ClassFileLoaderTest.java

package com.coderising.jvm.test;

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

import com.coderising.jvm.clasfile.ClassFile;
import com.coderising.jvm.clasfile.ClassIndex;
import com.coderising.jvm.constant.ClassInfo;
import com.coderising.jvm.constant.ConstantPool;
import com.coderising.jvm.constant.FieldRefInfo;
import com.coderising.jvm.constant.MethodInfo;
import com.coderising.jvm.constant.NameAndTypeInfo;
import com.coderising.jvm.constant.Utf8Info;
import com.coderising.jvm.loader.ClassFileLoader;

public class ClassFileLoaderTest {

	private static String path1 = "D:\\MyTest\\mini-jvm\\bin";
	private static String path2 = "C:\\temp";
	private final static String FULL_QUALIFIED_CLASS_NAME = "com/coderising/jvm/test/EmployeeV1";
	private static ClassFile clzFile = null;
	static{
		ClassFileLoader loader = new ClassFileLoader();
		loader.addClassPath(path1);
		String className = "com.coderising.jvm.test.EmployeeV1";
		
		clzFile = loader.loadClass(className);
		
	}
	
	@Before
	public void setUp() throws Exception {
	}

	@Test
	public void test() {
		ClassFileLoader loader = new ClassFileLoader();
		loader.addClassPath(path1);
		loader.addClassPath(path2);

		String clzPath = loader.getClassPath();

		Assert.assertEquals(path1 + ";" + path2, clzPath);
	}
	
	@Test
	public void ClassFileLengthTest(){
		ClassFileLoader loader = new ClassFileLoader();
		loader.addClassPath(path1);

		String className = "com.coderising.jvm.test.EmployeeV1";
		byte[] bytes = loader.readBinaryCode(className);

		Assert.assertEquals(1056, bytes.length);
	}

	@Test
	public void MagicNumberTest(){

		ClassFileLoader loader = new ClassFileLoader();
		loader.addClassPath(path1);

		String className = "com.coderising.jvm.test.EmployeeV1";
		byte[] byteCodes = loader.readBinaryCode(className);

		byte[] bytes = { byteCodes[0], byteCodes[1], byteCodes[2], byteCodes[3] };
		String actualString = byteToHexString(bytes);
		Assert.assertEquals("cafebabe", actualString);
	}

	private String byteToHexString(byte[] bytes) {

		StringBuffer buffer = new StringBuffer();
		for (int i = 0; i < bytes.length; i++) {
			byte b = bytes[i];
			int value = b & 0xFF;
			String strHex = Integer.toHexString(value);
			if (strHex.length() < 2) {
				strHex = "0" + strHex;
			}
			buffer.append(strHex);
		}
		return buffer.toString();
	}
	
	@Test
	public void testVersion(){
		
		Assert.assertEquals(0, clzFile.getMinorVersion());
		Assert.assertEquals(51, clzFile.getMajorVersion());
	}
	
	@Test
	public void testConstant��ool(){
		
		ConstantPool pool = clzFile.getConstantPool();
		
		Assert.assertEquals(53, pool.getConstantNumber());
		
		{
			ClassInfo clzInfo = (ClassInfo)pool.getConstantInfo(1);
			Assert.assertEquals(2, clzInfo.getUtf8Index());
			
			Utf8Info utf8Info = (Utf8Info)pool.getConstantInfo(2);
			Assert.assertEquals(FULL_QUALIFIED_CLASS_NAME, utf8Info.getValue());
		}
		
		{
			ClassInfo clzInfo = (ClassInfo)pool.getConstantInfo(3);
			Assert.assertEquals(4, clzInfo.getUtf8Index());
			
			Utf8Info utf8Info = (Utf8Info)pool.getConstantInfo(4);
			Assert.assertEquals("java/lang/Object", utf8Info.getValue());
		}
		
		{
			Utf8Info utf8Info = (Utf8Info)pool.getConstantInfo(5);
			Assert.assertEquals("name", utf8Info.getValue());
			
			utf8Info = (Utf8Info) pool.getConstantInfo(6);
			Assert.assertEquals("Ljava/lang/String;", utf8Info.getValue());
			
			utf8Info = (Utf8Info) pool.getConstantInfo(7);
			Assert.assertEquals("age", utf8Info.getValue());
			
			utf8Info = (Utf8Info) pool.getConstantInfo(8);
			Assert.assertEquals("I", utf8Info.getValue());
			
			utf8Info = (Utf8Info) pool.getConstantInfo(9);
			Assert.assertEquals("<init>", utf8Info.getValue());
			
			utf8Info = (Utf8Info) pool.getConstantInfo(10);
			Assert.assertEquals("(Ljava/lang/String;I)V", utf8Info.getValue());
			
			utf8Info = (Utf8Info) pool.getConstantInfo(11);
			Assert.assertEquals("Code", utf8Info.getValue());
		}
		
		{
			MethodInfo methodRef = (MethodInfo)pool.getConstantInfo(12);
			Assert.assertEquals(3, methodRef.getIndex_ClassInfo());
			Assert.assertEquals(13, methodRef.getIndex_NameAndType());
		}
		
		{
			NameAndTypeInfo nameAndTypeInfo = (NameAndTypeInfo) pool.getConstantInfo(13);
			Assert.assertEquals(9, nameAndTypeInfo.getIndex_Name());
			Assert.assertEquals(14, nameAndTypeInfo.getIndex_Describe());
		}
		
		{
			MethodInfo methodRef = (MethodInfo)pool.getConstantInfo(45);
			Assert.assertEquals(1, methodRef.getIndex_ClassInfo());
			Assert.assertEquals(46, methodRef.getIndex_NameAndType());
		}
		
		{
			Utf8Info utf8Info = (Utf8Info) pool.getConstantInfo(53);
			Assert.assertEquals("EmployeeV1.java", utf8Info.getValue());
		}
		
		{
			FieldRefInfo fieldRefInfo = (FieldRefInfo) pool.getConstantInfo(28);
			Assert.assertEquals(29, fieldRefInfo.getIndex_ClassInfo());
			Assert.assertEquals(31, fieldRefInfo.getIndex_NameAndType());
			
		}
		
	}

	
	@Test
    public void testClassIndex(){
    	
    	ClassIndex clzIndex = clzFile.getClassIndex();
    	ClassInfo thisClassInfo = (ClassInfo)clzFile.getConstantPool().getConstantInfo(clzIndex.getThisClassIndex());
    	ClassInfo superClassInfo = (ClassInfo)clzFile.getConstantPool().getConstantInfo(clzIndex.getSuperClassIndex());
    	
    	
    	Assert.assertEquals(FULL_QUALIFIED_CLASS_NAME, thisClassInfo.getClassName());
    	Assert.assertEquals("java/lang/Object", superClassInfo.getClassName());
    }
    
	
	
	
	
	
	
	
	
	
	
	
	
}