JAVA中的IO流的那些事基本数据操作流，序列化和反序列化

各种各样的数据流—学完你懵不懵&＃xff1f;-------------

基本数据操作流—Data。。


import java.io.*;public class Test {public static void main(String[] args) throws IOException {File file&＃61; new File("D:/Demo.txt");OutputStream ops&＃61; new FileOutputStream(file);DataOutputStream dos&＃61;new DataOutputStream(ops);dos.writeBoolean(false);dos.writeUTF("今天");dos.writeDouble(10.25);dos.writeByte(100);dos.close();}
}


这写入了些啥&＃xff1f;
看不懂—乱码&＃xff0c;因为是给机器看的&＃xff0c;想要读取数据需要用到DataIntputStream


import java.io.*;public class Test {public static void main(String[] args) throws IOException {File file&＃61; new File("D:/Demo.txt");InputStream is&＃61; new FileInputStream(file);DataInputStream dis&＃61; new DataInputStream(is);//按照顺序读取System.out.println(dis.readBoolean());System.out.println(dis.readUTF());System.out.println(dis.readDouble());System.out.println(dis.readByte());
dis.close();}
}


public class DataOutputStream extends FilterOutputStream implements DataOutput {
public class DataInputStream extends FilterInputStream implements DataInput {
DataIntput 接口用于将数据从一系列字节转换为 Java 基本类型&＃xff0c;并将这些字节读取为二进制流。
DataOutput 接口用于将数据从任意 Java 基本类型转换为一系列字节&＃xff0c;并将这些字节写入二进制流。同时还提供了一个将 String 转换成 UTF-8 修改版格式并写入所得到的系列字节的工具。

对于此接口中写入字节的所有方法&＃xff0c;如果由于某种原因无法写入某个字节&＃xff0c;则抛出 IOException。

对象序列化----


import java.io.*;public class Test {public static void main(String[] args) throws IOException {File file&＃61; new File("D:/Hello.txt");//目标文件OutputStream is&＃61; new FileOutputStream(file);//开辟输出流ObjectOutputStream oos&＃61; new ObjectOutputStream(is);//序列化oos.writeObject(new String("我的老家&＃xff0c;就住在这个屯"));oos.close();}
}


生成的文件看不懂&＃xff0c;再写一个程序读取就可以了&＃xff1b;

package HuiXin;import java.io.*;public class Test01 {public static void main(String[] args) throws IOException, ClassNotFoundException {File file&＃61; new File("D:/Hello.txt");InputStream is&＃61; new FileInputStream(file);ObjectInputStream ois&＃61; new ObjectInputStream(is);String per &＃61; (String) (ois.readObject());System.out.println(per);ois.close();}
}

自定义类序列化—要实现Serializable接口

import java.io.*;class Person implements Serializable {private static final long serialVersionUID &＃61; 1L;String name;int age;String gender;public Person(String name, int age, String gender) {this.name &＃61; name;this.age &＃61; age;this.gender &＃61; gender;}&＃64;Overridepublic String toString() {return "Person{" &＃43;"name&＃61;&＃39;" &＃43; name &＃43; &＃39;\&＃39;&＃39; &＃43;", age&＃61;" &＃43; age &＃43;", gender&＃61;&＃39;" &＃43; gender &＃43; &＃39;\&＃39;&＃39; &＃43;&＃39;}&＃39;;}
}public class Test {public static void main(String[] args) throws IOException {File file&＃61; new File("D:/Hello.txt");//目标文件OutputStream is&＃61; new FileOutputStream(file);//开辟输出流ObjectOutputStream oos&＃61; new ObjectOutputStream(is);//序列化oos.writeObject(new Person("孙悟空",18,"男"));oos.close();}
}

接下来反序列化–


import java.io.*;public class Test01 {public static void main(String[] args) throws IOException, ClassNotFoundException {File file&＃61; new File("D:/Hello.txt");InputStream is&＃61; new FileInputStream(file);ObjectInputStream ois&＃61; new ObjectInputStream(is);Person per &＃61; (Person) (ois.readObject());System.out.println(per);ois.close();}
}


import java.io.*;class Person implements Serializable {private static final long serialVersionUID &＃61; 792646246687698667L;transient String name;static int age;String gender;public String getName() {return name;}public void setName(String name) {this.name &＃61; name;}public Person(String name, int age, String gender) {this.name &＃61; name;this.age &＃61; age;this.gender &＃61; gender;}&＃64;Overridepublic String toString() {return "Person{" &＃43;"name&＃61;&＃39;" &＃43; name &＃43; &＃39;\&＃39;&＃39; &＃43;", age&＃61;" &＃43; age &＃43;", gender&＃61;&＃39;" &＃43; gender &＃43; &＃39;\&＃39;&＃39; &＃43;&＃39;}&＃39;;}
}public class Test {public static void main(String[] args) throws IOException {File file&＃61; new File("D:/Hello.txt");//目标文件OutputStream is&＃61; new FileOutputStream(file);//开辟输出流ObjectOutputStream oos&＃61; new ObjectOutputStream(is);//序列化oos.writeObject(new Person("孙悟空",18,"男"));oos.close();}
}



import java.io.*;public class Test01 {public static void main(String[] args) throws IOException, ClassNotFoundException {File file&＃61; new File("D:/Hello.txt");InputStream is&＃61; new FileInputStream(file);ObjectInputStream ois&＃61; new ObjectInputStream(is);Person per &＃61; (Person) (ois.readObject());System.out.println(per);ois.close();}
}

总结—
自定义数据序列化的时候必须要类中所有属性都要能够序列化&＃xff1b;
静态属性—static的数据不能被序列化&＃xff1b;
transenit修饰的也不能被序列化&＃xff1b;