Java文件字节流

时间 2021-03-01

标签 java 缓存 code xml 字符串 get input class 栏目 Java 繁體版

原文原文链接

//输出和输入流java

package com.kangkang.IO;缓存

import com.sun.xml.internal.ws.util.xml.CDATA;code

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;xml

public class demo01 {
public static void main(String[] args) throws IOException {
//数据的写入
byte[] data = {15,5,63,46};
File file = new File("example.123");
FileOutputStream outputStream = new FileOutputStream(file);字符串

outputStream.write(data,0,4);
    outputStream.close();
    System.out.println("Exit..");
}

}get

package com.kangkang.IO;input

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;it

public class demo02 {
public static void main(String[] args) throws IOException {
//数据的读取io

//用于接收数据的缓冲区，须要足够大
    byte[] buffer = new byte[50];
    // 能够使用绝对路径，如c:/加文件的目录
    // 也能够使用相对路径，把文件放在项目目录下
    File file = new File("kangkang.txt");
    // 从文件读取数据，存放进缓存区
    FileInputStream inputStream = new FileInputStream(file);
    int n = inputStream.read(buffer,0,50);
    inputStream.close();
    System.out.println("获取了"+n+"字节");
    System.out.println("Exit");
    String str = new String(buffer,0,n,"UTF-8");
    System.out.println(str);
}

}class

package com.kangkang.IO;

import java.io.File;
import java.io.FileOutputStream;

public class demo03 {
public static void main(String[] args) throws Exception{
//文件的写入

//字符串
    String str = "康康你好帅";
    //由于文件里面所有都是字节形式，因此要把字符串转换为字节才能写入文件中
    byte[] data = str.getBytes("UTF-8");
    File file = new File("kang.999");
    FileOutputStream outputStream = new FileOutputStream(file);
    outputStream.write(data);

    outputStream.close();
    System.out.println("Exit");
}

}

package com.kangkang.IO;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;

public class demo04 {
public static void main(String[] args) throws Exception {
// 读取文件的内容

byte[] buffer = new byte[100];
    File file = new File("kangkang.txt");
    FileInputStream inputStream = new FileInputStream(file);
    int n =inputStream.read(buffer,0,100);
    System.out.println("读取了"+n+"字节");
    inputStream.close();
    // 写入用什么格式，解码的时候也要用什么格式
    String str = new String(buffer,0,n,"UTF-8");
    System.out.println(str);
    System.out.println("Exit");
}

}