com.zaxxer.sansorm.internal.OrmReader Maven / Gradle / Ivy
/*
Copyright 2012, Brett Wooldridge
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.zaxxer.sansorm.internal;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
/**
* OrmReader
*/
// MULTIPLESTRINGS:OFF
public class OrmReader extends OrmBase
{
private static final int CACHE_SIZE = Integer.getInteger("com.zaxxer.sansorm.statementCacheSize", 500);
private static final Map fromClauseStmtCache;
static
{
fromClauseStmtCache = Collections.synchronizedMap(new LinkedHashMap(CACHE_SIZE) {
private static final long serialVersionUID = 6259942586093454872L;
@Override
protected boolean removeEldestEntry(java.util.Map.Entry eldest)
{
return this.size() > CACHE_SIZE;
}
});
}
public static List statementToList(PreparedStatement stmt, Class clazz, Object... args) throws SQLException
{
try
{
populateStatementParameters(stmt, args);
return resultSetToList(stmt.executeQuery(), clazz);
}
finally
{
stmt.close();
}
}
// COMPLEXITY:OFF
public static List resultSetToList(ResultSet resultSet, Class targetClass) throws SQLException
{
List list = new ArrayList();
if (!resultSet.next())
{
resultSet.close();
return list;
}
Introspected introspected = Introspector.getIntrospected(targetClass);
final boolean hasJoinColumns = introspected.hasSelfJoinColumn();
Map deferredSelfJoinFkMap = (hasJoinColumns ? new HashMap() : null);
Map idToTargetMap = (hasJoinColumns ? new HashMap() : null);
ResultSetMetaData metaData = resultSet.getMetaData();
final int columnCount = metaData.getColumnCount();
final String[] columnNames = new String[columnCount];
for (int column = columnCount; column > 0; column--)
{
columnNames[column - 1] = metaData.getColumnName(column).toLowerCase();
}
try
{
do
{
T target = targetClass.newInstance();
list.add(target);
for (int column = columnCount; column > 0; column--)
{
Object columnValue = resultSet.getObject(column);
if (columnValue == null)
{
continue;
}
String columnName = columnNames[column - 1];
if (hasJoinColumns && introspected.isSelfJoinColumn(columnName))
{
deferredSelfJoinFkMap.put(target, columnValue);
}
else
{
introspected.set(target, columnName, columnValue);
}
}
if (hasJoinColumns)
{
idToTargetMap.put(introspected.getActualIds(target)[0], target);
}
}
while (resultSet.next());
resultSet.close();
if (hasJoinColumns)
{
// set the self join object instances based on the foreign key ids...
String idColumn = introspected.getSelfJoinColumn();
for (Entry entry : deferredSelfJoinFkMap.entrySet())
{
T value = idToTargetMap.get(entry.getValue());
if (value != null)
{
introspected.set(entry.getKey(), idColumn, value);
}
}
}
}
catch (Exception e)
{
throw new RuntimeException(e);
}
return list;
}
// COMPLEXITY:ON
public static T statementToObject(PreparedStatement stmt, Class clazz, Object... args) throws SQLException
{
populateStatementParameters(stmt, args);
ResultSet resultSet = null;
try
{
resultSet = stmt.executeQuery();
if (resultSet.next())
{
T target = (T) clazz.newInstance();
return resultSetToObject(resultSet, target);
}
return null;
}
catch (Exception e)
{
throw new RuntimeException(e);
}
finally
{
if (resultSet != null)
{
resultSet.close();
}
stmt.close();
}
}
public static T resultSetToObject(ResultSet resultSet, T target) throws SQLException
{
Set ignoreNone = Collections.emptySet();
return resultSetToObject(resultSet, target, ignoreNone);
}
public static T resultSetToObject(ResultSet resultSet, T target, Set ignoredColumns) throws SQLException
{
ResultSetMetaData metaData = resultSet.getMetaData();
Introspected introspected = Introspector.getIntrospected(target.getClass());
for (int column = metaData.getColumnCount(); column > 0; column--)
{
String columnName = metaData.getColumnName(column).toLowerCase();
if (ignoredColumns.contains(columnName))
{
continue;
}
Object columnValue = resultSet.getObject(column);
if (columnValue == null)
{
continue;
}
introspected.set(target, columnName, columnValue);
}
return target;
}
public static T objectById(Connection connection, Class clazz, Object... args) throws SQLException
{
Introspected introspected = Introspector.getIntrospected(clazz);
StringBuilder where = new StringBuilder();
for (String column : introspected.getIdColumnNames())
{
where.append(column).append("=? AND ");
}
// the where clause can be length of zero if we are loading an object that is presumed to
// be the only row in the table and therefore has no id.
if (where.length() > 0)
{
where.setLength(where.length() - 5);
}
return objectFromClause(connection, clazz, where.toString(), args);
}
public static List listFromClause(Connection connection, Class clazz, String clause, Object... args) throws SQLException
{
String sql = generateSelectFromClause(clazz, clause);
PreparedStatement stmt = connection.prepareStatement(sql);
List list = statementToList(stmt, clazz, args);
stmt.close();
return list;
}
public static T objectFromClause(Connection connection, Class clazz, String clause, Object... args) throws SQLException
{
String sql = generateSelectFromClause(clazz, clause);
PreparedStatement stmt = connection.prepareStatement(sql);
return statementToObject(stmt, clazz, args);
}
public static int countObjectsFromClause(Connection connection, Class clazz, String clause, Object... args) throws SQLException
{
Introspected introspected = Introspector.getIntrospected(clazz);
String tableName = introspected.getTableName();
StringBuilder sql = new StringBuilder();
sql.append("SELECT COUNT(");
String countColumn = tableName + ".";
String[] idColumnNames = introspected.getIdColumnNames();
if (idColumnNames.length > 0)
{
countColumn += idColumnNames[0];
}
else
{
countColumn += introspected.getColumnNames()[0];
}
sql.append(countColumn).append(") FROM ").append(tableName).append(' ').append(tableName);
if (clause != null && !clause.isEmpty())
{
if (!clause.toUpperCase().contains("WHERE") && !clause.toUpperCase().contains("JOIN"))
{
sql.append(" WHERE ");
}
sql.append(' ').append(clause);
}
return numberFromSql(connection, sql.toString(), args).intValue();
}
public static Number numberFromSql(Connection connection, String sql, Object... args) throws SQLException
{
PreparedStatement stmt = connection.prepareStatement(sql);
try
{
populateStatementParameters(stmt, args);
ResultSet resultSet = stmt.executeQuery();
try
{
if (resultSet.next())
{
return (Number) resultSet.getObject(1);
}
return null;
}
finally
{
resultSet.close();
}
}
finally
{
if (stmt != null)
{
stmt.close();
}
}
}
private static String generateSelectFromClause(Class clazz, String clause)
{
String cacheKey = clazz.getName() + clause;
String sql = fromClauseStmtCache.get(cacheKey);
if (sql == null)
{
Introspected introspected = Introspector.getIntrospected(clazz);
String tableName = introspected.getTableName();
StringBuilder sqlSB = new StringBuilder();
sqlSB.append("SELECT ").append(getColumnsCsv(clazz, tableName)).append(" FROM ").append(tableName).append(' ').append(tableName);
if (clause != null && !clause.isEmpty())
{
if (!clause.toUpperCase().contains("WHERE") && !clause.toUpperCase().contains("JOIN"))
{
sqlSB.append(" WHERE ");
}
sqlSB.append(' ').append(clause);
}
sql = sqlSB.toString();
fromClauseStmtCache.put(cacheKey, sql);
}
return sql;
}
}
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