【转】20个开发人员非常有用的Java功能代码
【转】20个开发人员非常有用的Java功能代码
http://www.cn-java.com/www1/?viewnews-78759
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1. 把Strings转换成int和把int转换成String
//integer to numeric stringString a = String.valueOf(2); //numeric string to an int int i = Integer.parseInt(a);
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2. 向Java文件中添加文本
public void write(){BufferedWriter out = null; try { out = new BufferedWriter(new FileWriter("filename", true)); out.write("aString"); } catch (IOException e) { if (out != null) { try {out.close();} catch (IOException e1) {// TODO Auto-generated catch blocke1.printStackTrace();} }}}?3. 获取Java现在正调用的方法名
String methodName =Thread.currentThread().getStackTrace()[1].getMethodName();
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4. 在Java中将String型转换成Date型
public Date str2Date(){SimpleDateFormat format = new SimpleDateFormat( "dd.MM.yyyy" ); Date date = null;try {date = format.parse("12.12.2012");} catch (ParseException e) {// TODO Auto-generated catch blocke.printStackTrace();} return date;}?
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(); } } ?
6.将Java中的util.Date转换成sql.Date
这一片段显示如何将一个java util Date转换成sql Date用于数据库
java.util.Date utilDate = new java.util.Date(); java.sql.Date sqlDate = new java.sql.Date(utilDate.getTime());
?7. 使用NIO快速复制Java文件
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