Added line end delimiter and null string support

master
Abhinav Sarkar 2014-06-07 17:07:38 +05:30
父節點 f315c1ae4b
當前提交 8daf918fc8
共有 1 個檔案被更改,包括 50 行新增49 行删除

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@ -1,15 +1,7 @@
package com.bizo.hive.serde.csv;
import java.io.CharArrayReader;
import java.io.IOException;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Properties;
import au.com.bytecode.opencsv.CSVReader;
import au.com.bytecode.opencsv.CSVWriter;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hive.serde.Constants;
import org.apache.hadoop.hive.serde2.SerDe;
@ -26,68 +18,74 @@ import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoUtils;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;
import au.com.bytecode.opencsv.CSVReader;
import au.com.bytecode.opencsv.CSVWriter;
import java.io.*;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Properties;
/**
* CSVSerde uses opencsv (http://opencsv.sourceforge.net/) to serialize/deserialize columns as CSV.
*
*
* @author Larry Ogrodnek <ogrodnek@gmail.com>
*/
public final class CSVSerde implements SerDe {
private ObjectInspector inspector;
private String[] outputFields;
private int numCols;
private List<String> row;
private char separatorChar;
private char quoteChar;
private char escapeChar;
private String lineEnd;
private String nullDefinedAs;
@Override
public void initialize(final Configuration conf, final Properties tbl) throws SerDeException {
final List<String> columnNames = Arrays.asList(tbl.getProperty(Constants.LIST_COLUMNS).split(","));
final List<TypeInfo> columnTypes = TypeInfoUtils.getTypeInfosFromTypeString(tbl.getProperty(Constants.LIST_COLUMN_TYPES));
numCols = columnNames.size();
final List<ObjectInspector> columnOIs = new ArrayList<ObjectInspector>(numCols);
for (int i=0; i< numCols; i++) {
columnOIs.add(PrimitiveObjectInspectorFactory.javaStringObjectInspector);
}
this.inspector = ObjectInspectorFactory.getStandardStructObjectInspector(columnNames, columnOIs);
this.outputFields = new String[numCols];
row = new ArrayList<String>(numCols);
for (int i=0; i< numCols; i++) {
row.add(null);
}
separatorChar = getProperty(tbl, "separatorChar", CSVWriter.DEFAULT_SEPARATOR);
quoteChar = getProperty(tbl, "quoteChar", CSVWriter.DEFAULT_QUOTE_CHARACTER);
escapeChar = getProperty(tbl, "escapeChar", CSVWriter.DEFAULT_ESCAPE_CHARACTER);
lineEnd = tbl.getProperty("lineEnd", CSVWriter.DEFAULT_LINE_END);
nullDefinedAs = tbl.getProperty("nullDefinedAs", "\\N");
}
private final char getProperty(final Properties tbl, final String property, final char def) {
final String val = tbl.getProperty(property);
if (val != null) {
return val.charAt(0);
}
return def;
}
@Override
public Writable serialize(Object obj, ObjectInspector objInspector) throws SerDeException {
final StructObjectInspector outputRowOI = (StructObjectInspector) objInspector;
final List<? extends StructField> outputFieldRefs = outputRowOI.getAllStructFieldRefs();
if (outputFieldRefs.size() != numCols) {
throw new SerDeException("Cannot serialize the object because there are "
+ outputFieldRefs.size() + " fields but the table has " + numCols + " columns.");
@ -97,45 +95,48 @@ public final class CSVSerde implements SerDe {
for (int c = 0; c < numCols; c++) {
final Object field = outputRowOI.getStructFieldData(obj, outputFieldRefs.get(c));
final ObjectInspector fieldOI = outputFieldRefs.get(c).getFieldObjectInspector();
// The data must be of type String
final StringObjectInspector fieldStringOI = (StringObjectInspector) fieldOI;
// Convert the field to Java class String, because objects of String type
// can be stored in String, Text, or some other classes.
outputFields[c] = fieldStringOI.getPrimitiveJavaObject(field);
if (outputFields[c] == null) {
outputFields[c] = nullDefinedAs;
}
}
final StringWriter writer = new StringWriter();
final CSVWriter csv = newWriter(writer, separatorChar, quoteChar, escapeChar);
final CSVWriter csv = newWriter(writer, separatorChar, quoteChar, escapeChar, lineEnd);
try {
csv.writeNext(outputFields);
csv.close();
return new Text(writer.toString());
} catch (final IOException ioe) {
throw new SerDeException(ioe);
}
}
}
@Override
public Object deserialize(final Writable blob) throws SerDeException {
Text rowText = (Text) blob;
CSVReader csv = null;
try {
csv = newReader(new CharArrayReader(rowText.toString().toCharArray()), separatorChar, quoteChar, escapeChar);
csv = newReader(new CharArrayReader(rowText.toString().toCharArray()), separatorChar, quoteChar, escapeChar);
final String[] read = csv.readNext();
for (int i=0; i< numCols; i++) {
if (read != null && i < read.length) {
row.set(i, read[i]);
row.set(i, read[i] == nullDefinedAs ? null : read[i]);
} else {
row.set(i, null);
}
}
return row;
} catch (final Exception e) {
throw new SerDeException(e);
@ -149,22 +150,22 @@ public final class CSVSerde implements SerDe {
}
}
}
private CSVReader newReader(final Reader reader, char separator, char quote, char escape) {
// CSVReader will throw an exception if any of separator, quote, or escape is the same, but
private static CSVReader newReader(final Reader reader, char separator, char quote, char escape) {
// CSVReader will throw an exception if any of separator, quote, or escape is the same, but
// the CSV format specifies that the escape character and quote char are the same... very weird
if (CSVWriter.DEFAULT_ESCAPE_CHARACTER == escape) {
return new CSVReader(reader, separator, quote);
} else {
return new CSVReader(reader, separator, quote, escape);
return new CSVReader(reader, separator, quote, escape);
}
}
private CSVWriter newWriter(final Writer writer, char separator, char quote, char escape) {
private static CSVWriter newWriter(final Writer writer, char separator, char quote, char escape, String lineEnd) {
if (CSVWriter.DEFAULT_ESCAPE_CHARACTER == escape) {
return new CSVWriter(writer, separator, quote, "");
return new CSVWriter(writer, separator, quote, lineEnd);
} else {
return new CSVWriter(writer, separator, quote, escape, "");
return new CSVWriter(writer, separator, quote, escape, lineEnd);
}
}
@ -177,7 +178,7 @@ public final class CSVSerde implements SerDe {
public Class<? extends Writable> getSerializedClass() {
return Text.class;
}
public SerDeStats getSerDeStats() {
return null;
}