如何在本地磁盘众多的文件中寻找某一个class?

Question

两种方法，一，搜索Driver可能会搜索到，如果没有则用第二种方法
二寻找 *.jar必定有一个jar中含有此类。

Answer 1

如果你确信再classpath的话,直接class.forname不行么
或者直接classloader

Answer 2

Driver类可能在一个JAR文件里面
也可能在一个目录里面
如果在JAR里面，那么只要JAR文件在CLASSPATH中，并且被打包的目录结构符合包结构，那么编译器可以找到这个类，否则不能
如果在目录里面，com所在的目录要在CLASSPATH里面，com后的子目录要符合包结构，这样编译器也可以找到这个Driver类

Answer 3

Driver类可能在一个JAR文件里面
也可能在一个目录里面
如果在JAR里面，那么只要JAR文件在CLASSPATH中，并且被打包的目录结构符合包结构，那么编译器可以找到这个类，否则不能
如果在目录里面，com所在的目录要在CLASSPATH里面，com后的子目录要符合包结构，这样编译器也可以找到这个Driver类

Answer 4

to study_body(珍惜每一天):
我就是这么做的,我搜索出来所有的*.jar,总不见得我一个一个看吧 -_-!to  copyright(笨蛋白痴神经质),xioyoo(丁鹏),JavaBoyCaoJi(老曹):
我正是想把它从目录堆里面找出来,然后才能加到classpath中去

Answer 5

to  gavin1976(嘉文):
我已经写好了~~ :)

Answer 6

package findclass;
import java.util.*;
import java.io.*;
/**
 * <p>在本地磁盘的jar文件中寻找自己所需要的class</p>
 * <p>用法，只需要提供本地磁盘路径和所需要的class的全称（包括package等信息）</p>
 * <p>例如 org.w3c.dom.Document</p>
 * <p>Copyright: Copyright (c)Sinocomm 2002</p>
 * @author Gameboy999
 * @version 1.0
 */
public class fclass {  public static int count = 0;
  public fclass() {
  }  private static void FindClassInLocalSystem(String path,String classname)
  {
    if(path.charAt(path.length()-1) != '\\')
      path += '\\';
    File file = new File(path);
    if(!file.exists())
    {
      System.out.println("--------------------------------------------------------");
      System.out.println("error: Path not Existed! Please Check it out!");
      System.out.println("--------------------------------------------------------");
      return;
    }
    String[] filelist = file.list();
    for(int i = 0;i< filelist.length;i++)
    {
      File temp = new File(path + filelist[i]);
      if((temp.isDirectory() && !temp.isHidden() && temp.exists()))
      {
        FindClassInLocalSystem(path + filelist[i],classname);
      }
      else
      {
        if(filelist[i].endsWith("jar"))
        {
          try
          {
            java.util.jar.JarFile jarfile = new java.util.jar.JarFile(path + filelist[i]);
            for (Enumeration e = jarfile.entries() ; e.hasMoreElements() ;)
            {
              String name =e.nextElement().toString();
              if(name.equals(classname))
              {
                System.out.println("--------------------------------------------------------");
                System.out.println("No." + ++fclass.count);
                System.out.println("jar package:" + path + filelist[i]);
                System.out.println(name);
                System.out.println("--------------------------------------------------------");
              }
            }
          }
          catch(Exception eee)
          {
          }
        }
      }
    }  }  static public void main(String[] args) {
    if(args.length <2)
    {
      System.out.println("Usage:");
      System.out.println("the first parameter:[path to find] eg.  C:\\  d:\\Jbuilder   Tip:only '\\' can be used here");
      System.out.println("the first parameter:[class to find] eg. org.w3c.dom.Document");
      return;
    }
      String absoluteclassname = args[1].replace('.','/') + ".class";      System.out.println("Find class [" + args[1] + "] in path ["+ args[0] + "] results:");
      FindClassInLocalSystem(args[0],absoluteclassname);
      if(fclass.count == 0)
      {
        System.out.println("--------------------------------------------------------");
        System.out.println("Sorry,No such Jar!");
        System.out.println("--------------------------------------------------------");
      }
      System.out.println("Find Process Ended! Total Results:" + fclass.count);
  }
}

Answer 7

我做了一个console程序,参数有两个,前面一个是目录,后面一个是要找的class全称,结果表现形式如下:(我已经编译成win32 console application)c:\>findclass.exe d:\Jbuilder7 org.w3c.dom.Document
Find class [org.w3c.dom.Document] in path [d:\Jbuilder7] results:--------------------------------------------------------No.1jar package:d:\Jbuilder7\cocoon\lib\xerces_1_2.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.2jar package:d:\Jbuilder7\extras\ant\lib\crimson.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.3jar package:d:\Jbuilder7\extras\castor\lib\xerces-J_1.4.0.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.4jar package:d:\Jbuilder7\extras\jakarta-tomcat-3.3.1-src\bin\crimson.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.5jar package:d:\Jbuilder7\extras\jakarta-tomcat-3.3.1-src\bin\xalan.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.6jar package:d:\Jbuilder7\extras\jdom\lib\xerces.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.7jar package:d:\Jbuilder7\extras\xalan\xerces.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.8jar package:d:\Jbuilder7\extras\xerces\xerces.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.9jar package:d:\Jbuilder7\extras\BorlandXML\example\b2b\lib\parser.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.10jar package:d:\Jbuilder7\extras\BorlandXML\lib\jaxp-patch.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.11jar package:d:\Jbuilder7\extras\BorlandXML\lib\xalan.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.12jar package:d:\Jbuilder7\extras\BorlandXML\lib\xerces.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.13jar package:d:\Jbuilder7\extras\BorlandXML\lib\xml4j.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.14jar package:d:\Jbuilder7\jakarta-tomcat-3.3.1\lib\container\crimson.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.15jar package:d:\Jbuilder7\jakarta-tomcat-3.3.1\lib\container\xalan.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.16jar package:d:\Jbuilder7\jakarta-tomcat-4.0.3\common\lib\xerces.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.17jar package:d:\Jbuilder7\lib\bes\xmlrt.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.18jar package:d:\Jbuilder7\lib\help.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.19jar package:d:\Jbuilder7\lib\xerces.jarorg/w3c/dom/Document.class----------------------------------------------------------------------------------------------------------------No.20jar package:d:\Jbuilder7\lib\xml4j.jarorg/w3c/dom/Document.class--------------------------------------------------------Find Process Ended! Total Results:20