Java tutorial
/* * Copyright 2006-2012 the original author or authors. * * 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 * * https://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.springframework.batch.item.database.support; import static org.springframework.batch.support.DatabaseType.DB2; import static org.springframework.batch.support.DatabaseType.DB2VSE; import static org.springframework.batch.support.DatabaseType.DB2ZOS; import static org.springframework.batch.support.DatabaseType.DB2AS400; import static org.springframework.batch.support.DatabaseType.DERBY; import static org.springframework.batch.support.DatabaseType.H2; import static org.springframework.batch.support.DatabaseType.HSQL; import static org.springframework.batch.support.DatabaseType.MYSQL; import static org.springframework.batch.support.DatabaseType.ORACLE; import static org.springframework.batch.support.DatabaseType.POSTGRES; import static org.springframework.batch.support.DatabaseType.SQLITE; import static org.springframework.batch.support.DatabaseType.SQLSERVER; import static org.springframework.batch.support.DatabaseType.SYBASE; import java.util.HashMap; import java.util.LinkedHashMap; import java.util.Map; import javax.sql.DataSource; import org.springframework.batch.item.database.Order; import org.springframework.batch.item.database.PagingQueryProvider; import org.springframework.batch.support.DatabaseType; import org.springframework.beans.factory.FactoryBean; import org.springframework.jdbc.support.MetaDataAccessException; import org.springframework.util.Assert; import org.springframework.util.StringUtils; /** * Factory bean for {@link PagingQueryProvider} interface. The database type * will be determined from the data source if not provided explicitly. Valid * types are given by the {@link DatabaseType} enum. * * @author Dave Syer * @author Michael Minella */ public class SqlPagingQueryProviderFactoryBean implements FactoryBean<PagingQueryProvider> { private DataSource dataSource; private String databaseType; private String fromClause; private String whereClause; private String selectClause; private String groupClause; private Map<String, Order> sortKeys; private Map<DatabaseType, AbstractSqlPagingQueryProvider> providers = new HashMap<>(); { providers.put(DB2, new Db2PagingQueryProvider()); providers.put(DB2VSE, new Db2PagingQueryProvider()); providers.put(DB2ZOS, new Db2PagingQueryProvider()); providers.put(DB2AS400, new Db2PagingQueryProvider()); providers.put(DERBY, new DerbyPagingQueryProvider()); providers.put(HSQL, new HsqlPagingQueryProvider()); providers.put(H2, new H2PagingQueryProvider()); providers.put(MYSQL, new MySqlPagingQueryProvider()); providers.put(ORACLE, new OraclePagingQueryProvider()); providers.put(POSTGRES, new PostgresPagingQueryProvider()); providers.put(SQLITE, new SqlitePagingQueryProvider()); providers.put(SQLSERVER, new SqlServerPagingQueryProvider()); providers.put(SYBASE, new SybasePagingQueryProvider()); } /** * @param groupClause SQL GROUP BY clause part of the SQL query string */ public void setGroupClause(String groupClause) { this.groupClause = groupClause; } /** * @param databaseType the databaseType to set */ public void setDatabaseType(String databaseType) { this.databaseType = databaseType; } /** * @param dataSource the dataSource to set */ public void setDataSource(DataSource dataSource) { this.dataSource = dataSource; } /** * @param fromClause the fromClause to set */ public void setFromClause(String fromClause) { this.fromClause = fromClause; } /** * @param whereClause the whereClause to set */ public void setWhereClause(String whereClause) { this.whereClause = whereClause; } /** * @param selectClause the selectClause to set */ public void setSelectClause(String selectClause) { this.selectClause = selectClause; } /** * @param sortKeys the sortKeys to set */ public void setSortKeys(Map<String, Order> sortKeys) { this.sortKeys = sortKeys; } public void setSortKey(String key) { Assert.doesNotContain(key, ",", "String setter is valid for a single ASC key only"); Map<String, Order> keys = new LinkedHashMap<>(); keys.put(key, Order.ASCENDING); this.sortKeys = keys; } /** * Get a {@link PagingQueryProvider} instance using the provided properties * and appropriate for the given database type. * * @see FactoryBean#getObject() */ @Override public PagingQueryProvider getObject() throws Exception { DatabaseType type; try { type = databaseType != null ? DatabaseType.valueOf(databaseType.toUpperCase()) : DatabaseType.fromMetaData(dataSource); } catch (MetaDataAccessException e) { throw new IllegalArgumentException( "Could not inspect meta data for database type. You have to supply it explicitly.", e); } AbstractSqlPagingQueryProvider provider = providers.get(type); Assert.state(provider != null, "Should not happen: missing PagingQueryProvider for DatabaseType=" + type); provider.setFromClause(fromClause); provider.setWhereClause(whereClause); provider.setSortKeys(sortKeys); if (StringUtils.hasText(selectClause)) { provider.setSelectClause(selectClause); } if (StringUtils.hasText(groupClause)) { provider.setGroupClause(groupClause); } provider.init(dataSource); return provider; } /** * Always returns {@link PagingQueryProvider}. * * @see FactoryBean#getObjectType() */ @Override public Class<PagingQueryProvider> getObjectType() { return PagingQueryProvider.class; } /** * Always returns true. * @see FactoryBean#isSingleton() */ @Override public boolean isSingleton() { return true; } }