java的inputstream, outputstream, reader和writer的比較

標籤：

java的檔案讀寫有多種方式，在此通過代碼做以下比較。

 

比較一：FileWriter和FileReader

public class MyCode1 {       public static void main(String[] args) throws IOException {                      File f = new File("my.txt");                      FileWriter fw = new FileWriter(f);           fw.write("HELLO");           fw.close();                      FileReader fr = new FileReader(f);           System.out.println((char)fr.read());           fr.close();                  }}

輸出: H

可見，FileWriter可以批量寫入，但是FileReader每次只能讀取一個字元。

 

比較二：OutputStream和InputStream

public class MyCode1 {       public static void main(String[] args) throws IOException {                      File f = new File("my.txt");                      char[] data = new char[]{‘H‘, ‘E‘, ‘L‘, ‘L‘, ‘O‘};                   OutputStream os = new FileOutputStream(f);           os.write(data[0]);           os.close();                      InputStream is = new FileInputStream(f);           System.out.println((char)is.read());           is.close();                  }}

輸出: H

可見，OutputStream和InputStream每次只可以讀寫一個字元。

 

比較三：OutputStreamWriter和InputStreamReader

 

public class MyCode1 {       public static void main(String[] args) throws IOException {                      File f = new File("my.txt");                      OutputStream os = new FileOutputStream(f);           OutputStreamWriter osw = new OutputStreamWriter(os);           osw.write("HELLO");           osw.close();           os.close();                      InputStream is = new FileInputStream(f);           InputStreamReader isr = new InputStreamReader(is);           System.out.println((char)isr.read());           isr.close();           is.close();                  }}

 

輸出: H

可見，OutputStreamWriter可以批量寫入，但是InputStreamReader每次只能讀取一個字元。效果同FileWriter和FileReader。

 

比較四：BufferedWriter和BufferedReader

public class MyCode1 {       public static void main(String[] args) throws IOException {                      File f = new File("my.txt");                      OutputStream os = new FileOutputStream(f);           OutputStreamWriter osw = new OutputStreamWriter(os);           BufferedWriter bw = new BufferedWriter(osw);           bw.write("HELLO");           bw.close();           osw.close();           os.close();                      InputStream is = new FileInputStream(f);           InputStreamReader isr = new InputStreamReader(is);           BufferedReader br = new BufferedReader(isr);           System.out.println(br.readLine());           isr.close();           is.close();                  }}

輸出: HELLO

可見，BufferedWriter和BufferedReader可以批量讀寫。

 

java的inputstream, outputstream, reader和writer的比較