice = unitPrice;
}
@Override
public String toString() {
return "Product [Product Number: " + productNumber + ", Description: " + description + ", Unit Price: " + unitPrice + "]";
}
}