2銆佺幆澧冮厤緗細path錛欳:\Borland\JBuilder2005\jdk1.4\bin
3銆佸師紼嬪簭錛堜互.java涓哄悗緙錛夆斺斿瓧鑺傜爜錛?class涓哄悗緙錛夆斺擩VM
4銆佺▼搴忕粨鏋?br /> 娉ㄩ噴錛氬崟琛岋細// 澶氳錛?* */ 鏂囨。娉ㄩ噴錛?** */
5銆?JDK錛歫avac java javadoc
絎簩绔?br /> 1銆佹暟鎹被鍨嬪垎綾伙細鍘熷鏁版嵁綾誨瀷錛坒loat num; num=1.1234f;錛?nbsp;
寮曠敤鏁版嵁綾誨瀷(鏁扮粍銆佺被銆佹帴鍙?
2銆佹暟鎹被鍨嬭漿鎹細鑷姩鏁版嵁綾誨瀷杞崲銆佸己鍒舵暟鎹被鍨嬭漿鎹細錛堟暟鎹被鍨嬶級鍙橀噺鍚?br /> 3銆佹祦紼嬫帶鍒惰鍙ワ細鏉′歡鍒嗘敮錛歩f switch
寰幆錛歠or(int i=0;i<5;i++) while do-while
璺寵漿璇彞錛歝ontinue break
4銆佹暟緇勶細
int arrName[]; arrName=new int[10];
int arrName[]=new int[10];
int arrName[]={1,2,3};
int arrName[]=new int[]{1,2,3};
arrName.length 澶у皬
絎笁绔?br /> 1銆佺被
闈㈠悜瀵硅薄錛圤OP錛?灝佽銆佺戶鎵褲佸鎬?/font>
綾伙細灞炴э紙鍙橀噺錛夈佹柟娉?br />
class ClassName{
}
鏋勯犳柟娉曪細闅愬紡銆佸弬鏁板寲
鐗圭偣錛氭病鏈夎繑鍥炲肩被鍨嬨佹柟娉曚笌綾誨悓鍚嶃佷笉鍙互琚璞¤皟鐢ㄣ佸疄渚嬪寲鏃剁洿鎺ヨ皟鐢ㄣ佹瀯閫犲彲浠ラ噸杞?br />
2銆佸寘錛氶伩鍏嶅懡鍚嶅啿紿?br />
package packageName;
import packageName.className;
絎洓绔?br />
1銆佺戶鎵匡細瀛愮被緇ф壙鐖剁被錛坋xtends錛夛紝瀛愮被鍏鋒湁鐖剁被鐨勬墍鏈夊睘鎬у拰鏂規硶
鍏堣皟鐢ㄧ埗綾葷殑鏋勯犳柟娉?錛屽啀璋冪敤瀛愮被鐨勬瀯閫犳柟娉?br /> super( ):璋冪敤鐖剁被鐨勬瀯閫犳柟娉?/font>
2銆佸鎬侊細閲嶈澆錛堝悓涓綾婚噷錛夈侀噸鍐欙紙瀛愮被閲嶅啓鐖剁被鐨勬柟娉曪級
閲嶈澆錛?font color="blue">鏂規硶鍚嶇浉鍚屻佸弬鏁板垪琛ㄤ笉鍚屻佷笌榪斿洖鍊肩被鍨嬫棤鍏?/font>
閲嶅啓錛?font color="blue">鍙戠敓緇ф壙鍏崇郴錛屽瓙綾婚噸鍐欑埗綾葷殑鏂規硶錛屽瓙綾繪柟娉曚笌鐖剁被鐨勬柟娉曞悓鍚嶏紝瀹炰緥鍖栧瓙綾誨璞¤皟鐢ㄧ殑鏄瓙綾婚噸鍐欏悗鐨勬柟娉?
Super: 鐖剁被瀵硅薄 璋冪敤鐖剁被鐨勬柟娉?br />
Java閲屼笉鏀寔澶氱戶鎵?br /> 綾誨彲浠ュ疄鐜板涓帴鍙?錛歩nterface 鎵鏈夋柟娉曢兘鏄娊璞＄殑
瀹炵幇鎺ュ彛 錛歝lassName implements interfaceName1,interfaceName2
3銆佽闂慨楗扮錛歱ublic private protected 榛樿
鏂規硶鐨勮闂慨楗扮錛歴tatic final abstract
絎簲绔?
1銆佹崟鑾峰紓甯?try{
}catch錛堝紓甯哥被鍨?寮傚父鍚嶏級
finally錛堟棤璁烘槸鍚﹀凡寮曞彂寮傚父錛岃繖涓潡閮借鎵ц錛?br />
2銆佹姏鍑哄紓甯?throw 鍦ㄦ瀯閫犻噷浣跨敤
throws 鍦ㄦ瀯閫犲墠浣跨敤
3銆佽嚜瀹氫箟寮傚父 Exception 錛堥厤鍚坱hrow澶氱偣錛?
絎叚绔?lang
1銆丆haracter:
鏂規硶 璇存槑
isDigit() 紜畾瀛楃鏄惁涓?0 鑷?9 涔嬮棿鐨勬暟瀛?br /> isLetter() 紜畾瀛楃鏄惁涓哄瓧姣?br /> isLowerCase() 紜畾瀛楃鏄惁涓哄皬鍐欏艦寮?br /> isUpperCase() 紜畾瀛楃鏄惁涓哄ぇ鍐欏艦寮?br /> isWhiteSpace() 紜畾瀛楃鏄惁涓虹┖鏍兼垨鎹㈣絎?br /> isUnicodeIdentifierStart() 紜畾鏄惁鍏佽灝嗘寚瀹氬瓧絎︿綔涓?Unicode 鏍囪瘑絎︿腑鐨勯瀛楃
2銆丼tring:錛堜笉鍙樻э紝鎵鏈夋柟娉曚互榪斿洖鍊煎緱鏂瑰紡鎵ц錛?br /> length( ) //鑾峰緱瀛楃涓查暱搴?br /> equals( ) //姣旇緝瀛楃涓插兼槸鍚︾浉絳夛紙濡傛灉姣旇緝涓や釜瀵硅薄鏄惁鐩哥瓑錛? =錛?br />
鏂規硶 -----------------------------------------------------------------> 璇存槑
boolean equalsIgnoreCase (String value) 姝ゆ柟娉曟瘮杈冧袱涓瓧絎︿覆錛屽拷鐣ュぇ灝忓啓褰㈠紡
int compareTo(String value) 鎸夊瓧姣嶉『搴忔瘮杈冧袱涓瓧絎︿覆銆?br /> 濡傛灉涓や釜瀛楃涓茬浉絳夛紝鍒欒繑鍥?0錛?br /> 濡傛灉瀛楃涓插湪璇ュ間箣鍓嶏紝鍒欒繑鍥炲煎皬浜?0錛?br /> 濡傛灉瀛楃涓插湪璇ュ間箣鍚庯紝鍒欒繑鍥炲煎ぇ浜?0
boolean startsWith(String value) 媯鏌ヤ竴涓瓧絎︿覆鏄惁浠ュ彟涓涓瓧絎︿覆寮濮嬨?br /> boolean endsWith(String value) 媯鏌ヤ竴涓瓧絎︿覆鏄惁浠ュ彟涓涓瓧絎︿覆緇撴潫銆?br /> indexOf( ): 鎼滅儲鏌愪釜瀛楃涓插嚭鐜扮殑浣嶇疆錛堝鏋滄病鏈夋壘鍒幫紝榪斿洖-1錛?br /> 鏂規硶 ----------------------------------------------------> 璇存槑
public char charAt(int index) 姝ゆ柟娉曠敤浜庝粠鎸囧畾浣嶇疆鎻愬彇鍗曚釜瀛楃錛岃浣嶇疆鐢辯儲寮曟寚瀹氾紝绱㈠紩涓殑鍊煎繀欏諱負闈炶礋
public String substring(int index) 姝ゆ柟娉曠敤浜庢彁鍙栦粠浣嶇疆绱㈠紩寮濮嬬殑瀛楃涓查儴鍒?br /> public String substring(int beginindex, int endindex) 姝ゆ柟娉曠敤浜庢彁鍙?beginindex 鍜?endindex 浣嶇疆涔嬮棿鐨勫瓧絎︿覆閮ㄥ垎
public String concat(String str) 姝ゆ柟娉曠敤浜庤繛鎺ヤ袱涓瓧絎︿覆錛屽茍鏂板緩涓涓寘鍚皟鐢ㄥ瓧絎︿覆鐨勫瓧絎︿覆瀵硅薄
public String replace(char old, char new) 姝ゆ柟娉曠敤浜庡皢璋冪敤瀛楃涓蹭腑鍑虹幇鏌愪釜瀛楃鐨勬墍鏈変綅緗兘鏇挎崲涓哄彟涓涓瓧絎?br /> public String trim() 姝ゆ柟娉曠敤浜庤繑鍥炰竴涓墠鍚庝笉鍚換浣曠┖鏍肩殑璋冪敤瀛楃涓茬殑鍓湰
toLowerCase( ) //鎶婂瓧絎︿覆杞寲涓哄皬鍐?br /> toUpperCase( ) //鎶婂瓧絎︿覆杞寲涓哄ぇ鍐?br />
StringBuffer:
鏂規硶 ----------------------------------------------> 璇存槑
StringBuffer insert(String s,int index) 鍦ㄦ寚瀹氫綅緗?index)鎻掑叆鎸囧畾鐨勫瓧絎︿覆錛坰錛?br /> int length( ) 紜畾 StringBuffer 瀵硅薄鐨勯暱搴?br /> void setCharAt(int pos, char ch) 浣跨敤 ch 鎸囧畾鐨勬柊鍊艱緗?pos 鎸囧畾鐨勪綅緗笂鐨勫瓧絎?br /> String toString( ) 杞崲涓哄瓧絎︿覆褰㈠紡
StringBuffer reverse() 淇濈暀 StringBuffer 瀵硅薄涓殑瀛楃
StringBuffer delete(int start, int end) 姝ゆ柟娉曞皢鍒犻櫎璋冪敤瀵硅薄涓粠 start 浣嶇疆寮濮嬬洿鍒?end 鎸囧畾鐨勭儲寮?– 1 浣嶇疆鐨?瀛楃搴忓垪
StringBuffer deleteCharAt(int pos) 姝ゆ柟娉曞皢鍒犻櫎 pos 鎸囧畾鐨勭儲寮曞鐨勫瓧絎?br /> StringBuffer replace(int start, int end, String s) 姝ゆ柟娉曚嬌鐢ㄤ竴緇勫瓧絎︽浛鎹㈠彟涓緇勫瓧絎︺傚皢鐢ㄦ浛鎹㈠瓧絎︿覆浠?start 鎸囧畾鐨勪綅緗紑濮嬫浛鎹紝鐩村埌 end 鎸囧畾鐨勪綅緗粨鏉?br />
Math: 鏂規硶閮芥槸闈欐佺殑錛岃皟鐢ㄦ椂鐩存帴鐢ㄧ被鍚嶈皟鐢?/font>
Exa: Math.abs(-1);
鏂規硶 -------------------------------------------------> 璇存槑
double sin (double numvalue) 璁＄畻瑙?numvalue 鐨勬寮﹀?br /> double cos (double numvalue) 璁＄畻瑙?numvalue 鐨勪綑寮﹀?br /> double pow (double a, double b) 璁＄畻 a 鐨?b 嬈℃柟
double sqrt (double numvalue) 璁＄畻緇欏畾鍊肩殑騫蟲柟鏍?br /> int abs (int numvalue) 璁＄畻 int 綾誨瀷鍊?numvalue 鐨勭粷瀵瑰鹼紝涔熸帴鏀?long銆乫loat 鍜?double 綾誨瀷鐨勫弬鏁?br /> double ceil (double numvalue) 榪斿洖澶т簬絳変簬 numvalue 鐨勬渶灝忔暣鏁板?br /> double floor (double numvalue) 榪斿洖灝忎簬絳変簬 numvalue 鐨勬渶澶ф暣鏁板?br /> int max(int a, int b) 榪斿洖 int 鍨嬪?a 鍜?b 涓殑杈冨ぇ鍊鹼紝涔熸帴鏀?long銆乫loat 鍜?double 綾誨瀷鐨勫弬鏁?br /> int min(int a, int b) 榪斿洖 a 鍜?b 涓殑杈冨皬鍊鹼紝涔熷彲鎺ユ敹 long銆乫loat 鍜?double 綾誨瀷鐨勫弬鏁?br />
絎?绔?br />
Util:
1銆?nbsp; Date: Date objd=new Date(); objd.getTime(); //鑾峰彇姣
objd.toString(); //鏃墮棿瀛楃涓?br />
2銆?nbsp; Calendar Calendar objc=Calendar.getInstance(); objc.get(Calendar.Year)
3銆?nbsp; Random Random objr=new Random(); objr.nextInt(); objr.nextFloat(); objr.nextDouble();
4銆?nbsp; ArrayList:
a) Add() 娣誨姞鏁扮粍鍏冪礌
b) Get() 瀵熺湅鍏冪礌鍊?br /> c) indexOf() 鏌ョ湅鏌愬瓧絎︿覆絎竴嬈″嚭鐜扮殑浣嶇疆
d) lastIndexOf() 鏌ョ湅鏌愬瓧絎︿覆鏈鍚庝竴嬈″嚭鐜扮殑浣嶇疆
5銆?nbsp; LinkedList錛?br />
a) addLast() 浠庨摼琛ㄧ殑鏈鍚庝竴涓厓绱犳墽琛屽鍔?br /> b) addFirst() 浠庨摼琛ㄧ殑絎竴涓厓绱犳墽琛屽鍔?br /> c) removeFirst() 浠庨摼琛ㄧ殑絎竴涓厓绱犳墽琛屽垹闄?br /> d) removeLast() 浠庨摼琛ㄧ殑鏈鍚庝竴涓厓绱犳墽琛屽垹闄?br />
6銆?nbsp; HashMap:
鏂規硶錛歱ut(key,value) //娣誨姞
get(key) //鏌ユ壘
Exa:
public void add(HashMap objhm,String key,String value){
objhm.put(key,value);
}
public void put(HashMap objhm,String key){
System.out.println(key+"鐨勬垚緇╋細"+objhm.get(key));
}
瀹屾垚淇敼錛氬厛鍒犻櫎錛歳emove(key) //鍒犻櫎
鍦ㄦ坊鍔狅細put(key,value) //娣誨姞
Exa:
public void update(HashMap objhm,String key,String value){
objhm.remove(key);
objhm.put(key,value);
}
7銆?nbsp; Vector:
娣誨姞鍏冪礌錛歛ddElement( )
鎻掑叆錛歩nsertElementAt( )
鎼滅儲錛歩ndexOf( )
鑾峰緱絎竴涓厓绱狅細firstElement( )
鑾峰緱鏈鍚庝竴涓厓绱狅細lastElement( )
鑾峰緱瀹歸噺錛歝apacity( )
Exa1:
public void add(Vector objv,String str){
objv.addElement(str);
}
public void show(Vector objv){
int size=objv.size();
for(int i=0;i<size;i++){
System.out.println("絎?+(i+1)+"涓厓绱犵殑鍊兼槸錛?+objv.get(i));
}
}
Exa2:
public void addv(Vector objsup,Vector objsub){
objsup.addElement(objsub);
}
絎叓绔?io
鏂囦歡杈撳叆杈撳嚭錛?br />
1銆?nbsp; 鏂囨湰鏂囦歡錛?錛夊瓧鑺?br /> 璇伙細FileInputStream 鏂規硶錛歳ead()
Exa:
public void fileRead(String fileName){
try {
FileInputStream objfi = new FileInputStream(fileName);
try {
int size = objfi.available();
char ch[]=new char[100];
for(int i=0;i<size;i++){
ch[ i ]=(char)(objfi.read());
System.out.print(ch[ i ]);
}
objfi.close();
} catch (IOException ex1) {
}
} catch (FileNotFoundException ex) {
}
}
鍐欙細FileOutputStream 鏂規硶錛歸rite( )
Exa:
public void fileWrite(String fileName){
try {
FileOutputStream objfo = new FileOutputStream(fileName,true);
String str="ACCP";
byte []arrb=str.getBytes();
try {
objfo.write(arrb, 0, arrb.length);
objfo.close();
} catch (IOException ex1) {
}
} catch (FileNotFoundException ex) {
}
}
2錛夊瓧絎?br /> 璇伙細FileReader BufferedReader
鏂規硶錛歳eadLine()
Exa:
public void charRead(String fileName){
try {
FileReader objfr = new FileReader(fileName);
BufferedReader objbr=new BufferedReader(objfr);
String line = null;
try {
line = objbr.readLine();
while(line!=null){
System.out.println(line);
line=objbr.readLine();
}
objbr.close();
objfr.close();
} catch (IOException ex1) {
}
} catch (FileNotFoundException ex) {
}
}
鍐欙細FileWriter BufferedWriter
鏂規硶錛歸rite()
Exa:
public void charWrite(String fileName){
try {
FileWriter objfw = new FileWriter(fileName);
BufferedWriter objbw=new BufferedWriter(objfw);
objbw.write("t64");
objbw.write(" Very Good!");
objbw.newLine();
objbw.write("緇х畫鍔姏");
objbw.close();
objfw.close();
} catch (IOException ex) {
}
}
2銆?nbsp; 浜岃繘鍒?br /> 璇伙細FileInputStream DataInputStream
鏂規硶錛歳ead()
鍐欙細FileOutputStream DataOutputStream
鏂規硶錛歸rite()
Exa:
public void datacopy(String oldFileName,String newFileName){
try {
FileInputStream objfi = new FileInputStream(oldFileName);
DataInputStream objdi=new DataInputStream(objfi);
FileOutputStream objfo=new FileOutputStream(newFileName);
DataOutputStream objdo=new DataOutputStream(objfo);
try {
int temp = objdi.read();
while(temp!=-1){
objdo.write(temp);
temp=objdi.read();
}
objdo.flush();
objdo.close();
objdi.close();
objfi.close();
objfo.close();
} catch (IOException ex1) {
}
} catch (FileNotFoundException ex) {
}
}
鍚庨潰绔犺妭鐨勬葷粨
涓銆乯dbc:鏁版嵁搴撹繛鎺ュ鐞?br />
浜屻佹牳蹇冪被
1銆丏riverManager:椹卞姩綆＄悊鍣?br />
1銆佸緱鍒拌繛鎺?br /> --odbc
Connection con=DriverManager.getConnection("jdbc:odbc:緋葷粺dns","sa","sa");
--涓撶敤鎺ュ彛
Connection con=DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;databaseName=pubs","sa","");
2銆佽繛鎺?br /> Conenction con;
--浜х敓鎵цsql鐨勫璞?
--PreparedStatement
PreparedStatement ps=con.preparedStatement(sql);
--Statement
Statemnet st=con.createStatemenet();
3銆佹墽琛宻ql鐨勫璞?br /> --PreparedStatemenet鍙紶鍙傦紝濡傛灉涓涓猻ql澶氭閲嶅琚墽琛屼嬌鐢≒reparedStatement
PreparedStatement ps=con.preparedStatement("insert into a1(?,?,?)");
ps.setString(1,"1");
--鎵цinsert update delete
ps.executeUpdate();
--鎵цselect
ResultSet rs=ps.executeQuery();
--Statement:涓嶅彲浼犲弬錛屼笉閲嶅鎵ц鏃跺彲鐢?br /> Statement sm=con.createStatement();
--鎵цinsert update delete
sm.executeUpate("delete from customer");
--鎵цselect
ResultSet rs=sm.executeQuery("select * from customer");
4銆佺粨鏋滈泦(resultSet)錛岃鎯沖彇鍊煎繀欏籲ext 涓嬈?br /> --鍙栦竴琛?br /> if(rs.next())
{
}
--鍙栧琛?br /> while(rs.next())
{
}
www.javakf.com 2008-07-17 14:25 鍙戣〃璇勮
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