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java io如何执行

2026-03-24 16:39:16Java

Java IO 执行方法

Java IO（输入输出）操作主要通过 java.io 包中的类实现，用于处理文件读写、数据流传输等任务。以下是常见的执行方法：

文件读写操作

使用 FileInputStream 和 FileOutputStream 进行文件读写：

java io如何执行

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class FileIOExample {
    public static void main(String[] args) {
        try (FileInputStream fis = new FileInputStream("input.txt");
             FileOutputStream fos = new FileOutputStream("output.txt")) {
            int data;
            while ((data = fis.read()) != -1) {
                fos.write(data);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

缓冲流操作

使用 BufferedReader 和 BufferedWriter 提高读写效率：

java io如何执行

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class BufferedIOExample {
    public static void main(String[] args) {
        try (BufferedReader br = new BufferedReader(new FileReader("input.txt"));
             BufferedWriter bw = new BufferedWriter(new FileWriter("output.txt"))) {
            String line;
            while ((line = br.readLine()) != null) {
                bw.write(line);
                bw.newLine();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

对象序列化

使用 ObjectOutputStream 和 ObjectInputStream 实现对象序列化和反序列化：

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

class Person implements Serializable {
    private String name;
    private int age;

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    @Override
    public String toString() {
        return "Person{name='" + name + "', age=" + age + "}";
    }
}

public class ObjectIOExample {
    public static void main(String[] args) {
        Person person = new Person("Alice", 30);

        try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("person.ser"))) {
            oos.writeObject(person);
        } catch (IOException e) {
            e.printStackTrace();
        }

        try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream("person.ser"))) {
            Person deserializedPerson = (Person) ois.readObject();
            System.out.println(deserializedPerson);
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}

字符流操作

使用 InputStreamReader 和 OutputStreamWriter 处理字符流：

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

public class CharacterIOExample {
    public static void main(String[] args) {
        try (InputStreamReader isr = new InputStreamReader(new FileInputStream("input.txt"), "UTF-8");
             OutputStreamWriter osw = new OutputStreamWriter(new FileOutputStream("output.txt"), "UTF-8")) {
            int data;
            while ((data = isr.read()) != -1) {
                osw.write(data);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}