/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.metamodel.fixedwidth;
import java.io.File;
import java.io.InputStream;
import java.io.Reader;
import org.apache.metamodel.MetaModelException;
import org.apache.metamodel.QueryPostprocessDataContext;
import org.apache.metamodel.data.DataSet;
import org.apache.metamodel.schema.Column;
import org.apache.metamodel.schema.ColumnType;
import org.apache.metamodel.schema.MutableColumn;
import org.apache.metamodel.schema.MutableSchema;
import org.apache.metamodel.schema.MutableTable;
import org.apache.metamodel.schema.Schema;
import org.apache.metamodel.schema.Table;
import org.apache.metamodel.schema.TableType;
import org.apache.metamodel.util.AlphabeticSequence;
import org.apache.metamodel.util.FileHelper;
import org.apache.metamodel.util.FileResource;
import org.apache.metamodel.util.Resource;
import org.apache.metamodel.util.ResourceUtils;
/**
* DataContext implementation for fixed width value files.
*
* @author Kasper Sørensen
*/
public class FixedWidthDataContext extends QueryPostprocessDataContext {
private final Resource _resource;
private final FixedWidthConfiguration _configuration;
/**
* @deprecated use
* {@link #FixedWidthDataContext(File, FixedWidthConfiguration)}
* instead
*/
@Deprecated
public FixedWidthDataContext(String filename, String fileEncoding, int fixedValueWidth) {
this(new FileResource(filename), new FixedWidthConfiguration(fixedValueWidth));
}
/**
* @deprecated use
* {@link #FixedWidthDataContext(File, FixedWidthConfiguration)}
* instead
*/
@Deprecated
public FixedWidthDataContext(File file, String fileEncoding, int fixedValueWidth, int headerLineNumber) {
this(file, new FixedWidthConfiguration(headerLineNumber, fileEncoding, fixedValueWidth));
}
public FixedWidthDataContext(File file, FixedWidthConfiguration configuration) {
_resource = new FileResource(file);
_configuration = configuration;
}
public FixedWidthDataContext(Resource resource, FixedWidthConfiguration configuration) {
_resource = resource;
_configuration = configuration;
}
/**
* Gets the Fixed width value configuration used.
*
* @return a fixed width configuration
*/
public FixedWidthConfiguration getConfiguration() {
return _configuration;
}
/**
* Gets the file being read.
*
* @return a file
*
* @deprecated use {@link #getResource()} instead.
*/
@Deprecated
public File getFile() {
if (_resource instanceof FileResource) {
return ((FileResource) _resource).getFile();
}
return null;
}
/**
* Gets the resource being read
*
* @return
*/
public Resource getResource() {
return _resource;
}
@Override
protected Schema getMainSchema() throws MetaModelException {
final String schemaName = getDefaultSchemaName();
final MutableSchema schema = new MutableSchema(schemaName);
final String tableName = _resource.getName();
final MutableTable table = new MutableTable(tableName, TableType.TABLE, schema);
schema.addTable(table);
final FixedWidthReader reader = createReader();
final String[] columnNames;
try {
if (_configuration.getColumnNameLineNumber() != FixedWidthConfiguration.NO_COLUMN_NAME_LINE) {
for (int i = 1; i < _configuration.getColumnNameLineNumber(); i++) {
reader.readLine();
}
columnNames = reader.readLine();
} else {
columnNames = reader.readLine();
if (columnNames != null) {
AlphabeticSequence sequence = new AlphabeticSequence();
for (int i = 0; i < columnNames.length; i++) {
columnNames[i] = sequence.next();
}
}
}
} finally {
FileHelper.safeClose(reader);
}
if (columnNames != null) {
for (int i = 0; i < columnNames.length; i++) {
final String columnName = columnNames[i];
final MutableColumn column = new MutableColumn(columnName, ColumnType.VARCHAR, table, i, true);
column.setColumnSize(_configuration.getValueWidth(i));
table.addColumn(column);
}
}
return schema;
}
@Override
protected String getMainSchemaName() throws MetaModelException {
return ResourceUtils.getParentName(_resource);
}
@Override
public DataSet materializeMainSchemaTable(Table table, Column[] columns, int maxRows) {
final FixedWidthReader reader = createReader();
try {
for (int i = 1; i <= _configuration.getColumnNameLineNumber(); i++) {
reader.readLine();
}
} catch (IllegalStateException e) {
FileHelper.safeClose(reader);
throw e;
}
if (maxRows > 0) {
return new FixedWidthDataSet(reader, columns, maxRows);
} else {
return new FixedWidthDataSet(reader, columns, null);
}
}
private FixedWidthReader createReader() {
final InputStream inputStream = _resource.read();
final Reader fileReader = FileHelper.getReader(inputStream, _configuration.getEncoding());
final FixedWidthReader reader;
if (_configuration.isConstantValueWidth()) {
reader = new FixedWidthReader(fileReader, _configuration.getFixedValueWidth(),
_configuration.isFailOnInconsistentLineWidth());
} else {
reader = new FixedWidthReader(fileReader, _configuration.getValueWidths(),
_configuration.isFailOnInconsistentLineWidth());
}
return reader;
}
}