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第一次使用Extract Method(110) (三)

下一个步骤是找出程序中对于旧函数的所有引用(reference)点,并修改它们,让它们改用新函数. 下面是原本的程序:
class Customer...
public String statement() {
    double totalAmount = 0;
    int frequentRenterPoints = 0;
    Enumeration rentals = _rentals.elements();
    String result = "Rental Record for * " + getName() + "\n";
    while(rentals.hasMoreElements()) {
       double thisAmount = 0;
       Rental each = (Rental)rentals.nextElement();    //取得一笔租借记录

       thisAmount = amountFor(each);

       //   add frequent renter points(累加常客积点)
          frequentRenterPoints ++;
          if((each.getMovie().getPriceCode() == Movie.NEW_RELEASE) &&
             each.getDaysRented() > 1)
             frequentRenterPoints ++;

          result += "\t" + each.getMovie().getTitle() + "\t" +
             String.valueOf(thisAmount) + "\n";
          totalAmount += thisAmount;
    }
//   add footer lines(结尾打印)
    result += "Amount owed is " + String.valueOf(totalAmount) + " \n";
    result += "You earned " + String.valueOf(frequentRenterPoints) +
       "frequent renter points";
    return result;
}

本例之中,这个步骤很简单,因为我才刚刚产生新函数,只有一个地方使用了它.一般情况下你得在可能运用该函数的所有classes中查找一遍.
class Customer
public String statement() {
    double totalAmount = 0;
    int frequentRenterPoints = 0;
    Enumeration rentals = _rentals.elements();
    String result = "Rental Record for * " + getName() + "\n";
    while(rentals.hasMoreElements()) {
       double thisAmount = 0;
       Rental each = (Rental)rentals.nextElement();    //取得一笔租借记录

       thisAmount = each.getCharge();

       //   add frequent renter points(累加常客积点)
          frequentRenterPoints ++;
          if((each.getMovie().getPriceCode() == Movie.NEW_RELEASE) &&
             each.getDaysRented() > 1)
             frequentRenterPoints ++;

          result += "\t" + each.getMovie().getTitle() + "\t" +
             String.valueOf(thisAmount) + "\n";
          totalAmount += thisAmount;
    }
//   add footer lines(结尾打印)
    result += "Amount owed is " + String.valueOf(totalAmount) + " \n";
    result += "You earned " + String.valueOf(frequentRenterPoints) +
       "frequent renter points";
    return result;
}

posted @ 2005-08-15 13:00 ivaneeo 阅读(195) | 评论 (0) | 编辑收藏

第一次使用Extract Method(110) (二)

搬移[金额计算]代码
观察amountFor()时,我发现这个函数使用了来自Rental class的信息,却没有使用来自Customer class的信息.

class Customer...
public double amountFor(Rental aRental) {
    double result = 0;
    switch(aRental.getMovie().getPriceCode()) {   //取得影片出租价格
          case Movie.REGULAR:   //普通片
             result+= 2;
             if(aRental.getDaysRented() > 2)
                result+= (aRental.getDaysRented() - 2) * 1.5;
             break;
          case Movie.NEW_RELEASE:   //新片
             result+= aRental.getDaysRented() * 3;
             break;
          case Movie.CHILDRENS:   //儿童片
             result+= 1.5;
             if(aRental.getDaysRented() > 3)
                result+= (aRental.getDaysRented() - 3) * 1.5;
             break;
       }
    return result;
}
这立刻使我怀疑它是否被放错了位置.大多数情况下,函数应该放在它使用的数据的所属object(或说class)内,所以amountFor()应该移到Rental class去.为了这么做,我要运用Move Method(142).首先把代码拷贝到Rental class内,调整代码使之适应新家,然后重新编译.下面这样:

class Rental...
double getCharge() {
    double result = 0;
    switch(getMovie().getPriceCode()) {   //取得影片出租价格
          case Movie.REGULAR:   //普通片
             result+= 2;
             if(getDaysRented() > 2)
                result+= (getDaysRented() - 2) * 1.5;
             break;
          case Movie.NEW_RELEASE:   //新片
             result+= getDaysRented() * 3;
             break;
          case Movie.CHILDRENS:   //儿童片
             result+= 1.5;
             if(getDaysRented() > 3)
                result+= (getDaysRented() - 3) * 1.5;
             break;
       }
    return result;
}
这个例子里,[适应新家]意味去掉参数.此外,我还要在搬移的同时变更函数名称.

现在我可以测试新函数是否正常工作.只要改变Customer.amountFor()函数内容,使它委托(delegate)新函数即可:

class Customer...
    private double amountFor(Rental aRental) {
       return aRental.getCharge();
    }

posted @ 2005-08-15 11:03 ivaneeo 阅读(181) | 评论 (0) | 编辑收藏

第一次使用Extract Method(110) (一)

实例代码:
public String statement() {
    double totalAmount = 0;
    int frequentRenterPoints = 0;
    Enumeration rentals = _rentals.elements();
    String result = "Rental Record for * " + getName() + "\n";
    while(rentals.hasMoreElements()) {
       double thisAmount = 0;
       Rental each = (Rental)rentals.nextElement();    //取得一笔租借记录

       switch(each.getMovie().getPriceCode()) {   //取得影片出租价格
          case Movie.REGULAR:   //普通片
             thisAmount += 2;
             if(each.getDaysRented() > 2)
                thisAmount += (each.getDaysRented() - 2) * 1.5;
             break;
          case Movie.NEW_RELEASE:   //新片
             thisAmount += each.getDaysRented() * 3;
             break;
          case Movie.CHILDRENS:   //儿童片
             thisAmount += 1.5;
             if(each.getDaysRented() > 3)
                thisAmount += (each.getDaysRented() - 3) * 1.5;
             break;
       }

       //   add frequent renter points(累加常客积点)
          frequentRenterPoints ++;
          if((each.getMovie().getPriceCode() == Movie.NEW_RELEASE) &&
             each.getDaysRented() > 1)
             frequentRenterPoints ++;

          result += "\t" + each.getMovie().getTitle() + "\t" +
             String.valueOf(thisAmount) + "\n";
          totalAmount += thisAmount;
    }

    //   add footer lines(结尾打印)
    result += "Amount owed is " + String.valueOf(totalAmount) + " \n";
    result += "You earned " + String.valueOf(frequentRenterPoints) +
       "frequent renter points";
    return result;
}

第一步骤是找出代码的逻辑泥团并运用Extract Method(110).本例一个明显的逻辑泥团就是switch语句,把它提炼(extract)到独立函数中似乎比较好.

首先我得在这段代码里头找出函数内的局部变量(local variables)和参数(parameters).我找到了两个:each和thisAmount,前者并未被修改,后者会被修改.任何不会被修改的变量都可以被我当成参数传入新的函数,至于会被修改的变量就需格外小心.如果只有一个变量会被修改,我可以把它当作返回值.thisAmount是个临时变量,其值在每次循环起始处被设为0,并且在switch语句之前不会改变,所以我可以把新函数的返回值赋予它.

public String statement() {
    double totalAmount = 0;
    int frequentRenterPoints = 0;
    Enumeration rentals = _rentals.elements();
    String result = "Rental Record for * " + getName() + "\n";
    while(rentals.hasMoreElements()) {
       double thisAmount = 0;
       Rental each = (Rental)rentals.nextElement();    //取得一笔租借记录

       thisAmount = amountFor(each);

       //   add frequent renter points(累加常客积点)
          frequentRenterPoints ++;
          if((each.getMovie().getPriceCode() == Movie.NEW_RELEASE) &&
             each.getDaysRented() > 1)
             frequentRenterPoints ++;

          result += "\t" + each.getMovie().getTitle() + "\t" +
             String.valueOf(thisAmount) + "\n";
          totalAmount += thisAmount;
    }
//   add footer lines(结尾打印)
    result += "Amount owed is " + String.valueOf(totalAmount) + " \n";
    result += "You earned " + String.valueOf(frequentRenterPoints) +
       "frequent renter points";
    return result;
}

public double amountFor(Rental each) {
    double thisAmount = 0;
    switch(each.getMovie().getPriceCode()) {   //取得影片出租价格
          case Movie.REGULAR:   //普通片
             thisAmount += 2;
             if(each.getDaysRented() > 2)
                thisAmount += (each.getDaysRented() - 2) * 1.5;
             break;
          case Movie.NEW_RELEASE:   //新片
             thisAmount += each.getDaysRented() * 3;
             break;
          case Movie.CHILDRENS:   //儿童片
             thisAmount += 1.5;
             if(each.getDaysRented() > 3)
                thisAmount += (each.getDaysRented() - 3) * 1.5;
             break;
       }
    return thisAmount;
}

现在,已经把原本的函数分为两块,可以分别处理它们.我不喜欢amountFor()内的某些变量名称,现在是修改它们的时候.
下面是原本的代码:
   public double amountFor(Rental each) {
    double thisAmount = 0;
    switch(each.getMovie().getPriceCode()) {   //取得影片出租价格
          case Movie.REGULAR:   //普通片
             thisAmount += 2;
             if(each.getDaysRented() > 2)
                thisAmount += (each.getDaysRented() - 2) * 1.5;
             break;
          case Movie.NEW_RELEASE:   //新片
             thisAmount += each.getDaysRented() * 3;
             break;
          case Movie.CHILDRENS:   //儿童片
             thisAmount += 1.5;
             if(each.getDaysRented() > 3)
                thisAmount += (each.getDaysRented() - 3) * 1.5;
             break;
       }
    return thisAmount;
}

下面是易名后的代码:
public double amountFor(Rental aRental) {
    double result = 0;
    switch(aRental.getMovie().getPriceCode()) {   //取得影片出租价格
          case Movie.REGULAR:   //普通片
             result += 2;
             if(aRental.getDaysRented() > 2)
                result += (aRental.getDaysRented() - 2) * 1.5;
             break;
          case Movie.NEW_RELEASE:   //新片
             result += aRental.getDaysRented() * 3;
             break;
          case Movie.CHILDRENS:   //儿童片
             result += 1.5;
             if(aRental.getDaysRented() > 3)
                result += (aRental.getDaysRented() - 3) * 1.5;
             break;
       }
    return result;
}

posted @ 2005-08-15 10:15 ivaneeo 阅读(397) | 评论 (0) | 编辑收藏

重构词汇(1)

1.逻辑泥团(logical clump),这里是指类似下面的逻辑混在一起的代码:
...
    switch(each.getMovie().getPriceCode()) {
       case Movie.REGULAR:
          thisAmount += 2;
       .....
       case Movie.CHILDRENDS:
          thisAmount += 1.5;
          if(each.getDaysRented() > 3)
             thisAmount += (each.getDaysRented() - 3)*1.5;
       break;
    }
...
2.重构名录(refactoring catalog)是指常用的重构方法列出的名录.

posted @ 2005-08-15 09:44 ivaneeo 阅读(225) | 评论 (0) | 编辑收藏

快速而随性

快速而随性地(quick and dirty)地设计一个简单的程序并没有错.

posted @ 2005-08-12 15:53 ivaneeo 阅读(160) | 评论 (0) | 编辑收藏

在debian下jdk1.4.2中文乱码的解决

1.首先,把windows的simsun.ttc文件考到指定目录,重命名为simsun.ttf.

2.注册字体:到JAVA_HOME下的jre/lib/fonts下.编辑fonts.dir.具体如下:第一行的数字加一.在最后一行加入一句: simsun.ttf -default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.
可选字体的还有: simsun.ttf -SungtiL GB-medium-r-normal--0-0-0-0-c-0-gb2312.1988-0
simsun.ttf -misc-SimSun-medium-r-normal--*-%d-*-*-c-*-iso10646-1

3.修改JAVA_HOME下的jre/lib/的font.properties文件(这里的font.properties文件最好做备份).
($cp -v font.properties.zh_CN.Sun font.properties)

修改的地方有三处:
A.类似如下的 serif.0=-b&h-lucidabright-medium-r-normal--*-%d-*-*-p-*-iso8859-1
serif.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0
看到xxxx.1=后面的字体全部改成已经注册的字体.

B.类似如下的 fontset.serif.plain=\
-b&h-lucidabright-medium-r-normal--*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0
fontset.serif.plain=\后的第二行字体全部改成注册的字体.

C.最后一行:appendedfontpath=/usr/share/fonts/truetype.这里的/usr/share/fonts/truetype是simsun.ttf的考到的目录名.

具体文件如下：
# @(#)font.properties.zh_CN.Sun.linux 1.1 03/07/14
# Copyright 2003 Sun Microsystems, Inc. All rights reserved.
#

# Component Font Mappings For Linux zh_CN
#
serif.0=-b&h-lucidabright-medium-r-normal--*-%d-*-*-p-*-iso8859-1
serif.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

serif.italic.0=-b&h-lucidabright-medium-i-normal--*-%d-*-*-p-*-iso8859-1
serif.italic.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

serif.bold.0=-b&h-lucidabright-demibold-r-normal--*-%d-*-*-p-*-iso8859-1
serif.bold.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

serif.bolditalic.0=-b&h-lucidabright-demibold-i-normal--*-%d-*-*-p-*-iso8859-1
serif.bolditalic.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

sansserif.0=-b&h-lucidasans-medium-r-normal-sans-*-%d-*-*-p-*-iso8859-1
sansserif.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

sansserif.italic.0=-b&h-lucidasans-medium-i-normal-sans-*-%d-*-*-p-*-iso8859-1
sansserif.italic.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

sansserif.bold.0=-b&h-lucidasans-bold-r-normal-sans-*-%d-*-*-p-*-iso8859-1
sansserif.bold.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

sansserif.bolditalic.0=-b&h-lucidasans-bold-i-normal-sans-*-%d-*-*-p-*-iso8859-1
sansserif.bolditalic.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

monospaced.0=-b&h-lucidatypewriter-medium-r-normal-sans-*-%d-*-*-m-*-iso8859-1
monospaced.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

monospaced.italic.0=-b&h-lucidatypewriter-medium-r-normal-sans-*-%d-*-*-m-*-iso8859-1
monospaced.italic.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

monospaced.bold.0=-b&h-lucidatypewriter-bold-r-normal-sans-*-%d-*-*-m-*-iso8859-1
monospaced.bold.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

monospaced.bolditalic.0=-b&h-lucidatypewriter-bold-r-normal-sans-*-%d-*-*-m-*-iso8859-1
monospaced.bolditalic.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

dialog.0=-b&h-lucidasans-medium-r-normal-sans-*-%d-*-*-p-*-iso8859-1
dialog.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

dialog.italic.0=-b&h-lucidasans-medium-i-normal-sans-*-%d-*-*-p-*-iso8859-1
dialog.italic.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

dialog.bold.0=-b&h-lucidasans-bold-r-normal-sans-*-%d-*-*-p-*-iso8859-1
dialog.bold.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

dialog.bolditalic.0=-b&h-lucidasans-bold-i-normal-sans-*-%d-*-*-p-*-iso8859-1
dialog.bolditalic.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

dialoginput.0=-b&h-lucidatypewriter-medium-r-normal-sans-*-%d-*-*-m-*-iso8859-1
dialoginput.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

dialoginput.italic.0=-b&h-lucidatypewriter-medium-r-normal-sans-*-%d-*-*-m-*-iso8859-1
dialoginput.italic.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

dialoginput.bold.0=-b&h-lucidatypewriter-bold-r-normal-sans-*-%d-*-*-m-*-iso8859-1
dialoginput.bold.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

dialoginput.bolditalic.0=-b&h-lucidatypewriter-bold-r-normal-sans-*-%d-*-*-m-*-iso8859-1
dialoginput.bolditalic.1=-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

# Missing Glyph Character
#
default.char=274f

# Component Font Character Encodings
#
fontcharset.serif.0=sun.io.CharToByteISO8859_1
fontcharset.serif.1=sun.io.CharToByteGBK

fontcharset.sansserif.0=sun.io.CharToByteISO8859_1
fontcharset.sansserif.1=sun.io.CharToByteGBK

fontcharset.monospaced.0=sun.io.CharToByteISO8859_1
fontcharset.monospaced.1=sun.io.CharToByteGBK

fontcharset.dialog.0=sun.io.CharToByteISO8859_1
fontcharset.dialog.1=sun.io.CharToByteGBK

fontcharset.dialoginput.0=sun.io.CharToByteISO8859_1
fontcharset.dialoginput.1=sun.io.CharToByteGBK

# Exclusion Ranges
#

# XFontSet Information
#
fontset.serif.plain=\
-b&h-lucidabright-medium-r-normal--*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.serif.italic=\
-b&h-lucidabright-medium-i-normal--*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.serif.bold=\
-b&h-lucidabright-demibold-r-normal--*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.serif.bolditalic=\
-b&h-lucidabright-demibold-i-normal--*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.sansserif.plain=\
-b&h-lucidasans-medium-r-normal-sans-*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.sansserif.italic=\
-b&h-lucidasans-medium-i-normal-sans-*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.sansserif.bold=\
-b&h-lucidasans-bold-r-normal-sans-*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.sansserif.bolditalic=\
-b&h-lucidasans-bold-i-normal-sans-*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.monospaced.plain=\
-b&h-lucidatypewriter-medium-r-normal-sans-*-%d-*-*-m-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.monospaced.italic=\
-b&h-lucidatypewriter-medium-r-normal-sans-*-%d-*-*-m-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.monospaced.bold=\
-b&h-lucidatypewriter-bold-r-normal-sans-*-%d-*-*-m-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.monospaced.bolditalic=\
-b&h-lucidatypewriter-bold-r-normal-sans-*-%d-*-*-m-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.dialog.italic=\
-b&h-lucidasans-medium-i-normal-sans-*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.dialog.bold=\
-b&h-lucidasans-bold-r-normal-sans-*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.dialog.bolditalic=\
-b&h-lucidasans-bold-i-normal-sans-*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.dialog.plain=\
-b&h-lucidasans-medium-r-normal-sans-*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.dialoginput.italic=\
-b&h-lucidatypewriter-medium-r-normal-sans-*-%d-*-*-m-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.dialoginput.bold=\
-b&h-lucidatypewriter-bold-r-normal-sans-*-%d-*-*-m-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.dialoginput.bolditalic=\
-b&h-lucidatypewriter-bold-r-normal-sans-*-%d-*-*-m-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.dialoginput.plain=\
-b&h-lucidatypewriter-medium-r-normal-sans-*-%d-*-*-m-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

fontset.default=\
-b&h-lucidasans-medium-r-normal-sans-*-%d-*-*-p-*-iso8859-1,\
-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.

filename.-default-simsun-medium-r-normal--*-100-*-*-c-*-gb2312.1980-0.=/usr/share/fonts/truetype/simsun.ttf

appendedfontpath=/usr/share/fonts/truetype

posted @ 2005-08-11 13:38 ivaneeo 阅读(710) | 评论 (0) | 编辑收藏

一个有用的从Reader向InputStream转换的类

public class ReaderInputStream extends InputStream {
   protected Reader reader;
   protected ByteArrayOutputStream byteArrayOut;
   protected Writer writer;
   protected char[] chars;
   protected byte[] buffer;
   protected int index, length;

      /**
       * 带Reader参数构造函数
       *
       * @param reader - InputStream使用的Reader
       */
      public ReaderInputStream(Reader reader) {
        this.reader = reader;
        byteArrayOut = new ByteArrayOutputStream();
        writer = new OutputStreamWriter(byteArrayOut);
        chars = new char[1024];
      }

      /**
       * 带Reader和字符编码格式参数的构造函数
       *
       * @param reader   - InputStream使用的Reader
       * @param encoding - InputStream使用的字符编码格式.
       * @throws 如果字符编码格式不支持,则抛UnsupportedEncodingException异常
       */
      public ReaderInputStream(Reader reader, String encoding)
       throws UnsupportedEncodingException {
        this.reader = reader;
        byteArrayOut = new ByteArrayOutputStream();
        writer = new OutputStreamWriter(byteArrayOut, encoding);
        chars = new char[1024];
      }

      /**
       * @see java.io.InputStream#read()
       */
      public int read() throws IOException {
        if (index >= length)
          fillBuffer();
        if (index >= length)
          return -1;
        return 0xff & buffer[index++];
      }

      protected void fillBuffer() throws IOException {
        if (length < 0)
          return;
        int numChars = reader.read(chars);
        if (numChars < 0) {
          length = -1;
        } else {
          byteArrayOut.reset();
          writer.write(chars, 0, numChars);
          writer.flush();
          buffer = byteArrayOut.toByteArray();
          length = buffer.length;
          index = 0;
        }
      }

      /**
       * @see java.io.InputStream#read(byte[], int, int)
       */
      public int read(byte[] data, int off, int len) throws IOException {
        if (index >= length)
          fillBuffer();
        if (index >= length)
          return -1;
        int amount = Math.min(len, length - index);
        System.arraycopy(buffer, index, data, off, amount);
        index += amount;
        return amount;
      }

      /**
       * @see java.io.InputStream#available()
       */
      public int available() throws IOException {
        return (index < length) ? length - index :
            ((length >= 0) && reader.ready()) ? 1 : 0;
      }

      /**
       * @see java.io.InputStream#close()
       */
      public void close() throws IOException {
        reader.close();
      }

}

posted @ 2005-08-11 09:27 ivaneeo 阅读(2308) | 评论 (0) | 编辑收藏

使用缩略语(Abbreviations)

1. 启动emacs.
2.打开jde-mode方式.
3.在打开jde-abbrev-mode方式.

然后输入if,接着按空格键(输入if的条件);展开if语句.
if(i == 0) {
} // end of if (i == 0)

表 1. Abbreviations

语句	Abbreviation
`if-then`	`if`
`else`	`else`
`if-then-else`	`ife`
`else-if`	`eif`
`while`	`while`
`for`	`for`
`for (int I=0;I<UL;I++)`	`fori`
`for (Iterator i = c.iterator(); i.hasNext();)`	`foriter`
`main method`	`main`
`switch`	`switch`
`case`	`case`
`try`	`try`
`catch`	`catch`
`try finally`	`tryf`
`finally`	`finally`

posted @ 2005-08-09 11:01 ivaneeo 阅读(158) | 评论 (0) | 编辑收藏

在jde里注册jdk

首先,需打开jde模式.(M-x jde-mode)

在JDEE里注册一个新的jdk:

打开emacs.
输入 M-x customize-variable 并回车.
Emacs 提示你要自定义的变量名.
输入 jde-jdk-registry 并回车.
jde-jdk-registry 的配置界面.
按 INS 按钮.
显示 JDK 项.
输入JDK的版本号和 JDK 的安装路径.
重复先前的步骤.
按 State 按钮.
State 菜单显示.
选择 Save for Future Sessions .
Note
This saves the setting of jde-jdk-registry in your .emacs file.
按 Finish button保存.

选择JDK

选择 JDK:

输入 M-x customize-variable 并回车.

Emacs 提示你要自定义的变量.
输入 jde-jdk 并回车.
jde-jdk 的配置界面.
缓冲区里显示注册的jdk的列表.
按radio button 选择你要使用的jdk.
按State 按钮.
State 菜单显示.
选择 Save for Future Sessions.
按 Finish 按钮保存设置.

posted @ 2005-08-08 17:16 ivaneeo 阅读(351) | 评论 (0) | 编辑收藏

在firefox里安装java插件

我的java是jre1.4.2的.
首先是进入firefox的插件目录.我的是~/.mozilla/plugins.
然后是确定jre的插件目录.我的是~/programs/j2sdk1.4.2_08/jre/plugin/i386/ns610-gcc32.这里是使用gcc32的系统.
最后是做连接.具体如下:
$cd ~/.mozilla/plugins
$ln -s ~/programs/j2sdk1.4.2_08/jre/plugin/i386/ns610-gcc32/libjavaplugin_oji.so
重起firefox,确定插件是否安装成功.在firefox输入about:plugins.有就成功了.

posted @ 2005-08-08 14:54 ivaneeo 阅读(970) | 评论 (0) | 编辑收藏

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