Merge pull request #37 from Jamesmahaitao/master

FourthHomework

group11/1310368322/src/FourthHomework/BaseDataStructure/LRUPageFrame.java

@@ -0,0 +1,143 @@
+package DataStructure_4_LRU;
+
+import org.junit.runners.Parameterized.Parameters;
+
+/*
+ * 用双向链表实现LRU算法
+ */
+public class LRUPageFrame {
+	private static class Node{
+		Node prev;
+		Node next;
+		int pageNum = -1;// 物理页
+
+		Node(){
+
+		}
+	}
+
+	private int capacity;
+
+	private Node first;// 链表头
+	private Node last;// 链表尾
+	boolean tag = false;
+
+	public LRUPageFrame(int capacity){
+		this.capacity = capacity;
+
+		for(int i = 0; i < capacity; i++){
+			Node curNode = new Node();
+			if(null == first){
+				last = first = curNode;
+			}else{
+				last.next = curNode;
+				curNode.prev = last;
+				last = last.next;
+			}
+			last.next = null;
+		}
+	}
+	public void printList(){
+		Node curNode = first;
+		while(curNode != null){
+			curNode = curNode.next;
+		}
+	}
+	/*
+	 *  获取缓存中对象
+	 *  @param key
+	 *  @return
+	 */
+	public void access(int pageNum){
+		printList();
+		Node index = findLogicPage(pageNum);
+		modifyPhysicalPage(index,pageNum);	
+	}
+
+	/*
+	 * @param pageNum 表示要查询的逻辑页面
+	 * @return 若在物理页中找到要查询的逻辑页面，则返回该物理页节点的引用，否则返回null
+	 */
+	public Node findLogicPage(int pageNum){
+
+		Node index = null;
+		Node curNode = first;
+		while(curNode != null){
+			if(curNode.pageNum == pageNum){
+				index = curNode;
+				tag = true;
+			}
+			curNode = curNode.next;
+		}
+		return index;
+	}
+	/*
+	 * @prama index 代表了 有逻辑页的物理页的节点的引用
+	 */
+	public void modifyPhysicalPage(Node index,int pageNum){
+		push(pageNum,index);
+	}
+	/*
+	 *  @param pageNum 要 push的逻辑页面，  默认栈顶是 first, bottom 栈底  指定了栈的大小
+	 */
+	public void push(int pageNum,Node bottom){
+		Node index = checkWhichListNodeNotUsed();
+		if(index != null){
+			index.pageNum = pageNum;
+			return;
+		}
+
+		Node lastNode;
+		if(null == bottom){
+			lastNode = last;
+		}else{
+			lastNode = bottom;
+		}
+		Node curNode = lastNode.prev;
+		while(curNode != null){
+			lastNode.pageNum = curNode.pageNum;
+			lastNode = curNode;
+			curNode = curNode.prev;
+		}
+		lastNode.pageNum = pageNum;
+		return;
+	}
+
+	/* 
+	 * @return 返回物理页中 pageNum 没有被使用的节点的引用(返回栈中最下面的)，如果全部都被使用，则返回 null
+	 */
+	public Node checkWhichListNodeNotUsed(){
+		Node node = first;
+		Node index = null;
+		while(node != null){
+			if(node.pageNum == -1){
+				index = node;
+			}
+			node = node.next;
+		}
+		return index;
+	}
+
+	public String toString(){
+		StringBuffer buffer = new StringBuffer();
+		Node node = first;
+		while(node != null){
+			buffer.append(node.pageNum);
+
+			node = node.next;
+			if(node != null){
+				buffer.append(",");
+			}
+		}
+		return buffer.toString();
+	}
+
+
+
+
+
+
+
+
+
+}

group11/1310368322/src/FourthHomework/jvm/ClassFileLoader.java

@@ -0,0 +1,51 @@
+package com.coderising.jvm.loader;
+
+import java.io.BufferedInputStream;
+import java.io.DataInputStream;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.runners.Parameterized.Parameters;
+
+public class ClassFileLoader {
+	private List<String> clzPaths = new ArrayList<String>();
+	int countForClassPath = 0;
+	int countForReadBinaryCode = 0;
+	byte [] a = new byte[10000];
+
+	/*	从指定路径读取二进制文件流，并将其保存到一个字节数组中，并返回
+	 * 	@Parameters 指定路径
+	 *  @字节数组
+	 */
+	public byte[] readBinaryCode(String className) throws IOException{
+		DataInputStream dis = new DataInputStream(
+				new BufferedInputStream(new FileInputStream(className)));
+		for(int i = 0; dis.available() != 0; i++){
+			a[i] = dis.readByte();
+			countForReadBinaryCode++;
+		}	
+		byte []target = new byte[countForReadBinaryCode];
+		System.arraycopy(a, 0, target, 0, countForReadBinaryCode);
+		dis.close();
+		return target;
+	}
+
+	public void addClassPath(String path){
+		clzPaths.add(path);
+		countForClassPath++;
+	}
+
+	public String getClassPath(){
+		StringBuffer buffer = new StringBuffer();
+		for(int i = 0; i < countForClassPath; i++ ){
+			if(i==countForClassPath-1){
+				buffer.append(clzPaths.get(i));
+			}else{
+				buffer.append(clzPaths.get(i)+";");
+			}
+		}
+		return buffer.toString();
+	}
+}

group11/1310368322/src/FourthHomework/jvm/TestJVM.java

@@ -0,0 +1,7 @@
+package com.coderising.jvm.loader;
+
+public class TestJVM {
+	public static void main(String[] args) {
+		System.out.println("Hello");
+	}
+}

group11/1310368322/test/FourthHomework/BaseDataStructure/TestLRUPageFrame.java

@@ -0,0 +1,31 @@
+package DataStructure_4_LRU;
+
+import static org.junit.Assert.*;
+import org.junit.*;
+
+import org.junit.Test;
+
+public class TestLRUPageFrame {
+
+	@Test
+	public void testAccess() {
+		LRUPageFrame frame = new LRUPageFrame(3);// 物理页面存储容量为3个物理页面
+		frame.access(7);
+		frame.access(0);
+		frame.access(1);
+		Assert.assertEquals("1,0,7",frame.toString());
+		frame.access(2);
+		Assert.assertEquals("2,1,0",frame.toString());
+		frame.access(0);
+		Assert.assertEquals("0,2,1", frame.toString());
+		frame.access(0);
+		Assert.assertEquals("0,2,1",frame.toString());
+		frame.access(3);
+		Assert.assertEquals("3,0,2",frame.toString());
+		frame.access(0);
+		Assert.assertEquals("0,3,2",frame.toString());
+		frame.access(4);
+		Assert.assertEquals("4,0,3",frame.toString());
+	}
+
+}

group11/1310368322/test/FourthHomework/JVM/EmployeeV1.java

@@ -0,0 +1,28 @@
+package com.coderising.jvm.loader;
+
+public class EmployeeV1 {
+	private String name;
+	private int age;
+
+	public EmployeeV1(String name, int age){
+		this.name = name;
+		this.age = age;
+	}
+
+	public void setName(String name){
+		this.name = name;
+	}
+
+	public void setAge(int age){
+		this.age = age;
+	}
+
+	public void sayHello(){
+		System.out.println("Hello, this is class Employee");
+	}
+
+	public static void main(String[] args) {
+		EmployeeV1 p = new EmployeeV1("Andy",29);
+		p.sayHello();
+	}
+}

group11/1310368322/test/FourthHomework/JVM/TestClassFileLoader.java

@@ -0,0 +1,67 @@
+package com.coderising.jvm.loader;
+
+import static org.junit.Assert.*;
+
+import java.io.IOException;
+
+import org.junit.*;
+
+public class TestClassFileLoader {
+	static String path1 = "D:/ProgramWorld";
+	static String path2 = "D:/ProgramWorld/Java";
+	@Test
+	public void test() {
+		ClassFileLoader loader = new ClassFileLoader();
+		loader.addClassPath(path1);
+		loader.addClassPath(path2);
+		String clzPath = loader.getClassPath();
+		Assert.assertEquals(path1 + ";" + path2, clzPath);
+	}
+	@Test
+	public void testClassFileLength() throws IOException{
+		ClassFileLoader loader = new ClassFileLoader();
+		loader.addClassPath(path1);
+
+		String className = "D:/ProgramWorld/Java/Practice/LangSi/2017编程提高群/bin/com/coderising/jvm/loader/EmployeeV1.class";
+
+		byte[] byteCodes = loader.readBinaryCode(className);
+
+		// 注意： 这个字节数可能和你的JVM版本有关系，你可以看看编译好的类到底有多大
+		Assert.assertEquals(1058,byteCodes.length);
+	}
+	@Test
+	public void testMagicNumber() throws IOException{
+		ClassFileLoader loader = new ClassFileLoader();
+		loader.addClassPath(path1);
+		String className = "D:/ProgramWorld/Java/Practice/LangSi/2017编程提高群/bin/com/coderising/jvm/loader/EmployeeV1.class";
+		byte[] byteCodes = loader.readBinaryCode(className);
+		byte[] codes = new byte[]{ 
+				byteCodes[0],byteCodes[1],byteCodes[2],byteCodes[3]
+		};
+		String actualValue = this.byteToHexString(codes);
+		Assert.assertEquals("cafebabe",actualValue);
+
+	}
+
+	private String byteToHexString(byte[] codes){
+		StringBuffer buffer = new StringBuffer();
+		for(int i = 0; i < codes.length; i++){
+			byte b = codes[i];
+			int value = b & 0xFF;
+			String strHex = Integer.toHexString(value);
+			if(strHex.length() < 2){
+				strHex = "0" + strHex;
+			}
+			buffer.append(strHex);
+		}
+		return buffer.toString();
+	}
+
+
+
+
+
+
+
+
+}