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A library for relational-database-based persistence in Java.
//
// samskivert library - useful routines for java programs
// Copyright (C) 2001-2012 Michael Bayne, et al.
// http://github.com/samskivert/samskivert/blob/master/COPYING
package com.samskivert.depot.impl.jdbc;
import com.google.common.base.Joiner;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Collections;
import java.util.List;
import static com.samskivert.depot.Log.log;
/**
* A superclass to help with the shrinking subset of SQL our supported dialects can agree on,
* or when there is disagreement, implement the most standard-compliant version and let the
* dialectal sub-classes override.
*/
public abstract class BaseLiaison implements DatabaseLiaison
{
public BaseLiaison () {
super();
}
// we override all the interface methods here so that our subclasses can use @Override without
// incurring the wrath of the Eclipse Java 1.5 compiler; Jesus Fuck, why do we support 1.5?
// from DatabaseLiaison
public abstract boolean matchesURL (String url);
// from DatabaseLiaison
public abstract boolean isDuplicateRowException (SQLException sqe);
// from DatabaseLiaison
public abstract boolean isTransientException (SQLException sqe);
@Deprecated
public int lastInsertedId (Connection conn, String table, String column) throws SQLException {
return lastInsertedId(conn, null, table, column);
}
// from DatabaseLiaison
public int lastInsertedId (Connection conn, Statement istmt, String table, String column)
throws SQLException
{
// if this JDBC driver supports getGeneratedKeys, use it!
if (istmt != null && conn.getMetaData().supportsGetGeneratedKeys()) {
ResultSet rs = istmt.getGeneratedKeys();
if (rs.next()) {
return rs.getInt(column);
}
}
return fetchLastInsertedId(conn, table, column);
}
/**
* Requests the last inserted id for the specified table and column. This is used if a JDBC
* driver does not support {@code getGeneratedKeys} or an attempt to use that failed.
*/
protected int fetchLastInsertedId (Connection conn, String table, String column)
throws SQLException
{
throw new SQLException(
"Unable to obtain last inserted id [table=" + table + ", column=" + column + "]");
}
// from DatabaseLiaison
public boolean tableExists (Connection conn, String name) throws SQLException
{
ResultSet rs = conn.getMetaData().getTables(null, getSchemaName(), name, null);
while (rs.next()) {
String tname = rs.getString("TABLE_NAME");
if (name.equals(tname)) {
return true;
}
}
return false;
}
// from DatabaseLiaison
public boolean tableContainsColumn (Connection conn, String table, String column)
throws SQLException
{
ResultSet rs = conn.getMetaData().getColumns(null, getSchemaName(), table, column);
while (rs.next()) {
String tname = rs.getString("TABLE_NAME");
String cname = rs.getString("COLUMN_NAME");
if (tname.equals(table) && cname.equals(column)) {
return true;
}
}
return false;
}
// from DatabaseLiaison
public boolean tableContainsIndex (Connection conn, String table, String index)
throws SQLException
{
ResultSet rs = conn.getMetaData().getIndexInfo(null, getSchemaName(), table, false, true);
while (rs.next()) {
String tname = rs.getString("TABLE_NAME");
String iname = rs.getString("INDEX_NAME");
if (tname.equals(table) && index.equals(iname)) {
return true;
}
}
return false;
}
// from DatabaseLiaison
public boolean addIndexToTable (Connection conn, String table, List columns,
String ixName, boolean unique) throws SQLException
{
if (tableContainsIndex(conn, table, ixName)) {
return false;
}
ixName = (ixName != null ? ixName :
Joiner.on("_").join(columns.toArray(new String[columns.size()])));
StringBuilder update = new StringBuilder("CREATE ");
if (unique) {
update.append("UNIQUE ");
}
update.append("INDEX ").append(indexSQL(ixName)).append(" ON ").
append(tableSQL(table)).append(" (");
appendColumns(columns, update);
update.append(")");
executeQuery(conn, update.toString());
log("Database index '" + ixName + "' added to table '" + table + "'");
return true;
}
// from DatabaseLiaison
public void addPrimaryKey (Connection conn, String table, List columns)
throws SQLException
{
StringBuilder fields = new StringBuilder("(");
appendColumns(columns, fields);
fields.append(")");
String update = "ALTER TABLE " + tableSQL(table) + " ADD PRIMARY KEY " + fields.toString();
executeQuery(conn, update);
log("Primary key " + fields + " added to table '" + table + "'");
}
// from DatabaseLiaison
public void dropIndex (Connection conn, String table, String index) throws SQLException
{
executeQuery(conn, "DROP INDEX " + columnSQL(index));
}
// from DatabaseLiaison
public void dropPrimaryKey (Connection conn, String table, String pkName) throws SQLException
{
executeQuery(conn, "ALTER TABLE " + tableSQL(table) +
" DROP CONSTRAINT " + columnSQL(pkName));
}
// from DatabaseLiaison
public boolean addColumn (Connection conn, String table, String column, String definition,
boolean check) throws SQLException
{
if (check && tableContainsColumn(conn, table, column)) {
return false;
}
executeQuery(conn, "ALTER TABLE " + tableSQL(table) + " ADD COLUMN " +
columnSQL(column) + " " + definition);
log("Database column '" + column + "' added to table '" + table + "'.");
return true;
}
// from DatabaseLiaison
public boolean addColumn (Connection conn, String table, String column,
ColumnDefinition newColumnDef, boolean check)
throws SQLException
{
if (check && tableContainsColumn(conn, table, column)) {
return false;
}
executeQuery(conn, "ALTER TABLE " + tableSQL(table) + " ADD COLUMN " +
columnSQL(column) + " " + expandDefinition(newColumnDef));
log("Database column '" + column + "' added to table '" + table + "'.");
return true;
}
// from DatabaseLiaison
public boolean changeColumn (Connection conn, String table, String column, String type,
Boolean nullable, Boolean unique, String defaultValue)
throws SQLException
{
String defStr = expandDefinition(type, nullable != null ? nullable : false,
unique != null ? unique : false, defaultValue);
executeQuery(conn, "ALTER TABLE " + tableSQL(table) + " CHANGE " +
columnSQL(column) + " " + columnSQL(column) + " " + defStr);
log("Database column '" + column + "' of table '" + table + "' modified to have " +
"definition '" + defStr + "'.");
return true;
}
// from DatabaseLiaison
public boolean renameColumn (Connection conn, String table, String from, String to,
ColumnDefinition newColumnDef) throws SQLException
{
executeQuery(conn, "ALTER TABLE " + tableSQL(table) + " RENAME COLUMN " +
columnSQL(from) + " TO " + columnSQL(to));
log("Renamed column '" + from + "' on table '" + table + "' to '" + to + "'");
return true;
}
// from DatabaseLiaison
public abstract void createGenerator (Connection conn, String tableName, String columnName,
int initialValue)
throws SQLException;
// from DatabaseLiaison
public abstract void deleteGenerator (Connection conn, String tableName, String columnName)
throws SQLException;
// from DatabaseLiaison
public boolean dropColumn (Connection conn, String table, String column) throws SQLException
{
if (!tableContainsColumn(conn, table, column)) {
return false;
}
executeQuery(conn, "ALTER TABLE " + tableSQL(table) + " DROP COLUMN " + columnSQL(column));
log("Database column '" + column + "' removed from table '" + table + "'.");
return true;
}
// from DatabaseLiaison
public boolean createTableIfMissing (Connection conn, String table, List columns,
List declarations,
List primaryKeyColumns) throws SQLException {
return createTableIfMissing(conn, table, columns, declarations,
Collections.>emptyList(), primaryKeyColumns);
}
// from DatabaseLiaison
public boolean createTableIfMissing (Connection conn, String table, List columns,
List definitions,
List> uniqueConstraintColumns,
List primaryKeyColumns)
throws SQLException
{
if (tableExists(conn, table)) {
return false;
}
if (columns.size() != definitions.size()) {
throw new IllegalArgumentException("Column name and definition number mismatch");
}
StringBuilder builder = new StringBuilder("CREATE TABLE ").
append(tableSQL(table)).append(" (");
for (int ii = 0; ii < columns.size(); ii ++) {
if (ii > 0) {
builder.append(", ");
}
builder.append(columnSQL(columns.get(ii))).append(" ");
builder.append(expandDefinition(definitions.get(ii)));
}
if (uniqueConstraintColumns != null) {
for (List uCols : uniqueConstraintColumns) {
builder.append(", UNIQUE (");
appendColumns(uCols, builder);
builder.append(")");
}
}
if (primaryKeyColumns != null && !primaryKeyColumns.isEmpty()) {
builder.append(", PRIMARY KEY (");
appendColumns(primaryKeyColumns, builder);
builder.append(")");
}
builder.append(")");
executeQuery(conn, builder.toString());
log("Database table '" + table + "' created.");
return true;
}
// from DatabaseLiaison
public boolean dropTable (Connection conn, String name) throws SQLException
{
if (!tableExists(conn, name)) {
return false;
}
executeQuery(conn, "DROP TABLE " + tableSQL(name));
log("Table '" + name + "' dropped.");
return true;
}
// from DatabaseLiaison
public String getSchemaName ()
{
return null;
}
// from DatabaseLiaison
public abstract String tableSQL (String table);
// from DatabaseLiaison
public abstract String columnSQL (String column);
// from DatabaseLiaison
public abstract String indexSQL (String index);
/**
* Create an SQL string that summarizes a column definition in that format generally accepted
* in table creation and column addition statements, e.g. {@code INTEGER UNIQUE NOT NULL
* DEFAULT 100}.
*/
public String expandDefinition (ColumnDefinition def)
{
return expandDefinition(def.type, def.nullable, def.unique, def.defaultValue);
}
protected int executeQuery (Connection conn, String query) throws SQLException
{
Statement stmt = conn.createStatement();
try {
return stmt.executeUpdate(query);
} finally {
JDBCUtil.close(stmt);
}
}
protected String expandDefinition (String type, boolean nullable, boolean unique,
String defaultValue)
{
StringBuilder builder = new StringBuilder(type);
if (!nullable) {
builder.append(" NOT NULL");
}
if (unique) {
builder.append(" UNIQUE");
}
// append the default value if one was specified
if (defaultValue != null) {
builder.append(" DEFAULT ").append(defaultValue);
}
return builder.toString();
}
/** Escapes {@code columns} with {@link #columnSQL}, appends (comma-sepped) to {@code buf}. */
protected void appendColumns (Iterable columns, StringBuilder buf) {
int ii = 0;
for (String column : columns) {
if (ii++ > 0) {
buf.append(", ");
}
buf.append(columnSQL(column));
}
}
protected void log (String message) {
log.info(message);
}
}
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