以下java代码在运行时抛出此错误:ResultSet关闭后不允许操作 . 令人好奇的是,代码的预期功能正在完成 . 密码确实发生了变化,表明该语句确实已执行 . 最后的“失败”输出似乎表明代码在某处有异常 . 有任何想法吗?
private void ChangeSQLPassword(String userName,char[] pass) {
Connection conn = null;
String hashed = "";
String salt = "";
String concat = "";
try {
String url = "jdbc:mysql://localhost:3306/PM";
Class.forName("com.mysql.jdbc.Driver").newInstance();
conn = DriverManager.getConnection(url, "Tempuser", "temppass");
System.out.println("Database connection established");
} catch (Exception e) {
e.printStackTrace();
System.err.println("Cannot connect to database server");
} finally {
if (conn != null) {
try {
System.err.println("Connection not null...");
salt = getSalt();
hashed = sha256(pass,salt);
Statement sta3 = conn.createStatement();
ResultSet rs = sta3.executeQuery("SELECT * FROM pmusers"); //Select users
System.out.println(userName + " " + new String(pass));
while (rs.next() == true) { //Loop through results
if (rs.getString("username").equals(userName)) {
concat = concat.concat("UPDATE pmusers SET Hashed = '" + hashed + "', Salt = '" + salt + "' WHERE Username = '" + userName +"';");
sta3.executeUpdate(concat);
}
}
} catch (Exception e) { /* ignore close errors */
e.printStackTrace();
System.err.println("Failed.");
}
}
}
}
static String sha256(char[] input, String Salt) throws NoSuchAlgorithmException {
MessageDigest mDigest = MessageDigest.getInstance("SHA-256");
byte[] result;
StringBuffer sb = new StringBuffer();
try {
mDigest.update(Salt.getBytes("UTF-8"));
result = mDigest.digest(String.valueOf(input).getBytes("UTF-8"));
for (int i = 0; i < result.length; i++) {
sb.append(Integer.toString((result[i] & 0xff) + 0x100, 16).substring(1));
}
} catch (UnsupportedEncodingException e) {
System.out.println("Encoding failed.");
}
String hashed = org.apache.commons.codec.binary.Base64.encodeBase64URLSafeString(String.valueOf(sb).getBytes());
return hashed;
}
private static String getSalt() throws NoSuchAlgorithmException, NoSuchProviderException {
//Always use a SecureRandom generator
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG", "SUN");
//Create array for salt
byte[] salt = new byte[16];
//Get a random salt
sr.nextBytes(salt);
//return salt
return salt.toString();
}
堆栈跟踪:java.sql.SQLException:在com.mysql.jdbc.SQLError.createSQLException(SQLError.java:996)的com.mysql.jdbc.SQLError.createSQLException(SQLError.java:935)处关闭ResultSet后,不允许操作com.mysql.jdbc.SQLError.createSQLException(SQLError.java:924)在com.mysql.jdbc.SQLError.createSQLException(SQLError.java:870)在com.mysql.jdbc.ResultSetImpl.checkClosed(ResultSetImpl.java:734)在ServerInterface.access上的com.mysql.jdbc.ResultSetImpl.next(ResultSetImpl.java:6313)ServerInterface.access $ 300(ServerInterface.java:68)ServerInterface $ 2.actionPerformed(ServerInterface.java:) 277)在javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)在javax.swing.AbstractButton中$ Handler.actionPerformed(AbstractButton.java:2341)在javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)在javax.swing.plaf.basic.BasicButt的javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)在java.awt.Component.processMouseEvent(Component.java:6505)在javax.swing.JComponent.processMouseEvent(JComponent.java:3320)在java.awt.Component.processEvent(成分onListener.mouseReleased(BasicButtonListener.java:252) .java:6270)at java.awt.Container.processEvent(Container.java:2229)at java.awt.Component.dispatchEventImpl(Component.java:4861)at java.awt.Container.dispatchEventImpl(Container.java:2287)在Java.awt.Component.dispatchEvent(Component.java:4687)的java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)中,java.awt的java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492) . 位于java.awt.Comp的监视器上的java.awt.Window.dispatchEventImpl(Window.java:2719)中的java.awt.Container.dispatchEventImpl(Container.java:2273)中的LightweightDispatcher.dispatchEvent(Container.java:4422) .java:4687)at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)at java.awt.EventQueue.access $ 200(EventQueue.java:103)at java.awt.EventQueu E $ 3.run(EventQueue.java:694)在java.awt.EventQueue中$ 3.run(EventQueue.java:692)在java.security.AccessController.doPrivileged(本机方法)在java.security.ProtectionDomain $ 1.doIntersectionPrivilege(ProtectionDomain中.java:76)java.security.ProtectionDomain $ 1.doIntersectionPrivilege(ProtectionDomain.java:87)at java.awt.EventQueue $ 4.run(EventQueue.java:708)at java.awt.EventQueue $ 4.run(EventQueue.java) :706)在java.security.AccessController.doPrivileged(本机方法)在java.security.ProtectionDomain $ 1.doIntersectionPrivilege(ProtectionDomain.java:76)在java.awt.EventQueue.dispatchEvent(EventQueue.java:705)在java.awt中位于java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)的.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)位于java.awt.EventDispatchThread.pumpEvents的java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150) EventDispatchThread.java:146)at java.awt.EventDispatchThread.pumpEvents(EventDispatch Thread.java:138)at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
失败 .
非常感谢!
1 回答
你是双重使用
sta3
:试试