abstract char get(String name, char val)
描述 (Description)
java.io.ObjectInputStream.getField.get(String name, char val)方法从持久字段中获取指定char字段的值。
声明 (Declaration)
以下是java.io.ObjectInputStream.getField.get()方法的声明。
public abstract char get(String name, char val)
参数 (Parameters)
name - 字段的名称。
val - 如果name没有值，则使用默认值。
返回值 (Return Value)
此方法返回指定char字段的值。
异常 (Exception)
IOException - 如果从底层InputStream读取时存在I/O错误。
IllegalArgumentException - 如果name的类型不可序列化或字段类型不正确。
例子 (Example)
以下示例显示了java.io.ObjectInputStream.getField.get()方法的用法。
package com.iowiki;
import java.io.*;
public class ObjectInputStreamDemo 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 variable of a
System.out.println("" + a.var);
} catch (Exception ex) {
ex.printStackTrace();
}
}
static public class Example implements Serializable {
static char var = 'a';
// assign a new serialPersistentFields
private static final ObjectStreamField[] serialPersistentFields = {
new ObjectStreamField("var", Character.TYPE)
};
private void readObject(ObjectInputStream in)
throws IOException, ClassNotFoundException {
// get the field and assign it at string variable
ObjectInputStream.GetField fields = in.readFields();
// get var
var = (char) fields.get("var", 'a');
}
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 -
a
