1. 字符串有整型的相互轉換
1 2 3 | String a = String.valueOf(2); //integer to numeric string inti = Integer.parseInt(a); //numeric string to an int |
2. 向文件末尾添加內容
1 2 3 4 5 6 7 8 9 10 11 12 | BufferedWriter out = null; try{ out = newBufferedWriter(newFileWriter(”filename”, true)); out.write(”aString”); } catch(IOException e) { // error processing code } finally{ if(out != null) { out.close(); } } |
3. 得到當前方法的名字
1 | String methodName = Thread.currentThread().getStackTrace()[1].getMethodName(); |
4. 轉字符串到日期
1 2 | java.util.Date = java.text.DateFormat.getDateInstance().parse(date String); |
或者是：
1 2 3 | SimpleDateFormat format = newSimpleDateFormat( "dd.MM.yyyy"); Date date = format.parse( myString ); |
5. 使用JDBC鏈接Oracle
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 | publicclassOracleJdbcTest { String driverClass = "oracle.jdbc.driver.OracleDriver"; Connection con; publicvoidinit(FileInputStream fs) throwsClassNotFoundException, SQLException, FileNotFoundException, IOException { Properties props = newProperties(); props.load(fs); String url = props.getProperty("db.url"); String userName = props.getProperty("db.user"); String password = props.getProperty("db.password"); Class.forName(driverClass); con=DriverManager.getConnection(url, userName, password); } publicvoidfetch() throwsSQLException, IOException { PreparedStatement ps = con.prepareStatement("select SYSDATE from dual"); ResultSet rs = ps.executeQuery(); while(rs.next()) { // do the thing you do } rs.close(); ps.close(); } publicstaticvoidmain(String[] args) { OracleJdbcTest test = newOracleJdbcTest(); test.init(); test.fetch(); } } |