CODEWITHSUNDEEP
java
sabarirajan
sabarirajan

Reputation: 177

how to convert an input stream to a java object

ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(reg_be);
oos.flush();
oos.close();

InputStream is = new ByteArrayInputStream(baos.toByteArray());

This code convert Java Object to InputStream and how can I convert InputStream to an Object? I need to convert my Object to an InputStream then I pass it and I want to get my Object back.

Upvotes: 11

Views: 52697

Answers (4)

Buhake Sindi
Buhake Sindi

Reputation: 89189

ObjectInputStream ois = new ObjectInputStream(is);
Object object = ois.readObject();

Upvotes: 1

Satish Patro
Satish Patro

Reputation: 4414

ObjectInputStream ois = new ObjectInputStream(is);
Object object = ois.readObject();

As mentioned by @darijan is working fine. But again we need to do try, catch block for that code, & for blank input stream it will give EOF (End Of File) related error.

So, I am converting it to a string. Then if the string is not empty or null, then only I am converting it to Object using ObjectMapper

Although it's not an efficient approach, I don't need to worry about try-catch, null handling also is done in a string instead of the input stream

String responseStr = IOUtils.toString(is, StandardCharsets.UTF_8.name());
Object object = null;
// is not null or whitespace consisted string
if (StringUtils.isNotBlank(response)) {
    object = getJsonFromString(response);
}


// below codes are already used in project (Util classes)
private Object getJsonFromString(String jsonStr) {
    if (StringUtils.isEmpty(jsonStr)) {
        return new LinkedHashMap<>();
    }
    ObjectMapper objectMapper = getObjectMapper();

    Map<Object, Object> obj = null;
    try {
        obj = objectMapper.readValue(jsonStr, new TypeReference<Map<Object, Object>>() {
        });
    } catch (IOException e) {
        LOGGER.error("Unable to parse JSON : {}",e)
    }
    return obj;
}
private ObjectMapper getObjectMapper() {
    ObjectMapper objectMapper = new ObjectMapper();
    objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
    objectMapper.enable(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT);
    return objectMapper;
}

Upvotes: 0

darijan
darijan

Reputation: 9795

In try block you should write:

ObjectInputStream ois = new ObjectInputStream(is);
Object object = ois.readObject();

ObjectInputStream is initialized with another stream, e.g. BufferedInputStream or your input stream is.

Upvotes: 18

Aniket Thakur
Aniket Thakur

Reputation: 69025

Try the following

ObjectInputStream  ois = new ObjectInputStream(is);
Object obj = ois .readObject();

Upvotes: 0

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