1. public static String removeBlankAndDot(String target) { if (target != null) { StringBuffer buf = new StringBuffer(); for (int ii=0;ii<target.length();ii++) { char c = target.charAt(ii); if (c != ' ' && c != '.') buf.append(c); } return buf.toString(); } return null; } 2. public class DataLogger { private static PrintStream err = System.err; private static String filePath = "log"; private static String fileName = "my.data"; private static PrintWriter log; public static void logData(String logInfo) { try { if (log == null) { File file = new File(filePath + System.getProperty("file.separator") + fileName); log = new PrintWriter(new FileOutputStream(file)); } if (!logInfo.equals("")) { log.println(logInfo); log.flush(); } } catch (Exception e) { e.printStackTrace(err); System.exit(1); } } 3. public class Hello { public static void main(String[] args) { String name = "John"; char[] numbers = { '1', '0' }; System.out.println(name + " is the number " + numbers); } } 4. public class Hello { public static void main(String[] args) { Date d1 = new Date("1 Apr 98"); nextDateUpdate(d1); System.out.println("NextDay: " + d1); } private static void nextDateUpdate(Date arg) { arg = new Date(arg.getYear(), arg.getMonth(), arg.getDate() + 1); } } 5. // double values[100] initialized here double getValueForPeriod(int periodNumber) { try { return values[periodNumber]; } catch (ArrayIndexOutOfBoundException e) { return 0.0; } } 6. static void copy(String src, String dest) throws IOException { InputStream in = null; OutputStream out = null; try { in = new FileInputStream(src); out = new FileOutputStream(dest); byte[] buf = new byte[1024]; int n; while ((n = in.read(buf)) >= 0) { out.write(buf, 0, n); } } finally { if (in != null) in.close(); if (out != null) out.close(); } } 7. public class Timer { public static final Timer INSTANCE = new Timer(); private final int diffTime; private static final int CURRENT_YEAR = Calendar.getInstance().get(Calendar.YEAR); private Timer() { diffTime = CURRENT_YEAR - 1949; } public int diffTime() { return diffTime; } public static void main(String[] args) { System.out.println("diff Time is " + INSTANCE.diffTime()); } } 8. public String getStrTrim () { String string = new String(" 14 units "); string.trim(); return string; } 9. public class PingPong { public static synchronized void main(String[] a) { Thread t = new Thread() { public void run() { pong(); } }; t.run(); System.out.print("Ping"); } static synchronized void pong() { System.out.print("Pong"); } } 10. public class Stack { private Object[] elements; private int size = 0; public Stack(int initialCapacity) { this.elements = new Object[initialCapacity]; } public void push(Object e) { ensureCapacity(); elements[size++] = e; } public Object pop() { if (size == 0) throw new EmptyStackException(); return elements[--size]; } } 11. public boolean isYourTime(Date d) { Date d1 = new Date("1 Apr 98"); Date d2 = new Date("1 Apr 99"); return d.compareTo(d1) >= 0 && d.compareTo(d2) < 0; } 12. public final class Period { private final Date start; private final Date end; public Period(Date start, Date end) { this.start = start; this.end = end; // verify start >= end } public Date getStart() { return start; } } 13. publish Hashtable test(Hashtable ht) { // ... Hashtable newHt = new Hashtable(); // ... return newHt; } 14. public abstract class A { public abstract void process(); } public class DB extends A { public void process() { // retrieve data from database } } public class SAX extends A { public void process() { // processing the data from SAXparser } } 15. private List cheesesInStock = ... public Cheese[] getCheeses() { if (cheesesInStock.size() == 0) { return null; } } 16. public abstract class WorkQueue { private final List queue = new LinkedList(); protected WorkQueue() { new WorkerThread().start(); } public final void enqueue(Object workItem) { synchronized(queue) { queue.add(workItem); queue.notify(); } } protected abstract void processItem(Object workItem) throws InterruptedException; private class WorkerThread extends Thread { public void run() { while (true) { synchronized(queue) { // ... Object workItem = queue.remove(0); try { processItem(workItem); } catch (InterruptedException e) { return; } } } } } } class UseQueue extends WorkQueue { protected void processItem(Object workItem) throws InterruptedException { Thread child = new Thread() { public void run() { enqueue(workItem); } }; child.start(); child.join(); } } 17. public abstract class Asset { abstract protected powerDown(); // ... } public class ComputerAsset extends Asset { // ... protected void powerDown() { } } public class ComputerServer extends ComputerAsset { // ... public powerDown() { // empty } } public class BuildingAsset extends Asset { // ... protected void powerDown() { } } public class BuildingLight extends BuildingAsset { // ... protected void powerDown() { } } public class EmergencyLight extends BuildingLight { // ... public powerDown() { // empty } } public class ComputerMonitor extends ComputerAsset { // ... public powerDown() { // need do something } } public class RoomLights extends BuildingLight { // ... public powerDown() { // need do something } } public class BuildingManagement { Asset things[] = new Asset[24]; int numItems = 0; public void goodNight() { for (int i = 0; i < things.length; i++) { things[i].powerDown(); } } public void add(Asset thing) { // ... } } public static void main(String[] args) { BuildingManagement b1 = new BuildingManagement(); b1.add(new RoomLights(101)); b1.add(new EmergencyLight(100)); // ... b1.add(new ComputerMonitor(200)); b1.goodNight(); } 18. public int loadData(Connection conn, String sql) throws SQLException { // ... ResultSet rs = null; Object[] record = null; this.data = new ArrayList(); try { // ... while (rs.next()) { record = new Object[columnCount]; for (int i = 0; i < columnCount; i++) { record[i] = rs.getObject(i); } data.add(record); } } finally { // ... } } 19. public void printMetaData(Connection conn) { // ... DatabaseMetaData dmd = conn.getMetaData(); ResultSet rs = dmd.getTable(null,null,null,tabletypes); while (rs.next()) { // ... String table = rs.getString("TABLE_NAME"); ResultSet rs2 = dmd.getColumns(null,null,table,null); while (rs2.next()) { // ... } rs2.close(); } rs.close(); } 20. public void add1000(Vector v, String s) { for (int i = 0; i < 1000; i++) { v.add(s); } } 21. public void test() { // ... Hashtable ht = new Hashtable(); ... if (!ht.containsKey(key)) { return ht.get(key); } if (!ht.containsKey(key)) { ht.put(key, value); } } 22. String s = "info"; String p = null; public void func() { Vector v = new Vector(); v.addElement(s); // ... p = (String) v.elementAt(0); Vector v1 = new Vector(); // do other thing } 23. BufferedWriter fw = new BufferedWriter( new FileWriter("stock.dat")); String s = buy.toString(); fw.write(s, ...); 24. public void callManyTimes() { for (Iterator i = myList.iterator(); i.hasNext();) { Node node = (Node) i.next(); // ... } 25. Map first = new ... Map second = new ... boolean isSubmap = true; for (Iterator i = sencond.keySet().iterator(); i.hasNext();) { Object key = i.next(); Object valueInFirst = first.get(key); Object valueInSecond = second.get(key); if (valueInSecond == null) { if (valueInFirst != null) { // ... } } else if (!valueInSecond.equals(valueInFirst)) { // ... } } 26. public class test { public static void main(String[] args) { // ... try{ Connection con = DriveManager. ... new TablePrinter(con, "Names").walk(); } catch (SQLException e) { // ... } } } abstract class TableWalker { Connection con; String tableName; public TableWalker(Connection c, String tablename) { this.con = c; // ... } public void walk() throw SQLException { // ... ResultSet rs = stm.executeQuery(queryString); while(rs.next()) { execute(rs); } con.close(); // this is wrong place to stay } public abstract void execute(ResultSet rs) throws SQLException; } public class TablePrinter extends TableWalker { public TablePrinter(Connection c, String tablename) { super(c, tablename); } public void execute(ResultSet rs) throws SQLException { // ... } } 27. public class Work { private Hashtable ht = new Hashtable(); // ... public final void enHt(Object key, Object value) { synchronized(ht) { ht.put(key, value); } } } 28. public class A { private static String fileName = "myfile.txt"; ... public FileOutputStream writer = new FileOutputStream(fileName); public void write(int b) throws IOException { writer.write((byte)b); } ... } 29. public ManyMethodsCallThisFun () { ... for (int i = 0; i < size; i++) { Map<String, Record> map = Collections.synchronizedMap( new HashMap<String, Record>(states[i]); db.add(states[i], map); } ... } 30. public class A { public static void main (String[] args) { C c = new C(); c = null; System.gc(); } class C implements aListener { private D d = null; public C() { d = D.getInstance(); d.addaListener(this); } ... } class D { // D is Singleton ... public void removeaListener(aListener a) { ... } } } 31. String x = "Hello "; x += name; 32. private Node getNode(String key, Map map) { Nodekey nodekey = new Nodekey(key); Node n = (Node) map.get(nodekey); ... return n } 33. public class A { private String name = "foo"; ... public A() { setName("foo"); ... } public void setName(String s) { this.name = s; } ... } 34. public void readName() throws IOException { name = in.read(); } 35. interface Info { int PINK = 1; int BLUE = 2; ... } public class Graph implements Info { ... switch (color) { case PINK: ... } } 36. public void func(String str) { Runnable r = new Runnable() { public void run() { System.out.println(str); } }; Thread t = new Thread(r); t.start(); } 37. public class FileCopier { public FileCopier(String source, String dest) throws FileCopierEx { // catch IOException and throw FileCopierEx } } try { FileCopier fc = new filecopier(s, d); } catch (FilecopierEx fce) { ... } fc.docopy(); 38. BufferedOutputStream fos = new BufferedOutputStream( new FileOutputStream("stock.dat")); fos.write(buy.toBytes()); fos.flush(); fos.write(sell.toBytes()); fos.flush(); 39. if (s.startWith("a")) {...} if (s.startWith("cd")) {...} 40. try { ... System.out.write(somethings); } catch (IOException e) {...} 41. public class A { public static void main(String[] args) { ... StringBuffer word = null; switch(item) { case 1: word = new StringBuffer('M'); break; ... } word.append('e'); ... } } 42. EJB2 JNDI Object obj = context.lookup("java:comp/env/AccountHome"); 43. EJB2 public class Mysession implements SessionBean { SessionContext ctx; ... public Myfuc() throws mysessionException { try { withdraw(...); deposit(...); } catch (mysessionException e) { throw e; } } ... } |