Java tutorial
/* * Copyright 2014 Dan Haywood * * 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.isisaddons.module.excel.dom; import java.io.ByteArrayInputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.util.List; import java.util.Map; import com.google.common.collect.Lists; import com.google.common.collect.Maps; import org.apache.poi.openxml4j.exceptions.InvalidFormatException; import org.apache.poi.ss.usermodel.Cell; import org.apache.poi.ss.usermodel.CellStyle; import org.apache.poi.ss.usermodel.CreationHelper; import org.apache.poi.ss.usermodel.Row; import org.apache.poi.ss.usermodel.Sheet; import org.apache.poi.ss.usermodel.Workbook; import org.apache.poi.xssf.usermodel.XSSFWorkbook; import org.apache.isis.applib.DomainObjectContainer; import org.apache.isis.applib.annotation.Where; import org.apache.isis.applib.filter.Filter; import org.apache.isis.applib.filter.Filters; import org.apache.isis.applib.services.bookmark.BookmarkService; import org.apache.isis.applib.util.ObjectContracts; import org.apache.isis.core.metamodel.adapter.ObjectAdapter; import org.apache.isis.core.metamodel.adapter.mgr.AdapterManager; import org.apache.isis.core.metamodel.facets.object.viewmodel.ViewModelFacet; import org.apache.isis.core.metamodel.spec.ObjectSpecification; import org.apache.isis.core.metamodel.spec.SpecificationLoader; import org.apache.isis.core.metamodel.spec.feature.Contributed; import org.apache.isis.core.metamodel.spec.feature.ObjectAssociation; import org.apache.isis.core.metamodel.spec.feature.OneToOneAssociation; class ExcelConverter { private static final String XLSX_SUFFIX = ".xlsx"; @SuppressWarnings({ "unchecked", "deprecation" }) private static final Filter<ObjectAssociation> VISIBLE_PROPERTIES = Filters.and( ObjectAssociation.Filters.PROPERTIES, ObjectAssociation.Filters.staticallyVisible(Where.STANDALONE_TABLES)); static class RowFactory { private final Sheet sheet; private int rowNum; RowFactory(final Sheet sheet) { this.sheet = sheet; } public Row newRow() { return sheet.createRow((short) rowNum++); } } // ////////////////////////////////////// private final SpecificationLoader specificationLoader; private final AdapterManager adapterManager; private final BookmarkService bookmarkService; ExcelConverter(final SpecificationLoader specificationLoader, final AdapterManager adapterManager, final BookmarkService bookmarkService) { this.specificationLoader = specificationLoader; this.adapterManager = adapterManager; this.bookmarkService = bookmarkService; } // ////////////////////////////////////// <T> File toFile(final Class<T> cls, final List<T> domainObjects) throws IOException { final ObjectSpecification objectSpec = specificationLoader.loadSpecification(cls); final List<ObjectAdapter> adapters = Lists.transform(domainObjects, ObjectAdapter.Functions.adapterForUsing(adapterManager)); @SuppressWarnings("deprecation") final List<? extends ObjectAssociation> propertyList = objectSpec.getAssociations(VISIBLE_PROPERTIES); final Workbook wb = new XSSFWorkbook(); final String sheetName = cls.getSimpleName(); final File tempFile = File.createTempFile(ExcelConverter.class.getName(), sheetName + XLSX_SUFFIX); final FileOutputStream fos = new FileOutputStream(tempFile); final Sheet sheet = wb.createSheet(sheetName); final ExcelConverter.RowFactory rowFactory = new RowFactory(sheet); final Row headerRow = rowFactory.newRow(); // header row int i = 0; for (final ObjectAssociation property : propertyList) { final Cell cell = headerRow.createCell((short) i++); cell.setCellValue(property.getName()); } final CellMarshaller cellMarshaller = newCellMarshaller(wb); // detail rows for (final ObjectAdapter objectAdapter : adapters) { final Row detailRow = rowFactory.newRow(); i = 0; for (final ObjectAssociation oa : propertyList) { final Cell cell = detailRow.createCell((short) i++); final OneToOneAssociation otoa = (OneToOneAssociation) oa; cellMarshaller.setCellValue(objectAdapter, otoa, cell); } } // freeze panes sheet.createFreezePane(0, 1); wb.write(fos); fos.close(); return tempFile; } <T> List<T> fromBytes(final Class<T> cls, final byte[] bs, final DomainObjectContainer container) throws IOException, InvalidFormatException { final List<T> importedItems = Lists.newArrayList(); final ObjectSpecification objectSpec = specificationLoader.loadSpecification(cls); final ViewModelFacet viewModelFacet = objectSpec.getFacet(ViewModelFacet.class); try (ByteArrayInputStream bais = new ByteArrayInputStream(bs)) { final Workbook wb = org.apache.poi.ss.usermodel.WorkbookFactory.create(bais); final CellMarshaller cellMarshaller = this.newCellMarshaller(wb); final Sheet sheet = wb.getSheetAt(0); boolean header = true; final Map<Integer, Property> propertyByColumn = Maps.newHashMap(); for (final Row row : sheet) { if (header) { for (final Cell cell : row) { if (cell.getCellType() != Cell.CELL_TYPE_BLANK) { final int columnIndex = cell.getColumnIndex(); final String propertyName = cellMarshaller.getStringCellValue(cell); final OneToOneAssociation property = getAssociation(objectSpec, propertyName); if (property != null) { final Class<?> propertyType = property.getSpecification().getCorrespondingClass(); propertyByColumn.put(columnIndex, new Property(propertyName, property, propertyType)); } } } header = false; } else { // detail try { // Let's require at least one column to be not null for detecting a blank row. // Excel can have physical rows with cells empty that it seem do not existent for the user. ObjectAdapter templateAdapter = null; T imported = null; for (final Cell cell : row) { final int columnIndex = cell.getColumnIndex(); final Property property = propertyByColumn.get(columnIndex); if (property != null) { final OneToOneAssociation otoa = property.getOneToOneAssociation(); final Object value = cellMarshaller.getCellValue(cell, otoa); if (value != null) { if (imported == null) { // copy the row into a new object imported = container.newTransientInstance(cls); templateAdapter = this.adapterManager.adapterFor(imported); } final ObjectAdapter valueAdapter = this.adapterManager.adapterFor(value); otoa.set(templateAdapter, valueAdapter); } } else { // not expected; just ignore. } } if (imported != null) { if (viewModelFacet != null) { // if there is a view model, then use the imported object as a template // in order to create a regular view model. final String memento = viewModelFacet.memento(imported); final T viewModel = container.newViewModelInstance(cls, memento); importedItems.add(viewModel); } else { // else, just return the imported items as simple transient instances. importedItems.add(imported); } } } catch (final Exception e) { bais.close(); throw new ExcelService.Exception( String.format("Error processing Excel row nr. %d. Message: %s", row.getRowNum(), e.getMessage()), e); } } } } return importedItems; } private OneToOneAssociation getAssociation(final ObjectSpecification objectSpec, final String propertyName) { final List<ObjectAssociation> associations = objectSpec.getAssociations(Contributed.INCLUDED); for (final ObjectAssociation association : associations) { if (propertyName.equals(association.getName()) && association instanceof OneToOneAssociation) { return (OneToOneAssociation) association; } } return null; } static class Property { private final String name; private final Class<?> type; private final OneToOneAssociation property; private Object currentValue; public Property(final String name, final OneToOneAssociation property, final Class<?> type) { this.name = name; this.property = property; this.type = type; } public String getName() { return name; } public OneToOneAssociation getOneToOneAssociation() { return property; } public Class<?> getType() { return type; } public Object getCurrentValue() { return currentValue; } public void setCurrentValue(final Object currentValue) { this.currentValue = currentValue; } @Override public String toString() { return ObjectContracts.toString(this, "name,type,currentValue"); } } @SuppressWarnings("unused") private void autoSize(final Sheet sh, final int numProps) { for (int prop = 0; prop < numProps; prop++) { sh.autoSizeColumn(prop); } } // ////////////////////////////////////// protected CellMarshaller newCellMarshaller(final Workbook wb) { final CellStyle dateCellStyle = createDateFormatCellStyle(wb); final CellMarshaller cellMarshaller = new CellMarshaller(bookmarkService, dateCellStyle); return cellMarshaller; } protected CellStyle createDateFormatCellStyle(final Workbook wb) { final CreationHelper createHelper = wb.getCreationHelper(); final short dateFormat = createHelper.createDataFormat().getFormat("yyyy-mm-dd"); final CellStyle dateCellStyle = wb.createCellStyle(); dateCellStyle.setDataFormat(dateFormat); return dateCellStyle; } }