緩沖流原理

緩沖流原理

字節(jié)緩沖輸出流

package com.mujiachao.huanchongliu;

import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class BufferOut {
    public static void main(String[] args) throws IOException {
        FileOutputStream fileOutputStream = new FileOutputStream("F:\\電影\\111\\F.txt");
        BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(fileOutputStream);
        bufferedOutputStream.write("我把數(shù)據(jù)通過字節(jié)緩沖輸出流寫入硬盤".getBytes());
        bufferedOutputStream.close();
    }
}

字節(jié)緩沖輸入流

字節(jié)緩沖輸入流

package com.mujiachao.huanchongliu;

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.IOException;

public class BufferIn {
    public static void main(String[] args) throws IOException {
        FileInputStream fileInputStream = new FileInputStream("F:\\電影\\111\\F.txt");
//        BufferedInputStream bufferedInputStream = new BufferedInputStream(fileInputStream);
        BufferedInputStream bufferedInputStream = new BufferedInputStream(fileInputStream,2048);
//        int len=0;
//        while ((len=bufferedInputStream.read())!=-1){
//            System.out.println(len);
//        }
        int len=0;
        byte[] bytes=new byte[2048];
        while ((len=bufferedInputStream.read(bytes))!=-1){
            System.out.println(new String(bytes));
        }
        bufferedInputStream.close();
    }
}

緩沖流效率測試

package com.mujiachao.huanchongliu;

import java.io.*;

public class CopyCeSu {
    public static void main(String[] args) throws IOException {
        long l = System.currentTimeMillis();
        FileOutputStream fileOutputStream = new FileOutputStream("F:\\電影\\111\\JavaEE開發(fā)的顛覆者 Spring Boot實戰(zhàn)  完整版.pdf");
        FileInputStream fileInputStream = new FileInputStream("C:\\Users\\Administrator\\Desktop\\JavaEE開發(fā)的顛覆者 Spring Boot實戰(zhàn)  完整版.pdf");
        BufferedInputStream bufferedInputStream = new BufferedInputStream(fileInputStream);
        BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(fileOutputStream);
        int len=0;
        byte[] bytes=new byte[102400];
        while ((len=bufferedInputStream.read(bytes))!=-1){
            bufferedOutputStream.write(len);
        }
        bufferedOutputStream.close();
        bufferedInputStream.close();
        System.out.println(System.currentTimeMillis()-l+"毫秒");
    }

}

字符緩沖輸出流 bufferedWriter.newLine();換行

符緩沖輸出流

使用步驟

package com.mujiachao.huanchongliu;

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

public class BufferWriter {
    public static void main(String[] args) throws IOException {
        FileWriter fileWriter = new FileWriter("F:\\電影\\111\\a.txt");
        BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
        for (int i = 0; i < 10; i++) {
            bufferedWriter.write("字符緩沖輸出流");
            bufferedWriter.newLine();
        }
        bufferedWriter.close();
    }
}

字符緩沖輸入流 bufferedReader.readLine() 讀取一行

字符緩沖輸入流

步驟

package com.mujiachao.huanchongliu;

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

public class BufferReader {
    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new FileReader("F:\\電影\\111\\a.txt"));
        String s;
        while ((s=bufferedReader.readLine())!=null){
            System.out.println(s);
        }
        bufferedReader.close();
    }
}

練習，對文本內(nèi)容進行排序

對文本內(nèi)容進行排序

package com.mujiachao.huanchongliu;

import java.io.*;
import java.util.HashMap;

public class LianXi {
    public static void main(String[] args) throws IOException {
        HashMap<String, String> objectObjectHashMap = new HashMap<>();
        FileReader fileReader = new FileReader("F:\\電影\\111\\in.txt");
        FileWriter fileWriter = new FileWriter("F:\\電影\\111\\out.txt");
        BufferedReader bufferedReader = new BufferedReader(fileReader);
        BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
        String s;
        while ((s=bufferedReader.readLine())!=null){
            String[] split = s.split("\\.");
            objectObjectHashMap.put(split[0],split[1]);
        }
        for (String key:objectObjectHashMap.keySet()) {
            s=key+"."+objectObjectHashMap.get(key);
            bufferedWriter.write(s);
            bufferedWriter.newLine();
        }
        bufferedWriter.close();
        bufferedReader.close();
    }
}