ok

group26/2441547139/week4/ClassFileLoader.java

@@ -0,0 +1,57 @@
+package week4;
+
+import java.io.BufferedInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.FileInputStream;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Created by zndbl on 2017/4/9.
+ */
+public class ClassFileLoader {
+
+    private static final int BUFFER_SIZE = 1024;
+
+    private List<String> clzPaths = new ArrayList<String>();
+
+    public byte[] readBinaryCode(String className) {
+        for (String classPath : clzPaths) {
+            String fileName = classPath + className.replace(".", "\\") + ".class";
+            BufferedInputStream bis = null;
+            ByteArrayOutputStream baos = null;
+            try {
+                bis = new BufferedInputStream(new FileInputStream(fileName), BUFFER_SIZE);
+                baos = new ByteArrayOutputStream();
+                byte[] buffer = new byte[BUFFER_SIZE];
+                int len = 0;
+                while ((len = bis.read(buffer)) != -1) {
+                    baos.write(buffer, 0, len);
+                }
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+            return baos.toByteArray();
+        }
+        return null;
+    }
+
+    public void addClassPath(String classPath) {
+        if (classPath == null) {
+            return;
+        }
+        clzPaths.add(classPath);
+    }
+
+    public String getClassPath() {
+        StringBuilder sb = new StringBuilder();
+        int size = clzPaths.size();
+        for (int i = 0; i < size; i++) {
+            sb.append(clzPaths.get(i));
+            if (i + 1 < size) {
+                sb.append(";");
+            }
+        }
+        return sb.toString();
+    }
+}

group26/2441547139/week4/LruPageFrame.java

@@ -0,0 +1,136 @@
+package week4;
+
+/**
+ * 用双向链表实现LRU算法
+ *
+ * @author liuxin
+ */
+class LruPageFrame {
+
+    private static class Node {
+        Node prev;
+        Node next;
+        int pageNum;
+
+        Node() {
+        }
+
+        Node(int pageNum) {
+            this.pageNum = pageNum;
+        }
+    }
+
+    private int capacity;
+
+
+    private Node first;// 链表头
+    private Node last;// 链表尾
+
+
+    public LruPageFrame(int capacity) {
+
+        this.capacity = capacity;
+
+    }
+
+    /**
+     * 获取缓存中对象
+     *
+     * @param pageNum
+     * @return
+     */
+    public void access(int pageNum) {
+        if (first == null) {
+            first = new Node(pageNum);
+            first.next = first.prev = null;
+            last = first;
+        } else if (size() < capacity) {
+            Node node = new Node(pageNum);
+            if (last.prev == null) {
+                last.prev = node;
+                node.next = last;
+            } else {
+                node.next = first;
+                first.prev = node;
+                node.prev = null;
+            }
+            first = node;
+        } else if (size() >= capacity) {
+            Node node = getNode(pageNum);
+            LRU(node, pageNum);
+        }
+    }
+
+    /**
+     * lru算法
+     *
+     * @param node
+     * @param pageNum
+     */
+    private void LRU(Node node, int pageNum) {
+        if (node != null) {
+            if (last.pageNum == node.pageNum) {
+                last = node.prev;
+                last.next = null;
+                node.next = first;
+                first.prev = node;
+                node.prev = null;
+                first = node;
+            } else if (last.pageNum != node.pageNum && first.pageNum != node.pageNum) {
+                node.prev.next = node.next;
+                node.next.prev = node.prev;
+                node.prev = null;
+                node.next = first;
+                first = node;
+            }
+        } else {
+            last = last.prev;
+            last.next = null;
+            node = new Node(pageNum);
+            node.next = first;
+            first.prev = node;
+            first = node;
+        }
+    }
+
+    /**
+     * 根据数据在缓存中获取节点
+     *
+     * @param pageNum
+     * @return
+     */
+    private Node getNode(int pageNum) {
+        Node node = first;
+        while (node != null) {
+            if (node.pageNum == pageNum) {
+                return node;
+            }
+            node = node.next;
+        }
+        return null;
+    }
+
+    public int size() {
+        int num = 0;
+        Node node = first;
+        while (node != null) {
+            num++;
+            node = node.next;
+        }
+        return num;
+    }
+
+    public String toString() {
+        StringBuilder sb = new StringBuilder();
+        Node node = first;
+        while (node != null) {
+            sb.append(node.pageNum);
+            node = node.next;
+            if (node != null) {
+                sb.append(",");
+            }
+        }
+        return sb.toString();
+    }
+
+}

group26/2441547139/有道笔记.txt

@@ -1,3 +1,4 @@
 http://note.youdao.com/noteshare?id=63cfdc5e194deb6458f9733681088516   ����
 http://note.youdao.com/noteshare?id=3078d5c9a9f86e590973ee40ba3fdb25   ���������������
 http://note.youdao.com/noteshare?id=8fb7ea6223b152c647f09dc98882751b   lucene�򵥽���
+http://note.youdao.com/noteshare?id=930aef92deb715a6bbb265bc1799959e   mongodb��mysql�ļ򵥱Ƚ�