java - 如何使用ObjectOutputStream.writeObject()+Base64 (Java)深度序列化对象？

Question

我需要在java中序列化一个对象。目前我正在使用 this code 来做到这一点，它的作用是:

1. ObjectOutputStream.writeObject(obj);
2. Base64 编码 obj

并反转该过程。

它适用于类内部的基本类型，例如 long 和 int。

但是，该对象内的所有 String 对象都会变为 null。 我也需要将它们包含在内。有什么办法可以做到吗？

编辑:我正在使用的代码

// Modified from source: https://stackoverflow.com/questions/134492/how-to-serialize-an-object-into-a-string
public static Object FromString( String s )
{
    Object o = null;
    try {
        byte[] data = Base64.getDecoder().decode(s);
        ObjectInputStream ois = new ObjectInputStream(
                new ByteArrayInputStream(data));
        o = ois.readObject();
        ois.close();
    }
    catch(Exception e)
    {
        System.out.println(e);
    }
    return o;
}

// Modified from source: https://stackoverflow.com/questions/134492/how-to-serialize-an-object-into-a-string
public static String ToString( Serializable o )
{
    ByteArrayOutputStream baos = null;
    try {
        baos = new ByteArrayOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(baos);
        oos.writeObject(o);
        oos.close();
    }
    catch(Exception e)
    {
        System.out.println(e);
    }

    return Base64.getEncoder().encodeToString(baos.toByteArray());
}

编辑:Pojo

public class SignedTimestamp implements Serializable {

    private Long obj;
    private byte[] signature;
    private String signatureAsAString;
}

其他应用程序的输出(接收数据并反序列化):

obj = 1494609033621;

signature = null;

signatureAsAString = null;

Answer 1

我刚刚测试了您的代码，它工作正常。

我创建了一个名为SignedTimeStamp.java的源:

import java.io.*;

public class SignedTimestamp implements Serializable {
    private Long obj;
    private byte[] signature;
    private String signatureAsAString;

    public SignedTimestamp(Long obj, byte[] signature, String signatureAsAString) {
        this.obj = obj;
        this.signature = signature;
        this.signatureAsAString = signatureAsAString;
    }

    public Long getObj() {
        return this.obj;
    }

    public byte[] getSignature() {
        return this.signature;
    }

    public String getSignatureAsAString() {
        return this.signatureAsAString;
    }

}

并声明了另一个名为 Serializeds.java 的文件，其中包含您的代码: 导入 java.io.; 导入java.util.;

public class Serializables {
    public static Object FromString(String s) {
        Object o = null;
        try {
            byte[] data = Base64.getDecoder().decode(s);
            ObjectInputStream ois = new ObjectInputStream(
                    new ByteArrayInputStream(data));
            o = ois.readObject();
            ois.close();
        }
        catch(Exception e)
        {
            System.out.println(e);
        }
        return o;
    }

    // Modified from source: http://stackoverflow.com/questions/134492/how-to-serialize-an-object-into-a-string
    public static String ToString( Serializable o ) {
        ByteArrayOutputStream baos = null;
        try {
            baos = new ByteArrayOutputStream();
            ObjectOutputStream oos = new ObjectOutputStream(baos);
            oos.writeObject(o);
            oos.close();
        }
        catch(Exception e)
        {
            System.out.println(e);
        }

        return Base64.getEncoder().encodeToString(baos.toByteArray());
    }
}

然后，我在 Serialize.java 中创建了一个主类:

public class Serialize {

    public static void main(String[] args) throws Exception {
        SignedTimestamp o = new SignedTimestamp(100L, new byte[]{ (byte) 128 }, "Hello, world!");
        System.out.println(Serializables.ToString(o));
    }
}

这给我返回了这个结果:

sh-4.3$ java Serialize
rO0ABXNyAA9TaWduZWRUaW1lc3RhbXCGTHiJ+JenzgIAA0wAA29ianQAEExqYXZhL2xhbmcvTG9uZztbAAlzaWduYXR1cmV0AAJbQkwAEnNpZ25hdHVyZUFzQVN0cmluZ3QAEkxqYXZhL2xhbmcvU3RyaW5nO3hwc3IADmphdmEubGFuZy
5Mb25nO4vkkMyPI98CAAFKAAV2YWx1ZXhyABBqYXZhLmxhbmcuTnVtYmVyhqyVHQuU4IsCAAB4cAAAAAAAAABkdXIAAltCrPMX+AYIVOACAAB4cAAAAAGAdAANSGVsbG8sIHdvcmxkIQ==                                    
sh-4.3$ 

然后，我在Deserialize.java中创建了另一个主类:

public class Deserialize {

    public static void main(String[] args) throws Exception {
        String serialized = 
            "rO0ABXNyAA9TaWduZWRUaW1lc3RhbXCGTHiJ+JenzgIAA0wAA29ianQAEExqYXZhL2xhbmcvTG9uZztbAAlzaWduYXR1cmV0AAJbQkwAEnNpZ25hdHVyZUFzQVN0cmluZ3QAEkxqYXZhL2xhbmcvU3RyaW5nO3hwc3IADmphdmEubGFuZy" +
            "5Mb25nO4vkkMyPI98CAAFKAAV2YWx1ZXhyABBqYXZhLmxhbmcuTnVtYmVyhqyVHQuU4IsCAAB4cAAAAAAAAABkdXIAAltCrPMX+AYIVOACAAB4cAAAAAGAdAANSGVsbG8sIHdvcmxkIQ==";
        SignedTimestamp o = (SignedTimestamp) Serializables.FromString(serialized);

        System.out.println(o.getObj());
        System.out.println(o.getSignature());
        System.out.println(o.getSignatureAsAString());
    }

}

它返回这个:

sh-4.3$ java Deserialize                                                                                                                                                          
100                                                                                                                                                                               
[B@6bc7c054                                                                                                                                                                       
Hello, world!                                                                                                                                                                     
sh-4.3$ 

所以，总而言之，代码似乎运行完美。你是如何测试你的代码的？也许错误就在那里。