Merge pull request #42 from wanghongdi56/master

0326作业

group16/313001956/src/com/coderising/jvm/loader/ClassFileLoader.java

@@ -0,0 +1,56 @@
+package com.coderising.jvm.loader;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+public class ClassFileLoader {
+
+	private List<String> clzPaths = new ArrayList<String>();
+	 static final int BUFF_SIZE=1024;
+
+	public byte[] readBinaryCode(String className) {
+		byte[] barray = new byte[BUFF_SIZE];
+		try {
+
+			String pathname = clzPaths.get(0) + "\\" + className.replace('.', '\\')+".class";
+			File file = new File(pathname);
+			InputStream in = new FileInputStream(file);
+			int byteread = 0;
+			ByteArrayOutputStream baos = new ByteArrayOutputStream();
+			while ((byteread = in.read(barray)) != -1) {
+				baos.write(barray, 0, byteread);
+			}
+			return baos.toByteArray();
+		} catch (Exception e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+			return null;
+		}
+	}
+
+	public void addClassPath(String path) {
+		clzPaths.add(path);
+	}
+
+	public String getClassPath() {
+		int clzsize = clzPaths.size();
+		String str = "";
+		if (clzsize > 0) {
+			for (int i = 0; i < clzsize; i++) {
+				str += clzPaths.get(i);
+				if (i < clzsize - 1) {
+					str += ";";
+				}
+			}
+		}
+		return str;
+	}
+
+}

group16/313001956/src/com/coderising/jvm/test/ClassFileloaderTest.java

@@ -0,0 +1,91 @@
+package com.coderising.jvm.test;
+
+import org.junit.After;
+import  org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.coderising.jvm.loader.ClassFileLoader;
+
+
+
+
+
+public class ClassFileloaderTest {
+
+
+	//static String path1 = "C:\\Users\\liuxin\\git\\coding2017\\liuxin\\mini-jvm\\bin";
+	static String path1 = "D:\\Java2017\\GitHub\\coding2017\\group16\\313001956\\build\\classes";
+	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() {		
+
+		ClassFileLoader loader = new ClassFileLoader();
+		loader.addClassPath(path1);
+
+		String className = "com.coderising.jvm.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(1056, byteCodes.length);
+
+	}
+
+
+    @Test	
+	public void testMagicNumber(){
+    	ClassFileLoader loader = new ClassFileLoader();
+		loader.addClassPath(path1);
+		String className = "com.coderising.jvm.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();
+	}
+
+}

group16/313001956/src/com/coderising/jvm/test/EmployeeV1.java

@@ -0,0 +1,28 @@
+package com.coderising.jvm.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();    
+
+    }
+}

group16/313001956/src/com/coding/basic/linklist/LRUPageFrame.java

@@ -0,0 +1,135 @@
+package com.coding.basic.linklist;
+
+/**
+ * 用双向链表实现LRU算法
+ * 
+ * @author liuxin
+ *
+ */
+public class LRUPageFrame {
+
+	private static class Node {
+
+		Node prev;
+		Node next;
+		int pageNum;
+
+		Node() {
+		}
+	}
+
+	private int capacity;
+
+	private Node first;// 链表头
+	private Node last;// 链表尾
+
+	public LRUPageFrame(int capacity) {
+
+		this.capacity = capacity;
+		first = null;
+		last = null;
+	}
+
+	/**
+	 * 获取缓存中对象
+	 * 
+	 * @param key
+	 * @return
+	 */
+	public void access(int pageNum) {
+		Node node = new Node();
+		node.prev = null;
+		node.pageNum = pageNum;
+
+		if (first == null) {
+			node.next = null;
+			first = node;
+			return;
+		}
+		if(judgeEqual(node, pageNum)){
+			return;
+		}
+
+		node.next = first;
+		first.prev = node;
+		first = node;
+
+		if (last == null) {
+			judgeFull();
+		} else {
+			Node temp = last.prev;
+
+			last.prev = null;
+			last.next = null;
+			last.pageNum = 0;
+
+			temp.next = null;
+			last = temp;
+		}
+	}
+
+	private boolean judgeEqual(Node node, int pageNum) {
+		if (first.pageNum == pageNum) {
+			return true;
+		}
+		Node nd = first;
+		while (nd != null) {
+			if (nd.pageNum == pageNum) {
+				if (nd.next != null) {
+					nd.prev.next = nd.next;
+					nd.next.prev = nd.prev;
+					nd.prev = null;
+					nd.next = first;
+					first = nd;
+				} else {
+					if (last != null) {
+						last = nd.prev;
+					} 
+					nd.prev.next = null;
+
+					nd.prev = null;
+					nd.next = first;
+					first.prev=nd;
+					first = nd;
+				}
+
+				return true;
+			}
+			nd = nd.next;
+		}	
+		return false;
+	}
+
+	// 判断链表是否填充满了并设置last
+	private void judgeFull() {
+		int count = 0;
+		Node node = first;
+		while (node != null) {
+			count++;
+			if (count == this.capacity) {
+				last = node;
+				return;
+			}
+			node = node.next;
+		}
+
+		if (count >= this.capacity) {
+
+		}
+	}
+
+	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();
+	}
+
+}

group16/313001956/src/com/coding/basic/linklist/LRUPageFrameTest.java

@@ -0,0 +1,35 @@
+package com.coding.basic.linklist;
+
+import  org.junit.Assert;
+
+import org.junit.Test;
+
+
+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());
+		frame.access(0);
+		Assert.assertEquals("0,4,3", frame.toString());
+		frame.access(3);
+		Assert.assertEquals("3,0,4", frame.toString());
+	}
+
+}