- do {
- System.out.println("Count is: " + count);
- count++;
- } while (count < 11);
yes I took this from Wikipedia
个人推荐 并且对于 .
- boolean result = str1.equals(str2);
- boolean result = str1.equalsIgnoreCase(str2);
- int result = str1.indexOf(str2);
- int result = str1.indexOf(str2,5);
- String index = str1.substring(14);
- for (int i=0;i<str1.length();i++){
- char aChar = str1.charAt(i);
- }
- public class Main {
- public static void main(String[] args) {
- String str1 = "whatever string something";
- StringBuffer str1buff = new StringBuffer(str1);
- String str1rev = str1buff.reverse().toString();
- System.out.println(str1rev);
- }
- }
- public class Main {
- public static void main(String[] args) {
- String str1 = "reverse this string";
- Stack<Object> stack = new Stack<>();
- StringTokenizer strTok = new StringTokenizer(str1);
- while(strTok.hasMoreTokens()){
- stack.push(strTok.nextElement());
- }
- StringBuffer str1rev = new StringBuffer();
- while(!stack.empty()){
- str1rev.append(stack.pop());
- str1rev.append(" ");
- }
- System.out.println(str1rev);
- }
- }
- String strUpper = str1.toUpperCase();
- String strLower = str1.toLowerCase();
- String str1 = " asdfsdf ";
- str1.trim(); //asdfsdf
- str1.replace(" ","");
- String str = "tim,kerry,timmy,camden";
- String[] results = str.split(",");
- int[] myArray = new int[10];
- int[] tmp = new int[myArray.length + 10];
- System.arraycopy(myArray, 0, tmp, 0, myArray.length);
- myArray = tmp;
- for (Iterator it = map.entrySet().iterator();it.hasNext();){
- Map.Entry entry = (Map.Entry)it.next();
- Object key = entry.getKey();
- Object value = entry.getValue();
- }
- HashMap map = new HashMap();
- map.put(key1,obj1);
- map.put(key2,obj2);
- map.put(key2,obj2);
- int[] nums = {
- 1,
- 4,
- 7,
- 324,
- 0,
- -4
- };
- Arrays.sort(nums);
- System.out.println(Arrays.toString(nums));
- List<String> unsortList = new ArrayList<String>();
- unsortList.add("CCC");
- unsortList.add("111");
- unsortList.add("AAA");
- Collections.sort(unsortList);
- int index = arrayList.indexOf(obj);
- hashmap.containsValue(obj);
- hashmap.containsKey(obj);
- int[] nums = new int[] {
- 7,
- 5,
- 1,
- 3,
- 6,
- 8,
- 9,
- 2
- };
- Arrays.sort(nums);
- int index = Arrays.binarySearch(nums, 6);
- System.out.println("6 is at index: " + index);
- Object[] objects = arrayList.toArray();
- Object[] objects = hashmap.entrySet().toArray();
- Date todaysDate = new Date(); //todays date
- SimpleDateFormat formatter = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss"); //date format
- String formattedDate = formatter.format(todaysDate);
- System.out.println(formattedDate);
- Date mDate = new Date();
- Calendar mCal = Calendar.getInstance();
- mCal.setTime(mDate);
- Calendar mCal = Calendar.getInstance();
- Date mDate = mDate.getTime();
- public void StringtoDate(String x) throws ParseException{
- String date = "March 20, 1992 or 3:30:32pm";
- DateFormat df = DateFormat.getDateInstance();
- Date newDate = df.parse(date);
- }
- Date date = new Date();
- long time = date.getTime();
- time += 5*24*60*60*1000; //may give a numeric overflow error on IntelliJ IDEA
- Date futureDate = new Date(time);
- System.out.println(futureDate);
- Calendar today = Calendar.getInstance();
- today.add(Calendar.DATE,5);
- long diff = time1 - time2;
- diff = diff/(1000*60*60*24);
- boolean result = date1.equals(date2);
- Calendar cal = Calendar.getInstance();
- cal.get(Calendar.MONTH);
- cal.get(Calendar.YEAR);
- cal.get(Calendar.DAY_OF_YEAR);
- cal.get(Calendar.WEEK_OF_YEAR);
- cal.get(Calendar.DAY_OF_MONTH);
- cal.get(Calendar.DAY_OF_WEEK_IN_MONTH);
- cal.get(Calendar.DAY_OF_MONTH);
- cal.get(Calendar.HOUR_OF_DAY);
- long startTime = System.currentTimeMillis();
- //times flies by..
- long finishTime = System.currentTimeMillis();
- long timeElapsed = startTime-finishTime;
- System.out.println(timeElapsed);
- String pattern = "[TJ]im";
- Pattern regPat = Pattern.compile(pattern,Pattern.CASE_INSENSITIVE);
- String text = "This is Jim and that's Tim";
- Matcher matcher = regPat.matcher(text);
- if (matcher.find()){
- String matchedText = matcher.group();
- System.out.println(matchedText);
- }
- String pattern = "[TJ]im";
- Pattern regPat = Pattern.compile(pattern,Pattern.CASE_INSENSITIVE);
- String text = "This is jim and that's Tim";
- Matcher matcher = regPat.matcher(text);
- String text2 = matcher.replaceAll("Tom");
- System.out.println(text2);
- Pattern p = Pattern.compile("My");
- Matcher m = p.matcher("My dad and My mom");
- StringBuffer sb = new StringBuffer();
- boolean found = m.find();
- while(found){
- m.appendReplacement(sb,"Our");
- found = m.find();
- }
- m.appendTail(sb);
- System.out.println(sb);
- String pattern = "\\sa(\\w)*t(\\w)*"; //contains "at"
- Pattern regPat = Pattern.compile(pattern);
- String text = "words something at atte afdgdatdsf hey";
- Matcher matcher = regPat.matcher(text);
- while(matcher.find()){
- String matched = matcher.group();
- System.out.println(matched);
- }
- String pattern = "^a";
- Pattern regPat = Pattern.compile(pattern);
- Matcher matcher = regPat.matcher("");
- BufferedReader reader = new BufferedReader(new FileReader("file.txt"));
- String line;
- while ((line = reader.readLine())!= null){
- matcher.reset(line);
- if (matcher.find()){
- System.out.println(line);
- }
- }
- String pattern = "\\d$"; //any single digit
- String text = "line one\n line two\n line three\n";
- Pattern regPat = Pattern.compile(pattern, Pattern.MULTILINE);
- Matcher matcher = regPat.matcher(text);
- while (matcher.find()){
- System.out.println(matcher.group());
- }
- String str = "dsfdfsd54353%%%";
- try{
- int result = Integer.parseInt(str);
- }
- catch (NumberFormatException e){
- System.out.println("not valid");
- }
- Double a = 4.5;
- Double b= 4.5;
- boolean result = a.equals(b);
- if (result) System.out.println("equal");
- double doubleVal = 43.234234200000000234040324;
- float floatVal = 2.98f;
- long longResult = Math.round(doubleVal);
- int intResult = Math.round(floatVal);
- System.out.println(longResult + " and " + intResult); // 43 and 3
- double value = 2343.8798;
- NumberFormat numberFormatter;
- String formattedValue;
- numberFormatter = NumberFormat.getNumberInstance();
- formattedValue = numberFormatter.format(value);
- System.out.format("%s%n", formattedValue); //2.343,88
- double currency = 234546457.99;
- NumberFormat currencyFormatter;
- String formattedCurrency;
- currencyFormatter = NumberFormat.getCurrencyInstance();
- formattedCurrency = currencyFormatter.format(currency);
- System.out.format("%s%n", formattedCurrency); // $ 234.546.457,99
- int val = 25;
- String binaryStr = Integer.toBinaryString(val);
- String octalStr = Integer.toOctalString(val);
- String hexStr = Integer.toHexString(val);
- double rn = Math.random();
- int rint = (int) (Math.random()*10); // random int between 0-10
- System.out.println(rn);
- System.out.println(rint);
- double cos = Math.cos(45);
- double sin = Math.sin(45);
- double tan = Math.tan(45);
- double logVal = Math.log(125.5);
- //throw IOexception first
- BufferedReader inStream = new BufferedReader(new InputStreamReader(System.in));
- String inline ="";
- while (!(inline.equalsIgnoreCase("quit"))){
- System.out.println("prompt> ");
- inline=inStream.readLine();
- }
- StringBuffer buffer = new StringBuffer();
- Formatter formatter = new Formatter(buffer, Locale.US);
- formatter.format("PI: "+Math.PI);
- System.out.println(buffer.toString());
- BufferedReader br = new BufferedReader(new FileReader(textFile.txt)); //for reading
- BufferedWriter bw = new BufferedWriter(new FileWriter(textFile.txt)); //for writing
- InputStream is = new FileInputStream(fileName);
- int offset = 0;
- int bytesRead = is.read(bytes, ofset, bytes.length-offset);
- File file = new File(something.bin);
- RandomAccessFile raf = new RandomAccessFile(file,"rw");
- raf.seek(file.length());
- ZipFile file =new ZipFile(filename);
- Enumeration entries = file.entries();
- while(entries.hasMoreElements()){
- ZipEntry entry = (ZipEntry) entries.nextElement();
- if (entry.isDirectory()){
- //do something
- }
- else{
- //do something
- }
- }
- file.close();
- File f = new File("textFile.txt");
- boolean result = f.createNewFile();
- File f = new File("textFile.txt");
- File newf = new File("newTextFile.txt");
- boolean result = f.renameto(newf);
- File f = new File("somefile.txt");
- f.delete();
- File f = new File("somefile.txt");
- f.setReadOnly(); // making the file read only
- f.setLastModified(desired time);
- File f = new File("somefile.txt");
- long length = file.length();
- File f = new File("somefile.txt");
- boolean status = f.exists();
- File f = new File("somefile.txt");
- File dir = new File("directoryName");
- boolean success = f.renameTo(new File(dir, file.getName()));
- File f = new File("somefile.txt");
- File absPath = f.getAbsoluteFile();
- File f = new File("somefile.txt");
- boolean isDirectory = f.isDirectory();
- System.out.println(isDirectory); //false
- File directory = new File("users/ege");
- String[] result = directory.list();
- boolean result = new File("users/ege").mkdir();
- String serverName = "www.egek.us";
- Socket socket = new Socket(serverName, 80);
- System.out.println(socket);
- try {
- Socket sock = new Socket(server_name, tcp_port);
- System.out.println("Connected to " + server_name);
- sock.close( );
- } catch (UnknownHostException e) {
- System.err.println(server_name + " Unknown host");
- return;
- } catch (NoRouteToHostException e) {
- System.err.println(server_name + " Unreachable" );
- return;
- } catch (ConnectException e) {
- System.err.println(server_name + " connect refused");
- return;
- } catch (java.io.IOException e) {
- System.err.println(server_name + ' ' + e.getMessage( ));
- return;
- }
- package com.ege.example;
- javadoc -d \home\html
- -sourcepath \home\src
- -subpackages java.net
- jar cf project.jar *.class
- java -jar something.jar
来源: http://www.tuicool.com/articles/NBNniyJ