完成常量池解析

group02/812350401/pom.xml

@@ -44,7 +44,12 @@
             <artifactId>commons-io</artifactId>
             <version>2.5</version>
         </dependency>
-
+        <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>3.4</version>
+        </dependency>
     </dependencies>
 
 

group02/812350401/src/main/java/com/github/miniyk2012/coding2017/coderising/jvm/clz/ClassFile.java

@@ -48,9 +48,7 @@ public void setConstPool(ConstantPool pool) {
 	public void setClassIndex(ClassIndex clzIndex) {
 		this.clzIndex = clzIndex;		
 	}
-
-
-
+
 
 	public void print(){
 
@@ -60,8 +58,7 @@ public void print(){
 		System.out.println("Class Name:"+ getClassName());
 
 		System.out.println("Super Class Name:"+ getSuperClassName());
-
-
+
 	}
 
 	private String getClassName(){

group02/812350401/src/main/java/com/github/miniyk2012/coding2017/coderising/jvm/constant/ConstantPool.java

@@ -1,16 +1,18 @@
 package com.github.miniyk2012.coding2017.coderising.jvm.constant;
 
+import com.github.miniyk2012.coding2017.coderising.jvm.loader.ByteCodeIterator;
+
 import java.util.ArrayList;
 import java.util.List;
 
 public class ConstantPool {
 
 	private List<ConstantInfo> constantInfos = new ArrayList<ConstantInfo>();
-
-
+
 	public ConstantPool(){
 
 	}
+
 	public void addConstantInfo(ConstantInfo info){
 
 		this.constantInfos.add(info);

group02/812350401/src/main/java/com/github/miniyk2012/coding2017/coderising/jvm/constant/FieldRefInfo.java

@@ -33,12 +33,11 @@ public String toString(){
 	}
 
 	public String getClassName(){
-
 		ClassInfo classInfo = (ClassInfo) this.getConstantInfo(this.getClassInfoIndex());
 
-		UTF8Info utf8Info = (UTF8Info)this.getConstantInfo(classInfo.getUtf8Index());
-
-		return utf8Info.getValue();
+		// UTF8Info utf8Info = (UTF8Info)this.getConstantInfo(classInfo.getUtf8Index());
+		// return utf8Info.getValue();
+		return classInfo.getClassName();
 
 	}
 

group02/812350401/src/main/java/com/github/miniyk2012/coding2017/coderising/jvm/constant/MethodRefInfo.java

@@ -29,27 +29,28 @@ public void setNameAndTypeIndex(int nameAndTypeIndex) {
 	}
 
 	public String toString(){
-
 		return getClassName() +" : "+ this.getMethodName() + " : " + this.getParamAndReturnType() ;
 	}
+
 	public String getClassName(){
-		ConstantPool pool = this.getConstantPool();		
-		ClassInfo clzInfo = (ClassInfo)pool.getConstantInfo(this.getClassInfoIndex());
+		// ConstantPool pool = this.getConstantPool();
+		// ClassInfo clzInfo = (ClassInfo)pool.getConstantInfo(this.getClassInfoIndex());
+        ClassInfo  clzInfo = (ClassInfo)this.getConstantInfo(classInfoIndex);
 		return clzInfo.getClassName();
 	}
 
 	public String getMethodName(){
-		ConstantPool pool = this.getConstantPool();
-		NameAndTypeInfo  typeInfo = (NameAndTypeInfo)pool.getConstantInfo(this.getNameAndTypeIndex());
+		// ConstantPool pool = this.getConstantPool();
+		// NameAndTypeInfo  typeInfo = (NameAndTypeInfo)pool.getConstantInfo(this.getNameAndTypeIndex());
+        NameAndTypeInfo typeInfo = (NameAndTypeInfo)this.getConstantInfo(nameAndTypeIndex);
 		return typeInfo.getName();
 	}
 
 	public String getParamAndReturnType(){
-		ConstantPool pool = this.getConstantPool();
-		NameAndTypeInfo  typeInfo = (NameAndTypeInfo)pool.getConstantInfo(this.getNameAndTypeIndex());
+		// ConstantPool pool = this.getConstantPool();
+		// NameAndTypeInfo  typeInfo = (NameAndTypeInfo)pool.getConstantInfo(this.getNameAndTypeIndex());
+        NameAndTypeInfo typeInfo = (NameAndTypeInfo)this.getConstantInfo(nameAndTypeIndex);
 		return typeInfo.getTypeInfo();
 	}
 
-
-
 }

group02/812350401/src/main/java/com/github/miniyk2012/coding2017/coderising/jvm/constant/NameAndTypeInfo.java

@@ -28,14 +28,16 @@ public int getType() {
 
 
 	public String getName(){
-		ConstantPool pool = this.getConstantPool();
-		UTF8Info utf8Info1 = (UTF8Info)pool.getConstantInfo(index1);
+		// ConstantPool pool = this.getConstantPool();
+		// UTF8Info utf8Info1 = (UTF8Info)pool.getConstantInfo(index1);
+		UTF8Info utf8Info1 = (UTF8Info)getConstantInfo(index1);
 		return utf8Info1.getValue();
 	}
 
 	public String getTypeInfo(){
-		ConstantPool pool = this.getConstantPool();
-		UTF8Info utf8Info2 = (UTF8Info)pool.getConstantInfo(index2);
+		// ConstantPool pool = this.getConstantPool();
+		// UTF8Info utf8Info2 = (UTF8Info)pool.getConstantInfo(index2);
+		UTF8Info utf8Info2 = (UTF8Info)getConstantInfo(index2);
 		return utf8Info2.getValue();
 	}
 

group02/812350401/src/main/java/com/github/miniyk2012/coding2017/coderising/jvm/constant/UTF8Info.java

@@ -26,7 +26,5 @@ public String getValue() {
 	public void setValue(String value) {
 		this.value = value;
 	}
-
-
 
 }

group02/812350401/src/main/java/com/github/miniyk2012/coding2017/coderising/jvm/loader/ByteCodeIterator.java

@@ -1,5 +1,79 @@
 package com.github.miniyk2012.coding2017.coderising.jvm.loader;
 
+import com.github.miniyk2012.coding2017.coderising.jvm.util.Util;
+import org.apache.commons.lang3.ArrayUtils;
+
+import java.io.UnsupportedEncodingException;
+import java.util.Arrays;
+
 public class ByteCodeIterator {
+    private byte[] codes;
+    private int point = 0;
+
+    public ByteCodeIterator(byte[] codes) {
+        this.codes = codes;
+    }
+
+    public int nextU1toInt() {
+        byte[] u1 = new byte[] {codes[point++]};
+        return Util.byteToInt(u1);
+    }
+
+    public int nextU2toInt() {
+        byte[] u2 = new byte[] {codes[point++], codes[point++]};
+        return Util.byteToInt(u2);
+    }
+
+    /**
+     * 读取n个字节，并编码成UTF-8输出，point自动增加
+     * @param n
+     * @return
+     */
+    public String readUtf8(int n)
+    {
+        byte[] info = Arrays.copyOfRange(codes, point, point+n);
+        String utf8;
+        try {
+            utf8 = new String(info, "UTF-8");
+        } catch (UnsupportedEncodingException e) {
+            throw new RuntimeException("常量池UTF-8编码错误");
+        }
+        point += n;
+        return utf8;
+    }
+
+    /**
+     * 返回当前位置
+     * @return
+     */
+    public int position() {
+        return point;
+    }
+
+    /**
+     * n可正可负
+     * @param n
+     */
+    public void skip(int n) {
+        point = point + n;
+    }
+
+    public void seek(int n) {
+        if (n >= codes.length || n < 0) throw new IndexOutOfBoundsException();
+        point = n;
+    }
+
+    public static void main(String[] args) throws UnsupportedEncodingException {
+        byte[] codes = {0x00, 0x34, 0x00};
+        ByteCodeIterator byteCodeIterator = new ByteCodeIterator(codes);
+        System.out.println(byteCodeIterator.nextU2toInt());
+        System.out.println(byteCodeIterator.nextU1toInt());
 
+        byte[] codes2 = "Employee".getBytes("UTF-8");
+        byte[] codes3 = ArrayUtils.addAll(codes2, codes);
+        byteCodeIterator = new ByteCodeIterator(codes3);
+        System.out.println(byteCodeIterator.readUtf8(codes2.length));
+        System.out.println(byteCodeIterator.nextU2toInt());
+        System.out.println(byteCodeIterator.nextU1toInt());
+    }
 }

group02/812350401/src/main/java/com/github/miniyk2012/coding2017/coderising/jvm/loader/ClassFileParser.java

@@ -3,36 +3,110 @@
 import com.github.miniyk2012.coding2017.coderising.jvm.clz.AccessFlag;
 import com.github.miniyk2012.coding2017.coderising.jvm.clz.ClassFile;
 import com.github.miniyk2012.coding2017.coderising.jvm.clz.ClassIndex;
-import com.github.miniyk2012.coding2017.coderising.jvm.constant.ConstantPool;
-
-import java.io.UnsupportedEncodingException;
+import com.github.miniyk2012.coding2017.coderising.jvm.constant.*;
 
 
 public class ClassFileParser {
 
 	public ClassFile parse(byte[] codes) {
 
-
-
+		ClassFile clzFile = new ClassFile();
+        ByteCodeIterator byteCodeIterator = new ByteCodeIterator(codes);
+        byteCodeIterator.skip(4);  // skip magic
+        int minorVersion = byteCodeIterator.nextU2toInt();
+        int majorVersion = byteCodeIterator.nextU2toInt();
+        ConstantPool constantPool = parseConstantPool(byteCodeIterator);
+        AccessFlag accessFlag = parseAccessFlag(byteCodeIterator);
+        ClassIndex classIndex = parseClassInfex(byteCodeIterator);
 
-		return null;
+        clzFile.setMinorVersion(minorVersion);
+        clzFile.setMajorVersion(majorVersion);
+        clzFile.setConstPool(constantPool);
+        clzFile.setAccessFlag(accessFlag);
+        clzFile.setClassIndex(classIndex);
+        return clzFile;
 	}
 
-	private AccessFlag parseAccessFlag(ByteCodeIterator iter) {
-
-		return null;
+	protected AccessFlag parseAccessFlag(ByteCodeIterator iter) {
+	    int access_flags = iter.nextU2toInt();
+        AccessFlag accessFlag = new AccessFlag(access_flags);
+		return accessFlag;
 	}
 
-	private ClassIndex parseClassInfex(ByteCodeIterator iter) {
-
-		return null;
-
+	protected ClassIndex parseClassInfex(ByteCodeIterator iter) {
+        ClassIndex classIndex = new ClassIndex();
+        int thisClassIndex = iter.nextU2toInt();
+        int superClassIndex = iter.nextU2toInt();
+        classIndex.setThisClassIndex(thisClassIndex);
+        classIndex.setSuperClassIndex(superClassIndex);
+		return classIndex;
 	}
 
-	private ConstantPool parseConstantPool(ByteCodeIterator iter) {
-
-		return null;
+	protected ConstantPool parseConstantPool(ByteCodeIterator iter) {
+        ConstantPool constantPool = new ConstantPool();
+        int constant_pool_count = iter.nextU2toInt();
+        ConstantInfo constantInfo;
+        constantPool.addConstantInfo(new NullConstantInfo());
+        for (int i=1; i<constant_pool_count; i++) {
+            int tag = iter.nextU1toInt();
+            constantInfo = getConstantInfo(iter, tag, constantPool);
+            constantPool.addConstantInfo(constantInfo);
+        }
+        return constantPool;
 	}
 
-
+    protected ConstantInfo getConstantInfo(ByteCodeIterator iter, int tag, ConstantPool pool) {
+	    switch (tag) {
+            case ConstantInfo.UTF8_INFO: {
+                UTF8Info utf8Info = new UTF8Info(pool);
+                int length = iter.nextU2toInt();
+                String value = iter.readUtf8(length);
+                utf8Info.setLength(length);
+                utf8Info.setValue(value);
+                return utf8Info;
+            }
+            case ConstantInfo.FLOAT_INFO: {
+                throw new RuntimeException(String.format("FLOAT_INFO常量池类型[%d]还未实现", tag));
+            }
+            case ConstantInfo.CLASS_INFO: {
+                ClassInfo classInfo = new ClassInfo(pool);
+                int utf8Index = iter.nextU2toInt();
+                classInfo.setUtf8Index(utf8Index);
+                return classInfo;
+            }
+            case ConstantInfo.FIELD_INFO: {
+                FieldRefInfo fieldRefInfo = new FieldRefInfo(pool);
+                int classInfoIndex = iter.nextU2toInt();
+                fieldRefInfo.setClassInfoIndex(classInfoIndex);
+                int nameAndTypeIndex = iter.nextU2toInt();
+                fieldRefInfo.setNameAndTypeIndex(nameAndTypeIndex);
+                return fieldRefInfo;
+            }
+            case ConstantInfo.METHOD_INFO: {
+                MethodRefInfo methodRefInfo = new MethodRefInfo(pool);
+                int classInfoIndex = iter.nextU2toInt();
+                int nameAndTypeIndex = iter.nextU2toInt();
+                methodRefInfo.setClassInfoIndex(classInfoIndex);
+                methodRefInfo.setNameAndTypeIndex(nameAndTypeIndex);
+                return methodRefInfo;
+            }
+            case ConstantInfo.NAME_AND_TYPE_INFO: {
+                NameAndTypeInfo nameAndTypeInfo = new NameAndTypeInfo(pool);
+                int index1 = iter.nextU2toInt();
+                int index2 = iter.nextU2toInt();
+                nameAndTypeInfo.setIndex1(index1);
+                nameAndTypeInfo.setIndex2(index2);
+                return nameAndTypeInfo;
+            }
+            case ConstantInfo.STRING_INFO: {
+                StringInfo stringInfo = new StringInfo(pool);
+                int index = iter.nextU2toInt();
+                stringInfo.setIndex(index);
+                return stringInfo;
+            }
+            default: {
+                throw new RuntimeException(String.format("该常量池类型[%d]还未实现", tag));
+            }
+        }
+    }
 }

group02/812350401/src/main/java/com/github/miniyk2012/coding2017/coderising/jvm/test/ClassFileloaderTest.java

@@ -18,6 +18,16 @@ public class ClassFileloaderTest {
 	static String path2 = ClassFileloaderTest.class.getClassLoader().getResource("jvm").getPath();
     static ClassFile clzFile = null;
 
+    static {
+        ClassFileLoader loader = new ClassFileLoader();
+        loader.addClassPath(path1);
+        loader.addClassPath(path2);
+        String className = "com.github.miniyk2012.coding2017.jvm.test.EmployeeV1";
+
+        clzFile = loader.loadClass(className);
+        clzFile.print();
+    }
+
 	@Before
 	public void setUp() throws Exception {		 
 	}
@@ -51,7 +61,7 @@ public void testClassFileLength() {
 		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(1114, byteCodes.length);
+		Assert.assertEquals(1056, byteCodes.length);
 
 	}