假设我有一个可序列化的类AppMessage
。
我想将它作为byte[]
通过套接字传输到另一台机器,在那里从接收的字节重建它。
我怎么能实现这个目标?
答案 0 :(得分:384)
准备要发送的字节:
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutput out = null;
try {
out = new ObjectOutputStream(bos);
out.writeObject(yourObject);
out.flush();
byte[] yourBytes = bos.toByteArray();
...
} finally {
try {
bos.close();
} catch (IOException ex) {
// ignore close exception
}
}
从字节创建对象:
ByteArrayInputStream bis = new ByteArrayInputStream(yourBytes);
ObjectInput in = null;
try {
in = new ObjectInputStream(bis);
Object o = in.readObject();
...
} finally {
try {
if (in != null) {
in.close();
}
} catch (IOException ex) {
// ignore close exception
}
}
答案 1 :(得分:281)
最好的方法是使用Apache Commons Lang中的SerializationUtils
。
序列化:
byte[] data = SerializationUtils.serialize(yourObject);
要反序列化:
YourObject yourObject = SerializationUtils.deserialize(data)
如前所述,这需要Commons Lang库。它可以使用Gradle导入:
compile 'org.apache.commons:commons-lang3:3.5'
的Maven:
<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.5</version>
</dependency>
提及here
的更多方法或者,可以导入整个集合。请参阅this link
答案 2 :(得分:77)
如果您使用Java&gt; = 7,则可以使用{{3}}改进已接受的解决方案:
private byte[] convertToBytes(Object object) throws IOException {
try (ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutput out = new ObjectOutputStream(bos)) {
out.writeObject(object);
return bos.toByteArray();
}
}
反过来说:
private Object convertFromBytes(byte[] bytes) throws IOException, ClassNotFoundException {
try (ByteArrayInputStream bis = new ByteArrayInputStream(bytes);
ObjectInput in = new ObjectInputStream(bis)) {
return in.readObject();
}
}
答案 3 :(得分:5)
可以通过 SerializationUtils ,通过序列化&amp;反序列化方法由ApacheUtils将对象转换为byte [],反之亦然,如@uris answer中所述。
通过序列化将对象转换为byte []:
byte[] data = SerializationUtils.serialize(object);
通过反序列化::
将byte []转换为objectObject object = (Object) SerializationUtils.deserialize(byte[] data)
点击Download org-apache-commons-lang.jar
的链接点击:
整合.jar文件FileName - &gt; 打开Medule设置 - &gt; 选择您的模块 - &gt; 依赖关系 - &gt; 添加Jar文件,您就完成了。
希望这会有所帮助。
答案 4 :(得分:2)
我还建议使用SerializationUtils工具。我想对@Abilash做出错误的评论。 SerializationUtils.serialize()
方法不限制为1024字节,这与此处的另一个答案相反。
public static byte[] serialize(Object object) {
if (object == null) {
return null;
}
ByteArrayOutputStream baos = new ByteArrayOutputStream(1024);
try {
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(object);
oos.flush();
}
catch (IOException ex) {
throw new IllegalArgumentException("Failed to serialize object of type: " + object.getClass(), ex);
}
return baos.toByteArray();
}
乍一看,您可能认为new ByteArrayOutputStream(1024)
只允许固定大小。但是如果你仔细查看ByteArrayOutputStream
,你会发现如果有必要,流会增长:
此类实现数据所在的输出流 写入字节数组。缓冲区自动增长为数据 是写的。 可以使用
toByteArray()
和\ n检索数据toString()
。
答案 5 :(得分:1)
我想将它作为byte []通过套接字传输到另一台机器
// When you connect
ObjectOutputStream oos = new ObjectOutputStream(socket.getOutputStream());
// When you want to send it
oos.writeObject(appMessage);
从收到的字节重建它。
// When you connect
ObjectInputStream ois = new ObjectInputStream(socket.getInputStream());
// When you want to receive it
AppMessage appMessage = (AppMessage)ois.readObject();
答案 6 :(得分:1)
另一种有趣的方法来自@daily /etc/init.d/elasticsearch restart
com.fasterxml.jackson.databind.ObjectMapper
Maven依赖
byte[] data = new ObjectMapper().writeValueAsBytes(JAVA_OBJECT_HERE)
答案 7 :(得分:1)
如果您想要一个不错的无依赖项复制粘贴解决方案。抓取下面的代码。
MyObject myObject = ...
byte[] bytes = SerializeUtils.serialize(myObject);
myObject = SerializeUtils.deserialize(bytes);
import java.io.*;
public class SerializeUtils {
public static byte[] serialize(Serializable value) throws IOException {
ByteArrayOutputStream out = new ByteArrayOutputStream();
try(ObjectOutputStream outputStream = new ObjectOutputStream(out)) {
outputStream.writeObject(value);
}
return out.toByteArray();
}
public static <T extends Serializable> T deserialize(byte[] data) throws IOException, ClassNotFoundException {
try(ByteArrayInputStream bis = new ByteArrayInputStream(data)) {
//noinspection unchecked
return (T) new ObjectInputStream(bis).readObject();
}
}
}
答案 8 :(得分:0)
使用Java 8+的代码示例:
public class Person implements Serializable {
private String lastName;
private String firstName;
public Person() {
}
public Person(String firstName, String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
@Override
public String toString() {
return "firstName: " + firstName + ", lastName: " + lastName;
}
}
public interface PersonMarshaller {
default Person fromStream(InputStream inputStream) {
try (ObjectInputStream objectInputStream = new ObjectInputStream(inputStream)) {
Person person= (Person) objectInputStream.readObject();
return person;
} catch (IOException | ClassNotFoundException e) {
System.err.println(e.getMessage());
return null;
}
}
default OutputStream toStream(Person person) {
try (OutputStream outputStream = new ByteArrayOutputStream()) {
ObjectOutput objectOutput = new ObjectOutputStream(outputStream);
objectOutput.writeObject(person);
objectOutput.flush();
return outputStream;
} catch (IOException e) {
System.err.println(e.getMessage());
return null;
}
}
}
答案 9 :(得分:0)
Spring框架studentdoc_setting_index_mapping_type_overlayadjacency.json
{
"index": {
"mapping": {
"total_fields": {
"limit": "100000"
}
}
}
}
@Setting(settingPath = "studentdoc_setting_index_mapping_type_overlayadjacency.json")
public class StudentDoc {
}
org.springframework.util.SerializationUtils
答案 10 :(得分:0)
这只是已接受答案的优化代码形式,以防有人在生产中使用它:
public static void byteArrayOps() throws IOException, ClassNotFoundException{
String str="123";
byte[] yourBytes = null;
// Convert to byte[]
try(ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(bos);) {
out.writeObject(str);
out.flush();
yourBytes = bos.toByteArray();
} finally {
}
// convert back to Object
try(ByteArrayInputStream bis = new ByteArrayInputStream(yourBytes);
ObjectInput in = new ObjectInputStream(bis);) {
Object o = in.readObject();
} finally {
}
}