/*
* Copyright 2007 Kasper B. Graversen
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.supercsv.io;
import java.io.IOException;
import java.io.Writer;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import org.supercsv.cellprocessor.ift.CellProcessor;
import org.supercsv.exception.SuperCsvReflectionException;
import org.supercsv.prefs.CsvPreference;
import org.supercsv.util.MethodCache;
import org.supercsv.util.Util;
/**
* CsvBeanWriter writes a CSV file by mapping each field on the bean to a column in the CSV file (using the supplied
* name mapping).
*
* @author Kasper B. Graversen
* @author James Bassett
*/
public class CsvBeanWriter extends AbstractCsvWriter implements ICsvBeanWriter {
// temporary storage of bean values
private final List<Object> beanValues = new ArrayList<Object>();
// temporary storage of processed columns to be written
private final List<Object> processedColumns = new ArrayList<Object>();
// cache of methods for mapping from fields to columns
private final MethodCache cache = new MethodCache();
/**
* Constructs a new <tt>CsvBeanWriter</tt> with the supplied Writer and CSV preferences. Note that the
* <tt>writer</tt> will be wrapped in a <tt>BufferedWriter</tt> before accessed.
*
* @param writer
* the writer
* @param preference
* the CSV preferences
* @throws NullPointerException
* if writer or preference are null
*/
public CsvBeanWriter(final Writer writer, final CsvPreference preference) {
super(writer, preference);
}
/**
* Extracts the bean values, using the supplied name mapping array.
*
* @param source
* the bean
* @param nameMapping
* the name mapping
* @throws NullPointerException
* if source or nameMapping are null
* @throws SuperCsvReflectionException
* if there was a reflection exception extracting the bean value
*/
private void extractBeanValues(final Object source, final String[] nameMapping) throws SuperCsvReflectionException {
if( source == null ) {
throw new NullPointerException("the bean to write should not be null");
} else if( nameMapping == null ) {
throw new NullPointerException(
"the nameMapping array can't be null as it's used to map from fields to columns");
}
beanValues.clear();
for( int i = 0; i < nameMapping.length; i++ ) {
final String fieldName = nameMapping[i];
if( fieldName == null ) {
beanValues.add(null); // assume they always want a blank column
} else {
Method getMethod = cache.getGetMethod(source, fieldName);
try {
beanValues.add(getMethod.invoke(source));
}
catch(final Exception e) {
throw new SuperCsvReflectionException(String.format("error extracting bean value for field %s",
fieldName), e);
}
}
}
}
/**
* {@inheritDoc}
*/
public void write(final Object source, final String... nameMapping) throws IOException {
// update the current row/line numbers
super.incrementRowAndLineNo();
// extract the bean values
extractBeanValues(source, nameMapping);
// write the list
super.writeRow(beanValues);
}
/**
* {@inheritDoc}
*/
public void write(final Object source, final String[] nameMapping, final CellProcessor[] processors)
throws IOException {
// update the current row/line numbers
super.incrementRowAndLineNo();
// extract the bean values
extractBeanValues(source, nameMapping);
// execute the processors for each column
Util.executeCellProcessors(processedColumns, beanValues, processors, getLineNumber(), getRowNumber());
// write the list
super.writeRow(processedColumns);
}
}
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