天天冒出一堆新的东西！让人不知所措。
举个例子：jquery - angular - react - vue
这语言真的有毒。
如今的硬件，恐怕在浏览器中实现强类型语言JAVA来作为脚本语言都不比JS弱吧，哎真替applet感到冤枉。
老夫一直就觉得，浏览器一直是一个很奇葩的东西，HTML+CSS+JS本身，难道不能发明一种语言通过HTTP传输，然后直接调用OS级别的UI来渲染不就完了吗？
网页能实现的界面，我不信用操作系统的UI组件做不出来。
posted @
2018-04-01 00:19 West Farmer 阅读(164) |
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原文地址：
https://weblogs.java.net/blog/pat/archive/2004/10/stupid_scanner_1.html
正则表达式中，
\A是指一个字符串的开头，可能大家用惯了
^，而忽略了这个
\A， 但是^其实是指一行的开始，而不管一个字符串里面包含多少行，\A都只匹配第一行的开头。
那么我们可以用\A做点什么呢？，看下面这个例子：
static String convertStreamToString(java.io.InputStream is) {
java.util.Scanner s = new java.util.Scanner(is).useDelimiter("\\A");
return s.hasNext() ? s.next() : "";
}
相信大家都看懂了，用
\A作为分隔符，那么得到的当然就只有一个token，那就是整个字符串了。再配合Scanner，就轻易的将一个输入流转换为一个字符串了。
注意当需要做编码转换时，Scanner是有支持编码参数的构造方法的。
posted @
2013-11-28 09:38 West Farmer 阅读(1007) |
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摘要: Gson is library created by google guys, it is used for java bean to json serialization/deserialization. Gson can serialize any java bean, collection, map to json, and don't need to care about the...
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posted @
2013-11-22 19:22 West Farmer 阅读(5315) |
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编辑 收藏for example, we have a Combo whose "text" property is bound to a bean's "name" property like this:
IObservableValue nameObservable = BeansObservables.observeDetailValue(obserabedDriverProfile, "name", String.class);
ISWTObservableValue nameComboObservable = SWTObservables.observeText(driverClassCombo);
bindingContext.bindValue(nameComboObservable , nameObservable, new UpdateValueStrategy(UpdateValueStrategy.POLICY_UPDATE), null);
The variable "
obserabedDriverProfile" is a observed selection in a ListViewer, it's in a master-detail scenario. If we add some code like this:
obserabedDriverProfile.addValueChangeListener(new IValueChangeListener(){
@Override
public void handleValueChange(ValueChangeEvent event) {
DriverProfile dp = (DriverProfile)event.diff.getNewValue();
driverClassCombo.removeAll();
driverClassCombo.add(dp.getName();
driverClassCombo.setText(driverClassCombo.getItem(0));
}
});
every time you change the selection in the ListViewer, the selected bean's "name" property will be set to a empty string. Why? The
removeAll method of Combo will clear it's text, and combo's "text" property is bound to selected bean's "name" property. So, the right way is:
obserabedDriverProfile.addValueChangeListener(new IValueChangeListener(){
@Override
public void handleValueChange(ValueChangeEvent event) {
DriverProfile dp = (DriverProfile)event.diff.getNewValue();
String name = dp.getName;
driverClassCombo.removeAll();
driverClassCombo.add(name);
driverClassCombo.setText(driverClassCombo.getItem(0));
}
});
posted @
2013-04-14 15:24 West Farmer 阅读(248) |
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本文用英文写的，主要是考虑到本文分享的内容即使在google上也搜索不到（至少我是没有搜索到）。
My English is at a very low level, don't care about this fact, just focus on the idea shared here.
The idea comes from the source code of
ConfigurationElement which is located in package
org.eclipse.core.internal.registry, If you read through the source code, you can also get it. But I found there is no documentation about this topic, so I wrote this.
Sometimes we need to contribute java class to a extension point. And we can use
ConfigurationElement#
createExecutableExtension(String attributeName) to create an instance of it, if such a class is just a normal class, eclipse will call
class#newInstance(). But there is obvious restriction for using this approach, can't pass parameter in to create instance for example.
There are three different way how eclipse create instance of your class.
- normal, call class#newInstance()
- if your calss implements IExecutableExtension interface, IExecutableExtension#setInitializationData(IConfigurationElement config, String propertyName, Object data) will be called on the instance returned by class#newInstance()
- if your calss implements IExecutableExtensionFactory interface, IExecutableExtensionFactory#create() will be called
When you use the second method or the third method, you can
pass in parameters, check the source code of
ConfigurationElement, you will know how to do that. :D forgive me, I'm lazy.
posted @
2012-04-15 16:33 West Farmer 阅读(324) |
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SWT的Table不够强大，而且似乎有严重的性能问题。（貌似是调用OS的实现，但是在win7上面跑却非常慢，奇特！本地的性能不如虚拟机上跑的Swing）
好在SWT中可以嵌入AWT。
反正本人以前没有过多Swing的经验，但是在试玩了JTable之后发现确实很强大。
对于有兴趣的读者可以试一下，本文将分享如何使得JTable与JFace Data Binding Framework(下文中简称JDBF)一起协同工作。
通常像Table和List这种UI组件，展现的都是一个对象集合。JDBF 则为我们处理对象集合和UI界面的同步的问题。以List为例子，在Java中有java.util.List，而JFDB则提供了相应的
ObservableList类，这个类Wrap一个java.util.List，当你对其进行增删改时，与其绑定的UI组件会自动得到同步。但是ObservableList 的实现有个很大的问题就是对其的访问只限于其所属的Realm，这个Realm说白了就是SWT的UI线程，而当我们在SWT中嵌入AWT时，其中的AWT界面是跑在其自身的线程里面的。所以想要让JTable与JFace Data Binding Framework(下文中简称JDBF)一起协同工作还要解决多线程的问题。废话不多说了，直接上菜：
public class DOTableModel extends AbstractTableModel { /**
* the ObservableList instance to be shared with
*/
private ObservableList list;
private volatile Integer rowCount = null;
private volatile DOModel object;;
private final Object lock = new Object();
private static final long serialVersionUID = -8377145381412656796L;
public DOTableModel(ObservableList list){
this.list = list;
this.list.addListChangeListener(new IListChangeListener(){
@Override
public void handleListChange(ListChangeEvent event) {
for(ListDiffEntry de : event.diff.getDifferences()){
if(de.isAddition()){
DOTableModel.this.fireTableRowsInserted(de.getPosition(), de.getPosition());
}else{
DOTableModel.this.fireTableRowsDeleted(de.getPosition(), de.getPosition());
}
}
}
});
}
@Override
public int getRowCount() {
list.getRealm().exec(new Runnable(){
@Override
public void run() {
rowCount = list.size();
synchronized (lock) {
lock.notify();
}
}
});
synchronized (lock) {
while(rowCount == null){
try {
lock.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
return rowCount;
}
@Override
public int getColumnCount() {
return 11;
}
private void getObjectFromSWTRealm(final int rowIndex){
object = null;
list.getRealm().exec(new Runnable(){
@Override
public synchronized void run() {
object = (DOModel) list.get(rowIndex);
synchronized (lock) {
lock.notify();
}
}
});
synchronized (lock) {
while(object == null){
try {
lock.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
@Override
public Object getValueAt(final int rowIndex, int columnIndex) {
getObjectFromSWTRealm(rowIndex);
...
}
@Override
public void setValueAt(Object oValue, final int rowIndex, int columnIndex) {
getObjectFromSWTRealm(rowIndex);
...
}
@Override
public String getColumnName(int column) {
...
}
@Override
public boolean isCellEditable(int rowIndex, int columnIndex) {
return true;
}
}
posted @
2012-04-05 23:46 West Farmer 阅读(694) |
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编辑 收藏class Java {
Java Java;
Java() {
Java = Java(
this);
}
Java(Java Java) {
this.Java = Java;
}
Java Java() {
return Java.
this.Java;
}
Java Java(Java Java) {
return new Java(Java);
}
public static void main(String[] args) {
new Java().Java.Java().Java.Java();
}
}
原文地址
posted @
2012-04-05 23:25 West Farmer 阅读(577) |
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编辑 收藏public static void main(String[] args) throws IOException {
File sourceFile = new File("c:\\java\\A.java");
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
System.out.println(System.getProperties().getProperty("java.class.path") + ";F:\\IndigoSpace\\ejp");
compiler.run(null, null, null, "-cp", System.getProperties().getProperty("java.class.path") + ";F:\\IndigoSpace\\ejp", sourceFile.getPath());
System.out.println(new File("c:\\java\\").toURI().toURL());
URLClassLoader loader = new URLClassLoader(new URL[]{new File("c:\\java\\").toURI().toURL()});
try {
loader.loadClass("A");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
需要注意的是，上面的代码只有在JDK上才能运行，因为JDK里面才有javac。而且在实际应用中，你还要
自己将package声明转换成文件目录，否者装载类的时候就会找不到。
posted @
2011-10-21 17:05 West Farmer 阅读(328) |
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摘要: 原文地址：http://stackoverflow.com/questions/15496/hidden-features-of-java我选择几个有趣的：1. Double Brace Initialization Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHi...
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2011-10-12 13:11 West Farmer 阅读(364) |
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原代码是一个老外写的在桌面右下角弹出消息提示的一个类，我进行了改写。
任何改进，希望你能不吝分享。
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Scrollable;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.wb.swt.SWTResourceManager;
/**
* 具有淡入淡出效果且不需要用户点击关闭的消息提示框。
* @author ggfan@amarsoft
*
*/
public class Notifier {
private static final int DISPLAY_TIME = 2000;
private static final int FADE_TIMER = 50;
private static final int FADE_IN_STEP = 30;
private static final int FADE_OUT_STEP = 8;
private static final int FINAL_ALPHA = 225;
public static int DEFAULT_WIDTH = 150;
public static int DEFAULT_HEIGHT = 60;
private static Color _titleFgColor = SWTResourceManager.getColor(40, 73, 97);
private static Color _fgColor = _titleFgColor;
private static Color _bgFgGradient = SWTResourceManager.getColor(226, 239, 249);
private static Color _bgBgGradient = SWTResourceManager.getColor(177, 211, 243);
private static Color _borderColor = SWTResourceManager.getColor(40, 73, 97);
private static Image _oldImage;
// TODO Scrollable可能不合适
public static void notify(Scrollable scrollable, final String msg) {
final Shell parentShell = scrollable.getShell();
final Shell newShell = new Shell(parentShell, SWT.NO_FOCUS | SWT.NO_TRIM);
newShell.setLayout(new FillLayout());
newShell.setForeground(_fgColor);
newShell.setBackground(_bgBgGradient);
newShell.setBackgroundMode(SWT.INHERIT_FORCE);
scrollable.addDisposeListener(new DisposeListener(){ public void widgetDisposed(DisposeEvent e) {
newShell.dispose();
}
});
FillLayout layout = new FillLayout();
layout.marginWidth = 20;
layout.marginHeight = 20;
inner.setLayout(layout);
newShell.addListener(SWT.Resize, new Listener() {
public void handleEvent(Event event) {
try {
Rectangle rect = newShell.getClientArea();
Image newImage = new Image(Display.getDefault(), Math.max(1, rect.width), rect.height);
GC gc = new GC(newImage);
// 背景
gc.setForeground(_bgFgGradient);
gc.setBackground(_bgBgGradient);
gc.fillGradientRectangle(rect.x, rect.y, rect.width, rect.height, true);
// 边框
gc.setLineWidth(2);
gc.setForeground(_borderColor);
gc.drawRectangle(rect.x + 1, rect.y + 1, rect.width - 2, rect.height - 2);
gc.dispose();
newShell.setBackgroundImage(newImage);
if (_oldImage != null) {
_oldImage.dispose();
}
_oldImage = newImage;
} catch (Exception err) {
err.printStackTrace();
}
}
});
Label text = new Label(inner, SWT.WRAP | SWT.CENTER);
Font tf = text.getFont();
FontData tfd = tf.getFontData()[0];
tfd.setStyle(SWT.BOLD);
tfd.height = 8;
text.setFont(SWTResourceManager.getFont(tfd.getName(), 8, SWT.NORMAL));
text.setForeground(_fgColor);
text.setText(msg);
newShell.setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
if (Display.getDefault().getActiveShell() == null || Display.getDefault().getActiveShell().getMonitor() == null) {
return;
}
newShell.setLocation(computePoint(scrollable));
newShell.setAlpha(0);
newShell.setVisible(true);
fadeIn(newShell);
}
// TODO 当有滚动条出现的时候是否能够居中？
private static Point computePoint(Scrollable scrollable) {
Point p = scrollable.toDisplay(scrollable.getClientArea().x, scrollable.getClientArea().y);
int w = scrollable.getClientArea().width;
int h = scrollable.getClientArea().height;
p.x += w / 2 - DEFAULT_WIDTH / 2 ;
p.y += h / 2 - DEFAULT_HEIGHT / 2;
return p;
}
private static void fadeIn(final Shell _shell) {
Runnable run = new Runnable() {
@Override
public void run() {
try {
if (_shell == null || _shell.isDisposed()) {
return;
}
int cur = _shell.getAlpha();
cur += FADE_IN_STEP;
if (cur > FINAL_ALPHA) {
_shell.setAlpha(FINAL_ALPHA);
startTimer(_shell);
return;
}
_shell.setAlpha(cur);
Display.getDefault().timerExec(FADE_TIMER, this);
} catch (Exception err) {
err.printStackTrace();
}
}
};
Display.getDefault().timerExec(FADE_TIMER, run);
}
private static void startTimer(final Shell _shell) {
Runnable run = new Runnable() {
@Override
public void run() {
try {
if (_shell == null || _shell.isDisposed()) {
return;
}
fadeOut(_shell);
} catch (Exception err) {
err.printStackTrace();
}
}
};
Display.getDefault().timerExec(DISPLAY_TIME, run);
}
private static void fadeOut(final Shell _shell) {
final Runnable run = new Runnable() {
@Override
public void run() {
try {
if (_shell == null || _shell.isDisposed()) {
return;
}
int cur = _shell.getAlpha();
cur -= FADE_OUT_STEP;
if (cur <= 0) {
_shell.setAlpha(0);
if (_oldImage != null) {
_oldImage.dispose();
}
_shell.dispose();
return;
}
_shell.setAlpha(cur);
Display.getDefault().timerExec(FADE_TIMER, this);
} catch (Exception err) {
err.printStackTrace();
}
}
};
Display.getDefault().timerExec(FADE_TIMER, run);
}
}
posted @
2011-10-12 10:48 West Farmer 阅读(3254) |
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import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.jface.databinding.swt.SWTObservables;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.LineStyleEvent;
import org.eclipse.swt.custom.LineStyleListener;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.custom.VerifyKeyListener;
import org.eclipse.swt.events.TraverseEvent;
import org.eclipse.swt.events.TraverseListener;
import org.eclipse.swt.events.VerifyEvent;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.wb.swt.SWTResourceManager;
/**
* 关键字高亮编辑器。This class is a simple customized widget that wrappes a {@link org.eclipse.swt.custom.StyledText StyledText}.
* It consumes a keyword array and highlight them.
* @author ggfan@amarsoft
*
*/
public class KeywordsHighlightingEditor extends Composite{
private Color color = SWTResourceManager.getColor(SWT.COLOR_BLUE);
private Color variableColor = SWTResourceManager.getColor(SWT.COLOR_DARK_GREEN);
private String[] keywords;
private StyledText st;
public void setKeywordsColor(Color color){
this.color = color;
}
public void setKeywordsBgColor(Color color){
}
public IObservableValue observerContent(){
return SWTObservables.observeText(st, SWT.Modify);
}
public KeywordsHighlightingEditor(Composite parent, String[] keywords) {
super(parent, SWT.NONE);
this.keywords = keywords;
this.setLayout(new FillLayout());
st = new StyledText(this, SWT.WRAP | SWT.BORDER | SWT.V_SCROLL);
// 禁止回车键换行
st.addVerifyKeyListener(new VerifyKeyListener(){
public void verifyKey(VerifyEvent event) {
if(event.keyCode == SWT.CR){
event.doit = false;
}
}
});
// Tab键失去焦点而不是插入制表符
st.addTraverseListener(new TraverseListener(){
public void keyTraversed(TraverseEvent e) {
if (e.detail == SWT.TRAVERSE_TAB_NEXT || e.detail == SWT.TRAVERSE_TAB_PREVIOUS) {
e.doit = true;
}
}
});
st.addLineStyleListener(new SQLSegmentLineStyleListener());
}
private class SQLSegmentLineStyleListener implements LineStyleListener {
@Override
public void lineGetStyle(LineStyleEvent event) {
if(keywords == null || keywords.length == 0){
return;
}
List<StyleRange> styles = new ArrayList<StyleRange>();
int start = 0;
int length = event.lineText.length();
while (start < length) {
if (Character.isLetter(event.lineText.charAt(start))) {
StringBuffer buf = new StringBuffer();
int i = start;
for (; i < length && Character.isLetter(event.lineText.charAt(i)); i++) {
buf.append(event.lineText.charAt(i));
}
if(Arrays.asList(keywords).contains(buf.toString())) {
styles.add(new StyleRange(event.lineOffset + start, i - start, color, null, SWT.BOLD));
}
start = i;
}else if (event.lineText.charAt(start) == '#') {
StringBuffer buf = new StringBuffer();
buf.append('#');
int i = start + 1;
for (; i < length && Character.isLetter(event.lineText.charAt(i)); i++) {
buf.append(event.lineText.charAt(i));
}
if(buf.toString().matches("#[a-zA-Z]+\\d?")) {
styles.add(new StyleRange(event.lineOffset + start, i - start, variableColor, null, SWT.NORMAL));
}
start = i;
}
else{
start ++;
}
}
event.styles = (StyleRange[]) styles.toArray(new StyleRange[0]);
}
}
}
posted @
2011-10-12 10:42 West Farmer 阅读(929) |
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这个是英文的，比起国内的的一些编程问答网站不知道要强多少倍。
国内的问答类网站，各种答非所问，各种闲聊，各种复制粘贴。
do not google it before you think about it deep enough
do not ask before you google it
posted @
2011-10-11 17:02 West Farmer 阅读(179) |
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有的时候应用程序会hold一个对象实例，随着时间的推移，该对象所含的数据可能发生变化（比如调用setter方法改变一个属性的值）。
那么如何明确相比于一个特定的时刻，某个对象实例中的数据发生了变化呢？
方法肯定不止一种，我的方法是：
public static String hashOf(Serializable object) throws IOException, NoSuchAlgorithmException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oo = new ObjectOutputStream(baos);
oo.writeObject(object);
oo.flush();
MessageDigest messageDigest = MessageDigest.getInstance("MD5");
byte[] data = baos.toByteArray();
oo.close();
baos.close();
messageDigest.update(data, 0, data.length);
BigInteger hash = new BigInteger(1, messageDigest.digest());
return String.format("%1$032X", hash);
}
说白了就是把一个对象实例看作byte数组，然后对这个byte数组计算MD5，如果MD5值一样就表示所含数据一致。
MD5算法不是完美的，但是在实际应用中已经足够的，你也可以使用CRC32。
欢迎指正。
posted @
2011-10-11 16:51 West Farmer 阅读(311) |
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摘要: Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->package amarsoft.rcp.base.widgets;import java.io.File;import java.io.FileInputStream;im...
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posted @
2011-10-11 16:28 West Farmer 阅读(1541) |
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