Java 伯克利数据库中的变异错误
我正在使用Berkely DB,我有一个错误,说突变缺失。这是什么意思Java 伯克利数据库中的变异错误,java,berkeley-db,Java,Berkeley Db,我正在使用Berkely DB,我有一个错误,说突变缺失。这是什么意思 Exception: com.sleepycat.persist.evolve.IncompatibleClassException: Mutation is missing to evolve class: TopMoveDAO.TopMoveClass version: 0 Error: java.lang.ClassNotFoundException: TopMoveDAO.TopMoveClasscom.sleepy
Exception: com.sleepycat.persist.evolve.IncompatibleClassException: Mutation is missing to evolve class: TopMoveDAO.TopMoveClass version: 0 Error: java.lang.ClassNotFoundException: TopMoveDAO.TopMoveClasscom.sleepycat.persist.evolve.IncompatibleClassException: Mutation is missing to evolve class: TopMoveDAO.TopMoveClass version: 0 Error: java.lang.ClassNotFoundException: TopMoveDAO.TopMoveClass
在com.sleepycat.persist.impl.PersistCatalog.PersistCatalog.java:365
位于com.sleepycat.persist.impl.Store.Store.java:180
在com.sleepycat.persist.EntityStore.EntityStore.java:165
在TopMoveDAO.TopMovePut.setupTopMovePut.java:40
在TopMoveDAO.TopMovePut.runTopMovePut.java:59
在TopMoveDAO.TopMovePut.mainTopMovePut.java:84
package TopMoveDAO;
import java.io.File;
import java.util.Timer;
import java.util.TimerTask;
import com.sleepycat.je.DatabaseException;
import com.sleepycat.je.Environment;
import com.sleepycat.je.EnvironmentConfig;
import com.sleepycat.persist.EntityStore;
import com.sleepycat.persist.StoreConfig;
public class TopMovePut {
//private static File envHome = new File("C:/dev/je-3.3.75/");
private static File envHome = new File("C:/dev/db/berkeley");
private Environment envmnt;
private EntityStore store;
private TopMoveDA sda;
//Next we create a method that simply opens our database environment and entity store for us.
// The setup() method opens the environment and store
// for us.
public void setup()
throws DatabaseException {
EnvironmentConfig envConfig = new EnvironmentConfig();
StoreConfig storeConfig = new StoreConfig();
envConfig.setAllowCreate(true);
storeConfig.setAllowCreate(true);
// Open the environment and entity store
envmnt = new Environment(envHome, envConfig);
store = new EntityStore(envmnt, "EntityStore", storeConfig);
}
//We also need a method to close our environment and store.
// Close our environment and store.
public void shutdown()
throws DatabaseException {
store.close();
envmnt.close();
}
//Populate the entity store
private void run()
throws DatabaseException {
setup();
// Open the data accessor. This is used to store
// persistent objects.
sda = new TopMoveDA(store);
// Instantiate and store some entity classes
PriceElement pe1 = new PriceElement();
pe1.setSecCode("UNO");
pe1.setLastPrice(1);
sda.pIdx.put(pe1);
shutdown();
}
//main
public static void main(String args[]) {
//SimpleStorePut ssp = new SimpleStorePut();
TopMovePut tmp = new TopMovePut();
try {
//ssp.run();
tmp.run();
} catch (DatabaseException dbe) {
System.err.println("TopMovePut: " + dbe.toString());
dbe.printStackTrace();
} catch (Exception e) {
System.out.println("Exception: " + e.toString());
e.printStackTrace();
}
System.out.println("All done - TopMovePut.");
}
}
您每次都必须删除现有数据库。您必须编写一个变体来改进数据库。删除数据库并不能解决问题,只能绕过它,如果您还没有部署到生产环境中,这很好,但是如果您不想丢失现有数据,那么就编写一个变体 Berkley db会自动处理对持久实体的某些更改,例如添加字段。涉及删除数据或重命名字段的操作通常需要编写一个显式变体。当您开始使用突变时,您还必须使用突变将引用的版本号注释您的实体-即使突变是自动处理的,您也必须增加版本号。当您进行重大的结构更改(例如使用不同的主键)时,您必须进行整个存储转换 在复制环境中开发数据库时要小心。我强烈建议阅读以下内容: 链接:不可用。新的是