package com.coding.test;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import com.conding.jvm.loader.ClassFileLoader;
public class ClassFileloaderTest {
static String path1 = "D:\\workspace\\MyGithub\\coding2017\\group10\\904627477\\target\\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.coding.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(1040, byteCodes.length);
}
@Test
public void testMagicNumber(){
ClassFileLoader loader = new ClassFileLoader();
loader.addClassPath(path1);
String className = "com.coding.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();
}
}