postInstantiate buildSessionFactory慢/内存巨大的数据库

我无法发布所有更改，但是这里有一些想法：

1_
postInstanciate为所有实体和集合创建许多Entiy加载器（每个实体和每个集合的加载器类型很多），此操作应按需执行，应在需要时创建实体或集合加载器，而不是在会话工厂构建期间，即使您有500个实体，这也意味着用户将从所有实体中加载数据。

    private Map LoaderMap = new LoaderMap();//instead Hashmap      class LoaderMap extends HashMap{        @Override        public Object get(Object key) {          Object obj = super.get(key); if (obj==null){     boolean disableForUpdate = getSubclassTableSpan() > 1 &&  hasSubclasses() &&  !getFactory().getDialect().supportsOuterJoinForUpdate();     switch (key.toString()) {     case "NONE":         obj = createEntityLoader( LockMode.NONE );         break;     case "READ":         obj = createEntityLoader( LockMode.READ );     if (disableForUpdate){  put(LockMode.UPGRADE, obj );  put(LockMode.UPGRADE_NOWAIT, obj );  put(LockMode.UPGRADE_SKIPLOCKED, obj );  put(LockMode.FORCE, obj );put(LockMode.PESSIMISTIC_READ, obj );  put(LockMode.PESSIMISTIC_WRITE, obj );  put(LockMode.PESSIMISTIC_FORCE_INCREMENT, obj );}         break;     case "UPGRADE":         if (disableForUpdate)  obj = get("READ");          else  obj = createEntityLoader( LockMode.UPGRADE );     case "UPGRADE_NOWAIT":         if (disableForUpdate)  obj = get("READ");          else  obj = createEntityLoader( LockMode.UPGRADE_NOWAIT );     case "UPGRADE_SKIPLOCKED":         if (disableForUpdate)  obj = get("READ");          else  obj = createEntityLoader( LockMode.UPGRADE_SKIPLOCKED );     case "FORCE":         if (disableForUpdate)  obj = get("READ");          else  obj = createEntityLoader( LockMode.FORCE );     case "PESSIMISTIC_READ":         if (disableForUpdate)  obj = get("READ");          else  obj = createEntityLoader( LockMode.PESSIMISTIC_READ );     case "PESSIMISTIC_WRITE":         if (disableForUpdate)  obj = get("READ");          else  obj = createEntityLoader( LockMode.PESSIMISTIC_WRITE );     case "PESSIMISTIC_FORCE_INCREMENT":         if (disableForUpdate)  obj = get("READ");          else  obj = createEntityLoader( LockMode.PESSIMISTIC_FORCE_INCREMENT );     case "OPTIMISTIC":         obj = createEntityLoader( LockMode.READ );         break;     case "OPTIMISTIC_FORCE_INCREMENT":         obj = createEntityLoader( LockMode.READ );         break;     case "merge":         obj = new CascadeEntityLoader( AbstractEntityPersister.this, CascadingActions.MERGE, getFactory() );         break; case "refresh":         obj = new CascadeEntityLoader( AbstractEntityPersister.this, CascadingActions.REFRESH, getFactory() );         break;       default:         break;     }     put(key, obj); } return obj;        }    }    //Relational based Persisters should be content with this implementation    protected void createLoaders() {        if (true) return;....       }

2_
DirectPropertyAccessor为buildGetter方法调用两次getDeclaredField，为buildSetter调用两次，使用map是一个很好的优化。

public static final Map<Double, Field> tmp = new HashMap<Double, Field>();    private static Field getField(Class root, Class clazz, String name) throws PropertyNotFoundException {        if ( clazz==null || clazz==Object.class ) { throw new PropertyNotFoundException("field [" + name + "] not found on " + root.getName());         } double hash = name.hashCode() + clazz.hashCode()*1.1;        Field field = tmp.get( hash );        if (field==null)        try { field = clazz.getDeclaredField(name); tmp.put( hash, field );        }        catch (NoSuchFieldException nsfe) { field = getField( root, clazz.getSuperclass(), name );        }        field.setAccessible(true);        return field;    }

对Ulrich Scholz的响应
：我向项目添加了一个包含所有固定类的jar，在我的情况下，其Webapp应用程序部署在Tomcat上，您需要使用以下命令修复Jars的加载顺序：

<Context><Resources>      <PreResources className="org.apache.catalina.webresources.FileResourceSet"     base="${catalina.base}/webapps/AGIWERP/WEB-INF/lib/AAACLZ-1.0.jar"     webAppMount="/WEB-INF/lib/AAACLZ-1.0.jar" /></Resources></Context>

这意味着您的类应该在原始类之前加载