hibernate总是自己删除表中的所有数据 [英] hibernate always deletes all data from a table on its own
问题描述
您好我正在开发一个使用hibernate连接到存储文件的mysql数据库的spring mvc应用程序。
Hi i am developing a spring mvc app thats using hibernate to connect to a mysql database that stores files.
我有两种方法。一个从我选择的特定文件路径添加所有文件，另一个调用查询的方法返回一个从mysql存储的文件列表。
I have two methods. one that adds all files from a specific file path of my choosing and another method that invokes a query to return me a list of the files stored from mysql.
问题是这个。当我自己执行第一个方法，即填充数据库，它工作正常，我可以从mysql命令行看到该表的内容。然而，当我在填充后立即执行查询方法时，该表的内容立即完全消失。它好像hibernate只是暂时存储mysql中的数据或者mysql中的某个地方，它删除了imediatly的数据并且不保留它们。
The issue is this. When i execute the first method on its own ie populating the database, it works fine i can see the contents of that table from mysql command line. however, when i then execute the query method right after populating it, the contents of that said table is completely gone instantly. Its as if hibernate only stored the data in the mysql temporarily or somewhere in mysql, it deleted data imediatly and doesnt keep it their.
这是填充表的方法：
/**
* Test Method: ideal for another class to do this kind of work and this
* pass the FileObject into this class
*/
public void addSomeFiles() {
System.out.println("addSomeFiles");
File dir = new File(picturesPath);
String[] fileNames = dir.list();
for (int i = 0; i < fileNames.length; i++) {
System.out.println(fileNames[i]);
File file = new File(picturesPath + "\\" + fileNames[i]);
if (file.isFile()) {
FileObject fileO = contstructFileObject(file);
if (fileO == null) {
System.out.println("fileO is null!!!!!");
} else {
// addFile(fileO);
dbFileHelper.addFile(fileO);
}
}
}
System.out.println("//////////////");
// File file;
}
......... Hibernate模板类........
.........Hibernate template class........
public class DbFileHelper implements DbFileWrapper {
private HibernateTemplate hbTemplate;
//private static final String SQL_GET_FILE_LIST = "select filename, size, id, type from fileobject";
private static final String SQL_GET_FILE_LIST = "select new FileObject(filename, size, id, type) from FileObject";
public DbFileHelper() {
}
public void setHbTemplate(HibernateTemplate hbTemplate) {
System.out.println("setHbTemplate");
System.out.println("///////////////////");
System.out.println("///////////////////");
System.out.println("///////////////////");
this.hbTemplate = hbTemplate;
}
// ////////////////////////////////////////////////
@Override
public String addFile(FileObject file) {
// TODO Auto-generated method stub
System.out.println("addFile using hibernate");
if (hbTemplate == null) {
System.out.println("hbTemplate is null!! why?");
}
hbTemplate.saveOrUpdate(file);
hbTemplate.flush();
return "added succesfuly";
}
以下是进行查询的另一种方法：
And here is the other method that makes the query:
........................
........................
公开JSONArray getFileList（String type）{
public JSONArray getFileList(String type){
return constructJsonArray(dbFileHelper.getFileList(ALL));
}
private JSONArray constructJsonArray(List<FileObject> fileList ){
JSONArray mJsonArray = new JSONArray();
for (int i = 0; i < fileList.size(); i++) {
System.out.println("fileName = " + fileList.get(i).getFilename() );
//mJson.put("Filename", fileList.get(i).getFileName() );
mJsonArray.add( new JSONObject().put("File ID", fileList.get(i).getId() ));
mJsonArray.add( new JSONObject().put("Filename", fileList.get(i).getFilename() ));
mJsonArray.add( new JSONObject().put("File type", fileList.get(i).getType()));
mJsonArray.add( new JSONObject().put("File Size", fileList.get(i).getSize()));
}
return mJsonArray;
}
.......... hibernate模板类...... ....
..........hibernate Template class.......
private static final String SQL_GET_FILE_LIST = "select new FileObject(filename, size, id, type) from FileObject";
@Override
public List<FileObject> getFileList(String type) {
// TODO Auto-generated method stub
List<FileObject> files = hbTemplate.find(SQL_GET_FILE_LIST);
//hbTemplate.flush();
return files;
}
..........
..........
最后这是一个打印屏幕，显示我最初放在我的桌子里但是自己消失了：
Finally here is a print screen of what i originaly put inside my table but dissapears on its own:
http://img411.imageshack.us/img411/9553/filelisti.jpg
我错过了什么吗？
编辑：附加信息。
my hbm.xml
my hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.kc.models.FileObject" >
<class name="com.kc.models.FileObject" table="fileobject">
<id name="id" column="ID">
<generator class="native" />
</id>
<property name="filename" type="string" column="FILENAME" />
<property name="type" type="string" column="TYPE" />
<property name="size" type="double" column="SIZE" />
<property name="file" type="blob" length="1000000000" column="FILE" />
</class>
</hibernate-mapping>
我的控制器：
@Override
public ModelAndView handleRequest(HttpServletRequest request,
HttpServletResponse response) throws Exception {
// TODO call a method that returns a list of Mobile Apps.
testAddingSomeFilesToDb();
return new ModelAndView("" + "testJsonResponse", "jsonArray",
getFileList() );
}
private void testAddingSomeFilesToDb() {
ctx = new ClassPathXmlApplicationContext("zang-file-service.xml");
FileHelper file = (FileHelper) ctx.getBean("fileHelper");
file.addSomeFiles();
}
/**
* Get file list from sql server based on type
* @return file list in json
*/
private JSONArray getFileList() {
// TODO: Get request parameter that states what type of file extensions
// the client wants to recieve
ctx = new ClassPathXmlApplicationContext("zang-file-service.xml");
FileHelper file = (FileHelper) ctx.getBean("fileHelper");
return file.getFileList("all");
}
另一个编辑：
我的.xml文件配置会话工厂和休眠模板
my .xml file configuring the session factory and hibernate template
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:jee="http://www.springframework.org/schema/jee"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://www.springframework.org/schema/jee
http://www.springframework.org/schema/jee/spring-jee-2.0.xsd">
<!-- http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-2.0.xsd -->
<!-- Config properties files -->
<!-- Hibernate database stuff -->
<!-- <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations"> <list> <value>/properties/jdbc.properties</value>
</list> </property> </bean> -->
<!-- <bean id="dataSource1" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="${database.driver}" /> <property
name="url" value="${database.url}" /> <property name="username" value="${database.user}"
/> <property name="password" value="${database.password}" /> </bean> -->
<bean id="dataSource1"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/zangshop" />
<property name="username" value="root" />
<property name="password" value="password" />
</bean>
<!-- LocalSessionFactoryBean u need to put the hbm files in the WEB-INF/classes
root director -->
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource1"></property>
<property name="mappingResources">
<list>
<value>FileObject.hbm.xml</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.hbm2ddl.auto">create</prop>
</props>
</property>
</bean>
<bean id="hbTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate">
<property name="sessionFactory" ref="sessionFactory"></property>
</bean>
<bean id="dbFileHelper" class="com.kc.models.DbFileHelper">
<property name="hbTemplate" ref="hbTemplate"></property>
</bean>
<bean id="fileHelper" class="com.kc.models.FileHelper">
<property name="dbFileHelper" ref="dbFileHelper"></property>
</bean>
</beans>
推荐答案
我已修复问题
我改变了< prop key =hibernate.hbm2ddl.auto> create< / prop>
到< prop key =hibernate.hbm2ddl.auto> update< / prop> 并且工作正常
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