java中複製文字檔的方式我總結為14種(按字元讀取4中，按位元組讀取8種！？？)

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java中複製檔案的方式

如果按照字元來讀取的話，可以有4種，基本的2種，高效的2種，高效特殊的1種

第0種：

public class CopyFileDemo {public static void main(String[] args) throws Exception{//封裝資料來源BufferedReader reader = new BufferedReader(new FileReader("a.txt"));//封裝目的地BufferedWriter writer = new BufferedWriter(new FileWriter("b.txt"));//讀寫資料String line = null;while((line=reader.readLine())!=null){writer.write(line);writer.newLine();//添加新行，不然寫到檔案裡面的內容就沒有換行writer.flush();}//釋放資源writer.close();writer.close();}}

第一種：加入緩衝區Buffered一次讀取一個字元數組

public class CopyFileTest {public static void main(String[] args) throws Exception{//封裝資料來源BufferedReader reader = new BufferedReader(new FileReader("a.txt"));//封裝目的地BufferedWriter writer = new BufferedWriter(new FileWriter("b.txt"));//兩種方式其中一種一次讀取一個字元數組char[] chs = new char[1024];int len=0;while((len=reader.read(chs))!=-1){writer.write(chs,0,len);writer.flush();//記得重新整理}//釋放資源writer.close();reader.close();}}

第二種：加入緩衝區Buffered一次讀取一個字元

public class CopyFileTest {public static void main(String[] args) throws Exception{//封裝資料來源BufferedReader reader = new BufferedReader(new FileReader("a.txt"));//封裝目的地BufferedWriter writer = new BufferedWriter(new FileWriter("b.txt"));//一次讀取一個字元int ch=0;while((ch=reader.read())!=-1){writer.write(ch);}//釋放資源writer.close();reader.close();}}

第三種：普通的一次讀取一個字元數組

public class BufferedCopyFileTest {public static void main(String[] args) throws Exception{//封裝資料來源FileReader reader = new FileReader("a.txt");//封裝目的地FileWriter writer = new FileWriter("b.txt");//一次讀取一個字元數組char[] chs = new char[1024];int len=0;while((len=reader.read(chs))!=-1){writer.write(chs,0,len);writer.flush();}writer.close();reader.close();}}

第三種：普通的一次讀取一個字元

public class BufferedCopyFileTest {public static void main(String[] args) throws Exception{//封裝資料來源FileReader reader = new FileReader("a.txt");//封裝目的地FileWriter writer = new FileWriter("b.txt");//一次讀取一個字元int ch=0;while((ch=reader.read())!=-1){writer.write(ch);}writer.close();reader.close();}}

如果按照位元組來讀取的話，可以有8中

第一種：把位元組流轉換為字元流來一次讀取一個字元

public class Copy {public static void main(String[] args) throws Exception {//封裝資料來源（把位元組流轉換為字元流）InputStreamReader isr = new InputStreamReader(new FileInputStream("a.txt"));//封裝目的地（把位元組流轉換為字元流）OutputStreamWriter osw = new OutputStreamWriter(new FileOutputStream("b.txt"));//一次讀取一個字元int ch=0;while((ch=isr.read())!=-1){osw.write(ch);}//關閉資源osw.close();isr.close();}}

第二種：把位元組流轉換為字元流來一次讀取一個字元數組

public class Copy {public static void main(String[] args) throws Exception {//封裝資料來源（把位元組流轉換為字元流）InputStreamReader isr = new InputStreamReader(new FileInputStream("a.txt"));//封裝目的地（把位元組流轉換為字元流）OutputStreamWriter osw = new OutputStreamWriter(new FileOutputStream("b.txt"));//一次讀取一個字元數組char[] chs = new char[1024];int len=0;while((len=isr.read(chs))!=-1){osw.write(chs,0,len);osw.flush();}//關閉資源osw.close();isr.close();}}

  第三種：高效位元組流一次讀寫一個位元組數組：

 public static void method4(String srcString, String destString)                  throws IOException {              BufferedInputStream bis = new BufferedInputStream(new FileInputStream(                      srcString));              BufferedOutputStream bos = new BufferedOutputStream(                      new FileOutputStream(destString));                    byte[] bys = new byte[1024];              int len = 0;              while ((len = bis.read(bys)) != -1) {                  bos.write(bys, 0, len);              }                    bos.close();              bis.close();          }  

第四種：高效位元組流一次讀取一個字元：

 public static void method3(String srcString, String destString)                  throws IOException {              BufferedInputStream bis = new BufferedInputStream(new FileInputStream(                      srcString));              BufferedOutputStream bos = new BufferedOutputStream(                      new FileOutputStream(destString));                    int by = 0;              while ((by = bis.read()) != -1) {                  bos.write(by);                    }                    bos.close();              bis.close();          }  

第五種：普通的位元組流對象一次讀取一個位元組數組

public static void method2(String srcString, String destString)                  throws IOException {              FileInputStream fis = new FileInputStream(srcString);              FileOutputStream fos = new FileOutputStream(destString);                    byte[] bys = new byte[1024];              int len = 0;              while ((len = fis.read(bys)) != -1) {                  fos.write(bys, 0, len);              }                    fos.close();              fis.close();          }        

第六種：普通的位元組流對象一次讀取一個位元組

public static void method1(String srcString, String destString)                  throws IOException {              FileInputStream fis = new FileInputStream(srcString);              FileOutputStream fos = new FileOutputStream(destString);                    int by = 0;              while ((by = fis.read()) != -1) {                  fos.write(by);              }                    fos.close();              fis.close();          }  

第七種：BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream("a.txt")));
        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("b,txt")));然後一次讀取一個字元

第八種：BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream("a.txt")));
        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("b,txt")));然後一次讀取一個字元數組

注意複製圖片、視頻、音訊話，只有4種方式（位元組流讀取方式），不能用字元流讀取

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java中複製文字檔的方式我總結為14種(按字元讀取4中，按位元組讀取8種！？？)