Merge pull request #42 from Jiandan1357/master

5week

group23/601689050/.gitattributes

@@ -0,0 +1,17 @@
+# Auto detect text files and perform LF normalization
+* text=auto
+
+# Custom for Visual Studio
+*.cs     diff=csharp
+
+# Standard to msysgit
+*.doc	 diff=astextplain
+*.DOC	 diff=astextplain
+*.docx diff=astextplain
+*.DOCX diff=astextplain
+*.dot  diff=astextplain
+*.DOT  diff=astextplain
+*.pdf  diff=astextplain
+*.PDF	 diff=astextplain
+*.rtf	 diff=astextplain
+*.RTF	 diff=astextplain

group23/601689050/4weekLRU&JVM/JVM/loader/ClassFileLoader.java

@@ -0,0 +1,65 @@
+package loader;
+import org.apache.commons.io.IOUtils;
+import org.apache.commons.lang3.StringUtils;
+
+import java.io.*;
+import java.util.ArrayList;
+import java.util.List;
+/**
+ * Created by Lxx on 2017/4/23.
+ */
+public class ClassFileLoader {
+    private List<String> clzPaths = new ArrayList<String>();
+
+    public byte[] readBinaryCode(String className) {
+
+        className = className.replace('.', File.separatorChar) +".class";
+
+        for(String path : this.clzPaths){
+
+            String clzFileName = path + File.separatorChar + className;
+            byte[] codes = loadClassFile(clzFileName);
+            if(codes != null){
+                return codes;
+            }
+        }
+
+        return null;
+
+
+
+    }
+
+    private byte[] loadClassFile(String clzFileName) {
+
+        File f = new File(clzFileName);
+
+        try {
+
+            return IOUtils.toByteArray(new FileInputStream(f));
+
+        } catch (IOException e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+
+
+    public void addClassPath(String path) {
+        if(this.clzPaths.contains(path)){
+            return;
+        }
+
+        this.clzPaths.add(path);
+
+    }
+
+
+
+    public String getClassPath(){
+        return StringUtils.join(this.clzPaths,";");
+    }
+
+
+}

group23/601689050/4weekLRU&JVM/JVM/test/loader/ClassFileLoaderTest.java

@@ -0,0 +1,86 @@
+package test.loader;
+
+import loader.ClassFileLoader;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+public class ClassFileLoaderTest {
+    static String path1 = "D:\\JavaProject\\4week_minijvm\\out\\production\\4week_minijvm";
+    static String path2 = "D:\\temp";
+
+
+
+    @Before
+public void before() throws Exception { 
+} 
+
+@After
+public void after() throws Exception { 
+} 
+
+/** 
+* 
+* Method: readBinaryCode(String className) 
+* 
+*/
+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 = "test.loader.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 = "test.loader.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();
+    }
+
+} 

group23/601689050/4LRU&JVM/JVM/EmployeeV1.java → group23/601689050/4weekLRU&JVM/JVM/test/loader/EmployeeV1.java

@@ -1,4 +1,4 @@
-package com.test;
+package test.loader;
 
 public class EmployeeV1 {