转换流 inputstreamreader outputstreamwriter

//传入参数都需要 字节流 package 练习; import org.junit.Test; import java.io.*; /* inputstreamreader 字节流 ---》字符流 outputstreamwriter 字符流----》字节流 原理 是一套操作 其中他们的参数都需要字节流 */ public class InputStreamOutputStreamReader { // 字节流转换成字符流--------解码 @Test public void testInputStreamReader() { FileInputStream fi = null; InputStreamReader isr = null; try { File file = new File("F:\\java92\\src\\练习\\1.txt"); fi = new FileInputStream(file); // 字节流转换成字符流--------解码 //第二个参数表示读取文件的编码方式 isr = new InputStreamReader(fi, "gbk"); char[] ch = new char[20]; int len; while ((len = isr.read(ch)) != -1) { for (int i = 0; i < len; i++) { System.out.print(ch[i]); } } } catch (IOException e) { e.printStackTrace(); } finally { // 关闭流 try { if (isr != null) { isr.close(); } } catch (IOException e) { e.printStackTrace(); } try { if (fi != null) { fi.close(); } } catch (IOException e) { e.printStackTrace(); } } } @Test public void testOutStreamWrite() { FileInputStream fi = null; FileOutputStream fis = null; InputStreamReader isr = null; OutputStreamWriter osw = null; try { File file = new File("F:\\java92\\src\\练习\\1.txt"); File file2 = new File("F:\\java92\\src\\练习\\2.txt"); fi = new FileInputStream(file); fis = new FileOutputStream(file2); // 字符流转换成字节流--------编码 //第二个参数表示读取文件的编码方式 isr = new InputStreamReader(fi, "gbk"); osw = new OutputStreamWriter(fis, "utf8"); char[] ch = new char[20]; int len; while ((len = isr.read(ch)) != -1) { for (int i = 0; i < len; i++) { osw.write(ch[i]); } } } catch (IOException e) { e.printStackTrace(); } finally { // 关闭流 try { if (osw != null) { osw.close(); } } catch (IOException e) { e.printStackTrace(); } try { if (isr != null) { isr.close(); } } catch (IOException e) { e.printStackTrace(); } try { if (fi != null) { fi.close(); } } catch (IOException e) { e.printStackTrace(); } try { if (fis!=null) { fis.close(); } } catch (IOException e) { e.printStackTrace(); } } } }