abstract void put(String name, byte val)
描述 (Description)
java.io.ObjectOutputStream.PutField.put(String name, byte val)方法将命名字节字段的值放入持久字段中。
声明 (Declaration)
以下是java.io.ObjectOutputStream.PutField.put()方法的声明。
public abstract void put(String name, byte val)
参数 (Parameters)
name - 可序列化字段的名称。
val - 要分配给字段的值。
返回值 (Return Value)
此方法不返回值。
异常 (Exception)
IllegalArgumentException - 如果name与正在写入其字段的类的可序列化字段的名称不匹配,或者指定字段的类型不是byte 。
例子 (Example)
以下示例显示了java.io.ObjectOutputStream.PutField.put()方法的用法。
package com.iowiki;
import java.io.*;
public class ObjectOutputStreamDemo implements Serializable {
public static void main(String[] args) {
try {
// create a new file with an ObjectOutputStream
FileOutputStream out = new FileOutputStream("test.txt");
ObjectOutputStream oout = new ObjectOutputStream(out);
// write something in the file
oout.writeObject(new Example());
oout.flush();
oout.close();
// create an ObjectInputStream for the file we created before
ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.txt"));
// read an object from the stream and cast it to Example
Example a = (Example) ois.readObject();
// print var of a
System.out.println("" + a.var);
} catch (Exception ex) {
ex.printStackTrace();
}
}
static public class Example implements Serializable {
static byte var = 5;
// assign a new serialPersistentFields
private static final ObjectStreamField[] serialPersistentFields = {
new ObjectStreamField("var", Byte.TYPE)
};
private void readObject(ObjectInputStream in)
throws IOException, ClassNotFoundException {
// get the field and assign it at string variable
ObjectInputStream.GetField fields = in.readFields();
// check if string is defaulted, meaning if it has no value
byte b = 0;
var = (byte) fields.get("var", b);
}
private void writeObject(ObjectOutputStream out) throws IOException {
// write into the ObjectStreamField array the variable var
ObjectOutputStream.PutField fields = out.putFields();
fields.put("var", var);
out.writeFields();
}
}
}
让我们编译并运行上面的程序,这将产生以下结果 -
5