大家一起读Java美文

作为一个程序员,我们的休息时间在哪里?当你感到疲惫的时候,不妨静下心来,看一看别人写的代码,或者优秀程序员的杰作,可以说是另一种好的放松方式.
       虽然Java没有文学那么优美,用文字来表达情感,但Java却用另一种方式,A-Z等字符诉说着另一种情感,让我们大家一起来读Java,来发现美.
       今天比较清闲,就在网上找了一下源码,想到ibatis,也用了很久,而今天再想起的时候,发现已不是曾经的她了,而变成了mybatis,先了解了一下之后,从SVN上把源代码检索下来,
http://mybatis.googlecode.com/svn/trunk/,从IO包看了一下,当看到这个类的时候,产生了这个想法,如何让你的代码写的漂亮,写的全面,功能强大,扩展性强?如何让别人喜欢上你的代码?
       以下代码,整体来说,只是提供了3个方法,但每一个方法却又分成3块,而这些都很类似,看上去,就像一个,对于编程3年的我来说,这样的代码,无非就是最漂亮的,没有多余的代码,每一行,每一块,都有真实的意义.如果说,还要继续优化的,我想还是可以找出问题,不过,有些心里晓得就行了,不必争论.
       请仔细看一下吧,也许你看完之后,会有另类感觉.但有人也许会认为很不值得一提,毕竟优秀的代码太多了,而我在这里只是想要表达,我们也可以把Java代码当作一种美文读,不要感觉乏味,枯燥.
       请大家一起读Java美文,让我们一起从这里寻找快乐.

package org.apache.ibatis.io; 

import java.io.InputStream; 
import java.net.URL; 

/** 
* A class to wrap access to multiple class loaders making them work as one 
*/ 
public class ClassLoaderWrapper { 

  ClassLoader defaultClassLoader; 

  ClassLoaderWrapper() { 
  } 

  /** 
   * Get a resource as a URL using the current class path 
   * 
   * @param resource - the resource to locate 
   * @return the resource or null 
   */ 
  public URL getResourceAsURL(String resource) { 
    return getResourceAsURL(resource, new ClassLoader[]{ 
        defaultClassLoader, 
        Thread.currentThread().getContextClassLoader(), 
        getClass().getClassLoader(), 
        ClassLoader.getSystemClassLoader() 
    }); 
  } 

  /** 
   * Get a resource from the classpath, starting with a specific class loader 
   * 
   * @param resource    - the resource to find 
   * @param classLoader - the first classloader to try 
   * @return the stream or null 
   */ 
  public URL getResourceAsURL(String resource, ClassLoader classLoader) { 
    return getResourceAsURL(resource, new ClassLoader[]{ 
        classLoader, 
        defaultClassLoader, 
        Thread.currentThread().getContextClassLoader(), 
        getClass().getClassLoader(), 
        ClassLoader.getSystemClassLoader() 
    }); 
  } 

  /** 
   * Get a resource from the classpath 
   * 
   * @param resource - the resource to find 
   * @return the stream or null 
   */ 
  public InputStream getResourceAsStream(String resource) { 
    return getResourceAsStream(resource, new ClassLoader[]{ 
        defaultClassLoader, 
        Thread.currentThread().getContextClassLoader(), 
        getClass().getClassLoader(), 
        ClassLoader.getSystemClassLoader() 
    }); 
  } 

  /** 
   * Get a resource from the classpath, starting with a specific class loader 
   * 
   * @param resource    - the resource to find 
   * @param classLoader - the first class loader to try 
   * @return the stream or null 
   */ 
  public InputStream getResourceAsStream(String resource, ClassLoader classLoader) { 
    return getResourceAsStream(resource, new ClassLoader[]{ 
        classLoader, 
        defaultClassLoader, 
        Thread.currentThread().getContextClassLoader(), 
        getClass().getClassLoader(), 
        ClassLoader.getSystemClassLoader() 
    }); 
  } 

  /** 
   * Find a class on the classpath (or die trying) 
   * 
   * @param name - the class to look for 
   * @return - the class 
   * @throws ClassNotFoundException Duh. 
   */ 
  public Class> classForName(String name) throws ClassNotFoundException { 
    return classForName(name, new ClassLoader[]{ 
        defaultClassLoader, 
        Thread.currentThread().getContextClassLoader(), 
        getClass().getClassLoader(), 
        ClassLoader.getSystemClassLoader() 
    }); 
  } 

  /** 
   * Find a class on the classpath, starting with a specific classloader (or die trying) 
   * 
   * @param name        - the class to look for 
   * @param classLoader - the first classloader to try 
   * @return - the class 
   * @throws ClassNotFoundException Duh. 
   */ 
  public Class> classForName(String name, ClassLoader classLoader) throws ClassNotFoundException { 
    return classForName(name, new ClassLoader[]{ 
        classLoader, 
        defaultClassLoader, 
        Thread.currentThread().getContextClassLoader(), 
        getClass().getClassLoader(), 
        ClassLoader.getSystemClassLoader() 
    }); 
  } 

  /** 
   * Try to get a resource from a group of classloaders 
   * 
   * @param resource    - the resource to get 
   * @param classLoader - the classloaders to examine 
   * @return the resource or null 
   */ 
  InputStream getResourceAsStream(String resource, ClassLoader[] classLoader) { 
    for (ClassLoader cl : classLoader) { 
      if (null != cl) { 

        // try to find the resource as passed 
        InputStream returnValue = cl.getResourceAsStream(resource); 

        // now, some class loaders want this leading "/", so we'll add it and try again if we didn't find the resource 
        if (null == returnValue) returnValue = cl.getResourceAsStream("/" + resource); 

        if (null != returnValue) return returnValue; 
      } 
    } 
    return null; 
  } 

  /** 
   * Get a resource as a URL using the current class path 
   * 
   * @param resource    - the resource to locate 
   * @param classLoader - the class loaders to examine 
   * @return the resource or null 
   */ 
  URL getResourceAsURL(String resource, ClassLoader[] classLoader) { 

    URL url; 

    for (ClassLoader cl : classLoader) { 

      if (null != cl) { 

        // look for the resource as passed in... 
        url = cl.getResource(resource); 

        // ...but some class loaders want this leading "/", so we'll add it 
        // and try again if we didn't find the resource 
        if (null == url) url = cl.getResource("/" + resource); 

        // "It's always in the last place I look for it!" 
        // ... because only an idiot would keep looking for it after finding it, so stop looking already. 
        if (null != url) return url; 

      } 

    } 

    // didn't find it anywhere. 
    return null; 

  } 

  /** 
   * Attempt to load a class from a group of classloaders 
   * 
   * @param name        - the class to load 
   * @param classLoader - the group of classloaders to examine 
   * @return the class 
   * @throws ClassNotFoundException - Remember the wisdom of Judge Smails: Well, the world needs ditch diggers, too. 
   */ 
  Class> classForName(String name, ClassLoader[] classLoader) throws ClassNotFoundException { 

    for (ClassLoader cl : classLoader) { 

      if (null != cl) { 

        try { 

          Class> c = Class.forName(name, true, cl); 

          if (null != c) return c; 

        } catch (ClassNotFoundException e) { 
          // we'll ignore this until all classloaders fail to locate the class 
        } 

      } 

    } 

    throw new ClassNotFoundException("Cannot find class: " + name); 

  } 

}