我正在进行一个区块链仿真，矿工可以从内存中的文件读取区块链的当前状态，一旦他们挖掘了一个新的区块，就将更新后的链写入同一文件。然后其他矿工可以开始开采下一个区块，依此类推。我正在使用Java的FileInputStream，FileOutputStream，ObjectInputStream和ObjectOutputStream，但是在尝试读取区块链时，我总是收到IOException，特别是EOFException。
我在此站点上某处读取的内容可能是由于使用不同的FileInputStream，FileOutputStream，ObjectInputStream和ObjectOutputStream对象来写入和读取文件而导致的，所以我尝试在main中构造这些对象，然后将它们传递给构造函数每个矿工，但这不能解决问题。我创建了一个具有相同错误的最小示例，
package com.company;
import java.util.concurrent.*;
import java.io.*;
public class Main {
public static void main(String[] args) {
FileOutputStream outFile = null;
FileInputStream file = null;
ObjectOutputStream out = null;
ObjectInputStream in = null;
Obj testObj = new Obj();
testObj.data = 0;
// Serialization
try {
//Saving of object in a file
outFile = new FileOutputStream("testFile.ser");
file = new FileInputStream("testFile.ser");
out = new ObjectOutputStream(outFile);
in = new ObjectInputStream(file);
synchronized (file) {
// Method for serialization of object
out.writeObject(testObj);
}
} catch (IOException ex) {
System.out.println("IOException is caught main 1");
}
ExecutorService executor = Executors.newFixedThreadPool(10);
for (int i = 0; i <10 ; i++) {
executor.submit(new ObjModifier(file, outFile, in, out));
}
}
}
package com.company;
import java.io.*;
public class ObjModifier implements Runnable {
private FileInputStream file;
private FileOutputStream outFile;
private ObjectInputStream in;
private ObjectOutputStream out;
private Obj readObj;
@Override
public void run(){
while(!Thread.interrupted()){
// Deserialization
try
{
// Method for deserialization of object
synchronized (file) {
readObj = (Obj) in.readObject();
}
}
catch(IOException ex)
{
System.out.println("IOException is caught at ObjModifier " +
ex.getCause()+
ex.getMessage());
}
catch(ClassNotFoundException ex)
{
System.out.println("ClassNotFoundException is caught at ObjModifier");
}
//simulate downloading current blockchain
Obj myCopy = Obj.class.cast(DeepCopy.copy(readObj));
//simulate mining next block
for (int i = 0; i <10000 ; i++) {
int j = i;
}
myCopy.data += 1;
//write updated object to file
synchronized (outFile) {
// Serialization
try {
//Saving of object in a file
// Method for serialization of object
out.writeObject(myCopy);
} catch (IOException ex) {
System.out.println("IOException is caught at " + Thread.currentThread().getName());
}
}
}
}
public ObjModifier(FileInputStream file, FileOutputStream outFile, ObjectInputStream in, ObjectOutputStream out){
this.file = file;
this.outFile = outFile;
this.in = in;
this.out = out;
}
}
package com.company;
import java.io.IOException;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
/**
* Utility for making deep copies (vs. clone()'s shallow copies) of
* objects. Objects are first serialized and then deserialized. Error
* checking is fairly minimal in this implementation. If an object is
* encountered that cannot be serialized (or that references an object
* that cannot be serialized) an error is printed to System.err and
* null is returned. Depending on your specific application, it might
* make more sense to have copy(...) re-throw the exception.
*
* A later version of this class includes some minor optimizations.
*/
public class DeepCopy {
/**
* Returns a copy of the object, or null if the object cannot
* be serialized.
*/
public static Object copy(Object orig) {
Object obj = null;
try {
// Write the object out to a byte array
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(bos);
out.writeObject(orig);
out.flush();
out.close();
// Make an input stream from the byte array and read
// a copy of the object back in.
ObjectInputStream in = new ObjectInputStream(
new ByteArrayInputStream(bos.toByteArray()));
obj = in.readObject();
}
catch(IOException e) {
e.printStackTrace();
}
catch(ClassNotFoundException cnfe) {
cnfe.printStackTrace();
}
return obj;
}
}
package com.company;
import java.io.Serializable;
public class Obj implements Serializable {
public int data;
public Obj(){
}
}
消息
IOException is caught at ObjModifier nullnull
被打印到控制台，使用异常断点，我看到该异常实际上是EOF异常。
请让我知道我是否可以澄清任何事情，或提供更多信息。