Java tutorial
/* Copyright 2014 Georg Kohlweiss 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 com.github.gekoh.yagen.api; import org.apache.commons.lang.StringUtils; import org.hibernate.cfg.EJB3NamingStrategy; import org.hibernate.mapping.Constraint; import org.hibernate.mapping.ForeignKey; import org.hibernate.mapping.UniqueKey; import java.lang.reflect.Field; /** * @author Georg Kohlweiss */ public class DefaultNamingStrategy extends EJB3NamingStrategy implements NamingStrategy { private static final org.slf4j.Logger LOG = org.slf4j.LoggerFactory.getLogger(DefaultNamingStrategy.class); @Override public String classToTableName(String className) { try { Class<?> aClass = Class.forName(className); if (aClass.isAnnotationPresent(javax.persistence.Table.class)) { String tableName = aClass.getAnnotation(javax.persistence.Table.class).name(); if (StringUtils.isNotEmpty(tableName)) { return tableName(tableName); } } } catch (ClassNotFoundException ignore) { } return super.classToTableName(className); } @Override public String classToTableShortName(String className) { try { Class<?> aClass = Class.forName(className); String tableShortName = null; if (aClass.isAnnotationPresent(Table.class)) { tableShortName = aClass.getAnnotation(Table.class).shortName(); } if (StringUtils.isEmpty(tableShortName)) { try { Field tblShortNameField = aClass.getDeclaredField("TABLE_NAME_SHORT"); if (tblShortNameField != null) { tableShortName = tblShortNameField.get(null).toString(); } } catch (Exception ignore) { } } if (StringUtils.isEmpty(tableShortName)) { tableShortName = tableShortNameFromTableName(classToTableName(className)); } return tableShortName(tableShortName); } catch (ClassNotFoundException e) { throw new IllegalStateException("cannot get table short name from class " + className, e); } } @Override public String tableShortName(String tableShortName) { return tableShortName.toLowerCase(); } @Override public String tableShortNameFromTableName(String tableName) { return generateShortName(tableName, null, null); } @Override public String constraintName(String constraintName) { return constraintName; } @Override public String constraintName(Constraint constraint, String entityClass) { String name = constraint.getName(); if (constraint instanceof ForeignKey || constraint instanceof UniqueKey) { StringBuilder colList = new StringBuilder(); for (org.hibernate.mapping.Column column : (Iterable<? extends org.hibernate.mapping.Column>) constraint .getColumns()) { if (colList.length() > 0) { colList.append(", "); } colList.append(column.getName().toLowerCase()); } name = beautifyConstraintName(name, entityClass, tableName(constraint.getTable().getName()), concatColumnNames(colList.toString())); } return constraintName(name); } @Override public String constraintName(UniqueConstraint constraint) { return constraintName(constraint.name()); } @Override public String constraintName(CheckConstraint constraint) { return constraintName(constraint.name()); } @Override public String indexName(String indexName) { return indexName; } @Override public String indexName(Index index) { return indexName(index.name()); } @Override public String constraintName(String entityClass, String tableName, String colName, String suffix) { return constraintName(findName(entityClass, tableName, colName, suffix)); } @Override public String indexName(String entityClass, String tableName, String colName) { return findName(entityClass, tableName, colName, "_IX"); } @Override public String triggerName(String triggerName) { return triggerName; } @Override public String triggerName(String entityClass, String tableName, String colName, String suffix) { return triggerName(findName(entityClass, tableName, colName, suffix)); } @Override public String sequenceName(String sequenceName) { return sequenceName; } protected String beautifyConstraintName(String name, String entityClass, String tableName, String colList) { if (name.startsWith("FK") || name.startsWith("UK")) { String newName = findName(entityClass, tableName, colList, "_" + name.substring(0, 2)); LOG.debug("no constraint name specified for {}({}), using {}", new Object[] { tableName, colList, newName }); return newName; } return name; } public String findName(String entityClass, String tableName, String colName, String suffix) { String name = entityClass != null ? classToTableShortName(entityClass) : tableShortNameFromTableName(tableName); if (StringUtils.isEmpty(colName)) { if (tableName.length() + suffix.length() <= 30) { name = tableName; } } else { int remainingLength = 30 - name.length() - suffix.length(); if (remainingLength < 1) { throw new IllegalArgumentException( "cannot find object name, prefix " + name + " and suffix " + suffix + " too long"); } if (colName.length() > remainingLength - 1) { name += "_" + generateShortName(colName, remainingLength - 1, 5); } else { name += "_" + colName; } } return name + suffix; } public static String concatColumnNames(String columnNameList) { StringBuilder colName = new StringBuilder(); for (String s : columnNameList.split("[, ]")) { if (s.trim().length() < 1) { continue; } if (colName.length() > 0) { colName.append("_"); } colName.append(s.replace("_", "")); } return colName.toString(); } public static String generateShortName(String name, Integer maxLength, Integer charsPerGroup) { StringBuilder b = new StringBuilder(); int charsPg = charsPerGroup != null ? charsPerGroup : 1; int idx = 0, prevIdx = 0; while ((idx = name.indexOf('_', idx + 1)) > 0 && name.length() > idx) { b.append(name.substring(prevIdx, Math.min(Math.min(prevIdx + charsPg, name.length()), idx))); prevIdx = idx + 1; if (charsPg > 1) { b.append("_"); } } if (prevIdx > 0 && name.length() >= prevIdx) { b.append(name.substring(prevIdx, Math.min(prevIdx + charsPg, name.length()))); } if (b.length() < 1) { b.append(name); } if (maxLength != null && b.length() > maxLength) { b.delete(maxLength.intValue(), b.length()); } return b.toString(); } }