二进制文件的读写&序列化和反序列化
二进制文件的读写&序列化和反序列化1.二进制文件的读写
1.二进制文件:音频,视频,图片文件
DataInputStream:需要FileInputStream做参数
*
DataOutputStream:需要FileOutputStream做参数
packagecn.com.abner.IO.picObjiect;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
//C:\Users\Administrator\Desktop\新建文件夹\name.jpg复制到C:\Users\Administrator\Desktop\新建文件夹\pic
public class picremoveDemo {
public static void main(String[] args) {
//输入流
DataInputStream a=null;
FileInputStream b=null;
//输出流
DataOutputStream c=null;
FileOutputStream d=null;
try {
b=new FileInputStream("C:\\Users\\Administrator\\Desktop\\新建文件夹\\name.jpg");
a=new DataInputStream(b);
d=new FileOutputStream("C:\\Users\\Administrator\\Desktop\\新建文件夹\\pic\\newname.jpg");
c=new DataOutputStream(d);
int temp;
try {
while((temp=a.read())!=-1) {
c.write(temp);
}
} catch (IOException e) {
e.printStackTrace();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}finally {
try {
d.close();
c.close();
a.close();
b.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
2.序列化和反序列化
*
对象的读写
*
序列化:对象–>流中
*
对象对应的类必须实现Serializable接口,否则不能被序列化
*
ObjectOutputStream:需要FileOutputStream做参数
*
方法:writeObject(Object)
*
反序列化:流中–>对象
*
ObjectInputStream:需要FileInputStream做参数
*
方法:readObject( ) 【返回值为Object,需要强制转换】
packagecn.com.abner.IO.picObjiect;
import java.io.Serializable;
public class Student implements Serializable {
private String name;
private int age;
private transient String stuID;
public Student() {
}
public Student(String name, int age, String stuID) {
this.name = name;
this.age = age;
this.stuID = stuID;
}
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 String getStuID() {
return stuID;
}
public void setStuID(String stuID) {
this.stuID = stuID;
}
}
packagecn.com.abner.IO.picObjiect;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
//将学生类序列化和反序列化
public class ObjectRemove {
public static void main(String[] args) {
Student stu=new Student("Abner",25,"123");
ObjectOutputStream a=null;
FileOutputStream b=null;
ObjectInputStream c=null;
FileInputStream d=null;
try {
b=new FileOutputStream("C:\\Users\\Administrator\\Desktop\\新建文件夹\\student.txt");
try {
a=new ObjectOutputStream(b);
a.writeObject(stu);
d=new FileInputStream("C:\\Users\\Administrator\\Desktop\\新建文件夹\\student.txt");
c=new ObjectInputStream(d);
try {
Student stu1=(Student)c.readObject();
System.out.println(stu1.getName()+" "+stu1.getAge()+" "+stu1.getStuID()); //Abner 25 null
System.out.println(stu1.getName()+" "+stu1.getAge()); //Abner 25
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
} catch (IOException e) {
e.printStackTrace();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
3.transient关键字
定义属性加关键字,该属性取消序列化