???
//格式化日期為指定的格式
java.text.SimpleDateFormat format = new java.text.SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");
format.format(rs.getTimestamp("birth"))
//將字串符轉換成日期類型
java.text.SimpleDateFormat format = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
?java.util.Date date = format.parse("1981-10-25 10:20:25");
//在數據庫中將字符串轉成日期存入數據庫
birth=to_date(?,'YYYY-MM-DD HH24:MI:SS')
//發送SQL語句，執行存儲過程
java.sql.CallableStatement cs = con.prepareCall("{call addAge}")
//更新時使用數據庫的系統時間（sysdate）
"update student set birth=sysdate"
//IO的幾種常用通信方法---------------采用對象方式進行傳輸數據-------------------------
java.io.BufferedReader in = new java.io.BufferedReader(
??new java.io.InputStreamReader(socket.getInputStream()//System.in));
java.io.PrintWriter out = new java.io.PrintWriter(
?new java.io.OutputStreamWriter(new java.io.BufferedOutputStream(
?socket.getOutputStream())));
java.io.ObjectOutputStream out? = new java.io.ObjectOutputStream(
??new java.io.BufferedOutputStream(new java.io.FileOutputStream("t.dat")));
out.writeObject(s);
??out.flush();
??out.close();
java.io.ObjectInputStream in = new java.io.ObjectInputStream(
??new java.io.BufferedInputStream(new java.io.FileInputStream("t.dat")));
?Student ss = (Student)in.readObject();
--------------------------------------------------------------
//給按鈕添加事件 按鈕觸發數字自動滾動
this.button.addActionListener(
??new java.awt.event.ActionListener(){
?????
??public void actionPerformed(java.awt.event.ActionEvent e){
???new Thread(){
????? ??
????public void run(){
?????? while(true){
????? ?String s=txt.getText();
????? ?char c=s.charAt(s.length()-1);
????? ?String cs=s.substring(0,s.length()-1);
????? ?txt.setText(c+cs);
????? ?try{
????? ?Thread.sleep(1000);
????? ?}catch(Exception y){}
????? }?
????}
???}.start();
??}
?}
);
----------------------------------------
另一種添加事件的方法
button1.addActionListener( new CalculationListener());
//在剪切時候，它在一個內部類
class CalculationListener implements java.awt.event.ActionListener{
?public void actionPerformed(java.awt.event.ActionEvent e){
??javax.swing.JButton button? = (javax.swing.JButton)e.getSource();
???calc.calculate(button.getText());
??}
}
-----------------------------------------
啟動線程的幾種方法..
----------------------------
??R1 r = new R1();
??R1 w = new R1();
??Thread t = new Thread(r);
??Thread q = new Thread(w);
??t.start();
??q.start();
??new Thread(new W(socket)).start();
class R1 implements Runnable{
?public void run(){
??
?}
}
-----------------------------------
Thread1 t1 =new Thread1();
t1.start();
class Thread1 extends Thread{
?public void run(){
??
?}
}
命名線程：//Thread t2 = new Thread(new Thread3(10),"線程名")
得到線程序號：System.out.println (t2.getPriority());
?applet框架
-----------------------------
public class TestApplet extends javax.swing.JApplet{
?public? void init(){
??super.init();
?}
}
//設置窗口關閉時自動退出
this.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
------------------------------------------在lesson中有一個鼠標事件還沒有看通，有點復雜(day16)
//給按鈕添加事件的一種方法
? ?//按鈕調用
?button.addActionListener(new count2());
?//事件類繼承監聽器
?class count2 implements java.awt.event.ActionListener{
???public void actionPerformed(java.awt.event.ActionEvent e){
????counter();?
???}
??
?}
?//方法與其分開
?public void counter(){
??String s = jt1.getText();
??String m = jt2.getText();
??int n = Integer.parseInt(m);
??int u = Integer.parseInt(s);
??int w = n+u;
?
??jt3.setText(""+w);
?}
//為了代碼與窗體進行分開合作工作，因此將方法嵌入窗體中(“你中用我 我中有你”)
如：LotteryFunction lf = new LotteryFunction(this);
LotteryFunction 為功能類
將this作為工功能類構造的參數可很方便的在窗體顯示計算結果
------------------------------------------------------------------------------
如面板上有多個控件時，可用以下方法將其加入面板中
class MyPanel extends javax.swing.JPanel{
???javax.swing.JTextField[] texts = new javax.swing.JTextField[7];
???
???MyPanel(){
????this.setLayout(new java.awt.GridLayout(1,7,3,3));
????
????for(int i=0;i<texts.length;i++){
?????texts[i] = new javax.swing.JTextField();
?????texts[i].setBackground(java.awt.Color.green);
?????this.add(texts[i]);
????}
???}
}
------------------------------------------------------------
排序的代碼：
static int t;
int[] r ={8,9,7,6,5,4,3};
for(int i=0;i<r.length;i++){
?for(int j=1;j<r.length-i;j++){
??if(r[j]<r[j-1]){
??? t=r[j];
??? r[j]=r[j-1];
??? r[j-1]=t;?
??}
?}
}
--------------------------
如何給文件進行鎖定
public static void lock()throws Exception{
? ??java.io.FileOutputStream out = new java.io.FileOutputStream("c:\\TestIO.txt",true);
? ??java.nio.channels.FileChannel f = out.getChannel();
? ??
? ??java.nio.channels.FileLock lock = f.tryLock();
? ??
? ??if (lock!=null){
? ???System.out.println ("正在鎖定");
? ???Thread.sleep(100000);
? ???System.out.println ("解除完畢");
? ???lock.release();?
? ??}
?}
------------------------------
java.nio 如何進行文件傳輸的
java.io.FileInputStream in? = new java.io.FileInputStream("TestNIO.java");
? ?java.nio.channels.FileChannel ch = in.getChannel();
? ?java.nio.ByteBuffer buff? = java.nio.ByteBuffer.allocate(1024);
? ?while((ch.read(buff))!=-1){
? ??buff.flip();
? ??java.nio.charset.Charset ca = java.nio.charset.Charset.forName("gb2312");
?????//對緩存進行編碼設置后，再進行解析
? ??java.nio.CharBuffer cb = ca.decode(buff);
? ??System.out.println (cb);
? ??buff.clear();
??}
---------------文件傳輸
public static void copyfile()throws Exception{
? ??java.io.FileInputStream in? = new java.io.FileInputStream("TestNIO.java");
? ??java.nio.channels.FileChannel ch = in.getChannel();
? ??
? ??java.io.FileOutputStream out = new java.io.FileOutputStream("c:\\TestIO.java");
? ??java.nio.channels.FileChannel outch = out.getChannel();
? ??
? ??java.nio.ByteBuffer buff = java.nio.ByteBuffer.allocate(32);
? ??
? ??while((ch.read(buff))!=-1){
? ???buff.flip();
? ???outch.write(buff);
? ???buff.clear();
? ???
? ??}
? ??in.close();
? ??out.close();
? ??
? }
-------------------------------？？？關于java.nio.buff中的一些緩沖區的管理代碼還沒有看懂？？
幾種IO通信方法
1---------
java.io.BufferedInputStream in =new java.io.BufferedInputStream(
?????????new java.io.FileInputStream("TestIO.java"));
???
java.io.BufferedOutputStream out =new java.io.BufferedOutputStream(
?????????new java.io.FileOutputStream("c:\\t.txt"));
byte[] b =new byte[32];
??
??int len= 0 ;
??while((len=in.read(b))!=-1){
???out.write(b,0,len);
?????
??}
??out.flush();
??in.close();
??out.close();
2-----------
java.io.FileReader f =new java.io.FileReader("c:\\t.txt");
??char[] c = new char[32];
??int len=0;
??while((len=f.read(c))!=-1){
???System.out.println (new String(c,0,len));
??}
??
?f.close();
3------------------
java.io.BufferedReader r= new java.io.BufferedReader(new java.io.FileReader("TestIO.java"));
?
java.io.PrintWriter w= new java.io.PrintWriter(new java.io.BufferedWriter(new java.io.FileWriter("c:\\t.txt")));
?
?
?String line=null;
?
?while((line =r.readLine())!=null){
??w.println(line);
??
?}
??w.flush();
??r.close();
??w.close();
4-----------------------
java.io.PrintWriter p = new java.io.PrintWriter(new java.io.BufferedWriter(
?????????//是否在文件后進行追加數據（true）
?????new java.io.FileWriter("c:\\t.txt",true)));
??p.print("12");
??p.flush();
5------------------------
java.io.FileOutputStream out? = new java.io.FileOutputStream("c:\\t.txt");
???
???java.io.OutputStreamWriter write = new java.io.OutputStreamWriter(out,"UTF-8");
???
???write.write("2222222222");
???
???write.close();
5---------------------------從控制臺讀取數據
java.io.BufferedReader r? = new java.io.BufferedReader(
??????new java.io.InputStreamReader(System.in));
??????
??String s=r.readLine();
??System.out.println (s);
6-------------------------------向文件寫入數字
int i = 0;
??java.io.DataOutputStream out? =new java.io.DataOutputStream(
??????new java.io.BufferedOutputStream(new java.io.FileOutputStream("c:\\t.txt")));?
??
??out.writeInt(1);
??out.writeChar('a');
??out.writeInt(2);
??out.writeChar('b');
??//out.writeInt(4);
??out.flush();
??out.close();
??
??java.io.DataInputStream in =new java.io.DataInputStream(
??????new java.io.BufferedInputStream(new java.io.FileInputStream("c:\\t.txt")));
??while(i!=-1){
???System.out.println (i=in.readInt());
???//System.out.println (in.readDouble());
???System.out.println (in.readChar());?
??}?
7---------------------------------未看懂的代碼？？？？？？？？？？？？
java.io.RandomAccessFile r = new java.io.RandomAccessFile("c:\\t.txt","r");
???
???System.out.println (r.readInt());
???r.seek(0);
???System.out.println (r.readInt());
???r.seek(r.length()-8);
???System.out.println (r.readDouble());
???r.seek(r.length()-11);
???System.out.println (r.readUTF());??
//壓縮解壓文件的代碼--還未看
?public static void ZipFile()throws Exception{
???java.io.BufferedInputStream b = new java.io.BufferedInputStream(
????new java.io.FileInputStream("c:\\t.txt"));
????
???java.util.zip.ZipOutputStream z = new java.util.zip.ZipOutputStream(
????new java.io.BufferedOutputStream(new java.io.BufferedOutputStream(
?????new java.io.FileOutputStream("c:\\t.zip"))));
?????
???z.putNextEntry(new java.util.zip.ZipEntry("test.txt"));
???
???byte[] t = new byte[32];
???int len = 0;
???while((len=b.read(t))!=-1){
????z.write(t,0,len);//z.write(t);
???}
???
???z.flush();
???b.close();
???z.close();
?}?
----------
public static void unzip()throws Exception{
???java.util.zip.ZipFile? zip = new java.util.zip.ZipFile("c:\\t.zip");
???
???java.util.Enumeration enu = zip.entries();
???
???while(enu.hasMoreElements()){
??? ?java.util.zip.ZipEntry entry = (java.util.zip.ZipEntry)enu.nextElement();
??? ?java.io.InputStream in = zip.getInputStream(entry);
??? ?
??? ?java.io.BufferedOutputStream out = new java.io.BufferedOutputStream(
??? ???new java.io.FileOutputStream("c:\\test.txt"/*+entry.getName()*/));
??? ???
??? ?byte[] b = new byte[32];
??? ?int len =0;
??? ?while((len=in.read(b))!=-1){
??? ?? out.write(b,0,len);
??? ?}
???}
??}
------------------從控制臺向文件輸入數據
java.io.BufferedReader? in = new java.io.BufferedReader(new java.io.InputStreamReader(System.in));
? ? java.io.PrintStream out =new java.io.PrintStream(new java.io.BufferedOutputStream(new java.io.FileOutputStream("test.log")));
? ?// System.setErr(out);//可以使輸入轉向
? ?// System.setOut(out);//可以使輸入轉向
? ? while(true){
? ? ?out.println(in.readLine());
? ? ?out.flush();
---------------------添加多的一個“\”表示轉義符
java.io.File f2 = new java.io.File("c:\\test\\a\\b\\c");
實現文件類型的過濾方法-------1
String[] list = f2.list();
?System.out.println (java.util.Arrays.asList(list));
?list = f2.list(
??new java.io.FilenameFilter(){
???public boolean accept(java.io.File dir,String name){
????return name.endsWith(".java");
???}?
??}
?);
----------------------------2( 多個過濾方式)
String[] list = f2.list();
? list =f2.list(
??new java.io.FilenameFilter(){
???public boolean accept(java.io.File dir,String names){
??????
????boolean java= names.endsWith(".java");
????boolean txt = names.endsWith(".txt");
????return java || txt;
???}
??}?
?);
//String[] list = f2.list();
java.util.Arrays.asList(list)將數組轉成ArrayList
--------------------------------------------------刪除有文件的目錄實用代碼
public static void delDir(java.io.File dir){
?if(dir.isFile()){
??dir.delete();
?}else{
??java.io.File[] fis = dir.listFiles();
???for(int i=0;i<fis.length;i++){
????delDir(fis[i]);
???}
??dir.delete();
?}
}
------------------------------------------------------計算文件夾大小代碼
?System.out.println ("文件大小 "+s/1024+"? kB"+" = "+(float)s/1024/1024+"M");
?public? static double len(java.io.File dir){
??double s=0,len=0;
???if(dir.isFile()){
????s=dir.length();
???}else{
????java.io.File[] file = dir.listFiles();
????for(int i=0;i<file.length;i++){
?????len+=len(file[i]);
????}
???}
???return len+s;
?}
--------------------------------------------------------幾種集合類的使用
java.util.ArraryList list=new java.util.ArraryList();
?? ??list.add("abc");
??list.size();
??list.iterator();
java.util.HashSet set = new java.util.HashSet();
??for(int i=0;i<10;i++){
???set.add("abc"+i);
??}
??
java.util.Iterator it = set.iterator();
??while(it.hasNext()){
???System.out.println (it.next());
??}
?
java.util.HashMap map = new java.util.HashMap();
??map.put(new Integer(1),"002");
??map.put(new Integer(4),"001");
??System.out.println (map.get(new Integer(1)));
??System.out.println (map.get(new Integer(4)));
??
java.util.Set keys = map.keySet();//返回一個SET集合
??it=keys.iterator();
?while(it.hasNext()){
??Object o = it.next();
?? System.out.println (o+":"+map.get(o));
?}
-------------系統屬性的操作
java.util.Properties p = new java.util.Properties();
??FileInputStream f = new FileInputStream("c:\\a.properties");
??
??p.load(f);
??System.out.println (p.get("test.author"));
??System.out.println (p.get("test.version"));
??
??p.setProperty("test.author","llldiadsfsa");
??p.setProperty("test.address","meimei");
??p.setProperty("test.version","10.0");
??
??java.io.FileOutputStream out = new FileOutputStream("c:\\a.properties");
??p.save(out,"ruanwei");
??
??//p.store(out,"test");
??out.close();
---------------------------------------------------------------未懂代碼：以后再看？？？？////
?String str1 = args[0];
??String str2 = args[1];?????????????????
??
??if("int".equals(System.getProperty("precition"))){
???int i1 = Integer.parseInt(str1);
???int i2 = Integer.parseInt(str2);
???System.out.println ("i1"+"/"+"i2"+"="+divide(i1,i2));
??}else if("double".equals(System.getProperty("precition"))){
???double d1 = Double.parseDouble(str1);
???double d2 = Double.parseDouble(str2);
???System.out.println ("d1"+"/"+"d2"+"="+divide(d1,d2));
??}else if("你好".equals(System.getProperty("precition"))){
???System.out.println ("你好");
??}
?
?
?}
??public static int divide(int i1,int i2){
???return i1/i2;
??}
??public static double divide(double d1,double d2){
???return d1/d2;
??}
---------------------------------------------------------------------------------猜數字游戲代碼
class GuessGame{
?
?public static? void main(String[] args){
??outer:
??while(true){
????
????int num =1?+ (int)(Math.random()*100);
????int num1=20 ;
????System.out.println ("輸入數字"+num);
?????
????? ?inner:
????? ?while(num!=num1){
????? ??
????? ??java.io.BufferedReader in = new java.io.BufferedReader(
??????????new java.io.InputStreamReader(System.in));
????? ??try{
???????num1 = Integer.parseInt(in.readLine());
?????? ????if(num1>100 || num1<1){
????? ??? ??throw new java.lang.NumberFormatException();
????? ????}?
????? ????
???? ??}catch(java.io.IOException e){
????? ??? System.out.println ("io error"+e);
????? ??}catch(java.lang.NumberFormatException e2){
????? ???System.out.println ("請輸入正確的數字[1-100]");
????? ???continue ;
????? ??}
????? ???if(num>num1){
????? ????System.out.println ("is too small");
????? ???}else if(num<num1){
???? ????System.out.println ("is too large");
???? ???}else{
???? ????System.out.println ("ok");
???? ????
???? ????System.out.print ("還玩么? (y/n)");
???? ????
???? ?????try{
???? ??????if("y".equalsIgnoreCase(in.readLine())){
???? ???????continue outer;
???? ??????}
???? ?????}catch(java.io.IOException e){}
???? ???????break outer;
???? ???}
?????}
????}
??}?
??
??
}
---------------------------------------------------------------------從隨機數據取出與輸入相等的數據
static char[] getText(String s){
????int w = s.length();
????char[] cc =new char[w];
????
????int? index=0;
????while(true){
?????char? c = (char)(Math.random()*65536);
?????if(c==s.charAt(index)){
??????cc[index]=c;
??????index++;
??????if (index>=w){
???????break;
????????
??????}?
?????}
????}
???return cc;
??}
-----------------------------------------------------------------------多維數組的賦值------
??int[][] in= new int[5][];
??in[0]? = new int[]{0,1,2,3};
??in[1] = new? int[]{1,2};
--------------------------------------------------------覆蓋垃圾收集方法
public void finalize(){
?System.out.println ("000");
}
-----------------------------------------------------移位）
3>>1 正數移位 0011---》 0001? 為1(正數移位在前面加0)
-3>>1 負數移位 1011 -》1100--》1101 移位得 1110 --》1101--》1010 為-2（負數移位在前面加1）
-3>>>1? （這種移位以后再看？？？？？？？？？？？？？？？未懂）
-
-----------描述注釋文檔----------------javadoc -d 文件絕對路徑 -author -version private/public/protected
/**
?*
?*描述學生信息
?*@author 阮衛
?*@version 1.1
?*@docroot e:\lesson\day02\indexz
?*/
/**
*無參數據構造函數
*/
/**
* 有參數據構造函數
*@param n? 表示姓名
*/
/**
*方法說明
*/
-----------------------------------------------
Integer.MIN_VALUE
Short.MAX_VALUE
-----------------------------------
//在一常量池中引用的是同一地址
????q="sss";
????w="sss";