转换流的使用：
1、转换流属于处理流
InputStreamReader :将一个字节的输入流转换为字符的输入流
OutputStreamWriter:将一个字节的输出流转换为字符的输出流
2、提供字节流与字符流之间的转换
3、解码：字节、字节数组—>字符数组，字符串
编码：字符数组，字符串---->字节，字节数组
4、字符集
一、InputStreamReader的使用，具体代码如下：
/** * 演示使用InputStreamReader 转换流解决中文乱码问题 * 将字节流FileInputStream转成字符流InputStreamReader，指定编码gbk/utf-8 */ public class InputStreamReader_ { public static void main(String[] args) { String filePath = "D:\\a.txt"; InputStreamReader isr = null; try { //1.把FileInputStream转成InputStreamReader //2.指定编码gbk //isr = new InputStreamReader(new FileInputStream(filePath), "gbk"); //3.把InputStreamReader传入BufferedReader //BufferedReader bufferedReader = new BufferedReader(isr); //将2和3合在一起 BufferedReader bufferedReader = new BufferedReader(new InputStreamReader( new FileInputStream(filePath), "gbk")); //4.读取 String data = bufferedReader.readLine(); System.out.println("data=" + data); } catch (IOException e) { e.printStackTrace(); } finally { try { if (isr != null) { isr.close(); } } catch (IOException e) { e.printStackTrace(); } } } }
二、OutputStreamWriter的使用，具体代码如下：
/** * 演示OutputStreamWriter使用 * 把FileOutputStream字节流，转成字符流OutputStreamWriter * 指定处理的编码gbk/utf-8/utf8 */ public class OutputStreamWriter_ { public static void main(String[] args) { String filePath = "D:\\b.txt"; OutputStreamWriter osw = null; try { osw = new OutputStreamWriter(new FileOutputStream(filePath), "utf8"); osw.write("hello,筱路"); } catch (IOException e) { e.printStackTrace(); } finally { try { if (osw != null) { osw.close(); } } catch (IOException e) { e.printStackTrace(); } } } }
三、InputStreamReader 将一个字节的输入流转换为字符的输入流
@Test public void test1(){ InputStreamReader isr = null; try { FileInputStream fis = new FileInputStream("学习记录.txt"); isr = new InputStreamReader(fis); //使用系统默认的字符集 //参数2：指明了字符集，具体使用哪个字符集，取决于 学习文件.txt 保存时 使用的字符集 isr = new InputStreamReader(fis,"UTF-8"); char[] cbuf = new char[10]; int len; while ((len= isr.read(cbuf))!=-1){ String str = new String(cbuf,0,len); System.out.println(str); } } catch (IOException e) { e.printStackTrace(); } finally { if (isr!=null){ try { isr.close(); } catch (IOException e) { e.printStackTrace(); } } } }
四、将一个字符的输出流转换为一个字节的输出流
@Test public void test2() { InputStreamReader isr = null; OutputStreamWriter osw = null; try { //1.造文件、造流 File file1 = new File("学习记录.txt"); File file2 = new File("学习记录5.txt"); FileInputStream fis = new FileInputStream(file1); FileOutputStream fos = new FileOutputStream(file2); isr = new InputStreamReader(fis,"UTF-8"); osw = new OutputStreamWriter(fos,"GBK"); //2.读取，写入过程 int len; char[] cbuf = new char[5]; while ((len= isr.read(cbuf))!=-1){ osw.write(cbuf,0,len); } } catch (IOException e) { e.printStackTrace(); } finally { if (isr!=null){ try { isr.close(); } catch (IOException e) { e.printStackTrace(); } } if (osw!=null){ try { osw.close(); } catch (IOException e) { e.printStackTrace(); } } } }
