Moved the id field into DBBean instead of the sub class

This commit is contained in:
Ziver Koc 2010-10-07 11:27:02 +00:00
parent 0cc2f253e3
commit b8bf1946d5
2 changed files with 207 additions and 92 deletions

View file

@ -14,8 +14,10 @@ import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.logging.Logger;
import zutil.db.DBConnection;
import zutil.log.LogUtil;
/**
* <XMP>
@ -38,6 +40,10 @@ import zutil.db.DBConnection;
* @author Ziver
*/
public abstract class DBBean {
public static final Logger logger = LogUtil.getLogger();
/** The id of the bean **/
private Long id;
/**
* Sets the name of the table in the database
@ -45,9 +51,9 @@ public abstract class DBBean {
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
public @interface DBTable {
String value();
String value();
}
/**
* Sets the name of the table that links different DBBeans together
*/
@ -55,17 +61,20 @@ public abstract class DBBean {
@Target(ElementType.FIELD)
public @interface DBLinkTable {
/** The name of the Link table */
String name();
/** The name of the column that contains this objects id */
String column() default "";
String name();
/** The class of the linked bean */
Class<? extends DBBean> beanClass();
/** The name of the column that contains this objects id */
String column() default "";
}
/**
* Sets the field as the id column in the table
*/
@Retention(RetentionPolicy.RUNTIME)
/*@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
public @interface DBTableID {}
*/
/**
* A Class that contains information about a bean
@ -77,23 +86,23 @@ public abstract class DBBean {
protected Field id_field;
/** All the fields in the bean */
protected ArrayList<Field> fields;
protected DBBeanConfig(){
fields = new ArrayList<Field>();
}
}
/** This is a cache of all the initialized beans */
private static HashMap<Class<? extends DBBean>,DBBeanConfig> beanConfigs = new HashMap<Class<? extends DBBean>,DBBeanConfig>();
/** This value is for preventing recursive loops */
private boolean processing;
protected DBBean(){
if( !beanConfigs.containsKey( this.getClass() ) )
initBeanConfig( this.getClass() );
processing = false;
}
/**
* @return the ID field of the bean or null if there is non
*/
@ -102,7 +111,7 @@ public abstract class DBBean {
initBeanConfig( c );
return beanConfigs.get( c ).id_field;
}
/**
* @return all the fields except the ID field
*/
@ -111,7 +120,7 @@ public abstract class DBBean {
initBeanConfig( c );
return beanConfigs.get( c ).fields;
}
/**
* @return the configuration object for the specified class
*/
@ -120,7 +129,7 @@ public abstract class DBBean {
initBeanConfig( c );
return beanConfigs.get( c );
}
/**
* Caches the fields
*/
@ -129,113 +138,149 @@ public abstract class DBBean {
DBBeanConfig config = new DBBeanConfig();
// Find the table name
if( c.getAnnotation(DBTable.class) != null )
config.tableName = c.getAnnotation(DBTable.class).value().replace('\"', ' ');
config.tableName = c.getAnnotation(DBTable.class).value().replace('\"', ' ');
// Add the fields in the bean
for( Field field : fields ){
if( !Modifier.isTransient(field.getModifiers()) ){
if(field.getAnnotation(DBBean.DBTableID.class) != null)
config.id_field = field;
int mod = field.getModifiers();
if( !Modifier.isTransient( mod ) &&
!Modifier.isAbstract( mod ) &&
!Modifier.isFinal( mod ) &&
!Modifier.isStatic( mod ) &&
!Modifier.isInterface( mod ) &&
!Modifier.isNative( mod )){
//if(field.getAnnotation(DBBean.DBTableID.class) != null)
// config.id_field = field;
config.fields.add( field );
}
}
try {
config.id_field = DBBean.class.getDeclaredField("id");
config.id_field.setAccessible(true);
} catch (Exception e) {
e.printStackTrace();
}
beanConfigs.put(c, config);
}
/**
* Saves the Object to the DB
*/
@SuppressWarnings("unchecked")
public void save(DBConnection sql) throws SQLException{
public void save(DBConnection db) throws SQLException{
if(processing)
return;
processing = true;
Class<? extends DBBean> c = this.getClass();
DBBeanConfig config = beanConfigs.get(c);
try {
Object id = getFieldValue( config.id_field );
// Generate the SQL
StringBuilder query = new StringBuilder();
query.append("REPLACE INTO ? ");
if( id == null )
query.append("INSERT INTO ");
else query.append("UPDATE ");
query.append( config.tableName );
StringBuilder params = new StringBuilder();
for( Field field : config.fields ){
query.append(" ");
query.append(field.getName());
query.append("=?, ");
if( !List.class.isAssignableFrom(field.getType()) ){
params.append(" ");
params.append(field.getName());
params.append("=?,");
}
}
query.delete( query.length()-2, query.length());
PreparedStatement stmt = sql.getPreparedStatement( sql.toString() );
// add the table name
stmt.setObject(1, config.tableName);
if( params.length() > 0 ){
params.delete( params.length()-1, params.length());
query.append( " SET" );
query.append( params );
if( id != null )
query.append( " id=?" );
}
logger.fine("Save query: "+query.toString());
PreparedStatement stmt = db.getPreparedStatement( query.toString() );
// Put in the variables in the SQL
for(int i=0; i<config.fields.size() ;++i ){
Field field = config.fields.get(i);
// Another DBBean class
if( DBBean.class.isAssignableFrom( field.getType() )){
DBBean subobj = (DBBean)field.get(this);
subobj.save(sql);
stmt.setObject(i+2, getBeanConfig(subobj.getClass()) );
DBBean subobj = (DBBean)getFieldValue(field);
if(subobj != null){
subobj.save(db);
DBBeanConfig subconfig = getBeanConfig(subobj.getClass());
stmt.setObject(i+1, subobj.getFieldValue(subconfig.id_field) );
}
else
stmt.setObject(i+1, null);
}
// A list of DBBeans
else if( List.class.isAssignableFrom( field.getType() ) &&
field.getAnnotation( DBLinkTable.class ) != null){
List<DBBean> list = (List<DBBean>)field.get(this);
DBLinkTable linkTable = field.getAnnotation( DBLinkTable.class );
String subtable = linkTable.name();
String idcol = (linkTable.column().isEmpty() ? config.tableName : linkTable.column() );
DBBeanConfig subConfig = null;
for(DBBean subobj : list){
if(subConfig == null)
subConfig = beanConfigs.get( subobj.getClass() );
// Save links in link table
PreparedStatement subStmt = sql.getPreparedStatement("REPLACE INTO ? ?=? ?=?");
subStmt.setString(1, subtable);
subStmt.setString(2, idcol);
subStmt.setObject(3, config.id_field);
subStmt.setString(4, subConfig.tableName);
subStmt.setObject(5, subConfig.id_field.get(subobj));
DBConnection.exec(subStmt);
// Save the sub bean
subobj.save(sql);
List<DBBean> list = (List<DBBean>)getFieldValue(field);
if( list != null ){
DBLinkTable linkTable = field.getAnnotation( DBLinkTable.class );
String subtable = linkTable.name();
String idcol = (linkTable.column().isEmpty() ? config.tableName : linkTable.column() );
DBBeanConfig subConfig = null;
for(DBBean subobj : list){
if(subConfig == null)
subConfig = beanConfigs.get( subobj.getClass() );
// Save links in link table
PreparedStatement subStmt = db.getPreparedStatement("REPLACE INTO "+subtable+" SET ?=? ?=?");
subStmt.setString(1, idcol);
subStmt.setObject(2, config.id_field);
subStmt.setString(3, subConfig.tableName);
subStmt.setObject(4, subobj.getFieldValue(subConfig.id_field) );
DBConnection.exec(subStmt);
// Save the sub bean
subobj.save(db);
}
}
}
// Normal field
else
stmt.setObject(i+2, field.get(this));
else{
Object value = getFieldValue(field);
stmt.setObject(i+1, value);
}
}
if( id != null )
stmt.setObject(config.fields.size(), id);
// Execute the SQL
DBConnection.exec(stmt);
setFieldValue( config.id_field, db.getLastInsertID() );
} catch (SQLException e) {
throw e;
} catch (Exception e) {
throw new SQLException(e);
}
}
/**
* Deletes the object from the DB, WARNING will not delete sub beans
*/
public void delete(DBConnection sql){
public void delete(DBConnection db){
Class<? extends DBBean> c = this.getClass();
DBBeanConfig config = beanConfigs.get(c);
if( config.id_field == null )
throw new NoSuchElementException("DBTableID annotation missing in bean!");
try {
PreparedStatement stmt = sql.getPreparedStatement(
"DELETE FROM ? WHERE "+ config.id_field +"=?");
// Put in the variables in the SQL
stmt.setObject(1, config.tableName );
stmt.setObject(2, config.id_field.get(this) );
try {
String sql = "DELETE FROM "+config.tableName+" WHERE "+ config.id_field +"=?";
logger.fine("Load query: "+sql);
PreparedStatement stmt = db.getPreparedStatement( sql );
// Put in the variables in the SQL
logger.fine("Delete query: "+sql);
stmt.setObject(1, getFieldValue(config.id_field) );
// Execute the SQL
DBConnection.exec(stmt);
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* Loads all the rows in the table into a LinkedList
*
@ -249,13 +294,14 @@ public abstract class DBBean {
initBeanConfig( c );
DBBeanConfig config = beanConfigs.get(c);
// Generate query
PreparedStatement stmt = db.getPreparedStatement( "SELECT * FROM ?" );
stmt.setString(1, config.tableName);
String sql = "SELECT * FROM "+config.tableName;
logger.fine("Load query: "+sql);
PreparedStatement stmt = db.getPreparedStatement( sql );
// Run query
List<T> list = DBConnection.exec(stmt, DBBeanSQLResultHandler.createList(c, db) );
return list;
}
/**
* Loads all the rows in the table into a LinkedList
*
@ -270,15 +316,14 @@ public abstract class DBBean {
initBeanConfig( c );
DBBeanConfig config = beanConfigs.get(c);
// Generate query
PreparedStatement stmt = db.getPreparedStatement( "SELECT * FROM ? WHERE ?=? LIMIT 1" );
stmt.setString(1, config.tableName);
stmt.setString(2, config.id_field.getName());
stmt.setObject(3, id );
PreparedStatement stmt = db.getPreparedStatement( "SELECT * FROM "+config.tableName+" WHERE ?=? LIMIT 1" );
stmt.setString(1, config.id_field.getName());
stmt.setObject(2, id );
// Run query
T obj = DBConnection.exec(stmt, DBBeanSQLResultHandler.create(c, db) );
return obj;
}
/**
* Creates a specific table for the given Bean
*/
@ -289,8 +334,8 @@ public abstract class DBBean {
// Generate the SQL
StringBuilder query = new StringBuilder();
query.append("CREATE TABLE ? ( ");
query.append("CREATE TABLE "+config.tableName+" ( ");
for( Field field : config.fields ){
query.append(" ");
query.append( field.getName() );
@ -302,13 +347,11 @@ public abstract class DBBean {
query.delete( query.length()-2, query.length());
query.append(")");
PreparedStatement stmt = sql.getPreparedStatement( sql.toString() );
// add the table name
stmt.setObject(1, config.tableName);
// Execute the SQL
DBConnection.exec(stmt);
}
private static String classToDBName(Class<?> c){
if( c == String.class) return "CLOB"; // TEXT
else if(c == Short.class) return "SMALLINT";
@ -329,7 +372,7 @@ public abstract class DBBean {
else if(c == byte.class) return "BINARY(1)";
return null;
}
/**
* This is a workaround if the field is not visible to other classes
*
@ -345,7 +388,7 @@ public abstract class DBBean {
}
return null;
}
/**
* This is a workaround if the field is not visible to other classes
*
@ -360,4 +403,11 @@ public abstract class DBBean {
e.printStackTrace();
}
}
/**
* @return the object id or null if the bean has not bean saved yet
*/
public Long getId(){
return id;
}
}

View file

@ -5,16 +5,32 @@ import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.logging.Logger;
import zutil.db.DBConnection;
import zutil.db.SQLResultHandler;
import zutil.db.bean.DBBean.DBBeanConfig;
import zutil.db.bean.DBBean.DBLinkTable;
import zutil.log.LogUtil;
public class DBBeanSQLResultHandler<T> implements SQLResultHandler<T>{
public static final Logger logger = LogUtil.getLogger();
/** This is the time to live for the cached items **/
public static final long CACHE_TTL = 1000*60*10; // in ms
/** A cache for detecting recursion **/
protected static HashMap<Class<?>, HashMap<Object,DBBeanCache>> cache =
new HashMap<Class<?>, HashMap<Object,DBBeanCache>>();
/**
* A cache container that contains a object and last read time
*/
protected static class DBBeanCache{
public long timestamp;
public DBBean bean;
}
private Class<? extends DBBean> bean_class;
private DBBeanConfig bean_config;
private DBConnection db;
@ -108,16 +124,24 @@ public class DBBeanSQLResultHandler<T> implements SQLResultHandler<T>{
*/
@SuppressWarnings("unchecked")
private DBBean createBean(ResultSet result) throws SQLException{
try {
DBBean obj = bean_class.newInstance();
try {
Object id = result.getObject( bean_config.id_field.getName() );
DBBean obj = getCachedDBBean(bean_class, id);
if( obj != null )
return obj;
obj = bean_class.newInstance();
cacheDBBean(obj, id);
for( Field field : bean_config.fields ){
for( Field field : bean_config.fields ){
String name = field.getName();
// Another DBBean class
if( DBBean.class.isAssignableFrom( field.getType() )){
if(db != null){
DBBean subobj = DBBean.load(db, (Class<? extends DBBean>)field.getType(), result.getObject(name));
Object subid = result.getObject(name);
DBBean subobj = getCachedDBBean(field.getType(), subid);
if( subobj == null )
subobj = DBBean.load(db, (Class<? extends DBBean>)field.getType(), subid);
obj.setFieldValue(field, subobj);
}
}
@ -130,17 +154,16 @@ public class DBBeanSQLResultHandler<T> implements SQLResultHandler<T>{
String idcol = (linkTable.column().isEmpty() ? bean_config.tableName : linkTable.column() );
// Load list from link table
PreparedStatement subStmt = db.getPreparedStatement("SELECT * FROM ? WHERE ?=?");
subStmt.setString(1, subtable);
subStmt.setString(2, idcol);
subStmt.setObject(3, bean_config.id_field.get( obj ));
PreparedStatement subStmt = db.getPreparedStatement("SELECT * FROM "+subtable+" WHERE ?=?");
subStmt.setString(1, idcol);
subStmt.setObject(2, bean_config.id_field.get( obj ));
List<? extends DBBean> list = DBConnection.exec(subStmt,
DBBeanSQLResultHandler.createList((Class<? extends DBBean>)field.getType(), db));
DBBeanSQLResultHandler.createList(linkTable.beanClass(), db));
obj.setFieldValue(field, list);
}
}
// Normal field
else
else
obj.setFieldValue(field, result.getObject(name));
}
return obj;
@ -152,4 +175,46 @@ public class DBBeanSQLResultHandler<T> implements SQLResultHandler<T>{
}
}
/**
* Adds the given object to the cache
*
* @param obj is the object to cache
* @param id is the id object of the bean
*/
protected static void cacheDBBean(DBBean obj, Object id) {
DBBeanCache item = new DBBeanCache();
item.timestamp = System.currentTimeMillis();
item.bean = obj;
if( cache.containsKey(obj.getClass()) )
cache.get(obj.getClass()).put(id, item);
else{
HashMap<Object, DBBeanCache> map = new HashMap<Object, DBBeanCache>();
map.put(id, item);
cache.put(obj.getClass(), map);
}
}
/**
* @param c is the class of the bean
* @param id is the id object of the bean
* @return an cached DBBean object or null if the object is not cached or has expired
*/
protected static DBBean getCachedDBBean(Class<?> c, Object id){
if( cache.containsKey(c) ){
DBBeanCache item = cache.get(c).get(id);
// Check if the cache is valid
if( item != null && item.timestamp+CACHE_TTL > System.currentTimeMillis() ){
return item.bean;
}
// The cache is old, remove it and return null
else{
logger.finer("Cache to old: "+c.getName()+" ID: "+id);
cache.get(c).remove(id);
return null;
}
}
logger.finer("Cache miss: "+c.getName()+" ID: "+id);
return null;
}
}