1. 把Strings转换成int和把int转换成String
- String a = String.valueOf(2); //integer to numeric string
- int i = Integer.parseInt(a); //numeric string to an int
2. 向Java文件中添加文本
- Updated: Thanks Simone for pointing to exception. I have
- changed the code.
- BufferedWriter out = null;
- try {
- out = new BufferedWriter(new FileWriter(”filename”, true));
- out.write(”aString”);
- } catch (IOException e) {
- // error processing code
- } finally {
- if (out != null) {
- out.close();
- }
- }
3. 获取Java现在正调用的方法名
- String methodName = Thread.currentThread().getStackTrace()[1].getMethodName ();
4. 在Java中将String型转换成Date型
- java.util.Date = java.text.DateFormat.getDateInstance().parse(date String);
- or
- SimpleDateFormat format = new SimpleDateFormat( "dd.MM.yyyy" );
- Date date = format.parse( myString );
5. 通过Java JDBC链接Oracle数据库
- public class OracleJdbcTest
- {
- String driverClass = "oracle.jdbc.driver.OracleDriver";
- Connection con;
- public void init(FileInputStream fs) throws ClassNotFoundException,
- SQLException, FileNotFoundException, IOException
- {
- Properties props = new Properties();
- 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);
- }
- public void fetch() throws SQLException, 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 ();
- }
- public static void main(String[] args)
- {
- OracleJdbcTest test = new OracleJdbcTest ();
- test.init();
- test.fetch();
- }
- }
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