Java中的序列化，无效的类型代码00

Question

在串行化对象中读取时出现错误（java.io.StreamCorruptedException：invalid type code：00）。下面是实现Serializable类：

package guts; 

import cc.mallet.classify.*; 
import java.io.*; 


public class NaiveBayesWithID implements Serializable { 

private NaiveBayes nb; 
private static final long serialVersionUID = 1; 
    private static final int CURRENT_SERIAL_VERSION = 1; 

public NaiveBayesWithID(NaiveBayes nb) { 
this.nb = nb; 
} 
public NaiveBayesWithID(){ 
this.nb = null; 
} 

    public void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException { 
    int version = in.readInt(); 
    if (version != CURRENT_SERIAL_VERSION) 
     throw new ClassNotFoundException("Mismatched NaiveBayesTrainer versions: wanted " + 
       CURRENT_SERIAL_VERSION + ", got " + 
       version); 

    //default selections for the kind of Estimator used 

    NaiveBayesWithID test = (NaiveBayesWithID) in.readObject(); 
    // nb = test.returnNB(); 
    } 

    public void writeObject(ObjectOutputStream out) throws IOException 
    { 
    out.writeInt(CURRENT_SERIAL_VERSION); 

    //default selections for the kind of Estimator used 
    out.writeObject(this); 
    } 

    public NaiveBayes returnNB(){ 
    return nb; 
    } 

    public void setNB(NaiveBayes nb){ 
     this.nb = nb; 
    } 

} 

，这里是堆栈跟踪：

java.io.StreamCorruptedException: invalid type code: 00 
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1355) 
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1946) 
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1870) 
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1752) 
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1328) 
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:350) 
at java.util.ArrayList.readObject(ArrayList.java:593) 
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
at java.lang.reflect.Method.invoke(Method.java:597) 
at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:974) 
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1848) 
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1752) 
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1328) 
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:350) 
at cc.mallet.pipe.SerialPipes.readObject(SerialPipes.java:142) 
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
at java.lang.reflect.Method.invoke(Method.java:597) 
at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:974) 
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1848) 
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1752) 
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1328) 
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1946) 
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1870) 
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1752) 
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1328) 
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1946) 
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1870) 
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1752) 
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1328) 
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1946) 
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1870) 
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1752) 
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1328) 
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:350) 
at guts.NaiveBayesWithID.readObject(NaiveBayesWithID.java:29) 
at controllers.Application.predict(Application.java:481) 
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
at java.lang.reflect.Method.invoke(Method.java:597) 
at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:408) 
at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:403) 
at play.mvc.ActionInvoker.invoke(ActionInvoker.java:176) 
at play.server.PlayHandler$NettyInvocation.execute(PlayHandler.java:169) 
at play.Invoker$Invocation.run(Invoker.java:187) 
at play.server.PlayHandler$NettyInvocation.run(PlayHandler.java:149) 
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441) 
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) 
at java.util.concurrent.FutureTask.run(FutureTask.java:138) 
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:98) 
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:206) 
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) 
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) 
at java.lang.Thread.run(Thread.java:680) 

有谁知道我怎么可以得到错误的详细信息？或者java期待哪个对象？

Answer 1

您已经实现了一个递归writeObject方法：当你写一个实例到输出流，它调用writeObject方法，其中写道：一个int，然后写入对象输出流，它写一个int等。

serialVersionUID字段的目标是检查对象是否兼容。它由序列化机制本地完成。除非在类更改时更改serialVersionUID值，否则不必执行任何操作。

Answer 2

运行得到答案：

package so.java9217010; 
import java.io.*; 

public class SerializeMe implements Serializable{ 


    private String foo; 
    private static final long serialVersionUID = 1; 
    private static final int CURRENT_SERIAL_VERSION = 1; 

    public SerializeMe(String foo) { 
     this.foo = foo; 
    } 
    public SerializeMe(){ 
    } 

    public SerializeMe readObject(ObjectInputStream in) throws IOException, ClassNotFoundException { 
     int version = in.readInt(); 
     if (version != CURRENT_SERIAL_VERSION) 
      throw new ClassNotFoundException("Mismatched NaiveBayesTrainer versions: wanted " + 
        CURRENT_SERIAL_VERSION + ", got " + 
        version); 

     //default selections for the kind of Estimator used 

     return (SerializeMe) in.readObject(); 
     // nb = test.returnNB(); 
    } 

    public void writeObject(ObjectOutputStream out) throws IOException 
    { 
     out.writeInt(CURRENT_SERIAL_VERSION); 

     //default selections for the kind of Estimator used 
     out.writeObject(this); 
    } 

    public String returnNB(){ 
     return foo; 
    } 

    public void setNB(String foo){ 
     this.foo = foo; 
    } 
    public static void main(String[] args) throws Exception { 
     SerializeMe o = new SerializeMe("hello"); 
     ByteArrayOutputStream bout = new ByteArrayOutputStream(); 
     ObjectOutputStream oout = new ObjectOutputStream(bout); 

     o.writeObject(oout); 
     oout.flush(); 
     byte[] buff = bout.toByteArray(); 

     ByteArrayInputStream bin = new ByteArrayInputStream(buff); 
     ObjectInputStream oin = new ObjectInputStream(bin); 
     SerializeMe ro = o.readObject(oin); 
     System.out.format(
       "got: %s -- the problem is most likely in the library you are using ...\n", 
         ro.returnNB()); 
    } 
} 

Answer 3

如果JVM找不到类，当你试图读取序列化对象，将产生此异常。检查更新的jar/class文件在类路径中是否可用等。

如果从命令行运行mallet，它可能是从下载的发行版中查看解压缩的mallet jar和类文件，而不是在您下载的源代码库中创建的漂亮的新类文件中。

不要觉得太糟糕 - 我已经看到这种情况发生在其他人身上，并且自己做了（虽然我得到了更多信息“ClassNotFoundException”帮我弄明白:)

Answer 4

来到这里找到Mallet分类器反序列化的解决方案。最后，我的问题是我在一个Eclipse项目中训练并序列化模型，并试图在另一个Eclipse项目中反序列化。序列化对象中的一个类（在我创建的类中）只在前一个项目的类路径上，而不在后一个的类路径上。