chapter17.html

java 是一个很好的网络开发环境。由于它是通过解释的方法

  }
}

<font color=#0000ff>class</font> SourceCodeFile {
  <font color=#0000ff>public</font> <font color=#0000ff>static</font> <font color=#0000ff>final</font> String 
    startMarker = <font color=#004488>"</font><font color=#004488>/</font><font color=#004488>/:"</font>, <font color=#009900>// Start of source file</font>
    endMarker = <font color=#004488>"} </font><font color=#004488>/</font><font color=#004488>/</font><font color=#004488>/:~"</font>, <font color=#009900>// End of source</font>
    endMarker2 = <font color=#004488>"}; </font><font color=#004488>/</font><font color=#004488>/</font><font color=#004488>/:~"</font>, <font color=#009900>// C++ file end</font>
    beginContinue = <font color=#004488>"} </font><font color=#004488>/</font><font color=#004488>/</font><font color=#004488>/:Continued"</font>,
    endContinue = <font color=#004488>"</font><font color=#004488>/</font><font color=#004488>/</font><font color=#004488>/:Continuing"</font>,
    packMarker = <font color=#004488>"###"</font>, <font color=#009900>// Packed file header tag</font>
    eol = <font color=#009900>// Line separator on current system</font>
      System.getProperty(<font color=#004488>"line.separator"</font>),
    filesep = <font color=#009900>// System's file path separator</font>
      System.getProperty(<font color=#004488>"file.separator"</font>);
  <font color=#0000ff>public</font> <font color=#0000ff>static</font> String copyright = <font color=#004488>""</font>;
  <font color=#0000ff>static</font> {
    <font color=#0000ff>try</font> {
      BufferedReader cr =
        <font color=#0000ff>new</font> BufferedReader(
          <font color=#0000ff>new</font> FileReader(<font color=#004488>"Copyright.txt"</font>));
      String crin;
      <font color=#0000ff>while</font>((crin = cr.readLine()) != <font color=#0000ff>null</font>)
        copyright += crin + <font color=#004488>"\n"</font>;
      cr.close();
    } <font color=#0000ff>catch</font>(Exception e) {
      copyright = <font color=#004488>""</font>;
    }
  }
  <font color=#0000ff>private</font> String filename, dirname,
    contents = <font color=#0000ff>new</font> String();
  <font color=#0000ff>private</font> <font color=#0000ff>static</font> String chapter = <font color=#004488>"c02"</font>;
  <font color=#009900>// The file name separator from the old system:</font>
  <font color=#0000ff>public</font> <font color=#0000ff>static</font> String oldsep;
  <font color=#0000ff>public</font> String toString() {
    <font color=#0000ff>return</font> dirname + filesep + filename;
  }
  <font color=#009900>// Constructor for parsing from document file:</font>
  <font color=#0000ff>public</font> SourceCodeFile(String firstLine, 
      BufferedReader in) {
    dirname = chapter;
    <font color=#009900>// Skip past marker:</font>
    filename = firstLine.substring(
        startMarker.length()).trim();
    <font color=#009900>// Find space that terminates file name:</font>
    <font color=#0000ff>if</font>(filename.indexOf(' ') != -1)
      filename = filename.substring(
          0, filename.indexOf(' '));
    System.out.println(<font color=#004488>"found: "</font> + filename);
    contents = firstLine + eol;
    <font color=#0000ff>if</font>(copyright.length() != 0)
      contents += copyright + eol;
    String s;
    <font color=#0000ff>boolean</font> foundEndMarker = <font color=#0000ff>false</font>;
    <font color=#0000ff>try</font> {
      <font color=#0000ff>while</font>((s = in.readLine()) != <font color=#0000ff>null</font>) {
        <font color=#0000ff>if</font>(s.startsWith(startMarker))
          Pr.error(<font color=#004488>"No end of file marker for "</font> +
            filename);
        <font color=#009900>// For this program, no spaces before </font>
        <font color=#009900>// the "package" keyword are allowed</font>
        <font color=#009900>// in the input source code:</font>
        <font color=#0000ff>else</font> <font color=#0000ff>if</font>(s.startsWith(<font color=#004488>"package"</font>)) {
          <font color=#009900>// Extract package name:</font>
          String pdir = s.substring(
            s.indexOf(' ')).trim();
          pdir = pdir.substring(
            0, pdir.indexOf(';')).trim();
          <font color=#009900>// Capture the chapter from the package</font>
          <font color=#009900>// ignoring the 'com' subdirectories:</font>
          <font color=#0000ff>if</font>(!pdir.startsWith(<font color=#004488>"com"</font>)) {
            <font color=#0000ff>int</font> firstDot = pdir.indexOf('.');
            <font color=#0000ff>if</font>(firstDot != -1)
              chapter = 
                pdir.substring(0,firstDot);
            <font color=#0000ff>else</font>
              chapter = pdir;
          }
          <font color=#009900>// Convert package name to path name:</font>
          pdir = pdir.replace(
            '.', filesep.charAt(0));
          System.out.println(<font color=#004488>"package "</font> + pdir);
          dirname = pdir;
        }
        contents += s + eol;
        <font color=#009900>// Move past continuations:</font>
        <font color=#0000ff>if</font>(s.startsWith(beginContinue))
          <font color=#0000ff>while</font>((s = in.readLine()) != <font color=#0000ff>null</font>)
            <font color=#0000ff>if</font>(s.startsWith(endContinue)) {
              contents += s + eol;
              <font color=#0000ff>break</font>;
            }
        <font color=#009900>// Watch for end of code listing:</font>
        <font color=#0000ff>if</font>(s.startsWith(endMarker) ||
           s.startsWith(endMarker2)) {
          foundEndMarker = <font color=#0000ff>true</font>;
          <font color=#0000ff>break</font>;
        }
      }
      <font color=#0000ff>if</font>(!foundEndMarker)
        Pr.error(
          <font color=#004488>"End marker not found before EOF"</font>);
      System.out.println(<font color=#004488>"Chapter: "</font> + chapter);
    } <font color=#0000ff>catch</font>(IOException e) {
      Pr.error(<font color=#004488>"Error reading line"</font>);
    }
  }
  <font color=#009900>// For recovering from a packed file:</font>
  <font color=#0000ff>public</font> SourceCodeFile(BufferedReader pFile) {
    <font color=#0000ff>try</font> {
      String s = pFile.readLine();
      <font color=#0000ff>if</font>(s == <font color=#0000ff>null</font>) <font color=#0000ff>return</font>;
      <font color=#0000ff>if</font>(!s.startsWith(packMarker))
        Pr.error(<font color=#004488>"Can't find "</font> + packMarker
          + <font color=#004488>" in "</font> + s);
      s = s.substring(
        packMarker.length()).trim();
      dirname = s.substring(0, s.indexOf('#'));
      filename = s.substring(s.indexOf('#') + 1);
      dirname = dirname.replace(
        oldsep.charAt(0), filesep.charAt(0));
      filename = filename.replace(
        oldsep.charAt(0), filesep.charAt(0));
      System.out.println(<font color=#004488>"listing: "</font> + dirname 
        + filesep + filename);
      <font color=#0000ff>while</font>((s = pFile.readLine()) != <font color=#0000ff>null</font>) {
        <font color=#009900>// Watch for end of code listing:</font>
        <font color=#0000ff>if</font>(s.startsWith(endMarker) ||
           s.startsWith(endMarker2)) {
          contents += s;
          <font color=#0000ff>break</font>;
        }
        contents += s + eol;
      }
    } <font color=#0000ff>catch</font>(IOException e) {
      System.err.println(<font color=#004488>"Error reading line"</font>);
    }
  }
  <font color=#0000ff>public</font> <font color=#0000ff>boolean</font> hasFile() { 
    <font color=#0000ff>return</font> filename != <font color=#0000ff>null</font>; 
  }
  <font color=#0000ff>public</font> String directory() { <font color=#0000ff>return</font> dirname; }
  <font color=#0000ff>public</font> String filename() { <font color=#0000ff>return</font> filename; }
  <font color=#0000ff>public</font> String contents() { <font color=#0000ff>return</font> contents; }
  <font color=#009900>// To write to a packed file:</font>
  <font color=#0000ff>public</font> <font color=#0000ff>void</font> writePacked(DataOutputStream out) {
    <font color=#0000ff>try</font> {
      out.writeBytes(
        packMarker + dirname + <font color=#004488>"#"</font> 
        + filename + eol);
      out.writeBytes(contents);
    } <font color=#0000ff>catch</font>(IOException e) {
      Pr.error(<font color=#004488>"writing "</font> + dirname + 
        filesep + filename);
    }
  }
  <font color=#009900>// To generate the actual file:</font>
  <font color=#0000ff>public</font> <font color=#0000ff>void</font> writeFile(String rootpath) {
    File path = <font color=#0000ff>new</font> File(rootpath, dirname);
    path.mkdirs();
    PrintWriter p =
      IO.psOpen(<font color=#0000ff>new</font> File(path, filename));
    p.print(contents);
    IO.close(p);
  }
}

<font color=#0000ff>class</font> DirMap {
  <font color=#0000ff>private</font> Hashtable t = <font color=#0000ff>new</font> Hashtable();
  <font color=#0000ff>private</font> String rootpath;
  DirMap() {
    rootpath = System.getProperty(<font color=#004488>"user.dir"</font>);
  }
  DirMap(String alternateDir) {
    rootpath = alternateDir;
  }
  <font color=#0000ff>public</font> <font color=#0000ff>void</font> add(SourceCodeFile f){
    String path = f.directory();
    <font color=#0000ff>if</font>(!t.containsKey(path))
      t.put(path, <font color=#0000ff>new</font> Vector());
    ((Vector)t.get(path)).addElement(f);
  }
  <font color=#0000ff>public</font> <font color=#0000ff>void</font> writePackedFile(String fname) {
    DataOutputStream packed = IO.dosOpen(fname);
    <font color=#0000ff>try</font> {
      packed.writeBytes(<font color=#004488>"###Old Separator:"</font> +
        SourceCodeFile.filesep + <font color=#004488>"###\n"</font>);
    } <font color=#0000ff>catch</font>(IOException e) {
      Pr.error(<font color=#004488>"Writing separator to "</font> + fname);
    }
    Enumeration e = t.keys();
    <font color=#0000ff>while</font>(e.hasMoreElements()) {
      String dir = (String)e.nextElement();
      System.out.println(
        <font color=#004488>"Writing directory "</font> + dir);
      Vector v = (Vector)t.get(dir);
      <font color=#0000ff>for</font>(<font color=#0000ff>int</font> i = 0; i &lt; v.size(); i++) {
        SourceCodeFile f = 
          (SourceCodeFile)v.elementAt(i);
        f.writePacked(packed);
      }
    }
    IO.close(packed);
  }
  <font color=#009900>// Write all the files in their directories:</font>
  <font color=#0000ff>public</font> <font color=#0000ff>void</font> write() {
    Enumeration e = t.keys();
    <font color=#0000ff>while</font>(e.hasMoreElements()) {
      String dir = (String)e.nextElement();
      Vector v = (Vector)t.get(dir);
      <font color=#0000ff>for</font>(<font color=#0000ff>int</font> i = 0; i &lt; v.size(); i++) {
        SourceCodeFile f = 
          (SourceCodeFile)v.elementAt(i);
        f.writeFile(rootpath);
      }
      <font color=#009900>// Add file indicating file quantity</font>
      <font color=#009900>// written to this directory as a check:</font>
      IO.close(IO.dosOpen(
        <font color=#0000ff>new</font> File(<font color=#0000ff>new</font> File(rootpath, dir),
          Integer.toString(v.size())+<font color=#004488>".files"</font>)));
    }
  }
}

<font color=#0000ff>public</font> <font color=#0000ff>class</font> CodePackager {
  <font color=#0000ff>private</font> <font color=#0000ff>static</font> <font color=#0000ff>final</font> String usageString =
  <font color=#004488>"usage: java CodePackager packedFileName"</font> +
  <font color=#004488>"\nExtracts source code files from packed \n"</font> +