Java字符流读写数据的两种方式

第一种方式：逐个字符进行读写操作(代码注释以及详细内容空闲补充)

package IODemo;

import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class CopyFileDemo {

 /**
  * @param args
  * @throws IOException
  */
 public static void main(String[] args) throws IOException {

  FileReader fr=new FileReader("Demo.txt");

  FileWriter fw=new FileWriter("Demo1.txt");
  int ch=0;
  while((ch=fr.read())!=-1){//单个字符进行读取
   fw.write(ch);//单个字符进行写入操作
  }
  fw.close();
  fr.close();
 }

}

第二种方式：自定义缓冲区，使用read(char buf[])方法，此方法较为高效

package IODemo;

import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class CopyFileDemo2 {

 private static final int BUFFER_SIZE = 1024;

 /**
  * @param args
  */
 public static void main(String[] args) {

  FileReader fr = null;
  FileWriter fw = null;
  try {
   fr = new FileReader("Demo.txt");//工程所在目录
   fw = new FileWriter("Demo2.txt");
   char buf[] = new char[BUFFER_SIZE];
   int len = 0;
   while ((len = fr.read(buf)) != -1) {
    fw.write(buf, 0, len);
   }
  } catch (Exception e) {
   // TODO: handle exception
  } finally {
   if (fr != null) {
    try {
     fr.close();
    } catch (IOException e) {
     System.out.println("读写失败");
    }
   }
   if (fw != null) {
    try {
     fw.close();
    } catch (IOException e) {
     System.out.println("读写失败");
    }
   }
  }

 }

}