diff --git a/group01/1298552064/src/week04/lru/LRUPageFrame.java b/group01/1298552064/src/week04/lru/LRUPageFrame.java new file mode 100644 index 0000000000..b00ff2c116 --- /dev/null +++ b/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(); + } +} diff --git a/group01/1298552064/src/week04/minijvm/loader/ClassFileLoader.java b/group01/1298552064/src/week04/minijvm/loader/ClassFileLoader.java new file mode 100644 index 0000000000..2e80e89587 --- /dev/null +++ b/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 clzPaths = new ArrayList(); + + 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(); + } +} diff --git a/group01/1298552064/src/week04/test/ClassFileloaderTest.java b/group01/1298552064/src/week04/test/ClassFileloaderTest.java new file mode 100644 index 0000000000..18b42f859d --- /dev/null +++ b/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(); + } +} diff --git a/group01/1298552064/src/week04/test/EmployeeV1.java b/group01/1298552064/src/week04/test/EmployeeV1.java new file mode 100644 index 0000000000..1c292f7744 --- /dev/null +++ b/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(); + + } +} diff --git a/group01/1298552064/src/week04/test/LRUPageFrameTest.java b/group01/1298552064/src/week04/test/LRUPageFrameTest.java new file mode 100644 index 0000000000..6fbf3ddef9 --- /dev/null +++ b/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()); + } +}