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aldream — Wed, 05 Dec 2007 15:22:00 GMT

HTML 4.01/XHTML 1.0标签
HTML 事�g
HTML 声明
w3school 在线教程

aldream 2007-12-05 23:22 发表评论

与�Q何qq用户聊天

aldream — Wed, 21 Nov 2007 07:52:00 GMT

摘要: tencent://Message/?Uin=%num% 阅读全文

aldream 2007-11-21 15:52 发表评论

使用links方式安装Eclipse插�g

aldream — Mon, 12 Nov 2007 10:19:00 GMT

eclispe惛_��大家都很熟�?zh��n)�了(ji��n)，一般来��_(d��)��eclipse插�g都是安装在plugins目录下。不�q�这样一来，当安装了(ji��n)许多插�g之后�Q�eclipse变的很大�Q�最主要的是不便于更新和��理众多插�g。用links方式安装eclipse插�g�Q�可以解册��个问题�?

当前配置XP SP1�Q�eclipse3.0.1

现在假设我的eclipse安装目录是D:"eclipse�Q�待安装插�g目录是D:"plug-in �Q�我��要安装LanguagePackFeature�Q�语�a�包）(j��)、emf-sdo-xsd-SDK、GEF-SDK、Lomboz�q�四个插件�?/p>

先把�q�四个插件程序全部放在D:"plug-in目录里，分别解压。如Lomboz3.0.1.zip解压成Lomboz3.0.1目录�Q�这个目录包含一个plugins目录�Q�要先在Lomboz3.0.1目录中新��Z��个子目录eclipse�Q�然后把plugins目录�U�d��到刚建立的eclipse目录中，即目录结构要是这��L(f��ng)��Q�D:"plug-in"Lomboz3.0.1"eclipse"plugins

Eclipse ��会(x��)到指定的目录下去查找 eclipse"features 目录和eclipse"plugins 目录�Q�看是否有合法的功能部�g和（或）(j��)插�g。也��是��_(d��)��目标目录必须包含一�?"eclipse 目录。如果找刎ͼ�附加的功能部件和插�g在运行期配置是将是可用的�Q�如果链接文件是在工作区创徏之后��d��的，附加的功能部件和插�g�?x��)作为新的配�|�变更来�? 理�?

其它压羃文�g解压后若已经包含eclipse"plugins目录�Q�则不需要徏立eclipse目录�?/p>

然后�?nbsp;eclipse安装目录D:"eclipse目录中徏立一个子目录links�Q�在links目录中徏立一个link文�g�Q�比�? LanguagePackFeature.link�Q�改文�g内容�?nbsp; path=D:/plug-in/LanguagePackFeature 卌��个link文�g要对应一个刚解压后的插�g目录�?/p>

说明�Q?/strong>

　1. 插�g可以分别安装在多个自定义的目录中�?/p>
　2. 一个自定义目录可以安装多个插�g�?/p>
　3. link文�g的文件名�?qi��ng)扩展名可以取�Q意名�U�ͼ�比如ddd.txt�Q�myplugin都可以�?/p>
　4. link文�g中path=插�g目录的path路径分隔要用""或是/

　5. 在links目录也可以有多个link文�g�Q�每个link文�g中的path参数都将生效�?/p>
　6. 插�g目录可以使用相对路径�?/p>
7. 可以在links目录中徏立一个子目录�Q��{�U�L��时不用的插�g到此子目录中�Q�加快eclipse启动�?nbsp;

8. 如果安装后看不到插�g�Q�把eclipse 目录下的configuration目录删除�Q�重启即可�?/p>

aldream 2007-11-12 18:19 发表评论

Log4j向导(tomcat example)

aldream — Mon, 12 Nov 2007 07:17:00 GMT
     摘要: 原文出处�Q�http://www.laliluna.de/download/log4j-tutorial-en.pdf

This tutorial explains how to set up log4j with email, files and stdout. It compares XML to properties configuration files, shows how to change LogLevels for a running application. Furthermore, we explain best practices on logging and exception handling.  阅读全文

aldream 2007-11-12 15:17 发表评论

eclipse Junit��试向导

aldream — Mon, 12 Nov 2007 07:10:00 GMT
原文出处�Q?a >http://www.laliluna.de/assets/tutorials/junit-testing-en.pdf

JUnit is a simple Java testing framework to write tests for you Java application. This tutorial gives you an overview of the features of JUnit and shows a little example how you can write tests for your Java application.

General

Author:

Sascha Wolski

Sebastian Hennebrueder

http://www.laliluna.de/tutorials.html ? Tutorials for Struts, EJB, xdoclet and eclipse.

Date:

April, 12 2005

Software:

Eclipse 3.x

Junit 2.x

Source code:

http://www.laliluna.de/assets/tutorials/junit-testing-source.zip

PDF Version

http://www.laliluna.de/assets/tutorials/junit-testing-en.pdf

What is JUnit

JUnit is a simple open source Java testing framework used to write and run repeatable automated tests. It is an instance of the xUnit architecture for unit testing framework. Eclipse supports creating test cases and running test suites, so it is easy to use for your Java applications.

JUnit features include:

Assertions for testing expected results

Test fixtures for sharing common test data

Test suites for easily organizing and running tests

Graphical and textual test runners

What is a test case

A test case is a class which holds a number of test methods. For example if you want to test some methods of a class Book you create a class BookTest which extends the JUnit TestCase class and place your test methods in there.

How you write and run a simple test

Create a subclass of TestCase:

public class BookTest extends TestCase{
//..
}

Write a test method to assert expected results on the object under test:

Note: The naming convention for a test method is testXXX()

public void testCollection() {
Collection collection = new ArrayList();
assertTrue(collection.isEmpty());
}

Write a suite() method that uses reflection to dynamically create a test suite containing all the testXXX() methods:

public static Test suite(){
return new TestSuite(BookTest.class);
}

Activate the JUnit view in Eclipse (Window > Show View > Other.. > Java > JUnit).

You find the JUnit tab near the Package Explorer tab. You can change the position of the tab by drag and drop it.

Right click on the subclass of TestCase and choose Run > JUnit Test to run the test.

Using a test fixture

A test fixture is useful if you have two or more tests for a common set of objects. Using a test fixture avoids duplicating the test code necessary to initialize and cleanup those common objects for each test.

To create a test fixture, define a setUp() method that initializes common object and a tearDown() method to cleanup those objects. The JUnit framework automatically invokes the setUp() method before a each test is run and the tearDown() method after each test is run.

The following test uses a test fixture:

public class BookTest2 extends TestCase {

private Collection collection;

protected void setUp() {
collection = new ArrayList();
}

protected void tearDown() {
collection.clear();
}

public void testEmptyCollection(){
assertTrue(collection.isEmpty());
}
}

Dynamic and static way of running single tests

JUnit supports two ways (static and dynamic) of running single tests.

In static way you override the runTest() method inherited form TestCase class and call the desired test case. A convenient way to do this is with an anonymous inner class.

Note: Each test must be given a name, so you can identify it if it fails.

TestCase test = new BookTest("equals test") {
public void runTest() {
testEquals();
}
};

The dynamic way to create a test case to be run uses reflection to implement runTest. It assumes the name of the test is the name of the test case method to invoke. It dynamically finds and invokes the test method. The dynamic way is more compact to write but it is less static type safe. An error in the name of the test case goes unnoticed until you run it and get a NoSuchMethodException. We leave the choice of which to use up to you.

TestCast test = new BookTest("testEquals");

What is a TestSuite

If you have two tests and you'll run them together you could run the tests one at a time yourself, but you would quickly grow tired of that. Instead, JUnit provides an object TestSuite which runs any number of test cases together. The suite method is like a main method that is specialized to run tests.

Create a suite and add each test case you want to execute:

public static void suite(){
TestSuite suite = new TestSuite();
suite.addTest(new BookTest("testEquals"));
suite.addTest(new BookTest("testBookAdd"));
return suite;
}

Since JUnit 2.0 there is an even simpler way to create a test suite, which holds all testXXX() methods. You only pass the class with the tests to a TestSuite and it extracts the test methods automatically.

Note: If you use this way to create a TestSuite all test methods will be added. If you do not want all test methods in the TestSuite use the normal way to create it.

Example:

public static void suite(){
return new TestSuite(BookTest.class);
}

A little example

Create a new Java project named JUnitExample.

Add a package de.laliluna.tutorial.junitexample where you place the example classes and a package test.laliluna.tutorial.junitexample where you place your test classes.

The class Book

Create a new class Book in the package de.laliluna.tutorial.junitexample.

Add two properties title of type String and price of type double.

Add a constructor to set the two properties.

Provide a getter- and setter-method for each of them.

Add a method trunk for a method equals(Object object) which checks if the object is an instance of the class Book and the values of the object are equal. The method return a boolean value.

Note: Do not write the logic of the equals(..) method, we do it after finish creating the test method.

The following source code shows the class Book.

public class Book {

private String title;
private double price;

/**
* Constructor
*
* @param title
* @param price
*/
public Book(String title,
double price) {
this.title = title;
this.price = price;
}

/**
* Check if an object is an instance of book
* and the values of title and price are equal
* then return true, otherwise return false
*/
public boolean equals(Object object) {

return false;
}

public double getPrice() {
return price;
}

public void setPrice(double price) {
this.price = price;
}

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}
}

The test case BookTest

Create a new test case BookTest in the package test.laliluna.tutorial.junitexample Right click on the package and choose New > JUnit Test Case.

In the wizard choose the methods stubs setUp(), tearDown() and constructor().

The following source code shows the class BookTest

public class BookTest extends TestCase {

/**
* setUp() method that initializes common objects
*/
protected void setUp() throws Exception {
super.setUp();
}

/**
* tearDown() method that cleanup the common objects
*/
protected void tearDown() throws Exception {
super.tearDown();
}

/**
* Constructor for BookTest.
* @param name
*/
public BookTest(String name) {
super(name);
}

}

Now we want to write a test for the equals(..) method of the class Book. We provide three private properties, book1, book2 and book3 of type Book.

private Book book1;
private Book book2;
private Book book3;

Within the setUp() method we initializes the three properties with some values. Property book1 and book3 are the same.

protected void setUp() throws Exception {
super.setUp();
book1 = new Book("ES", 12.99);
book2 = new Book("The Gate", 11.99);
book3 = new Book("ES", 12.99);
}

Within the tearDown() method we cleanup the properties:

protected void tearDown() throws Exception {
super.tearDown();
book1 = null;
book2 = null;
book3 = null;
}

Now, add a test method testEquals() to the test case. Within the method we use the assertFalse() method of the JUnit framework to test if the return-value of the equals(..) method is false, because book1 and book2 are not the same. If the return-value is false the logic of the equals() method is correct, otherwise there is a logical problem while comparing the objects. We want to test if the method compares the objects correctly by using the assertTrue() method. Book1 and Book3 are the same, because both are an instance of the class Book and have the same values.

The following source code shows the testEquals() method:

public void testEquals(){
assertFalse(book2.equals(book1));
assertTrue(book1.equals(book1));
}

Writing the logic of the equals() method

We have finished the test and now we can add the logic to the equals() method stub. Open the class Book and add the logic to the equals() method. First we check if the object given by the method is an instance of Book. Then compare the properties title and price, if they are equal return true.

public boolean equals(Object object) {
if (object instanceof Book) {
Book book = (Book) object;
return getTitle().equals(book.getTitle())
&& getPrice() == book.getPrice();
}
return false;
}

Create the suite() method

In order to run the test method testEquals() add a method suite() to the class BookTest.

Note: You can also create a separate class where you add the suite() method.

Within the method create a new instance of TestSuite and use the method addTest(..) to add a test. Here we use the dynamically way to add a test to a TestSuite.

The method looks like the follows:

public static Test suite(){
TestSuite suite = new TestSuite();
suite.addTest(new BookTest("testEquals"));
return suite;
}

Run the test

After finishing all test methods we want to run the JUnit test case. Right mouse button on the class BookTest and choose Run As > JUnit Test.

On the JUnit view (Menu Windows -> show view) of Eclipse you can see how many runs, errors and failures occurred.

aldream 2007-11-12 15:10 发表评论

在eclipse调试JSP和java�E�序

aldream — Mon, 12 Nov 2007 06:53:00 GMT
原文出处�Q?a >http://www.laliluna.de/assets/tutorials/debugging-jsp-java-tutorial-en.pdf

This tutorial gives you an overview of how to use the debugging feature of eclipse to debug your web or Java projects.

General

Author:

Sascha Wolski

Sebastian Hennebrueder

http://www.laliluna.de/tutorial.html ? Tutorials for Struts, JSF, EJB, Hibernate, xdoclet, eclipse and more.

Datum:

January, 25 2005
Development Tools

Eclipse 3.x

MyEclipse plugin 3.8

(A cheap and quite powerful Extension to Eclipse to develop Web Applications and EJB (J2EE) Applications. I think that there is a test version availalable at MyEclipse.)

PDF Version des Tutorials

http://www.laliluna.de/assets/tutorials/debugging-jsp-java-tutorial-en.pdf

Introduction

The Eclipse Platform features a Java debugger that provides all standard debugging functionality, including the ability to perform step execution, setting of breakpoints and values, inspecting variables and values, and to suspend and resume threads. With the extension MyEclipse you are able to debug JSP and included files too.

The debug perspective

First we will explain the debug perspective. You can activate the perspective under Windows > Open Perspective > Other...

Alternatively, you can click on the debug icon of the perspective tool bar.

Debug view

The Debug view displays the stack trace for the suspended threads for each target you are debugging. Each entry is the variable state of a method right when it called the next method. The view allows you to manage the debugging of a program in the workbench.

Variables view

The view displays information about the variables in the selected class. You can get information about the variable like value, size and more from this view.

Breakpoints view

The view lists all breakpoints you have set in the workbench project. In this view, you can enable or disable breakpoints, remove them, or add a new ones. You can also double-click a breakpoint to display its location in the editor.

This view also lists Java exception breakpoints, which suspend execution at the point where the exception is thrown. You can add or remove exceptions.

Expressions view

You can inspect data from each class of a suspended thread, and other places in this view. It opens automatically when an item is added to the view.

Debug a web project

In the next steps I will explain how you can debug a project. I will refer to the project JSP + Servlet you can download on our site. http://www.laliluna.de/assets/tutorials/java-servlets-jsp-tutorial.zip

Open the class BookEdit.java and set a breakpoint in the method doGet(..) at line 72. You can set a breakpoint by double-click on the info bar on the left edge of the editor, or right click Toggle Breakpoint.

Set the second breakpoint in the bookEdit.jsp file on the HTML start tag at line 14.

Note: If you don't have installed MyEclipse, you can't set a breakpoint in jsp and included files.

To see all breakpoints you can use the Breakpoints view in the debug perspective.

Breakpoint Properties

You can apply some properties to each breakpoint, for example how many times a breakpoint can hit before it suspends the thread or on which condition it suspends the thread.

Select the breakpoint right mouse button and choose the option Breakpoint Properties.

Hit Count

The hit count sets a number of times the breakpoint can be executed before the thread suspends. Very helpful in a loop expression or if you want to know the value of a expression after some hits.

Enable Condition

There are two options to suspend a thread by using a condition.

if the enabled condition is true

if the enabled condition changes

If you want that the condition suspends the thread when it is true select the option condition is true on Suspend when.

Example:

action.equals("edit");

If you want that the condition suspends the thread when the value of the condition changes select the option value of the condition changes on Suspend when.

Suspend Policy

You can define if the breakpoint suspends only the thread or the complete virtual machine.

Deploy and Debug

Now we want to debug the project, so deploy it and call it in your web browser.
Choose Edit on the list of books.

After you clicked the Edit link, eclipse shows you the following confirm window. You can choose if you want to switch to the debug perspective. Yes, you want it ;- )

The first entry in the debug view represents the state of the method where the breakpoint was set. You can preview the state of a entry simply by clicking on it, also the file will be open where the method is placed.

You can see the values of all variables of the selected entry in the Variables view.

A marked line and an arrow at the breakpoint shows that the debugger is suspended on this line.

If you've decided that you missed an important place in the execution process, perhaps the breakpoint was in the wrong place, or maybe you accidentally stepped over some code you wanted to inspect earlier in the process. Eclipse has a feature called Drop to frame, that essentially lets you 'rewind' the execution to the beginning of any method in the stack. This is especially useful when you perform variable modification or code hot swapping.
Right click on the frame and choose the option Drop to Frame.

Inspect expressions

To get informations about expression, you can inspect a expression. Right click on the marked expression, you want to inspect and choose Inspect or press Ctrl + Shift + I. A pop-up window appears that holds the informations about the expression.

Watch expressions

Watch is similar to inspect an expression. Watch means that the expression will be added to the Expressions view, where you can watch the informations about the expression. Add two expressions to the Expressions view.

Mark the expressions, right click and choose Watch.

Now the two expression are in the Expressions view.

Display expressions

If you want to display the type and the value of an expression, mark the expression and choose the Display option from the context menu (right mouse button) or press Ctrl + Shift + D.

Run to Line

If you set a breakpoint and somewhere under the breakpoint is a line you want to go, you can use the option Run to Line. The code between the breakpoint and the selected line will be executed. Select the line you want to go, press the right mouse button and choose the option Run to Line or use the key binding Ctrl + R.

Debugging JSP files (supported by MyEclipse)

Debugging a JSP file is the same like debugging a Java class, but the most features (Watch, Inspect, etc) are not implemented. The only way to get the values of variables is the Variables view.

That's it. You will only need to debug, when you make mistakes. Avoid them and forget the tutorial.

aldream 2007-11-12 14:53 发表评论

嵌套诊断环境NDC

aldream — Sun, 11 Nov 2007 06:51:00 GMT
�? 多用户�ƈ发的环境下，通常是由不同的线�E�分别处理不同的客户端请求。此时要在日志信息中区分��Z��同的客户端，你可以�ؓ(f��)每一个线�E�生成一个Logger�Q�从而从一堆日志信息中区分出哪些信息是属于哪个�U�程的，但这�U�方式�ƈ不高效。Log4J巧妙��C��用了(ji��n)Neil Harrison提出�?#8220;NDC�Q�嵌套诊断环境）(j��)”机制来解册��个问题。Log4J为同一�c�d��的线�E�生成一个Logger�Q�多个线�E�共享��用，而它仅在�? 志信息中��d��能够区分不同�U�程的信息。NDC是什么？举例来说�Q�如果一个Servlet接到�q�发��h��Ӟ��为每一个客��L(f��ng)��创徏一个新的线�E�，然后分配一个用于保存该��h��上下文的NDC堆栈。该上下文可能是发出��h��的主机名、IP地址或其它�Q何可以用于标识该��h��的信息。这��P��׃��不同的客��L(f��ng)��处理�U�程��h��? 同的NDC堆栈�Q�即使这个Servlet同时生成多个�U�程处理不同的请求，�q�些日志信息仍然可以区分出来�Q�就好像Log4J为每一个线�E�都单独生成�?ji��n)一�? Logger实例一栗��在Log4J中是通过org.apache.log4j.NDC实现�q�种机制的。��用NDC的方法也很简单，步骤如下�Q?

1. 在进入一个环境时调用NDC.push(String)�Q�然后创��Z��个NDC�Q?

2. 所做的日志操作输出中包括了(ji��n)NDC的信息；

3. ��d��该环境时调用NDC.pop�Ҏ(gu��)��Q?

4. 当从一个线�E�中退出时调用NDC.remove�Ҏ(gu��)��Q�以侉K��放资源�?

下面是一个模拟记录来自不同客��L(f��ng)��h��事�g的例子，代码如下�Q?br />
import org.apache.log4j.Logger;
import org.apache.log4j.NDC;
public class TestNDC {
static Logger log = Logger.getLogger(TestNDC.class.getName());
public static void main(String[] args) {
  log.info("Make sure %x is in your layout pattern!");
  // 从客��L(f��ng)��获得IP地址的例�?/span>
  String[] ips = {"192.168.0.10","192.168.0.27"};
  for (int i = 0; i<ips.length ; i++)  // 模拟一个运行方�?/span>
  {
   // ��IP放进 NDC�?/span>
   NDC.push(ips[i]);
   log.info("A NEW client connected, who's ip should appear in this log message.");
   NDC.pop();
  }
  NDC.remove();
  log.info("Finished.");
}
}
注意配置文�g中的布局格式中一定要加上%x。系�l�输出如下：(x��)

INFO   - Make sure %x is in your layout pattern!
INFO  192.168.0.10 - A NEW client connected, who's ip should appear in this log message.
INFO  192.168.0.27 - A NEW client connected, who's ip should appear in this log message.
INFO   - Finished.

aldream 2007-11-11 14:51 发表评论

一个Junit例子(转自caterpillar.onlyfun.net)

aldream — Sat, 10 Nov 2007 16:55:00 GMT
使用JUnit時，�(zh��n)�主要都是透過�J�承TestCase��別來撰寫測試案例，預設上�?zh��n)�可以使用testXXX() 名稱來撰寫單元測試�?br />
在測試一個單元方法時�Q�有時�?zh��n)�會需要��它一些物件作為運行時的資料，例如�(zh��n)�撰寫下面這個測試案例：(x��)

MaxMinTest.java

1 package onlyfun.caterpillar.test;
2
3 import onlyfun.caterpillar.MaxMinTool;
4 import junit.framework.TestCase;
5
6 public class MaxMinTest extends TestCase {
7     public void testMax() {
8         int[] arr = {-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5};
9         assertEquals(5, MaxMinTool.getMax(arr));
10     }
11
12     public void testMin() {
13         int[] arr = {-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5};
14         assertEquals(-5, MaxMinTool.getMin(arr));
15     }
16
17     public static void main(String[] args) {
18         junit.swingui.TestRunner.run(MaxMinTest.class);
19     }
20 }

�(zh��n)�將�a�計的MaxMinTool包括靜態�Ҏ(gu��)��getMax()與getMin()�Q�當�(zh��n)��它一個整敔R��列，它們將個別傛_��陣列中的最大��D��最��|��然的，�(zh��n)�所準備的陣列重複出珑֜�兩個單元測試之中，重複的程式碼在設�a�中可以減少��儘量減��，在這兩個單元測試中�Q�整敔R��列的準備是單元方法所需要的資源�Q? 我們稱之為fixture�Q�也��是一個測試時所需要的資源集合�?br />
fixture必須與上下文�Q�Context�Q�無關，也就是與�E�式埯��前後無關�Q�這樣才符合單元測試的意涵�Q�為此，通常��所需的fixture撰寫在單元方法之中，如此在單元測試開始時創徏fixture�Q�並於結束後��h��fixture�?br />
然而對於重複出珑֜�各個單元測試中的fixture�Q��?zh��n)�可以集中加以��理�Q��?zh��n)�可以在繼承TestCase之後�Q�重新定��?span style="font-weight: bold;">setUp()�?span style="font-weight: bold;">tearDown()�Ҏ(gu��)��Q�將數個單元測試所需要的fixture在setUp()中創建，並在tearDown()中銷毀�Q�例如：(x��)

MaxMinTest.java

1 package onlyfun.caterpillar.test;
2
3 import onlyfun.caterpillar.MaxMinTool;
4 import junit.framework.TestCase;
5
6 public class MaxMinTest extends TestCase {
7     private int[] arr;
8
9     protected void setUp() throws Exception {
10         super.setUp();
11         arr = new int[]{-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5};
12     }
13
14     protected void tearDown() throws Exception {
15         super.tearDown();
16         arr = null;
17     }
18
19     public void testMax() {
20         assertEquals(5, MaxMinTool.getMax(arr));
21     }
22
23     public void testMin() {
24         assertEquals(-5, MaxMinTool.getMin(arr));
25     }
26
27     public static void main(String[] args) {
28         junit.swingui.TestRunner.run(MaxMinTest.class);
29     }
30 }

setUp()�Ҏ(gu��)��會在每一個單元測試testXXX()�Ҏ(gu��)��開始前被呼叫�Q�因而整敔R��列會被徏立，而tearDown()會在每一個單元測�? testXXX()�Ҏ(gu��)��i�束後被呼叫�Q�因而整敔R��列參考名�E�將會參考至null�Q�如此一來，�(zh��n)�可以將fixture的管理集中在 setUp()與tearDown()�Ҏ(gu��)��之後�?br />
最後按照測試案例的內容�Q��?zh��n)�完成MaxMinTool��別�Q?

MaxMinTool.java

1 package onlyfun.caterpillar;
2
3 public class MaxMinTool {
4     public static int getMax(int[] arr) {
5         int max = Integer.MIN_VALUE;
6
7         for(int i = 0; i < arr.length; i++) {
8             if(arr[i] > max)
9                 max = arr[i];
10         }
11
12         return max;
13     }
14
15     public static int getMin(int[] arr) {
16         int min = Integer.MAX_VALUE;
17
18         for(int i = 0; i < arr.length; i++) {
19             if(arr[i] < min)
20                 min = arr[i];
21         }
22
23         return min;
24     }
25 }

Swing介面的TestRunner在測試失敗時會顯�C�紅色的��子�Q�而在測試成功後會��示�E�色的棒子，�?"Keep the bar green to keep the code clean." 正是JUnit的名�a��Q�也是測試的最�i�目的�?br />

aldream 2007-11-11 00:55 发表评论

Log4j优化

aldream — Sat, 10 Nov 2007 15:31:00 GMT
一个经常引用的依靠于logging的参数是可以计算的花贏V��这是一个合理的概念�Q�一个适度的应用程序可能��生成千上万个日志��h��。许多努力花在测量和调试logging的优化上。Log4j要求快速和�Ҏ(gu��)��：(x��)速度最重要�Q�弹性是其次�?br /> 用户应该注意随后的优化徏议�?br /> 9.1 日志为禁用时�Q�日志的优化
当日志被��d��的关闭，一个日志请求的��p��{�于一个方法的调用加上整数的比较时间�?br /> �?33mhz的Pentium II 机器上这个花贚w��常�?-50�U�秒之间�?br /> 然而，�Ҏ(gu��)��调用包括参数构徏的隐藏花贏V�?br /> 例如�Q�对于logger cat�Q?br />
logger.debug("Entry number: " + i + " is " + String.valueOf(entry));
引�v�?ji��n)构��Z��息参数的��p��Q�例如，转化整数i和entry��C��个string�Q��ƈ且连接中间字�W�串�Q�不��信息是否被输出。这个参数的构徏��p��可能是很高，它主要决定于被调用的参数的大��?br /> 避免参数构徏的花费应如下�Q?br />
if(logger.isDebugEnabled() {
logger.debug("Entry number: " + i + " is " + String.valueOf(entry[i]));
}

如果logger的debug被关闭这��不�?x��)招致参数构建的��p��。另一斚w��Q�如果logger是debug的话�Q�它?y��u)��生两�ơ判�?logger是否能用的花贏V��一�ơ是在debugenabled�Q�一�ơ是debug。这是无关紧要的�Q�因为判断日志是否可用只占日志实际花�Ҏ(gu��)��间的�U?%�?br /> 在Log4j里，日志��h��在Logger �cȝ��实例里。Logger 是一个类�Q�而不是一个接口。这大量的减��了(ji��n)在方法调用上的弹性化的花贏V�?br /> 当然用户采用预处理或�~�译旉��技术去�~�译出所有的日志声明。这��导致完��的执行成效�?br /> 然而因��Z��q�制应用�E�序不包括�Q何的日志声明的结果，日志不可能对那个二进制程序开启。以我的观点�Q�以�q�种较大的代��h��换取较小的性能优化是不值得的�?br /> 9.2 当日志状态�ؓ(f��)启用�Ӟ��日志的优�?/strong>
�q�是本质上的优化logger的层�ơ。当日志状态�ؓ(f��)开�Q�Log4j依然需要比较请求的�U�别与logger的��别。然而，logger可能没有被安排一个��别；它们��从它们的father�l�承。这��P��在��承之前，logger可能需要搜索它的祖先�?br /> �q�里有一个认真的努力使层�ơ的搜烦(ch��)��可能的快。例如，子logger仅仅�q�接到它的存在的father logger�?br /> 在先前展�C�的BasicConfigurator 例子中，名�ؓ(f��)com.foo.bar 的logger是连接到根logger�Q�因此绕�q�了(ji��n)不存在的logger com和com.foo。这��显著的改善执行的速度�Q�特别是解析logger的层�l�构时�?br /> 典型的层�ơ结构的解析的花�Ҏ(gu��)��logger��d��关闭时的三倍�?br /> 9.3 日志信息的输出时�Q�日志的优化
�q�是主要��p��在日志输出的格式化和发送它到它的输出源上。这里我们再一�ơ的付出努力以��格式化执行的��可能快。同appender一栗��实际上典型的花费大�U�是100-300毫秒�?br /> 详情看org.apache.log4.performance.Logging�?br /> 虽然Log4j有许多特点，但是它的�W�一个设计目标还是速度。一些Log4j的组件已�l�被重写�q�很多次以改善性能。不�q�，投稿者经常提��Z��(ji��n)新的优化。你应该满意的知道，以SimpleLayout的配�|�执行测试已�l�展�C�Z��(ji��n)Log4j的输出同System.out.println一样快�?br />

aldream 2007-11-10 23:31 发表评论

aldream — Fri, 09 Nov 2007 18:06:00 GMT
     摘要: 在Web 应用中，应该在哪儿对Log4J�q�行配置呢？首先要明��，Log4J必须在应用的其它代码执行前完成初始化。因为Servlet 是在Web服务器启动时立即装入的，所以，在Web应用中一般��用一个专门的Servlet来完成Log4J的配�|�，�q�保证在web.xml的配�|�中�Q�这个Servlet位于其它Servlet之前。下面是一个例子，代码如下�Q?nbsp; 阅读全文

aldream 2007-11-10 02:06 发表评论

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html

与�Q何qq用户聊天

使用links方式安装Eclipse插�g

Log4j向导(tomcat example)

eclipse Junit���试向导

General

What is JUnit

What is a test case

How you write and run a simple test

Using a test fixture

Dynamic and static way of running single tests

What is a TestSuite

A little example

The class Book

The test case BookTest

Writing the logic of the equals() method

Create the suite() method

Run the test

在eclipse调试JSP和java�E�序

General

Introduction

The debug perspective

Debug view

Variables view

Breakpoints view

Expressions view

Debug a web project

Breakpoint Properties

Hit Count

Enable Condition

Suspend Policy

Deploy and Debug

Inspect expressions

Watch expressions

Display expressions

Run to Line

Debugging JSP files (supported by MyEclipse)

嵌套诊断环境NDC

一个Junit例子(转自caterpillar.onlyfun.net)

Log4j优化

eclipse Junit��试向导