1. 速度慢。有时候editor最大化要点好几次才work。如果打开大的project，eclipse虽然慢但还可以work，netbeans基本上就死在那儿了。
2. 今天发现有时候键盘会失去响应。
3. Junit test，如果测试fail的话，比如说assertNull("xxx should be null", "string")，fail掉以后，message “xxx should be null"需要到output的窗口才可以看到，eclipse整合到一个窗口了。
4. 插件偏少，比如说hibernate的插件，groovy的插件。
5. 在我的linux下，错误提示都是乱码...
   

1. For ruby和rails的版本还蛮好用的。
2. 觉得最好用的就是code template，eclipse上不能用tab键trigger，而且eclipse里面允许重名的template，所以还要选，哪怕只有一个template。而且，eclipse里template只能在编辑java里使用。
   

Blogged with Flock

Tags: java, ajax

Blogged with Flock

Tags: java

Blogged with Flock

Tags: java

Tags: java

Instead of interface, I use Closure for callback

Blogged with Flock

Tags: hibernategroovy

发送soap message的代码如下:

public class MessageSender {
/**
* Logger for this class
*/
private static final Log logger = LogFactory.getLog(MessageSender.class);

private HttpClient httpClient;
private PostMethod postMethod;
private MessageFactory messageFactory;
private String url;
private NameValuePair sessionId;

public MessageSender(String ip){
this.httpClient = new HttpClient();

try {
this.messageFactory = MessageFactory.newInstance();
} catch (SOAPException e) {
logger.error(e.getMessage());
}

this.url = generateRequestUrl(ip);
}

private String generateRequestUrl(String ip) {
return "http://" + ip + ":8080/vantage/TR069";
}

public SOAPMessage sendMessage(SOAPMessage input) throws IOException, SOAPException {
this.postMethod = new PostMethod(this.url);
byte[] dataAsBytes = null;

if (input == null) {
logger.debug("Send a empty post");
dataAsBytes = new byte[0];
} else {

ByteArrayOutputStream data = new ByteArrayOutputStream();
input.writeTo(data);
dataAsBytes = data.toByteArray();
}

RequestEntity entity = new ByteArrayRequestEntity(dataAsBytes);
this.postMethod.setRequestEntity(entity);

if (this.sessionId != null) {
this.postMethod.addParameter(this.sessionId);
}

this.httpClient.executeMethod(this.postMethod);

sessionId = this.postMethod.getParameter("SessionID");

InputStream in = this.postMethod.getResponseBodyAsStream();

if (null == in) {
return null;
}

return this.messageFactory.createMessage(null, in);
}
}

最初的code里面,只有一个PostMethod,这样每次会一直keep一个http连接.因为在server端,只直接用http session来保存server的状态的,所以必须要是保持是一个session.用一个PostMethod可以做到这点.不过奇怪的是,在发第二次请求的时候,怎么都拿不到http connection.也不知道是不是httpclient的bug.后来才每次调用都重新create一个PostMethod,但是把第一次得到的sessionID add进去.

inverse会影响到save时候的行为。如果一端的inverse设为true，则save应该在另一端进行

The Java language gives you all the room you need to write code that would be very difficult for others to understand. Java also permits you to write code that is very easy to understand. Most development teams would prefer the latter.

A style guide provides provides a map so that the code generated by a group of programmers will be consistent and, therefore, easier to read and maintain. Many people do not care for the style guide offered by Sun. This document is one alternative.

This document covers most areas where there could be confusion or difference of opinion. Areas that have never been a problem in our experience are undocumented.

1 - Formatting

1.1 - Indentation

All indents are four spaces. All indenting is done with spaces, not tabs. (examples and reasoning)
Matching braces always line up vertically in the same column as their construct. (examples)
All if, while and for statements must use braces even if they control just one statement. (reasoning and examples)


1.2 - Spacing

All method names should be immediately followed by a left parenthesis.
All array dereferences should be immediately followed by a left square bracket.
Binary operators should have a space on either side.
Unary operators should be immediately preceded or followed by their operand.
Commas and semicolons are always followed by whitespace.
All casts should be written with no spaces.
The keywords if, while, for, switch, and catch must be followed by a space.
(examples)


1.3 - Class Member Ordering

class Order
{
    // fields

    // constructors

    // methods
}

1.4 - Maximum Line Length

Avoid making lines longer than 120 characters. (reasoning)

1.5 - Parentheses

Parentheses should be used in expressions not only to specify order of precedence, but also to help simplify the expression. When in doubt, parenthesize.

2 - Identifiers

All identifiers use letters ('A' through 'Z' and 'a' through 'z') and numbers ('0' through '9') only. No underscores, dollar signs or non-ascii characters.

2.1 - Classes and Interfaces

All class and interface identifiers will use mixed case. The first letter of each word in the name will be uppercase, including the first letter of the name. All other letters will be in lowercase, except in the case of an acronym, which will be all upper case. (examples)

2.2 - Packages

Package names will use lower case characters only. Try to keep the length under eight (8) characters. Multi-word package names should be avoided. (examples)

2.3 - All Other Identifiers

All other identifiers, including (but not limited to) fields, local variables, methods and parameters, will use the following naming convention. This includes identifiers for constants.

The first letter of each word in the name will be uppercase, except for the first letter of the name. All other letters will be in lowercase, except in the case of an embedded acronym, which will be all uppercase. Leading acronyms are all lower case. (examples and reasoning)

Hungarian notation and scope identification are not allowed. (reasoning and examples)

Test code is permitted to use underscores in identifiers for methods and fields. (reasoning and examples)

3 - Coding

3.1 - Constructs to Avoid

Never use do..while. (examples and reasoning)
Never use return in the middle of a method. (reasoning)
Never use continue. (reasoning)
Never use break other than in a switch statement. (reasoning)

3.2 - Do Not Compound Increment Or Decrement Operators

Use a separate line for an increment or decrement. (examples and reasoning)

Never use pre-increment or pre-decrement (examples and reasoning)

3.3 - Initialization

Declare variables as close as possible to where they are used. (examples)

3.4 - Access

All fields must be private, except for some constants.

4 - Self-Documenting Code

				"Any fool can write code that a computer can understand.
Good programmers write code that humans can understand."

		

--- Martin Fowler, Refactoring: Improving the Design of Existing Code

Rather than trying to document how you perform a complex algorithm, try to make the algorithm easier to read by introducing more identifiers. This helps in the future in case the algorithm changes but someone forgets to change the documentation. (examples and reasoning)

原文链接在 http://www.javaranch.com/style.jsp

比如说有这样一个类Server,要根据server.properties来初始化,一开始的代码是这样的:

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Properties;

/**
* @author sting
*/
public class Server {
private static final String FILE = "conf" + File.separator + "server.properties";

public void initial() throws IOException {
FileInputStream in = new FileInputStream(System.getProperty("APP_HOME") + File.separator + FILE);
Properties properties = new Properties();
properties.load(in);
// initial
}
}

文件路径和文件名都是hard code,很难测试. 我们首先把initial()重构一下,代码如下:

public void initial(InputStream in) throws IOException {
Properties properties = new Properties();
properties.load(in);
// initial
}

至少,测试时,我们可以传进来自己的InputStream,也可以方便的时候测试用的server.properties,或者干脆使用内联的文件,代码如下:

class ServerTest extends TestCase {
private Server server;

public void setUp() throws Exception {
this.server = new Server();
}

public void testInitial() throws Exception {
String serverProperties = "port=8080\n" +
"run_mode=normal";
InputStream in = new ByteArrayInputStream(serverProperties.getBytes());

this.server.initial(in);
// assert
}
}

但是,在实际工作的代码中,文件名和路径依然要hard code进代码中.这时,我们可以使用spring中的Resource接口来进一步改进我们的代码.

public class Server {
private Resource resource;

public void setResource(Resource r) {
this.resource = r;
}

public void initial() throws IOException {
Properties properties = new Properties();
properties.load(this.resource.getInputStream());
// initial
}
}

再加一段spring的配置文件:

<beans>
<bean id="server" class="Server">
<property name="resource" value="classpath:server.properties"/>
</bean>
</beans>

这样,Server的代码完全与文件的具体路径和文件名无关,仅仅用配置文件就可以指定,表达更清楚,也更易于测试.

当然,仅限于已经使用spring的项目.