1. The java.util.regex API
Now that we've covered the theory of how to construct regular
expressions, the
hard part is over. All that's left is to investigate the Java API for applying
regexes: searching for them in strings, retrieving captured text, and replacing
matches with substitution text.
1.1 Pattern
As we've said, the regex patterns that we write as strings are,
in actuality, little programs describing how to match text. At runtime, the Java
regex package compiles these little programs into a form that it can execute
against some target text. Several simple convenience methods accept strings
directly to use as patterns. More generally, however, Java allows you to
explicitly compile your pattern and encapsulate it in an instance of a
Pattern
object. This is the most efficient way to handle patterns that
are used more than once, because it eliminates needlessly recompiling the
string. To compile a pattern, we use the static method Pattern.compi ......
import java.io.File;
import java.io.IOException;
import java.util.Scanner;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JTextArea;
public class DisplayFile {
/**
* @param args
*/
public static void main(String[] args)throws IOException {
// TODO Auto-generated method stub
JFrame frame =new JFrame("Display File");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTextArea ta=new JTextArea(20,30);
......
———————————————————
付出的努力非常人所能想象
————————————————————
那我可以肯定的说，100个程序员里至少有10个人付出的努力非常人想象，但是坚持超过三年的不会超过5个，超过5年的不会超过1个
01年开始到现在见的程序员多了，认识的也多了，像楼主这样有觉悟的也多了，甚至工作半年后有楼主这样觉悟的人也多了。
在这里并不是摆资格，说什么01年 00年，在编程上我还才入门，尽管这5年里我每年休息的时间很少超过10天，每天很少凌晨1点前睡觉（两年前都是凌晨2点睡觉），尽管我知道以前写的代码大部分都是垃圾，尽管我现在可以说，我写出的代码绝对不是垃圾，� ......
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
public class Notepad extends JFrame {
// 系统组件声明
private JMenuBar menuBar = new JMenuBar();
private JEditorPane content = new JEditorPane();
private JScrollPane scroll = new JScrollPane(content);
private JFileChooser filechooser = new JFileChooser() ;
private BorderLayout bord = new BorderLayout();
private JLabel statusBar = new JLabel();
private JPanel pane = new JPanel();
private File file = null;
// 定义文件菜单
private JMenu fileMenu = new JMenu();
private JMenuItem newMenuItem = new JMenuItem();
private JMenuItem openMenuItem = new JMenuItem();
private JMenuItem saveMenuItem = new JMenuItem();
private JMenuItem saveAsMenuItem = new JMenuItem();
private JMenuItem pageSetupMenuItem = new JMenuItem();
private JMenuItem printMenuItem = new JMenuItem();
private JMenuItem exitMenuItem = new JMenuItem();
// 定义风格菜单
private JMenu styleMenu = new JMen ......
import java.awt.*;
import java.awt.event.*;
public class MyCalculator {
private Frame f;
private TextField tf = new TextField(30);
private long result;
private boolean append=false;
private char operator='=';
private Button[] btn=new Button[15];
public MyCalculator() {
initComponent();
}
private void initComponent() {
f = new Frame("My Calculator V1.0");
f.setLayout(new BorderLayout()); //The frame uses BorderLayout
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent evt) {
System.exit(0);
&nb ......
UTF8转换成GB2312 当我们在基于HTTP协议的JSP或Servlet的应用中获取数据或发送请求时，JVM会把输送的数据编码成UTF8格式。如果我们直接从HTTP流中提取中文数据，提取的结果为“????”（可能更多问号），为转换成我们能够理解的中文字符，我们需要把UTF8转换成GB2312，借助ISO-8859-1标准编码能够轻易的实现，下面的代码实现了这一功能：
byte [] b;
String utf8_value;
utf8_value = request.getParameter("NAME");//从HTTP流中取"NAME"的UTF8数据
b = utf8_value.getBytes("8859_1"); //中间用ISO-8859-1过渡
String name = new String(b, "GB2312"); //转换成GB2312字符
在知道流长度的情况下将输入流转换成字节数组 Java中的输入流抽象类InputStream有int read(byte[] b, int off, int len)方法，参数中byte[] b是用来存放从InputStream中读取的数据,int off指定数组b的偏移地址，也就是数组b的起始下标，int len指定需要读取的长度，方法返回实际读取的字节数。刚学Java的朋友可能要说：先定义一个与流长度等长的字节数组，调用read方法，指定起始下标为0，指定读取长度与数组长度等长，不是一下子可以读出来了吗？说的没错，笔者曾经也试着这样读� ......
最新文章 :