这是非常糟糕的代码-书面上没有用。您有很多工作要做。
我建议您研究一下并丢弃代码：
package persistence;import java.sql.*;import java.util.*;public class DatabaseUtils { private static final String DEFAULT_DRIVER = "oracle.jdbc.driver.OracleDriver"; private static final String DEFAULT_URL = "jdbc:oracle:thin:@host:1521:database"; private static final String DEFAULT_USERNAME = "username"; private static final String DEFAULT_PASSWORD = "password"; public static void main(String[] args) { long begTime = System.currentTimeMillis(); String driver = ((args.length > 0) ? args[0] : DEFAULT_DRIVER); String url = ((args.length > 1) ? args[1] : DEFAULT_URL); String username = ((args.length > 2) ? args[2] : DEFAULT_USERNAME); String password = ((args.length > 3) ? args[3] : DEFAULT_PASSWORD); Connection connection = null; try { connection = createConnection(driver, url, username, password); DatabasemetaData meta = connection.getmetaData(); System.out.println(meta.getDatabaseProductName()); System.out.println(meta.getDatabaseProductVersion()); String sqlQuery = "SELECt PERSON_ID, FIRST_NAME, LAST_NAME FROM PERSON ORDER BY LAST_NAME"; System.out.println("before insert: " + query(connection, sqlQuery, Collections.EMPTY_LIST)); connection.setAutoCommit(false); String sqlUpdate = "INSERT INTO PERSON(FIRST_NAME, LAST_NAME) VALUES(?,?)"; List parameters = Arrays.asList("Foo", "Bar"); int numRowsUpdated = update(connection, sqlUpdate, parameters); connection.commit(); System.out.println("# rows inserted: " + numRowsUpdated); System.out.println("after insert: " + query(connection, sqlQuery, Collections.EMPTY_LIST)); } catch (Exception e) { rollback(connection); e.printStackTrace(); } finally { close(connection); long endTime = System.currentTimeMillis(); System.out.println("wall time: " + (endTime - begTime) + " ms"); } } public static Connection createConnection(String driver, String url, String username, String password) throws ClassNotFoundException, SQLException { Class.forName(driver); if ((username == null) || (password == null) || (username.trim().length() == 0) || (password.trim().length() == 0)) { return DriverManager.getConnection(url); } else { return DriverManager.getConnection(url, username, password); } } public static void close(Connection connection) { try { if (connection != null) { connection.close(); } } catch (SQLException e) { e.printStackTrace(); } } public static void close(Statement st) { try { if (st != null) { st.close(); } } catch (SQLException e) { e.printStackTrace(); } } public static void close(ResultSet rs) { try { if (rs != null) { rs.close(); } } catch (SQLException e) { e.printStackTrace(); } } public static void rollback(Connection connection) { try { if (connection != null) { connection.rollback(); } } catch (SQLException e) { e.printStackTrace(); } } public static List<Map<String, Object>> map(ResultSet rs) throws SQLException { List<Map<String, Object>> results = new ArrayList<Map<String, Object>>(); try { if (rs != null) { ResultSetmetaData meta = rs.getmetaData(); int numColumns = meta.getColumnCount(); while (rs.next()) { Map<String, Object> row = new HashMap<String, Object>(); for (int i = 1; i <= numColumns; ++i) { String name = meta.getColumnName(i); Object value = rs.getObject(i); row.put(name, value); } results.add(row); } } } finally { close(rs); } return results; } public static List<Map<String, Object>> query(Connection connection, String sql, List<Object> parameters) throws SQLException { List<Map<String, Object>> results = null; PreparedStatement ps = null; ResultSet rs = null; try { ps = connection.prepareStatement(sql); int i = 0; for (Object parameter : parameters) { ps.setObject(++i, parameter); } rs = ps.executeQuery(); results = map(rs); } finally { close(rs); close(ps); } return results; } public static int update(Connection connection, String sql, List<Object> parameters) throws SQLException { int numRowsUpdated = 0; PreparedStatement ps = null; try { ps = connection.prepareStatement(sql); int i = 0; for (Object parameter : parameters) { ps.setObject(++i, parameter); } numRowsUpdated = ps.executeUpdate(); } finally { close(ps); } return numRowsUpdated; }}
