IO流练习

最新推荐文章于 2021-08-03 19:08:56 发布

TU_BO

最新推荐文章于 2021-08-03 19:08:56 发布

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本文链接：https://blog.youkuaiyun.com/TU_BO/article/details/78652523

3:复制文本文件:有5种方式

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class Copytxt {
public static void main(String[] args) throws IOException {
    method1();
    method2();
    method3();
    method4();
    method5();
}

private static void method5() throws FileNotFoundException, IOException {
    BufferedReader br=new BufferedReader(new FileReader("ArrayListInHashMap.java"));
    BufferedWriter bw=new BufferedWriter(new FileWriter("e.txt"));
    String line=null;
    while((line=br.readLine())!=null) {
        bw.write(line);
        bw.newLine();
    }
    br.close();
    bw.close();
}

private static void method4() throws FileNotFoundException, IOException {
    BufferedInputStream bis=new BufferedInputStream(new FileInputStream("ArrayListInHashMap.java"));
    BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream("d.txt"));
    byte[] bys=new byte[1024];
    int len=0;
    while((len=bis.read(bys))!=-1) {
        bos.write(bys, 0, len);
    }
    bos.close();
    bis.close();
}

private static void method3() throws FileNotFoundException, IOException {
    BufferedInputStream bis=new BufferedInputStream(new FileInputStream("ArrayListInHashMap.java"));
    BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream("c.txt"));
    int by=0;
    while((by=bis.read())!=-1) {
        bos.write(by);
    }
    bos.close();
    bis.close();
}

private static void method2() throws FileNotFoundException, IOException {
    FileInputStream fis=new FileInputStream("ArrayListInHashMap.java");
    FileOutputStream fos=new FileOutputStream("a.txt");
    byte[] bys=new byte[1024];
    int len=0;
    while((len=fis.read(bys))!=-1) {
        fos.write(bys, 0, len);
    }
    fos.close();
    fis.close();
}

private static void method1() throws FileNotFoundException, IOException {
    FileInputStream fis=new FileInputStream("ArrayListInHashMap.java");
    FileOutputStream fos=new FileOutputStream("b.txt");
    int by=0;
    while((by=fis.read())!=-1) {
        fos.write(by);
    }
    fos.close();
    fis.close();
}
}

4:复制图片:4种方式

public class CopyJpg {
public static void main(String[] args) throws IOException {
    method1();
    method2();
    method3();
    method4();

}

private static void method4() throws FileNotFoundException, IOException {
    BufferedInputStream bis=new BufferedInputStream(new FileInputStream("timg.jpg"));
    BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream("d.jpg"));
    byte[] bys=new byte[1024];
    int len=0;
    while((len=bis.read(bys))!=-1) {
        bos.write(bys, 0, len);
    }
    bos.close();
    bis.close();
}

private static void method3() throws FileNotFoundException, IOException {
    BufferedInputStream bis=new BufferedInputStream(new FileInputStream("timg.jpg"));
    BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream("c.jpg"));
    int by=0;
    while((by=bis.read())!=-1) {
        bos.write(by);
    }
    bos.close();
    bis.close();
}

private static void method2() throws FileNotFoundException, IOException {
    FileInputStream fis=new FileInputStream("timg.jpg");
    FileOutputStream fos=new FileOutputStream("b.jpg");
    byte[] bys=new byte[1024];
    int len=0;
    while((len=fis.read(bys))!=-1) {
        fos.write(bys, 0, len);
    }
    fos.close();
    fis.close();
}

private static void method1() throws FileNotFoundException, IOException {
    FileInputStream fis=new FileInputStream("timg.jpg");
    FileOutputStream fos=new FileOutputStream("a.jpg");
    int by=0;
    while((by=fis.read())!=-1) {
        fos.write(by);
    }
    fos.close();
    fis.close();
}
}

5:已知s.txt文件中有这样的一个字符串：“hcexfgijkamdnoqrzstuvwybpl”
请编写程序读取数据内容，把数据排序后写入ss.txt中。

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;



public class CopyString {
public static void main(String[] args) throws IOException {
    FileInputStream fis=new FileInputStream("String.txt");
    FileOutputStream fos=new FileOutputStream("StringSort.txt");
    ArrayList<Character> al=new ArrayList<Character>();
    int by=0;
    while((by=fis.read())!=-1) {
        al.add((char)by);
    }
    Collections.sort(al);
    for(Character s:al) {
        fos.write((int)s);
    }
}
}

String.txt内容:hcexfgijkamdnoqrzstuvwybpl
StringSort.txt内容:abcdefghijklmnopqrstuvwxyz

6:键盘录入5个学生信息(姓名,语文成绩,数学成绩,英语成绩),按照总分从高到低存入文本文件

package weekends_10;

import java.io.Serializable;

public class Student implements Serializable,Comparable<Student>{
    String name;
public Student(String name, String chinese, String math, String english) {
        super();
        this.name = name;
        Chinese = chinese;
        this.math = math;
        English = english;
    }
public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
String Chinese;
String math;
String English;
public String getChinese() {
    return Chinese;
}
public void setChinese(String chinese) {
    Chinese = chinese;
}
public String getMath() {
    return math;
}
public void setMath(String math) {
    this.math = math;
}
public String getEnglish() {
    return English;
}
public void setEnglish(String english) {
    English = english;
}
public int getSum() {
    return Integer.parseInt(Chinese)+Integer.parseInt(English)+Integer.parseInt(math);
}
public Student(String chinese, String math, String english) {
    super();
    Chinese = chinese;
    this.math = math;
    English = english;
}
@Override
public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((Chinese == null) ? 0 : Chinese.hashCode());
    result = prime * result + ((English == null) ? 0 : English.hashCode());
    result = prime * result + ((math == null) ? 0 : math.hashCode());
    result = prime * result + ((name == null) ? 0 : name.hashCode());
    return result;
}
@Override
public boolean equals(Object obj) {
    if (this == obj)
        return true;
    if (obj == null)
        return false;
    if (getClass() != obj.getClass())
        return false;
    Student other = (Student) obj;
    if (Chinese == null) {
        if (other.Chinese != null)
            return false;
    } else if (!Chinese.equals(other.Chinese))
        return false;
    if (English == null) {
        if (other.English != null)
            return false;
    } else if (!English.equals(other.English))
        return false;
    if (math == null) {
        if (other.math != null)
            return false;
    } else if (!math.equals(other.math))
        return false;
    if (name == null) {
        if (other.name != null)
            return false;
    } else if (!name.equals(other.name))
        return false;
    return true;
}
public Student() {
    super();
    // TODO Auto-generated constructor stub
}
@Override
public String toString() {
    return "Student [name=" + name + ", Chinese=" + Chinese + ", math=" + math + ", English=" + English + "]";
}
@Override
public int compareTo(Student s) {
    int num=s.getSum()-this.getSum();
    int num1=num==0?s.getName().compareTo(this.getName()):num;
    return num1;
}

}

import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;
import java.util.TreeSet;

public class StudentDemo {
public static void main(String[] args) throws IOException {

TreeSet<Student> ts=new TreeSet<Student>();
Scanner sc=new Scanner(System.in);
for(int i=0;i<5;i++) {
    Student s=new Student();
    System.out.println("请输入第"+(i+1)+"个学生的名字");
    String name = sc.nextLine();
    s.setName(name);
    System.out.println("请输入第"+(i+1)+"个学生的数学成绩");
    String math = sc.nextLine();
    s.setMath(math);
    System.out.println("请输入第"+(i+1)+"个学生的英语成绩");
    String English = sc.nextLine();
    s.setEnglish(English);
    System.out.println("请输入第"+(i+1)+"个学生的语文成绩");
    String chinese = sc.nextLine();
    s.setChinese(chinese);
    ts.add(s);
}
FileWriter fos=new FileWriter("Student.txt");
for(Student s:ts) {
    fos.write("姓名"+s.getName());
    fos.write("  ");
    fos.write("总分"+String.valueOf(s.getSum()));
    fos.write("  ");
    fos.write("语文"+s.getChinese());
    fos.write("  ");
    fos.write("英语"+s.getEnglish());
    fos.write("  ");
    fos.write("数学"+s.getMath());
    fos.write("\r\n");
    fos.flush();
}
fos.close();
}
}