Javanio

liuxun · liuxun · commit 6354945c8cea · 2017-12-04T18:34:56.000+08:00
diff --git a/src/main/java/com/algorithm/study/demo/nio/ChannelTest.java b/src/main/java/com/algorithm/study/demo/nio/ChannelTest.java
@@ -0,0 +1,53 @@
+package com.algorithm.study.demo.nio;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.charset.Charset;
+import java.nio.charset.CharsetDecoder;
+
+/**
+ * @author liuxun
+ * @version V1.0
+ * @Description: JavaNio Channel 
+ * @date 2017/12/4
+ */
+public class ChannelTest {
+    public static void main(String[] args) throws IOException {
+        try {
+            Charset charset = Charset.forName("GBK");
+            //Java.nio.charset.Charset处理了字符转换问题。它通过构造CharsetEncoder和CharsetDecoder将字符序列转换成字节和逆转换。
+            CharsetDecoder decoder = charset.newDecoder();
+
+            RandomAccessFile raf = new RandomAccessFile("E:\\data.txt", "rw");
+            FileChannel fc = raf.getChannel();
+            //create buffer with capatity of 512 bytes
+            ByteBuffer buffer = ByteBuffer.allocate(512);
+            CharBuffer cb = CharBuffer.allocate(512);
+            //写入数据到Buff
+            int count = fc.read(buffer);
+            while (count != -1) {
+                System.out.println("count = "+count);
+                //通过flip()方法将Buffer从写模式切换到读模式
+                buffer.flip();
+                decoder.decode(buffer, cb, false);
+                cb.flip();
+                //从Buffer中读取数据
+                while (cb.hasRemaining()) {
+                    System.out.print(cb.get());
+                }
+                System.out.println();
+                //清空缓冲区
+                buffer.clear();
+                cb.clear();
+                count = fc.read(buffer);
+            }
+            raf.close();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+}
