[add] add GatherTest for nio

brianway · brianway · commit 6a4b02c6b140 · 2019-06-18T23:59:59.000+08:00
diff --git a/java-io/src/test/java/com/brianway/java/nio/tutorial/GatherTest.java b/java-io/src/test/java/com/brianway/java/nio/tutorial/GatherTest.java
@@ -0,0 +1,37 @@
+package com.brianway.java.nio.tutorial;
+
+import com.brianway.learning.java.nio.tutorial.BufferDemo;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.charset.Charset;
+
+/**
+ * @auther brian
+ * @since 2019/6/18 23:51
+ */
+public class GatherTest {
+
+    private String path = BufferDemo.class.getResource("/").getPath() + "gather.txt";
+
+    @Test
+    public void testGatheringWrites() throws IOException {
+        RandomAccessFile aFile = new RandomAccessFile(path, "rw");
+        FileChannel channel = aFile.getChannel();
+        ByteBuffer header = ByteBuffer.allocate(128);
+        ByteBuffer body = ByteBuffer.allocate(1024);
+
+        header.put("这是头".getBytes(Charset.forName("UTF-8")));
+        body.put("this is body.".getBytes(Charset.forName("UTF-8")));
+        header.flip();
+        body.flip();
+        //write data into buffers
+        ByteBuffer[] bufferArray = {header, body};
+        // 注意只有position和limit之间的数据才会被写入
+        channel.write(bufferArray);
+        channel.close();
+    }
+}
