对象的读写
使用ObjectInputStream和ObjectOutputStream读写对象(序列化与反序列化)。
只有字节流没有字符流
- .类必须实现Serializable接口
- 给类加个序列化编号，给类定义一个标记，新的修改后的类还可以操作曾经序列化的对象
- 静态是不能被序列化的，序列化只能对堆中的进行序列化 ，不能对“方法区”中的进行序列化
- 不需要序列化的字段前加 transient
小例子：
先创建一个Dog对象并序列化:
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package com.uwo9.test03; import java.io.Serializable; public class Dog implements Serializable { private static final long serialVersionUID = 2809685095868158625L; String name; String color;} |
再创建一个Student对象并序列化：
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package com.uwo9.test03; import java.io.Serializable; public class Student implements Serializable { private static final long serialVersionUID = 9078616504949971001L; static public String schoolName; private transient String name; private transient int age; private double score; private Dog dog; public Student() { super(); } public Student(String name, int age, double score, Dog dog) { super(); this.name = name; this.age = age; this.score = score; this.dog = dog; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public double getScore() { return score; } public void setScore(double score) { this.score = score; } @Override public String toString() { return "Student [name=" + name + ", age=" + age + ", score=" + score + "]"; } } |
将数据写入对象流并存入文件
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package com.uwo9.test03; import java.io.File;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.ObjectOutputStream;import java.util.ArrayList;import java.util.Collections; public class Test01 { public static void main(String[] args) { Dog dog = new Dog(); dog.name = "大黄"; dog.color = "Yellow"; Student student1 = new Student("学生1", 18, 99,dog); Student student2 = new Student("学生2", 19, 99,dog); Student student3 = new Student("学生3", 20, 99,dog); Student.schoolName = "某某大学"; File file = new File("E:/Temp/Test1.txt"); ObjectOutputStream oos = null; try { oos = new ObjectOutputStream(new FileOutputStream(file)); //oos.writeObject(student); ArrayList<Student> arrayList = new ArrayList<>(); Collections.addAll(arrayList, student1,student2,student3); oos.writeObject(arrayList); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); }finally { try { oos.close(); } catch (IOException e) { e.printStackTrace(); } } } } |
从指定文件中读取对象
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package com.uwo9.test03; import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.IOException;import java.io.ObjectInputStream;import java.util.ArrayList; public class Test02 { public static void main(String[] args) { // 从指定的文件中读取对象 File file = new File("E:/Temp/Test1.txt"); ObjectInputStream ois=null; try { ois = new ObjectInputStream(new FileInputStream(file)); // 读取对象 // Student stu = (Student)ois.readObject(); // System.out.println("读取到的数据为:"+stu); @SuppressWarnings("unchecked") ArrayList<Student> arrayList = (ArrayList<Student>) ois.readObject(); for (Student student : arrayList) { System.out.println(student); } } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); }finally { try { ois.close(); } catch (IOException e) { e.printStackTrace(); } } } } |
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原文链接：https://blog.csdn.net/huanyinghanlang/article/details/78828347
