Java IO 文件流的读,文件流写Writer,Reader,InputStream,OutputStream封装！
package com.app.io;import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.DataInputStream;import java.io.DataOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.FileReader;import java.io.FileWriter;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.io.OutputStreamWriter;import java.io.PrintWriter;import java.io.Reader;import java.io.Writer;/** *@DEMO:napp *@Author:jilongliang *@Date:2013-7-25 * *实际上字节流在操作时本身不会用到缓冲区（内存），是文件本身直接操作的，而字符流在操作时使用了缓冲区，通过缓冲区再操作文件。 * *字符流和字节流是根据处理数据的不同来区分的。字节流按照8位传输，字符流按照16位传输 *由于字符流使用Unicode字符集，支持多国文字，因此若流要跨越多种平台传输，应使用字符流。 * *char型是字符型,占2个字节,默认数值'\u0000',取值范围'\u0000'~'\uffff' *byte是字节型,占1个字节,默认数值0,取值范围-128～127 *boolean 无符号 8 位 *byte 无符号,8 位 *char 无符号,16 位 *short 有符号,16 位 *int \ 有符号,32 位 *long 有符号,64 位 *float 32 位 *double 64 位 * *字节流输出--->>程序-->>字节流---->文件(直接操作文件) * *字符流输出--->>程序-->>字符流---->>缓存--->>文件(数据线放在缓存,之后再从缓存写入文件) * * *@Description字节流 *@InputStream * FileInputStream, FilterInputStream,BufferedInputStream, CheckedInputStream, CipherInputStream, * DataInputStream, DeflaterInputStream, DigestInputStream, InflaterInputStream, LineNumberInputStream, * ProgressMonitorInputStream, PushbackInputStream ,AudioInputStream, ByteArrayInputStream, FileInputStream, * ObjectInputStream, PipedInputStream, SequenceInputStream, StringBufferInputStream -------------------------------------------- *@OutputStream * FileOutputStream, FilterOutputStream,BufferedOutputStream, CheckedOutputStream, CipherOutputStream, * DataOutputStream, DeflaterOutputStream, DigestOutputStream, InflaterOutputStream, LineNumberOutputStream, * ProgressMonitorOutputStream, PushbackOutputStream ,AudioOutputStream, ByteArrayOutputStream, FileOutputStream, * ObjectOutputStream, PipedOutputStream, SequenceOutputStream, StringBufferOutputStream *-------------------------------------------- * *@Description字符流 *@Writer * BufferedWriter, CharArrayWriter, FilterWriter, OutputStreamWriter, PipedWriter, PrintWriter, StringWriter * *@Reader * *BufferedReader, CharArrayReader, FilterReader, InputStreamReader, PipedReader, StringReader * */public class IO {private static String content = "",line=System.getProperty("line.separator");//换行相当于\nprivate static File f=new File("");public static void main(String[] args) {//String separator=f.separator;//与系统有关的默认名称分隔符，为了方便，它被表示为一个字符串String path = "D:/test/a.txt";//String text = reader1(path);//writer1(path, "D:/test/a1.txt");//writer2(path, "D:/test/c.txt");//writer3(path, "D:/test/d.txt");//writer4(path, "D:/test/d.txt");//char c=reader2(path);//System.out.print(c);//String text=reader2(path);//System.out.println(text);//writer5(path,"d:/test/f.txt");//writer6(path,"d:/test/e.txt");String s=reader3(path);System.out.println(s);}/** * 读文件流 * @param formPath从哪里读取的文件路径 * @return */public static String reader1(String formPath) {FileReader read = null;BufferedReader reader = null;try {read = new FileReader(new File(formPath));reader = new BufferedReader(read);StringBuffer buffer = new StringBuffer("");content = reader.readLine();while (content != null) {buffer.append(content).append(line);content = reader.readLine();}return content = buffer.toString();//返回} catch (Exception e) {e.printStackTrace();} finally {try {if (reader != null)reader.close();if (read != null)read.close();} catch (Exception e) {e.printStackTrace();}}return "";//没值就返回空}/** * 读文件 * @param formPath * @return */public static String reader2(String formPath){try {InputStream is=new FileInputStream(new File(formPath));InputStreamReader reader=new InputStreamReader(is);//不够大的时候读不出来全部内容来的,他不像available拿多所就读多少char c[] = new char[1024*1024];//1M=1024*1024,根据需求定int len = reader.read(c); content=new String(c, 0, len);if(reader!=null)reader.close();//if(is!=null)is.close();return content;} catch (Exception e) {e.printStackTrace();}return "";}/** * InputStreamReader * ByteArrayOutputStream * ByteArrayInputStream * @param formPath * @return */public static String reader3(String formPath){String newName="";try {InputStream is=new FileInputStream(new File(formPath));InputStreamReader reader=new InputStreamReader(is);//不够大的时候读不出来全部内容来的,他不像available拿多所就读多少char c[] = new char[is.available()];//1M=1024*1024,根据需求定int len = reader.read(c); content=new String(c, 0, len);ByteArrayOutputStream bout = new ByteArrayOutputStream();DataOutputStream dout = new DataOutputStream(bout);dout.writeUTF(content);byte[] buff = bout.toByteArray();ByteArrayInputStream bin = new ByteArrayInputStream(buff);DataInputStream dis = new DataInputStream(bin);newName = dis.readUTF();bout.flush();dout.flush();bout.close();dout.close();dis.close();} catch (Exception e) {e.printStackTrace();}return newName;}/** * 写文件 * BufferedWriter * BufferedReader * @param formPath * @param toPath */public static boolean writer1(String formPath,String toPath){Reader reader=null;Writer writer=null;boolean flag=true;BufferedWriter buffWriter=null;BufferedReader buffReader=null;try {reader=new FileReader(new File(formPath));writer = new FileWriter(new File(toPath));//writer不能关闭buffWriter=new BufferedWriter(writer);//这个写完可以关闭buffReader=new BufferedReader(reader);content=buffReader.readLine();while(content!=null){buffWriter.write(line+content);content=buffReader.readLine();buffWriter.flush();//只要用到缓冲区就flush//其实关闭了缓冲区,就是关闭缓冲区中流的对象. //写一次flush是为了防止停电就挂了~}reader.close();buffReader.close();buffWriter.close();} catch (Exception e) {e.printStackTrace();return false;} return flag;}/** * 写文件 * PrintWriter * Writer * Reader * BufferedReader * @param formPath * @param toPath */public static boolean writer2(String formPath,String toPath){Reader reader=null;//FileReader reader=null;PrintWriter writer=null;//PrintWriterboolean flag=true;BufferedWriter buffWriter=null;//此对象有换行newLineBufferedReader buffReader=null;//为了提高效率,使用字符缓冲流BufferedReader try {reader=new FileReader(new File(formPath));writer = new PrintWriter(new File(toPath));//writer不能关闭buffWriter=new BufferedWriter(writer);//这个写完可以关闭buffReader=new BufferedReader(reader);content=buffReader.readLine();while(content!=null){buffWriter.write(line+content);content=buffReader.readLine();}reader.close();buffReader.close();buffWriter.close();} catch (Exception e) {e.printStackTrace();return false;} return flag;}/** * 写文件 * InputStream * OutputStream * FileInputStream * FileOutputStream * @param from * @param to */public static void writer3(String from, String to) { try { InputStream in = new FileInputStream(new File(from)); OutputStream out = new FileOutputStream(new File(to)); byte[] buff = new byte[in.available()]; //byte[] buff = new byte[1024 * 1024]; int len = 0; while ((len = in.read(buff)) != -1) { out.write(buff, 0, len); } in.close(); out.close(); } catch (Exception e) { e.printStackTrace(); } } /** * 写文件 * @param from * @param to */public static void writer4(String from, String to) { try { InputStream in = new FileInputStream(new File(from)); OutputStream out = new FileOutputStream(new File(to)); byte[] buff = new byte[in.available()]; in.read(buff);out.write(buff);in.close(); out.close(); } catch (Exception e) { e.printStackTrace(); } } /** * 写文件 * @param formPath * @param toPath * @return */public static boolean writer5(String formPath,String toPath) {try {InputStream input=new FileInputStream(new File(formPath));OutputStream output=new FileOutputStream(new File(toPath));byte [] byf=new byte[1024*1024];//这里就不能填那么大啦 byte不同char,byteint len=0;while((len=input.read())!=-1){//input.read(byf);//读output.write(byf, 0, len); //output.write(byf);//写}if(output!=null)output.close();if(input!=null)input.close();} catch (Exception e) {e.printStackTrace();return false;} return true; }/** * 文件处理 * Writer * OutputStreamWriter * @param content * OutputStreamWriter * @param toPath写到那个路径下 * @return */public static boolean writer6(String content, String toPath) { boolean flag = true; try { Writer out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(toPath), "utf-8"));//设置编码 out.write(line + content); out.close(); } catch (Exception ex) { ex.printStackTrace(); return false; } return flag; } /** * BufferedOutputStream 套DataOutputStream套FileOutputStream * 据说管道套管道效率效率比较高,具体没测试过! * BufferedInputStream bis = new BufferedInputStream(new DataInputStream(new FileInputStream(new File(formPath)))); * * @param formPath * @param toPath写到那个路径下 * @return */public static boolean writer7(String formPath, String toPath) { boolean flag = true; /** *这里就不能填那么大啦 byte不同char,byte */byte[] byt = new byte[1];try {//BufferedInputStream bis = new BufferedInputStream(new FileInputStream(formPath)); BufferedInputStream bis = new BufferedInputStream(new DataInputStream(new FileInputStream(new File(formPath)))); DataOutputStream dos=new DataOutputStream(new FileOutputStream(new File(toPath))); BufferedOutputStream bos=new BufferedOutputStream(dos); while(bis.read(byt)!=-1) { bos.write(byt); System.out.println("文件已经写完!"); } bos.flush(); bos.close();} catch (Exception ex) { ex.printStackTrace(); return false; } return flag; } /** * * BufferedInputStream * ByteArrayOutputStream * @param formPath * @param toPath * @return */public static boolean writer8(String formPath,String toPath){try {BufferedInputStream bis=new BufferedInputStream(new FileInputStream(new File(formPath)));ByteArrayOutputStream baos=new ByteArrayOutputStream();int c=bis.read();//读取bis流中的下一个字节while(c!=-1){ baos.write(c); c=bis.read();}bis.close();byte byt[]=baos.toByteArray();FileOutputStream out=new FileOutputStream(new File(toPath));out.write(byt);out.close();} catch (Exception e) {e.printStackTrace();return false;}return true;}}
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1 楼 wzpwap123 2013-07-26 有没有试过copy个pptx文件，原始文件流形式，可前后两个文件大小不一致，后面的打开要修复一下，怎么回事？？坐等。。。。 2 楼 jilong-liang 2013-07-26 wzpwap123 写道有没有试过copy个pptx文件，原始文件流形式，可前后两个文件大小不一致，后面的打开要修复一下，怎么回事？？坐等。。。。