Java IO流文件的复制的几种方法(字节流，字符流，缓冲流)

本文链接：https://blog.youkuaiyun.com/wang_gmail/article/details/34823409

本文详细介绍了四种不同的文件复制方法：字节流、缓冲流、字符流及带缓冲的字符流。通过具体的Java代码示例展示了如何使用这些方法来高效地复制文件。

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1：字节流(InputStream和OutputStream )

FileCopyInputStreamAndOutputStream.java 源代码如下：

package com.io.test;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class FileCopyInputStreamAndOutputStream {

	public static void main(String[] args) throws IOException {
		InputStream inputStream = new FileInputStream("hello.txt");
		OutputStream outputStream = new FileOutputStream("hello4.txt");
		byte[] buffer = new byte[20];
		int len = 0;
		while((len = inputStream.read(buffer)) != -1){
			outputStream.write(buffer, 0, len);
		}
		outputStream.close();
		inputStream.close();
	}

}

2：缓冲流(BufferedInputStream和BufferedOutputStream )

FileCopyInputStreamAndOutputStream.java 源代码如下：

package com.io.test;


import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class FileCopyBufferedInputStreamAndBufferedOutputStream {
	public static void main(String[] args) throws IOException {
		
		InputStream in = new FileInputStream("hello.txt");
		BufferedInputStream bufferedInputStream = new BufferedInputStream(in );
		
		OutputStream out = new FileOutputStream("hello3.txt");
		BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(out );
		
		byte[] buffer = new byte[1024];
		int len = 0;
		while((len = bufferedInputStream.read(buffer)) != -1){
			bufferedOutputStream.write(buffer, 0, len);
		}
		bufferedOutputStream.close();
		bufferedInputStream.close();
	}
}

3：缓冲流(BufferedReader和BufferedWriter )

FileCopyBufferReaderAndBufferWriter.java 源代码如下：

package com.io.test;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;

public class FileCopyBufferReaderAndBufferWriter {

	public static void main(String[] args) throws IOException {
		Reader in = new FileReader("hello.txt");
		BufferedReader bufferedReader = new BufferedReader(in );
		
		Writer out = new FileWriter("hello2.txt");
		BufferedWriter bufferedWriter = new BufferedWriter(out );
		
		String string = null;
		while((string = bufferedReader.readLine()) != null){
			bufferedWriter.write(string+"\n");
		}
		
		bufferedWriter.close();
		bufferedReader.close();
	}

}

4：字符流(Reader和Writer )

FileCopyReaderAndWriter.java 源代码如下：

package com.io.test;

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

public class FileCopyReaderAndWriter {

	public static void main(String[] args) throws IOException {
		Reader reader = new FileReader("hello.txt");
		Writer writer = new FileWriter("hello1.txt");
		char[] c = new char[20];
		int len = 0;
		while((len = reader.read(c)) != -1){
			writer.write(c, 0, len);
		}
		writer.close();
		reader.close();
	}

}