MISTECH 技術手抄本

使用 Hibernate Tool 產生 Model 時, FetchType 預設是 FetchType.LAZY , 但在執行時, 卻常會產生類似下列 no Session 的錯誤訊息

org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.spring.jwt.db.maria.model.authentication.User.userAuthorities, could not initialize proxy - no Session

這時候需要在 Method 前加入 @Transactional 就可以解決

@Test @Transactional public void testUserAuthority() { User user = userRepository.findById(1L).get(); JwtUser jwtUser = JwtUserFactory.create(user); logger.info(jwtUser.getUsername()); } 

使用 Spring Boot 2 建置系統就是希望快速. 若專案範圍小的話, 資料庫倒是可以考慮使用 H2 database 來建罝

在 build.gradle 上加入

compile('com.h2database:h2') 

然後編輯 application.properties

server.port=8088 # =============================== # H2 # =============================== spring.h2.console.enabled=true spring.datasource.url=jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE spring.datasource.driverClassName=org.h2.Driver spring.datasource.username=sa spring.datasource.password= spring.jpa.database-platform=org.hibernate.dialect.H2Dialect 

 環境: ApacheFriends XAMPP Version 7.1.7

在 Tomcat 的 server.xml 裡設定

環境:

eclipse : https://eclipse.org/downloads/packages/release/Neon/3

python: Python 3.6.1

django: Django-1.11.1.tar.gz

先下載 Python 3.6.1 安裝在 C:\Python\Python36-32 然後增加 Path

用 Hibernet Tool 自動產生的 Domain Code，對於 FOREIGN KEY 會以 annotation:  @ManyToMany(fetch = FetchType.LAZY) 來作註，但執行時會發生下列的錯誤

Struts Problem Report

Struts has detected an unhandled exception:

作法如下:

http://stackoverflow.com/questions/26616723/java-lang-nosuchmethoderror-javax-persistence-table-indexesljavax-persistenc

If you are using Jboss 7.1.1, jboss already has hibernate-jpa-2.0 in its classpath, so during runtime it uses the one in its classpath, not the one you've deployed with your app , to point jboss to the hibernate-jpa-2.1 do the following:

1. copy hibernate-jpa-2.1-api-1.0.0.final.jar to the following directory : jboss-as-7.1.1.Final/modules/javax/persistence/api/main

2. open module.xml and change the resource-root as follows : resource-root path="hibernate-jpa-2.1-api-1.0.0.final.jar" (pointing it to jpa 2.1)

3. re-compile and re-deploy your app, then you are good to go.

module.xml 檔案內容, 置換成 hibernate-jpa-2.1-api-1.0.0.Final.jar :

所需軟體

1. OS: windows 7

2. xampp-portable-win32-5.5.38-3-VC11.zip

3. FreeRADIUS.net-1.1.7-r0.0.2.exe - 6.74 MB - Licence: GNU/LGPL

4. NTRadPing 測試工具

在目錄 %JBOSS_HOME%\modules\com\microsoft\sqlserver\jdbc\main 下放入 module.xml & sqljdbc42.jar。

module.xml 的內容