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[Resolvido] Streams de Objectos

DRS

By DRS
in Java

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DRS void

DRS

Posted
Posted (edited)

Boas pessoal, no programa que estou a fazer ao compilar aparece as seguintes notas:

Note: TstProduto2.java uses unchecked or unsafe operations.

Note: Recompile with -Xlint:unchecked for details.

e ao executar aparece:

writing aborted; java.io.NotSerializableException: Produto

Eu não percebo porque este erro já que eu implementei a interface Serializable...

O programa que estou a fazer é por motivos didacticos retirado do livro "JAVA6" em que estou a tentar aprender "Streams de Objectos". O meu ficheiro "TstProduto1.java" consiste em criar um ficheiro (Stock.dat) e escrever objectos no mesmo, o ficheiro "TstProduto2.java" consiste em ler os objectos desse mesmo ficheiro e lê-los no programa, mas neste ultimo teste da o tal erro...

"Produto.java"

import java.util.*;
import java.io.*;
public class Produto implements Serializable{

private final long serialVersionUID = 1L; //ID de Serialização para instâncias desta classe

//Variáveis de instância
private String codigo;
private String nome;
private int quant;
private Set<String> comps; //codigo dos componentes

//Construtor completo
public Produto (String cod, String nom, int qt, HashSet<String> cps){
codigo = cod;
nome = nom;
quant = qt;
comps = new HashSet<String>();
for(String c : cps){ comps.add(c); }
}

//Métodos de instância
public String daCod() { return codigo; }
public String daNome() { return nome; }
public int daQuant() { return quant; }

public HashSet<String> daComps(){
HashSet<String> cps = new HashSet<String>();
for(String c : comps){ cps.add(c); }
return cps;
}

public Produto clone(){
return new Produto(codigo, nome, quant, this.daComps());
}

//Método toString()
public String toString(){
StringBuilder s = new StringBuilder();
s.append("----------------------\n");
s.append("Codigo: ");
s.append("\t");
s.append(codigo + "\n");
s.append("Nome: " );
s.append("\t");
s.append(nome + "\n");
s.append("\t");
s.append(quant + "\n");
int num = comps.size();
s.append("Componentes: ");
s.append(num + "\n");
for(String c : comps){ s.append(c + "\n"); }
return s.toString();
}
//método alternativo a toString()
public String asString(){

String s = "--------------------\n";
s = s + "Codigo: " + "\t" + codigo + "\n";
s = s + "Nome: " + "\t" + nome + "\n";
s = s + "Quant: " + "\t" + quant + "\n";
int num = comps.size();
s = s + "Componentes: " + num + "\n";

for(String c : comps){
s = s + c + "\n";
}

return s.toString();
}
}

"TstProduto1.java"

import java.io.*;
import java.util.*;
import static java.lang.System.out;
import static java.lang.Math.random;
//INTRODUÇÂO AS STREAMS DE OBJECTOS, "OBJECTOUTPUTSTREAM" e "OBJECTINPUTSTREAM"...

//Classe de Teste
public class TstProduto1{

private static final int MAXPRODS = 100000;

//Método auxiliar para criação do HashMap
public static HashMap<Integer, Produto> criaFichas(){

HashMap<Integer, Produto> stk = new HashMap<Integer, Produto>();
HashSet<String> comps = new HashSet<String>();
int c = 0;
Produto p = null;

for(int i = 1; i <= MAXPRODS; i++){
c = 0 + (int)(random()*5); //Numero de componentes de 0 .. c
if(c>0){
for(int n = 1; n<= c; n++){ comps.add("CMP" + i%99 + n); }
}
p = new Produto("" + i, "PROD" + i%99, 1 + (int)(random()*1000), comps);
stk.put(i, p.clone());
comps.clear();
}
return stk; //Devolve HashMap com as 100.000 fichas...
}

public static void main(String[] args){

HashMap<Integer, Produto> stockNovo = new HashMap<Integer, Produto>();
HashSet<String> comps = new HashSet<String>();

stockNovo = criaFichas(); //Cria as MAXPRODS fichas

GregorianCalendar call = new GregorianCalendar();

//Implementação do "ObjectOutputStream" e "FileOutputStream"...
//Grava "Stock" num ObjectStream...
try{
//Criando o ficheiro "Stock.dat" que guarda objectos e o "objecto stream" que aponta para o ficheiro...
ObjectOutputStream oout = new ObjectOutputStream(new FileOutputStream("Stock.dat"));

oout.writeObject(stockNovo); //Escreve Objectos no ficheiro...
oout.flush();
oout.close();

}catch(IOException e){
out.println(e.getMessage());
}

GregorianCalendar cal2 = new GregorianCalendar();
long difMils = cal2.getTimeInMillis()-call.getTimeInMillis();
out.println(stockNovo.size() + "fichas em " + difMils + "ms");
out.println("--------------------------------------");
}
}

"TstProduto2.java" (É aqui que ocorre o problema)

import java.io.*;
import java.util.*;
import static java.lang.System.out;
import static java.lang.Math.random;
//INTRODUÇÂO AS STREAMS DE OBJECTOS, "OBJECTOUTPUTSTREAM" e "OBJECTINPUTSTREAM"...
//Classe de Teste
public class TstProduto2{

private static final int MAXPRODS = 100000;

//Método auxiliar para criação do HashMap
public static HashMap<Integer, Produto> criaFichas(){

HashMap<Integer, Produto> stk = new HashMap<Integer, Produto>();
HashSet<String> comps = new HashSet<String>();
int c = 0;
Produto p = null;

for(int i = 1; i <= MAXPRODS; i++){
c = 0 + (int)(random()*5); //Numero de componentes de 0 .. c
if(c>0){
for(int n = 1; n<= c; n++){ comps.add("CMP" + i%99 + n); }
}
p = new Produto("" + i, "PROD" + i%99, 1 + (int)(random()*1000), comps);
stk.put(i, p.clone());
comps.clear();
}
return stk; //Devolve HashMap com as 100.000 fichas...
}

public static void main(String[] args){

HashMap<Integer, Produto> stockNovo = new HashMap<Integer, Produto>();
HashSet<String> comps = new HashSet<String>();

stockNovo = criaFichas(); //Cria as MAXPRODS fichas

GregorianCalendar call = new GregorianCalendar();

//Implementação do "ObjectInputStream" e "FileInputStream"...
//Lê de novo as MAXPRODS fichas contidas na "ObjectStream"...
try{

ObjectInputStream oin = new ObjectInputStream(new FileInputStream("Stock.dat"));

stockNovo = (HashMap<Integer,Produto>) oin.readObject();

//Escreve o stock lido no programa...
/*for(Produto pr : stockNovo.values()){
out.println(pr);
}*/

oin.close();

}
catch(IOException e){ out.println(e.getMessage()); }
catch(ClassNotFoundException e){ out.println(e.getMessage()); }

GregorianCalendar cal2 = new GregorianCalendar();
long difMils = cal2.getTimeInMillis()-call.getTimeInMillis();
out.println(stockNovo.size() + "fichas em " + difMils + "ms");
out.println("--------------------------------------");
}
}

Agradeço quaisquer ajudas. Obrigado.

PS: Desculpem lá o titulo, foi um engano...

Edited by apocsantos
HappyHippyHippo stack overflow

HappyHippyHippo

Posted
Posted (edited) 
HashMap<Integer, Produto> stockNovo = new HashMap<Integer, Produto>();
...
oout.writeObject(stockNovo);

stockNovo é um HashMap, e essa classe não implementa o Serializable

ps : por acaso implementa.

diz em que linha a exceção é lançada

Edited by HappyHippyHippo
IRC : sim, é algo que ainda existe >> #p@p
DRS void

DRS

Posted
  • Author
Posted

O programa não indica a linha, uma coisa tenho a certeza, o erro so começou a dar depois de fazer o "try/catch" de "TstProduto 2".

Notas e erros na consola:

[sun Dec 09][15:44:40][Objects] $ javac TstProduto2.java

Note: TstProduto2.java uses unchecked or unsafe operations.

Note: Recompile with -Xlint:unchecked for details.

[sun Dec 09][15:44:53][Objects] $ java TstProduto2

writing aborted; java.io.NotSerializableException: Produto

100000fichas em 19ms

--------------------------------------

[sun Dec 09][15:45:00][Objects] $

DRS void

DRS

Posted
  • Author
Posted

[sun Dec 09][15:45:00][Objects] $ javac -verbose TstProduto2.java

[parsing started RegularFileObject[TstProduto2.java]]

[parsing completed 18ms]

[search path for source files: .]

[search path for class files: /usr/lib/jvm/jdk1.7.0/jre/lib/resources.jar,/usr/lib/jvm/jdk1.7.0/jre/lib/rt.jar,/usr/lib/jvm/jdk1.7.0/jre/lib/sunrsasign.jar,/usr/lib/jvm/jdk1.7.0/jre/lib/jsse.jar,/usr/lib/jvm/jdk1.7.0/jre/lib/jce.jar,/usr/lib/jvm/jdk1.7.0/jre/lib/charsets.jar,/usr/lib/jvm/jdk1.7.0/jre/lib/jfr.jar,/usr/lib/jvm/jdk1.7.0/jre/classes,/usr/lib/jvm/jdk1.7.0/jre/lib/ext/sunjce_provider.jar,/usr/lib/jvm/jdk1.7.0/jre/lib/ext/sunpkcs11.jar,/usr/lib/jvm/jdk1.7.0/jre/lib/ext/localedata.jar,/usr/lib/jvm/jdk1.7.0/jre/lib/ext/sunec.jar,/usr/lib/jvm/jdk1.7.0/jre/lib/ext/zipfs.jar,/usr/lib/jvm/jdk1.7.0/jre/lib/ext/dnsns.jar,.]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/System.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Object.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Math.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/util/HashMap.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Integer.class)]]

[loading RegularFileObject[./Produto.class]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/String.class)]]

[checking TstProduto2]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/AutoCloseable.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Number.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/util/Map.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/util/HashSet.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/util/Collection.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/util/AbstractSet.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/util/AbstractCollection.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/util/AbstractMap.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/util/GregorianCalendar.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/io/ObjectInputStream.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/io/FileInputStream.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/io/FileDescriptor.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/io/File.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/io/InputStream.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/io/IOException.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Exception.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Throwable.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/io/PrintStream.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/io/FilterOutputStream.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/io/OutputStream.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/ClassNotFoundException.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/ReflectiveOperationException.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/util/Calendar.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Error.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/io/FileNotFoundException.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/RuntimeException.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Byte.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Character.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Short.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Long.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Float.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Double.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Boolean.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Void.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/StringBuilder.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/CharSequence.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/io/Serializable.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Comparable.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/AbstractStringBuilder.class)]]

[loading ZipFileIndexFileObject[/usr/lib/jvm/jdk1.7.0/lib/ct.sym(META-INF/sym/rt.jar/java/lang/StringBuffer.class)]]

[wrote RegularFileObject[TstProduto2.class]]

[total 268ms]

Note: TstProduto2.java uses unchecked or unsafe operations.

Note: Recompile with -Xlint:unchecked for details.

[sun Dec 09][16:13:45][Objects] $

Baderous try-catch user

Baderous

Posted
Posted (edited)

Testei o teu código e não obtive nenhum erro. Não terás tu alterado a classe Produto após teres gravado o ficheiro Stock.dat e agora estás a querer ler objectos com um formato diferente daquele esperado pelo mecanismo de desserialização e isso provoca o erro? Experimenta eliminar o ficheiro Stock.dat e correr outra vez a escrita + leitura desse ficheiro.

O warning deve-se ao cast que fazes no readObject(), para resolver deves encapsular esse HashMap numa classe e depois fazer o cast para esse novo tipo.

Edited by Baderous
  • Vote 1

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