字符流相关操作（读、写、copy）

字符流只能处理字符

读取操作

package cn.chars;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;

/*
 * 纯文本读取
 * 
 */
public class Demo01 {
    public static void main(String[] args) {
        //1.建立联系
        File src=new File("C:/Users/Administrator/Desktop/sun/b.txt");
        //2.选择流
        Reader reader=null;
        try {
            reader=new FileReader(src);
            //3.读取操作
            char[] s=new char[1024];
            int len=0;
            try {
                while(-1!=(len=reader.read(s))) {
                    String info=new String(s,0,len);
                    System.out.println(info);
                }
            } catch (IOException e) {
                e.printStackTrace();
                System.out.println("文件读取失败");
            }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            System.out.println("源文件不存在");
        }
        finally {
            if(null!=reader) {
                try {
                    reader.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    System.out.println("是空的");
                }
            }
        }
        
    }
}

写入操作

package cn.chars;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Writer;

public class Demo02 {
    public static void main(String[] args) {
        File src =new File("C:/Users/Administrator/Desktop/sun/a.txt");
        Writer writer=null;
        try {
            writer =new FileWriter(src,true);
            String str="这是一句话"; 
            writer.write(str);
            writer.append("hello world");
            writer.flush();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            System.out.println("源文件不存在");
        } 
        finally {
            if(null!=writer) {
                try {
                    writer.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    System.out.println("关闭失败");
                }
            }
        }
        
    }
}

copy操作

package cn.chars;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;

/*
 * 纯文本拷贝
 * 
 */
public class CopyFile {
    public static void main(String[] args) throws IOException {
        File src=new File("C:/Users/Administrator/Desktop/sun/a.txt");
        File src2=new File("C:/Users/Administrator/Desktop/sun/b.txt");
        Reader reader=null;
        Writer writer=null;
        try {
            reader=new FileReader(src);
            writer=new FileWriter(src2);
            //3.读取操作
            char[] s=new char[1024];
            int len=0;
            try {
                while(-1!=(len=reader.read(s))) {
                    String info=new String(s,0,len);
                    System.out.println(info);
                    writer.write(s, 0,len);
                }
                writer.flush();
            } catch (IOException e) {
                e.printStackTrace();
                System.out.println("文件读取失败");
            }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            System.out.println("源文件不存在");
        }
        finally {
            if(null!=writer) {
                writer.close();
            }
            if(null!=reader) {
                try {
                    reader.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    System.out.println("是空的");
                }
            }
            
        }
    }
}