java各种文件的读写，通过不同的方式进行操作。

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:/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=reader1(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BufferedReadertry {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;}}