[update] add ScatterTest from nio

brianway · brianway · commit 2c8cdc8c077c · 2019-06-18T23:49:51.000+08:00
diff --git a/java-io/pom.xml b/java-io/pom.xml
@@ -11,4 +11,10 @@
 
     <artifactId>java-io</artifactId>
 
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+        </dependency>
+    </dependencies>
 </project>
diff --git a/java-io/src/main/java/com/brianway/learning/java/nio/tutorial/BufferDemo.java b/java-io/src/main/java/com/brianway/learning/java/nio/tutorial/BufferDemo.java
@@ -26,7 +26,6 @@ public static void main(String[] args) throws IOException {
 
             //make buffer ready for read
             buf.flip();
-
             while (buf.hasRemaining()) {
                 // read 1 byte at a time
                 System.out.print((char) buf.get());
diff --git a/java-io/src/test/java/com/brianway/java/nio/tutorial/ScatterTest.java b/java-io/src/test/java/com/brianway/java/nio/tutorial/ScatterTest.java
@@ -0,0 +1,53 @@
+package com.brianway.java.nio.tutorial;
+
+import com.brianway.learning.java.nio.tutorial.BufferDemo;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+
+/**
+ * @auther brian
+ * @since 2019/6/18 23:24
+ */
+public class ScatterTest {
+
+    private String path = BufferDemo.class.getResource("/").getPath() + "scatter.txt";
+
+    @Test
+    public void testScatteringReads() throws IOException {
+        RandomAccessFile aFile = new RandomAccessFile(path, "rw");
+        FileChannel fc = aFile.getChannel();
+
+        //create buffer with capacity of 48 bytes
+        ByteBuffer header = ByteBuffer.allocate(8);
+        ByteBuffer body = ByteBuffer.allocate(1024);
+
+        ByteBuffer[] bufferArray = {header, body};
+        long bytesRead = fc.read(bufferArray);
+        // System.out.println(bytesRead);
+        Assert.assertEquals(26, bytesRead);
+        //print header
+        System.out.println("---header(" + header.limit() + "bytes)---");
+        header.flip();
+        while (header.hasRemaining()) {
+            // read 1 byte at a time
+            System.out.print((char) header.get());
+        }
+        header.clear();
+
+        // print body
+        body.flip();
+        System.out.println("---body(" + body.limit() + "bytes)----");
+        while (body.hasRemaining()) {
+            // read 1 byte at a time
+            System.out.print((char) body.get());
+        }
+        header.clear();
+        body.clear();
+        fc.close();
+    }
+}
diff --git a/java-io/src/test/resources/scatter.txt b/java-io/src/test/resources/scatter.txt
@@ -0,0 +1,3 @@
+1234567
+qwertyusfdf
+asdsad
