Merge pull request onlyliuxin#71 from GallenZhang/master

第四次作业提交

group01/1298552064/src/week04/lru/LRUPageFrame.java

@@ -0,0 +1,116 @@
+package week04.lru;
+
+public class LRUPageFrame {
+	private static class Node {
+
+		Node prev;
+		Node next;
+		int pageNum;
+
+		Node(Node prev, Node next, int pageNum) {
+			this.prev = prev;
+			this.next = next;
+			this.pageNum = pageNum;
+		}
+	}
+
+	private int capacity;
+
+	private Node first;// 链表头
+	private Node last;// 链表尾
+	private int size; // 链表长度
+
+	public LRUPageFrame(int capacity) {
+		this.capacity = capacity;
+	}
+
+	/**
+	 * 获取缓存中对象
+	 * 
+	 * @param key
+	 * @return
+	 */
+	public void access(int pageNum) {
+		int index = find(pageNum);
+		if (size != 0) {
+			if(index >= 0){
+				remove(index);
+			}else if(size == capacity){
+				remove(size - 1);
+			}
+		}
+		addToHead(pageNum);
+	}
+
+	public void remove(int index) {
+		if (index == 0) {
+			if(size == 1){
+				first = last = null;
+			}else{
+				first = first.next;
+				first.prev = null;
+			}
+		} else if (index == (size - 1)) {
+			if(size == 1){
+				first = last = null;
+			}else{
+				last = last.prev;
+				last.next = null;
+			}
+		} else {
+			Node node = first;
+			for (int i = 1; i < index; i++) {
+				node = node.next;
+			}
+
+			Node nxt = node.next;
+
+			node.next = nxt.next;
+			(nxt.next).prev = node;
+			nxt = null;
+		}
+		size--;
+	}
+
+	public int find(int pageNum) {
+		int index = 0;
+		Node cur = first;
+		while (cur != null) {
+			if (pageNum == cur.pageNum) {
+				return index;
+			}
+			cur = cur.next;
+			index++;
+		}
+		return -1;
+	}
+
+	public void addToHead(int pageNum) {
+		// 链表为空
+		if (first == null) {
+			Node node = new Node(null, null, pageNum);
+			first = node;
+			last = node;
+		} else {
+			Node node = new Node(null,first,pageNum);
+			first.prev = node;
+			first = node;
+		}
+		size ++;
+	}
+
+	@Override
+	public String toString() {
+		StringBuilder buffer = new StringBuilder();
+		Node node = first;
+		while (node != null) {
+			buffer.append(node.pageNum);
+
+			node = node.next;
+			if (node != null) {
+				buffer.append(",");
+			}
+		}
+		return buffer.toString();
+	}
+}

group01/1298552064/src/week04/minijvm/loader/ClassFileLoader.java

@@ -0,0 +1,67 @@
+package week04.minijvm.loader;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+public class ClassFileLoader {
+	private List<String> clzPaths = new ArrayList<String>();
+
+	public byte[] readBinaryCode(String className) throws IOException {
+		if(className == null){
+			return null;
+		}
+
+		boolean isFileExist = false;
+		File file = null;
+		String classPath = className.replace(".", "\\"); 
+		for(int i = 0 ; i < clzPaths.size(); i++){
+			String basePath = clzPaths.get(i);
+			file = new File(basePath + File.separator + classPath + ".class");
+
+			if(file.exists()){
+				isFileExist = true;
+				break;
+			}
+		}
+
+		//找不到类
+		if(!isFileExist){
+			throw new FileNotFoundException();
+		}
+
+		//读取字节码文件到数组
+		FileInputStream in = new FileInputStream(file);
+		ByteArrayOutputStream bos = new ByteArrayOutputStream();
+		byte [] rs = new byte[1024];
+		int len = 0;
+		while((len = in.read(rs)) != -1){
+			bos.write(rs, 0, len);
+		}
+		bos.close();
+		in.close();
+		System.out.println("readBinaryCode:" + " file size = " + file.length());
+		return bos.toByteArray();
+	}
+
+	public void addClassPath(String path) {
+		if(! clzPaths.contains(path)){
+			clzPaths.add(path);
+		}
+	}
+
+	public String getClassPath() {
+		StringBuffer buffer = new StringBuffer();
+		for(int i = 0;i < clzPaths.size();i++){
+			buffer.append(clzPaths.get(i));
+			if(i != clzPaths.size() - 1){
+				buffer.append(";");
+			}
+		}
+		return buffer.toString();
+	}
+}

group01/1298552064/src/week04/test/ClassFileloaderTest.java

@@ -0,0 +1,78 @@
+package week04.test;
+
+import java.io.IOException;
+
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import week04.minijvm.loader.ClassFileLoader;
+
+
+public class ClassFileloaderTest {
+	static String path1 = "D:\\Git_2017\\coding2017\\group01\\1298552064\\bin";
+	static String path2 = "C:\\temp";
+
+	@Before
+	public void setUp() throws Exception {
+	}
+
+	@After
+	public void tearDown() throws Exception {
+	}
+
+	@Test
+	public void testClassPath() {
+		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 = "week04.test.EmployeeV1";
+
+		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(1032, byteCodes.length);
+
+	}
+
+	@Test
+	public void testMagicNumber() throws IOException {
+		ClassFileLoader loader = new ClassFileLoader();
+		loader.addClassPath(path1);
+		String className = "week04.test.EmployeeV1";
+		byte[] byteCodes = loader.readBinaryCode(className);
+		byte[] codes = new byte[] { byteCodes[0], byteCodes[1], byteCodes[2],
+				byteCodes[3] };
+
+		String acctualValue = this.byteToHexString(codes);
+
+		Assert.assertEquals("cafebabe", acctualValue);
+	}
+
+	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();
+	}
+}

group01/1298552064/src/week04/test/EmployeeV1.java

@@ -0,0 +1,30 @@
+package week04.test;
+
+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();
+
+	}
+}

group01/1298552064/src/week04/test/LRUPageFrameTest.java

@@ -0,0 +1,29 @@
+package week04.test;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import week04.lru.LRUPageFrame;
+
+public class LRUPageFrameTest {
+	@Test
+	public void testAccess() {
+		LRUPageFrame frame = new LRUPageFrame(3);
+		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());
+	}
+}