在目錄中查找類位於哪個jar包中

做Java開發的人可能都遇到過面對一大堆的jar包但是自己不知道需要的那些個類到底位於哪個jar包中，使用下面的代碼，這個問題就可以迎刃而解了。
import java.io.File;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

public class FindInJar {
public String className;

public ArrayList jarFiles = new ArrayList();

public FindInJar() {
}

public FindInJar(String className) {
this.className = className;
}

public void setClassName(String className) {
this.className = className;
}

public List findClass(String dir, boolean recurse) {
searchDir(dir, recurse);
return this.jarFiles;
}

protected void searchDir(String dir, boolean recurse) {
try {
File d = new File(dir);
if (!d.isDirectory()) {
return;
}
File[] files = d.listFiles();
for (int i = 0; i < files.length; i++) {
if (recurse && files[i].isDirectory()) {
searchDir(files[i].getAbsolutePath(), true);
} else {
String filename = files[i].getAbsolutePath();
if (filename.endsWith(".jar")||filename.endsWith(".zip")) {
ZipFile zip = new ZipFile(filename);
Enumeration entries = zip.entries();
while (entries.hasMoreElements()) {
ZipEntry entry = (ZipEntry) entries.nextElement();
String thisClassName = getClassName(entry);
if (thisClassName.equals(this.className) || thisClassName.equals(this.className + ".class")) {
this.jarFiles.add(filename);
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}

public List getFilenames() {
return this.jarFiles;
}

protected String getClassName(ZipEntry entry) {
StringBuffer className = new StringBuffer(entry.getName().replace(’/', ‘.’));
return className.toString();
}

public static void main(String args[]) {
FindInJar findInJar = new FindInJar("javax.mail.Session");
List jarFiles = findInJar.findClass("d:/libs/", true);
if (jarFiles.size() == 0) {
System.out.println("Not Found");
} else {
for (int i = 0; i < jarFiles.size(); i++) {
System.out.println(jarFiles.get(i));
}
}
}
}

main方法中的findClass方法的第二個參數是是否對指定的目錄遞歸進行處理，一般都會要這樣做的吧。