//工具類
package com.maoge.stream;
import java.io.File;
public class StreamUtils {
?? ?//用于定義每次讀取的長度
?? ?public static final int BUFFER_LENGTH=512;
?? ?//文件對象
?? ?public static File FILE_FOR_READ;
?? ?public static File FILE_FOR_WRITE;
?? ?static{
?? ??? ?FILE_FOR_READ=new File("C:\\test.txt");?
?? ??? ?FILE_FOR_WRITE=new File("C:\\result.txt");?
?? ?}
}

寫入過程

package com.maoge.stream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
public class OutputStreamDemo {
?? ?public static void main(String[] args){
?? ??? ?writeToFile();
?? ?}
?? ?public static void writeToFile(){
?? ??? ?byte buffer[]=buffer=new String("hello world!").getBytes();
?? ??? ?OutputStream out=null;
?? ??? ?try {
?? ??? ??? ?out = new FileOutputStream(StreamUtils.FILE_FOR_WRITE);
?? ??? ??? ?out.write(buffer, 0, buffer.length);
?? ??? ?} catch (Exception ex) {
?? ??? ??? ?System.out.println(ex.toString());
?? ??? ?}finally{
?? ??? ??? ?try {
?? ??? ??? ??? ?out.close();
?? ??? ??? ?} catch (IOException ioEx) {
?? ??? ??? ??? ?System.out.println(ioEx.toString());
?? ??? ??? ?}
?? ??? ?}?? ?
?? ?}
}

3.文件復(fù)制示例

直接演示復(fù)制圖片，因為圖片也是二進(jìn)制位組成的

源文件test.jpg這個需要找個圖片，目的文件result.jpg這個是復(fù)制后生產(chǎn)的

//工具類
package com.maoge.stream;
import java.io.File;
public class StreamUtils {
?? ?//用于定義每次讀取的長度
?? ?public static final int BUFFER_LENGTH=512;
?? ?//文件對象
?? ?public static File FILE_FOR_READ;
?? ?public static File FILE_FOR_WRITE;
?? ?static{
?? ??? ?FILE_FOR_READ=new File("C:\\test.jpg");?
?? ??? ?FILE_FOR_WRITE=new File("C:\\result.jpg");?
?? ?}
}

復(fù)制過程，該方法是OutputStreamDemo類的靜態(tài)方法。

public static void fileCopy(){
?? ??? ?FileInputStream in=null;
?? ??? ?FileOutputStream out=null;
?? ??? ?try {
?? ??? ??? ?in=new FileInputStream(StreamUtils.FILE_FOR_READ);
?? ??? ??? ?out=new FileOutputStream(StreamUtils.FILE_FOR_WRITE);
?? ??? ??? ?int c;
?? ??? ??? ?while((c=in.read())!=-1)
?? ??? ??? ??? ?out.write(c);
?? ??? ?} catch (Exception ex) {
?? ??? ??? ?System.out.println(ex.toString());
?? ??? ?}finally{
?? ??? ??? ?try {
?? ??? ??? ??? ?in.close();
?? ??? ??? ?} catch (IOException ioEx) {
?? ??? ??? ??? ?System.out.println(ioEx.toString());
?? ??? ??? ?}
?? ??? ??? ?try {
?? ??? ??? ??? ?out.close();
?? ??? ??? ?} catch (IOException ioEx) {
?? ??? ??? ??? ?System.out.println(ioEx.toString());
?? ??? ??? ?}
?? ??? ?}
?? ?}

java寫入文件問題(FileOutputStream的使用)

實現(xiàn)在控制臺寫入相關(guān)文字，并添加到指定的文件中，并實現(xiàn)讀取文件內(nèi)容

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Scanner;
?
public class Fileout {
?? ?Scanner inScanner = new Scanner(System.in);
?? ?public void f(String address) throws IOException
?? ?{
?? ?
?? ?FileOutputStream out=new FileOutputStream(address, true);
?? ?String buf;
?? ?System.out.println("請輸入");
?? ?buf= inScanner.nextLine();
?? ?byte buy[]=buf.getBytes();
?? ?out.write(buy);
?? ?
?? ?FileInputStream fin=new FileInputStream(address);?? ?
?? ?byte[] bs=new byte[1024];?? ?
?? ?int count=0;?? ?
?
?? ?while((count=fin.read(bs))>0)?? ??? ??? ??? ?
?? ?{
?? ?
?? ??? ?
?? ??? ?String str=new String(bs,0,count);?? ?//反復(fù)定義新變量：每一次都 重新定義新變量，接收新讀取的數(shù)據(jù)
?
?? ??? ?System.out.println(str);?? ??? ?//反復(fù)輸出新變量：每一次都 輸出重新定義的新變量
?? ?}
?? ?fin.close();
?? ?}
?? ?public static void main(String[] args) throws IOException {
?? ??? ?
?? ??? ?Fileout out=new Fileout();
?? ??? ?out.f("f://student.txt");?? ?
?? ?}
}