小练习一则

JBoss Seam 1.2.1GA的发行包的src里，有一些文件中有莫名其妙的0xA0字符，本来想用shell搞定的，结果搞了半天也没有用sed弄出完整的解决方案，最后只好用Java语言写了，顺带着也练练groovy和ruby.

最初的Java代码是这样的：

java 代码

import java.io.*;

public class Wash {
    public static void main(String[] args) {
        File root = new File("c:/ProgramFiles/jboss-seam-1.2.1.GA/src");
        wash(new File("c:/temp/seamsrc"));
    }

    private static void washFile(File file) throws IOException {
        String path = file.getAbsolutePath();
        System.out.println("Washing file: " + path);
        File temp = new File(path + ".bak");
        temp.createNewFile();
        FileInputStream in = new FileInputStream(file);
        FileOutputStream out = new FileOutputStream(temp);
        byte bbyte;
        boolean modified = false;
        while ((bbyte = (byte) in.read()) != -1) {
            if (bbyte != (byte) 0xa0) {
                out.write(bbyte);
            } else {
                modified = true;
            }
        }
        in.close();
        out.close();
        if (modified) {
            file.delete();
            temp.renameTo(new File(path));
        } else {
            temp.delete();
        }
    }

    private static void washDir(File dir) throws IOException {
        for (File file : dir.listFiles()) {
            if (file.isDirectory()) {
                washDir(file);
            } else {
                washFile(file);
            }
        }
    }
}

想了想washFile和washDir可以合并，于是refactor了一下，成为这样

java 代码

import java.io.*;

public class Wash {
    public static void main(String[] args) {
        wash(new File("c:/ProgramFiles/jboss-seam-1.2.1.GA/src"));
    }

    private static void wash(File file) {
        if (file.isFile()) {
            String path = file.getAbsolutePath();
            System.out.print("Washing file: " + path+" ...");
            File temp = new File(path + ".bak");
            FileInputStream in = null;
            FileOutputStream out = null;
            boolean modified = false;

            try {
                temp.createNewFile();
                in = new FileInputStream(file);
                out = new FileOutputStream(temp);
                byte bbyte;
                while ((bbyte = (byte) in.read()) != -1) {
                    if (bbyte != (byte) 0xa0) {
                        out.write(bbyte);
                    } else {
                        modified = true;
                    }
                }
            } catch (IOException e) {
                e.printStackTrace();
                System.exit(-1);
            } finally {
                try {
                    assert (in != null && out != null);
                    in.close();
                    out.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (modified) {
                file.delete();
                temp.renameTo(new File(path));
                System.out.println("File "+file.getAbsolutePath()+" washed.");
            } else {
                System.out.println("Not modified, removing temp file "+temp.getAbsolutePath());
                temp.delete();
            }
        } else {
            for (File child : file.listFiles()) {
                wash(child);
            }
        }
    }

}

下面是groovy的版本 ：

java 代码

wash = { dir ->
    dir.eachFile { child ->
        if(child.isFile()){
            path = child.absolutePath
            print "washing file "+path+"..."
            temp = new File(path+".bak")
            modified = false;
            temp.withOutputStream { outputStream ->
                child.eachByte{ bbyte ->
                    if(bbyte != (byte)0xa0){
                        outputStream.write(bbyte)
                    } else {
                      modified = true
                    }
                }
            }
           if(modified){
               child.delete()
               temp.renameTo(new File(path))
               println("File "+path +" washed.")
           } else {
               println("Not modified, removing temp file "+temp.absolutePath)
               temp.delete()
           }
        } else {
            println("washing subdirectory..."+child.absolutePath)
            wash(child)
        }
    }
}

wash(new File("c:/temp/seamsrc"))

groovy跟java还是亲啊，有了java版本，groovy版本很快就出来了。代码量确实有缩减，还了解到groovy的closure的作用域与def的使用有些关联。其实在这段代码中外层的wash closure跟method的定义已经没啥区别了。

在做ruby时，发现ruby的文件操作API极度混乱，在javaeye ruby版本发了点牢骚，还跟人论战了一把，后来我的想法得到了松底迪的支持，挺高兴，于是就有了fileex的实现。使用fileex后的ruby实现代码如下：

ruby 代码

require "fileex"

def wash(dir)
    dir.each{ |child|
        if child.directory?
            wash(child)
        else
            path = child.path
            puts "washing file #{path}..."
            temp = File.new("#{path}.bak").create.open("w+")
            modified = false
            child.open.each_byte{ |byte|
                temp.putc(byte)
                if byte!=0xA0
                    temp.putc(byte)
                else
                    modified = true
                end
            }
            child.close
            temp.close
            if modified
                puts "File #{path} washed."
                child.delete
                temp.rename(path)
            else
                temp.delete
            end
        end
    }
end

wash("c:/temp/seamsrc".to_file)

这下终于爽了。