package org.openslx.imagemaster.db;
import java.io.Closeable;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
/**
* Class for creating {@link PreparedStatement}s with named parameters. Based on
* <a href=
* "http://www.javaworld.com/article/2077706/core-java/named-parameters-for-preparedstatement.html?page=2"
* >Named Parameters for PreparedStatement</a>
*/
public class MysqlStatement implements Closeable {
private static final QueryCache cache = new QueryCache();
private final PreparsedQuery query;
private final PreparedStatement statement;
private final List<ResultSet> openResultSets = new ArrayList<>();
MysqlStatement(Connection con, String sql) throws SQLException {
PreparsedQuery query;
synchronized (cache) {
query = cache.get(sql);
}
if (query == null) {
query = parse(sql);
synchronized (cache) {
cache.put(sql, query);
}
}
this.query = query;
this.statement = con.prepareStatement(query.sql);
}
/**
* Returns the indexes for a parameter.
*
* @param name parameter name
* @return parameter indexes
* @throws IllegalArgumentException if the parameter does not exist
*/
private List<Integer> getIndexes(String name) {
List<Integer> indexes = query.indexMap.get(name);
if (indexes == null) {
throw new IllegalArgumentException("Parameter not found: " + name);
}
return indexes;
}
/**
* Sets a parameter.
*
* @param name parameter name
* @param value parameter value
* @throws SQLException if an error occurred
* @throws IllegalArgumentException if the parameter does not exist
* @see PreparedStatement#setObject(int, java.lang.Object)
*/
public void setObject(String name, Object value) throws SQLException {
List<Integer> indexes = getIndexes(name);
for (Integer index : indexes) {
statement.setObject(index, value);
}
}
/**
* Sets a parameter.
*
* @param name parameter name
* @param value parameter value
* @throws SQLException if an error occurred
* @throws IllegalArgumentException if the parameter does not exist
* @see PreparedStatement#setString(int, java.lang.String)
*/
public void setString(String name, String value) throws SQLException {
List<Integer> indexes = getIndexes(name);
for (Integer index : indexes) {
statement.setString(index, value);
}
}
/**
* Sets a parameter.
*
* @param name parameter name
* @param value parameter value
* @throws SQLException if an error occurred
* @throws IllegalArgumentException if the parameter does not exist
* @see PreparedStatement#setInt(int, int)
*/
public void setInt(String name, int value) throws SQLException {
List<Integer> indexes = getIndexes(name);
for (Integer index : indexes) {
statement.setInt(index, value);
}
}
/**
* Sets a parameter.
*
* @param name parameter name
* @param value parameter value
* @throws SQLException if an error occurred
* @throws IllegalArgumentException if the parameter does not exist
* @see PreparedStatement#setLong(int, long)
*/
public void setLong(String name, long value) throws SQLException {
List<Integer> indexes = getIndexes(name);
for (Integer index : indexes) {
statement.setLong(index, value);
}
}
/**
* Sets a parameter.
*
* @param name parameter name
* @param value parameter value
* @throws SQLException if an error occurred
* @throws IllegalArgumentException if the parameter does not exist
* @see PreparedStatement#setBoolean(int, boolean)
*/
public void setBoolean(String name, boolean value) throws SQLException {
List<Integer> indexes = getIndexes(name);
for (Integer index : indexes) {
statement.setBoolean(index, value);
}
}
/**
* Sets a parameter.
*
* @param name parameter name
* @param value parameter value
* @throws SQLException if an error occurred
* @throws IllegalArgumentException if the parameter does not exist
* @see PreparedStatement#setBoolean(int, boolean)
*/
public void setBinary(String name, byte[] value) throws SQLException {
List<Integer> indexes = getIndexes(name);
for (Integer index : indexes) {
statement.setBytes(index, value);
}
}
/**
* Executes the statement.
*
* @return true if the first result is a {@link ResultSet}
* @throws SQLException if an error occurred
* @see PreparedStatement#execute()
*/
public boolean execute() throws SQLException {
return statement.execute();
}
/**
* Executes the statement, which must be a query.
*
* @return the query results
* @throws SQLException if an error occurred
* @see PreparedStatement#executeQuery()
*/
public ResultSet executeQuery() throws SQLException {
ResultSet rs = statement.executeQuery();
openResultSets.add(rs);
return rs;
}
/**
* Executes the statement, which must be an SQL INSERT, UPDATE or DELETE
* statement; or an SQL statement that returns nothing, such as a DDL
* statement.
*
* @return number of rows affected
* @throws SQLException if an error occurred
* @see PreparedStatement#executeUpdate()
*/
public int executeUpdate() throws SQLException {
return statement.executeUpdate();
}
/**
* Closes the statement.
*
* @see Statement#close()
*/
@Override
public void close() {
for (ResultSet rs : openResultSets) {
try {
rs.close();
} catch (SQLException e) {
//
}
}
try {
statement.close();
} catch (SQLException e) {
// Nothing to do
}
}
/**
* Adds the current set of parameters as a batch entry.
*
* @throws SQLException if something went wrong
*/
public void addBatch() throws SQLException {
statement.addBatch();
}
/**
* Executes all of the batched statements.
*
* See {@link Statement#executeBatch()} for details.
*
* @return update counts for each statement
* @throws SQLException if something went wrong
*/
public int[] executeBatch() throws SQLException {
return statement.executeBatch();
}
// static methods
private static PreparsedQuery parse(String query) {
int length = query.length();
StringBuffer parsedQuery = new StringBuffer(length);
Map<String, List<Integer>> paramMap = new HashMap<>();
boolean inSingleQuote = false;
boolean inDoubleQuote = false;
boolean hasBackslash = false;
int index = 1;
for (int i = 0; i < length; i++) {
char c = query.charAt(i);
if (hasBackslash) {
// Last char was a backslash, so we ignore the current char
hasBackslash = false;
} else if (c == '\\') {
// This is a backslash, next char will be escaped
hasBackslash = true;
} else if (inSingleQuote) {
// End of quoted string
if (c == '\'') {
inSingleQuote = false;
}
} else if (inDoubleQuote) {
// End of quoted string
if (c == '"') {
inDoubleQuote = false;
}
} else {
// Not in string, look for named params
if (c == '\'') {
inSingleQuote = true;
} else if (c == '"') {
inDoubleQuote = true;
} else if (c == ':' && i + 1 < length && Character.isJavaIdentifierStart(query.charAt(i + 1))) {
int j = i + 2;
while (j < length && Character.isJavaIdentifierPart(query.charAt(j))) {
j++;
}
String name = query.substring(i + 1, j);
c = '?'; // replace the parameter with a question mark
i += name.length(); // skip past the end of the parameter
List<Integer> indexList = paramMap.get(name);
if (indexList == null) {
indexList = new ArrayList<>();
paramMap.put(name, indexList);
}
indexList.add(new Integer(index));
index++;
}
}
parsedQuery.append(c);
}
return new PreparsedQuery(parsedQuery.toString(), paramMap);
}
// private helper classes
private static class PreparsedQuery {
private final Map<String, List<Integer>> indexMap;
private final String sql;
public PreparsedQuery(String sql, Map<String, List<Integer>> indexMap) {
this.sql = sql;
this.indexMap = indexMap;
}
}
private static class QueryCache extends LinkedHashMap<String, PreparsedQuery> {
private static final long serialVersionUID = 1L;
public QueryCache() {
super(30, (float) 0.75, true);
}
@Override
protected boolean removeEldestEntry(Map.Entry<String, PreparsedQuery> eldest) {
return size() > 40;
}
}
}
