大佬帮帮忙，急， 在线等 万分感谢！

作业还是自己做吧。。。。。。

上面的都太复杂了，，人家还是个学生，太残忍了，。。。
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

/***
**Created by emk on 2017/11/8.

**/
public class TextFile {
public static void main(String []args){
TextFile textFile = new TextFile();
String filePath = "C:/abc/abc.txt";
String result = textFile.readFile(filePath);
System.out.println("读取到的文件中值："+result);
result = result.toLowerCase();
System.out.println("写入到文件中的值："+result);
textFile.writeFile(filePath,result);
}

private String readFile(String filePath) {
    FileInputStream fileInputStream = null;
    String result = "";
    try{
        fileInputStream = new FileInputStream(filePath);
        int size = fileInputStream.available();
        byte[] array = new byte[size];
        fileInputStream.read(array);
        result = new String(array);
    }catch (Exception e){e.printStackTrace();}finally {
        if (fileInputStream !=null){
            try {
                fileInputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    return result;
}
public void writeFile(String filePath, String content){
    FileOutputStream fileOutputStream = null;
    try{
        fileOutputStream = new FileOutputStream(filePath);
        byte[] array = content.getBytes();
        fileOutputStream.write(array);
    }catch (Exception e){e.printStackTrace();}finally {
        if (fileOutputStream != null){
            try{fileOutputStream.close();} catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

}

楼主的问题明显带大学作业的风格啊。。

大佬聪明，学渣求教，随便给个注释，或者讲讲这么做呗！表示不会

主要就是io流的使用，好好看看java的IO自然就会了
1.io读取本地文件，然后将文件的内容利用String自带的方法很容易大小写转换，然后再用io流写入本地
2.指明了用ObjectIO 这个开发中不常用，应该也不难，和上面的文件io流应该差别不大

唉，虽然咱上学的时候也是学渣呢，帮你一把，不过你得看明白代码，要不然下次还是一样。

package cn.baokx.traning;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

public class Test {
    public static void main(String[] args) {
        fun1("D://aaa.txt","D://bbb.txt");
    }

    public static void fun1(String fromPath,String toPath){
        File fromFile = new File(fromPath);
        if(!fromFile.exists()) throw new RuntimeException("来源文件不存在："+fromPath);
        if(fromFile.isDirectory()) throw new RuntimeException("来源文件是文件夹："+fromPath);

        File toFile = new File(toPath);
        BufferedReader br = null;
        BufferedWriter bw = null;
        try{
            br = new BufferedReader(new InputStreamReader(new FileInputStream(fromFile)));
            bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(toFile)));
            boolean firstLine = true;
            String lineStr1 = null;
            while ((lineStr1 = br.readLine()) != null) {
                if(firstLine){
                    firstLine = false;
                }else{
                    bw.newLine();
                }
                bw.write(firstCharToUpperCase(lineStr1));
            }
        }catch(Exception e){
            e.printStackTrace();
            throw new RuntimeException(e);
        }finally{
            if(br != null){
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                    throw new RuntimeException(e);
                }
            }
            if(bw != null){
                try {
                    bw.close();
                } catch (IOException e) {
                    e.printStackTrace();
                    throw new RuntimeException(e);
                }
            }
        }
    }

    //首字母大写
    public static String firstCharToUpperCase(String str){
        if(str == null) return null;
        if(str.length()>1){
            char [] charArr = str.toCharArray();
            if(charArr[0] >= 'a' && charArr[0] <= 'z'){
                charArr[0] = (char) (charArr[0] - ' ');
            }
            str = new String(charArr);
        }
        return str;
    }
}

 package cn.baokx.traning;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.Serializable;

class Student implements Serializable{
    private static final long serialVersionUID = 1L;

    private int age;
    private String name;
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Override
    public String toString() {
        return "name:"+name+",age:"+age;
    }
}
public class Test2 {
    public static void main(String[] args) throws IOException, ClassNotFoundException {
        Student stu = new Student();
        stu.setName("张三");
        stu.setAge(30);
        writeObject("D://stu.obj",stu);
        stu = readObject("D://stu.obj");
        System.out.println(stu);
    }

    public static void writeObject(String toPath,Student obj) throws IOException{
        File file = new File(toPath);
        OutputStream outputStream = new FileOutputStream(file);
        ObjectOutputStream objectOutputStream = new ObjectOutputStream(outputStream);
        objectOutputStream.writeObject(obj);
        objectOutputStream.close();
    }

    public static Student readObject(String fromPath) throws IOException, ClassNotFoundException{
        File file = new File(fromPath);
        InputStream inputStream = new FileInputStream(file);
        ObjectInputStream objectInputStream = new ObjectInputStream(inputStream);
        Student stu = (Student)objectInputStream.readObject();
        objectInputStream.close();
        return stu;
    }
}

可以使用工具IOutils啊 很快的

我也来玩一下
import java.io.*;
import java.util.Arrays;
public class test {**
**public static void main(String[] args) {
String formPath = "F:\temp.txt";
String toPath ="F:\dest.txt";
readFile(formPath,toPath);
}

private static void readFile(String formPath, String toPath) {
    try {
        BufferedInputStream fis = null;
        BufferedOutputStream fos = null;
        //输入流
        File  fromFile = new File(formPath);
        fis = new BufferedInputStream(new FileInputStream(fromFile));

        //输出流
        File toFile = new File(toPath);
        fos = new BufferedOutputStream(new FileOutputStream(toFile));
        byte[] buffer = new byte[1024];
        int temp = 0;
        while ((temp=fis.read(buffer))!=-1){
            byte[] sbuf = toUpperString(buffer);
            fos.write(sbuf);
        }
        fis.close();
        fos.close();
    }catch (IOException e){
        e.printStackTrace();
    }

}

private static byte[] toUpperString(byte[] buffer) {
    String sbuffer=new String(buffer).trim().toUpperCase();
    byte[] sbuf = sbuffer.getBytes();
    return sbuf;
}

}