【发布时间】:2015-02-07 03:04:55
【问题描述】:
我创建了一个客户端应用程序,它从数据库 (Oracle) 中获取一些数据并将它们序列化。对于一些数据(每 100 次发生一次),当序列化数据时,会失败并出现以下异常:
Exception in thread "main" java.io.InvalidClassException: org.jdom.Element; local class incompatible: stream classdesc serialVersionUID = -5756298698047880134, local class serialVersionUID = -1584223699423688446
at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:621) at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:621)
数据与其他应用程序一起插入到数据库中。
看看谷歌,我发现也许应该定义一个serialVersionUID。我这样做了(我不完全确定它是正确的)但没有解决。我的代码:
public class Test1{
/(private static final long serialVersionUID = -5756298698047880134L;//-1584223699423688446L
public static void main(String[] args) throws Exception {
// TODO code application logic here
ExecutionContext ret = null;
System.out.println("Connection with BD...");
String url = "url";
String user = "user";
String password = "password";
Connection conn = DriverManager.getConnection(url, user, password);
System.out.println("Connection ok...");
System.out.println("Create Query...");
String query = "SELECT ... FROM ...";
Statement st = conn.createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_UPDATABLE);
ResultSet rs = st.executeQuery(query);
if (rs.next()) {
Blob blob = rs.getBlob("EXECUTION_CONTEXT");
if (blob == null) {
System.out.println ("Blob null");
}
try{
InputStream is = blob.getBinaryStream();
GZIPInputStream gzip = new GZIPInputStream(is);
ObjectInputStream os = new ObjectInputStream(gzip);
//Here is where fail:
ret = (ExecutionContext)os.readObject();
//
}catch(ZipException ie){
if(ie.getMessage().equals("Not in GZIP format")){
System.out.println("Not in GZIP format");
InputStream is = blob.getBinaryStream();
ObjectInputStream os = new ObjectInputStream(is);
//Here is where fail:
ret = (ExecutionContext) os.readObject();
//
}else{
JOptionPane.showMessageDialog(null, "Error when extracting data");
}
}
}
}
}
有什么想法吗?
编辑解决方案:
在我选择序列化对象的ExecutionContext类中,在这个类中必须实现Serializable并定义serialVersionUID。
ret = (ExecutionContext) os.readObject();
【问题讨论】:
标签: java database serialization serializable