Java tutorial
/* * Data Hub Service (DHuS) - For Space data distribution. * Copyright (C) 2013,2014,2015 GAEL Systems * * This file is part of DHuS software sources. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as * published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package fr.gael.dhus.database.liquibase; import java.io.BufferedOutputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.sql.Blob; import java.sql.PreparedStatement; import java.sql.ResultSet; import org.apache.commons.compress.utils.IOUtils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import liquibase.change.custom.CustomTaskChange; import liquibase.database.Database; import liquibase.database.jvm.JdbcConnection; import liquibase.exception.CustomChangeException; import liquibase.exception.SetupException; import liquibase.exception.ValidationErrors; import liquibase.resource.ResourceAccessor; public class CopyProductImagesBlobToFile implements CustomTaskChange { private static Log logger = LogFactory.getLog(CopyProductImagesBlobToFile.class); @Override public String getConfirmationMessage() { return null; } @Override public void setFileOpener(ResourceAccessor resource_accessor) { } @Override public void setUp() throws SetupException { } @Override public ValidationErrors validate(Database arg0) { return null; } /** * This method executes: * - extraction of quicklooks and thumbnails from the database to files, * - references these files into the data base. * * remove/update processes are let to liquibase scripts. */ @Override public void execute(Database database) throws CustomChangeException { PreparedStatement products = null; ResultSet products_res = null; JdbcConnection db_connection = (JdbcConnection) database.getConnection(); try { products = db_connection.prepareStatement("SELECT PRODUCT.ID ID," + " PRODUCT.DOWNLOAD_PATH DWN_PATH, " + " PRODUCT.PATH PRODUCT_PATH," + " IMAGE.QUICKLOOK QUICKLOOK," + " IMAGE.THUMBNAIL THUMBNAIL " + "FROM PRODUCTS PRODUCT, PRODUCT_IMAGES IMAGE " + "WHERE PRODUCT.IMAGES_ID=IMAGE.ID"); products_res = products.executeQuery(); while (products_res.next()) { Blob ql = (Blob) products_res.getObject("QUICKLOOK"); Blob th = (Blob) products_res.getObject("THUMBNAIL"); long id = products_res.getLong("ID"); String download_path = products_res.getString("DWN_PATH"); String product_path = products_res.getString("PRODUCT_PATH"); if (download_path == null) { logger.error("No download path for product '" + product_path + "': product images not managed"); continue; } // copy blobs into files and update products table if (ql != null) { // Copy file String ql_path = download_path.replaceAll("(?i)(.*).zip", "$1-ql.gif"); blobToFile(ql, ql_path); // Update products table PreparedStatement product_flags_stmt = null; // Add related flags try { product_flags_stmt = db_connection .prepareStatement("UPDATE PRODUCTS SET QUICKLOOK_PATH=? WHERE ID=?"); product_flags_stmt.setString(1, ql_path); product_flags_stmt.setLong(2, id); product_flags_stmt.execute(); } finally { if (product_flags_stmt != null) try { product_flags_stmt.close(); } catch (Exception e) { logger.warn("Cannot close Statement !"); } } } if (th != null) { String th_path = download_path.replaceAll("(?i)(.*).zip", "$1-th.gif"); blobToFile(th, th_path); // Update products table PreparedStatement product_flags_stmt = null; // Add related flags try { product_flags_stmt = db_connection .prepareStatement("UPDATE PRODUCTS SET THUMBNAIL_PATH=? WHERE ID=?"); product_flags_stmt.setString(1, th_path); product_flags_stmt.setLong(2, id); product_flags_stmt.execute(); } finally { if (product_flags_stmt != null) try { product_flags_stmt.close(); } catch (Exception e) { logger.warn("Cannot close Statement !"); } } } } // RUN CHECKPOINT TO clean lob data PreparedStatement product_flags_stmt = null; try { product_flags_stmt = db_connection.prepareStatement("CHECKPOINT DEFRAG"); product_flags_stmt.execute(); } catch (Exception e) { logger.error("Cannot perform database checkpoint defrag command", e); } finally { if (product_flags_stmt != null) try { product_flags_stmt.close(); } catch (Exception e) { logger.warn("Cannot close Statement !", e); } } } catch (Exception e) { throw new CustomChangeException("Cannot move Blobs from product", e); } finally { if (products_res != null) { try { products_res.close(); } catch (Exception e) { logger.warn("Cannot close ResultSet !"); } } if (products != null) { try { products.close(); } catch (Exception e) { logger.warn("Cannot close Statement !"); } } //if (db_connection!=null) try { db_connection.close (); } // catch (Exception e) {} } } private void blobToFile(Blob blob, String out) { InputStream is = null; OutputStream os = null; BufferedOutputStream bos = null; try { is = blob.getBinaryStream(); os = new FileOutputStream(out); bos = new BufferedOutputStream(os); IOUtils.copy(is, bos); bos.flush(); } catch (Exception e) { logger.error("Cannot copy blob into '" + out + "'.", e); } finally { if (is != null) { try { is.close(); } catch (IOException e) { logger.warn("Cannot close InputStream !"); } } if (bos != null) { try { bos.close(); } catch (IOException e) { logger.warn("Cannot close BufferedOutputStream !"); } } if (os != null) { try { os.close(); } catch (IOException e) { logger.warn("Cannot close OutputStream !"); } } } } }