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Added support for hand-registered migrations (untested).

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git-svn-id: https://samskivert.googlecode.com/svn/trunk@2005 6335cc39-0255-0410-8fd6-9bcaacd3b74c
This commit is contained in:
mdb
2006-12-21 19:06:18 +00:00
parent 1e6043b264
commit 5d9c17a853
5 changed files with 301 additions and 130 deletions
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src/java/com/samskivert/jdbc/depot/DepotMarshaller.java
+176 -113
View File
@@ -21,7 +21,6 @@
package com.samskivert.jdbc.depot;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
@@ -37,6 +36,7 @@ import java.util.HashSet;
import java.util.Set;
import java.util.logging.Level;
import com.samskivert.io.PersistenceException;
import com.samskivert.jdbc.depot.annotation.Computed;
import com.samskivert.jdbc.depot.annotation.Entity;
import com.samskivert.jdbc.depot.annotation.GeneratedValue;
@@ -101,7 +101,8 @@ public class DepotMarshaller<T>
int mods = field.getModifiers();
// check for a static constant schema version
if ((mods & Modifier.STATIC) != 0 && field.getName().equals(SCHEMA_VERSION_FIELD)) {
if (java.lang.reflect.Modifier.isStatic(mods) &&
field.getName().equals(SCHEMA_VERSION_FIELD)) {
try {
_schemaVersion = (Integer)field.get(null);
} catch (Exception e) {
@@ -111,7 +112,8 @@ public class DepotMarshaller<T>
}
// the field must be public, non-static and non-transient
if (((mods & Modifier.PUBLIC) == 0) || ((mods & Modifier.STATIC) != 0) ||
if (!java.lang.reflect.Modifier.isPublic(mods) ||
java.lang.reflect.Modifier.isStatic(mods) ||
field.getAnnotation(Transient.class) != null) {
continue;
}
@@ -292,104 +294,12 @@ public class DepotMarshaller<T>
}
/**
* Initializes the table used by this marshaller. If the table does not exist, it will be
* created. If the schema version specified by the persistent object is newer than the database
* schema, it will be migrated.
* Returns true if this marshaller has been initialized ({@link #init} has been called), its
* migrations run and it is ready for operation. False otherwise.
*/
public void init (Connection conn)
throws SQLException
public boolean isInitialized ()
{
// if we have no table (i.e. we're a computed entity), we have nothing to create
if (getTableName() == null) {
return;
}
// check to see if our schema version table exists, create it if not
JDBCUtil.createTableIfMissing(conn, SCHEMA_VERSION_TABLE,
new String[] { "persistentClass VARCHAR(255) NOT NULL",
"version INTEGER NOT NULL" }, "");
// now create the table for our persistent class if it does not exist
if (!JDBCUtil.tableExists(conn, getTableName())) {
log.fine("Creating table " + getTableName() + " (" +
StringUtil.join(_columnDefinitions, ", ") + ") " + _postamble);
JDBCUtil.createTableIfMissing(conn, getTableName(), _columnDefinitions, _postamble);
updateVersion(conn, 1);
}
// if we have a key generator, initialize that too
if (_keyGenerator != null) {
_keyGenerator.init(conn);
}
// if schema versioning is disabled, stop now
if (_schemaVersion < 0) {
return;
}
// make sure the versions match
int currentVersion = readVersion(conn);
if (currentVersion == _schemaVersion) {
return;
}
log.info("Migrating " + getTableName() + " from " +
currentVersion + " to " + _schemaVersion + "...");
// otherwise try to migrate the schema; doing column additions magically and running any
// registered hand-migrations
DatabaseMetaData meta = conn.getMetaData();
ResultSet rs = meta.getColumns(null, null, getTableName(), "%");
HashSet<String> columns = new HashSet<String>();
while (rs.next()) {
columns.add(rs.getString("COLUMN_NAME"));
}
for (String fname : _columnFields) {
FieldMarshaller fmarsh = _fields.get(fname);
if (columns.contains(fmarsh.getColumnName())) {
continue;
}
// otherwise add the column
String coldef = fmarsh.getColumnDefinition();
String query = "alter table " + getTableName() + " add column " + coldef;
// try to add it to the appropriate spot
int fidx = ListUtil.indexOf(_allFields, fmarsh.getColumnName());
if (fidx == 0) {
query += " first";
} else {
query += " after " + _allFields[fidx-1];
}
log.info("Adding column to " + getTableName() + ": " + coldef);
Statement stmt = conn.createStatement();
try {
stmt.executeUpdate(query);
} finally {
stmt.close();
}
// if the column is a TIMESTAMP column, we need to run a special query to update all
// existing rows to the current time because MySQL annoyingly assigns them a default
// value of "0000-00-00 00:00:00" regardless of whether we explicitly provide a
// "DEFAULT" value for the column or not
if (coldef.toLowerCase().indexOf(" timestamp") != -1) {
query = "update " + getTableName() + " set " + fmarsh.getColumnName() + " = NOW()";
log.info("Assigning current time to TIMESTAMP column: " + query);
stmt = conn.createStatement();
try {
stmt.executeUpdate(query);
} finally {
stmt.close();
}
}
}
// TODO: run any registered hand migrations
updateVersion(conn, _schemaVersion);
return _initialized;
}
/**
@@ -628,6 +538,167 @@ public class DepotMarshaller<T>
return pstmt;
}
/**
* This is called by the persistence context to register a migration for the entity managed by
* this marshaller.
*/
protected void registerMigration (EntityMigration migration)
{
_migrations.add(migration);
}
/**
* Initializes the table used by this marshaller. This is called automatically by the {@link
* PersistenceContext} the first time an entity is used. If the table does not exist, it will
* be created. If the schema version specified by the persistent object is newer than the
* database schema, it will be migrated.
*/
protected void init (PersistenceContext ctx)
throws PersistenceException
{
if (_initialized) { // sanity check
throw new IllegalStateException(
"Cannot re-initialize marshaller [type=" + _pclass + "].");
}
_initialized = true;
// if we have no table (i.e. we're a computed entity), we have nothing to create
if (getTableName() == null) {
return;
}
// check to see if our schema version table exists, create it if not
ctx.invoke(new Modifier(null) {
public int invoke (Connection conn) throws SQLException {
JDBCUtil.createTableIfMissing(
conn, SCHEMA_VERSION_TABLE,
new String[] { "persistentClass VARCHAR(255) NOT NULL",
"version INTEGER NOT NULL" }, "");
return 0;
}
});
// now create the table for our persistent class if it does not exist
ctx.invoke(new Modifier(null) {
public int invoke (Connection conn) throws SQLException {
if (!JDBCUtil.tableExists(conn, getTableName())) {
log.fine("Creating table " + getTableName() + " (" +
StringUtil.join(_columnDefinitions, ", ") + ") " + _postamble);
JDBCUtil.createTableIfMissing(
conn, getTableName(), _columnDefinitions, _postamble);
updateVersion(conn, 1);
}
return 0;
}
});
// if we have a key generator, initialize that too
if (_keyGenerator != null) {
ctx.invoke(new Modifier(null) {
public int invoke (Connection conn) throws SQLException {
_keyGenerator.init(conn);
return 0;
}
});
}
// if schema versioning is disabled, stop now
if (_schemaVersion < 0) {
return;
}
// make sure the versions match
int currentVersion = ctx.invoke(new Modifier(null) {
public int invoke (Connection conn) throws SQLException {
String query = "select version from " + SCHEMA_VERSION_TABLE +
" where persistentClass = '" + getTableName() + "'";
Statement stmt = conn.createStatement();
try {
ResultSet rs = stmt.executeQuery(query);
return (rs.next()) ? rs.getInt(1) : 1;
} finally {
stmt.close();
}
}
});
if (currentVersion == _schemaVersion) {
return;
}
log.info("Migrating " + getTableName() + " from " +
currentVersion + " to " + _schemaVersion + "...");
// otherwise try to migrate the schema
final HashSet<String> columns = new HashSet<String>();
ctx.invoke(new Modifier(null) {
public int invoke (Connection conn) throws SQLException {
DatabaseMetaData meta = conn.getMetaData();
ResultSet rs = meta.getColumns(null, null, getTableName(), "%");
while (rs.next()) {
columns.add(rs.getString("COLUMN_NAME"));
}
return 0;
}
});
// run our pre-default-migrations
for (EntityMigration migration : _migrations) {
if (migration.runBeforeDefault() &&
migration.shouldRunMigration(currentVersion, _schemaVersion)) {
ctx.invoke(migration);
}
}
// do our "default" migrations magically
for (String fname : _columnFields) {
FieldMarshaller fmarsh = _fields.get(fname);
if (columns.contains(fmarsh.getColumnName())) {
continue;
}
// otherwise add the column
String coldef = fmarsh.getColumnDefinition();
String query = "alter table " + getTableName() + " add column " + coldef;
// try to add it to the appropriate spot
int fidx = ListUtil.indexOf(_allFields, fmarsh.getColumnName());
if (fidx == 0) {
query += " first";
} else {
query += " after " + _allFields[fidx-1];
}
log.info("Adding column to " + getTableName() + ": " + coldef);
ctx.invoke(new Modifier.Simple(query));
// if the column is a TIMESTAMP column, we need to run a special query to update all
// existing rows to the current time because MySQL annoyingly assigns them a default
// value of "0000-00-00 00:00:00" regardless of whether we explicitly provide a
// "DEFAULT" value for the column or not
if (coldef.toLowerCase().indexOf(" timestamp") != -1) {
query = "update " + getTableName() + " set " + fmarsh.getColumnName() + " = NOW()";
log.info("Assigning current time to TIMESTAMP column: " + query);
ctx.invoke(new Modifier.Simple(query));
}
}
// run our post-default-migrations
for (EntityMigration migration : _migrations) {
if (!migration.runBeforeDefault() &&
migration.shouldRunMigration(currentVersion, _schemaVersion)) {
ctx.invoke(migration);
}
}
// record our new version in the database
ctx.invoke(new Modifier(null) {
public int invoke (Connection conn) throws SQLException {
updateVersion(conn, _schemaVersion);
return 0;
}
});
}
protected void updateVersion (Connection conn, int version)
throws SQLException
{
@@ -645,20 +716,6 @@ public class DepotMarshaller<T>
}
}
protected int readVersion (Connection conn)
throws SQLException
{
String query = "select version from " + SCHEMA_VERSION_TABLE +
" where persistentClass = '" + getTableName() + "'";
Statement stmt = conn.createStatement();
try {
ResultSet rs = stmt.executeQuery(query);
return (rs.next()) ? rs.getInt(1) : 1;
} finally {
stmt.close();
}
}
protected void requireNotComputed (String action)
throws SQLException
{
@@ -700,6 +757,12 @@ public class DepotMarshaller<T>
/** Used when creating and migrating our table schema. */
protected String _postamble = "";
/** Indicates that we have been initialized (created or migrated our tables). */
protected boolean _initialized;
/** A list of hand registered entity migrations to run prior to doing the default migration. */
protected ArrayList<EntityMigration> _migrations = new ArrayList<EntityMigration>();
/** The name of the table we use to track schema versions. */
protected static final String SCHEMA_VERSION_TABLE = "DepotSchemaVersion";
}