我正在尝试连接我的数据库。当我运行项目并尝试输入用户名和密码时，我收到以下错误：
Nov 22, 2015 10:56:29 PM com.dts.core.util.LoggerManager writeLogWarning
WARNING: java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
at com.dts.core.util.LoggerManager.writeLogWarning(LoggerManager.java:62)
at com.dts.core.dao.AbstractDataAccessObject.getConnection(AbstractDataAccessObject.java:51)
at com.dts.dae.dao.SecurityDAO.<init>(SecurityDAO.java:23)
at org.apache.jsp.LoginAction_jsp._jspService(LoginAction_jsp.java:124)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
java.lang.NullPointerException
at com.dts.dae.dao.SecurityDAO.loginCheck(SecurityDAO.java:93)
at org.apache.jsp.LoginAction_jsp._jspService(LoginAction_jsp.java:124)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
以下是相应的java代码
LoggerManager.java
package com.dts.core.util;
import java.io.File;
import java.io.PrintStream;
import java.util.logging.FileHandler;
import java.util.logging.Level;
import java.util.logging.LogManager;
import java.util.logging.Logger;
import java.util.logging.SimpleFormatter;
public class LoggerManager {
public static Logger logger = Logger.getLogger(LoggerManager.class.getName());;
LoggerManager() throws InstantiationException {
throw new InstantiationException("This is an util class and should not be instantiated.");
}
public static Logger getLogger(String file) {
String dir = file.substring(0, file.lastIndexOf("/"));
System.out.println("-----dir----" + dir);
if (logger == null) {
logger = Logger.getLogger("LoggerManager");
}
try {
File f = new File(dir);
boolean success = f.exists();
if (!success) {
success = f.mkdir();
}
LogManager lm = LogManager.getLogManager();
FileHandler fh = new FileHandler(file, true);
logger = Logger.getLogger("LoggerManager");
logger.setUseParentHandlers(false);
lm.addLogger(logger);
logger.setLevel(Level.INFO);
fh.setFormatter(new SimpleFormatter());
logger.addHandler(fh);
} catch (Exception e) {
logger.log(Level.INFO, e.toString(), e.fillInStackTrace());
}
return logger;
}
public static void writeLogInfo(Exception e) {
logger.log(Level.INFO, e.toString(), e.fillInStackTrace());
}
public static void writeLogSevere(Exception e) {
logger.log(Level.SEVERE, e.toString(), e.fillInStackTrace());
}
public static void writeLogWarning(Exception e) {
logger.log(Level.WARNING, e.toString(), e.fillInStackTrace());
}
public static void writeLogInfo(String info) {
logger.log(Level.INFO, info);
}
public static void writeLogSevere(String severe) {
logger.log(Level.SEVERE, severe);
}
public static void writeLogWarning(String warning) {
getLogger(warning).log(Level.WARNING, warning);
}
}
数据库连接java代码如下：
AbstractDataAccessObject.java
package com.dts.core.dao;
import com.dts.core.util.LoggerManager;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
public class AbstractDataAccessObject {
Connection con;
static Properties props;
public AbstractDataAccessObject() {}
public Properties getProperties() {
return props;
}
public void setProperties(Properties props) {
AbstractDataAccessObject.props = props;
}
public Connection getConnection() {
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe", "Bug", "dog567");
} catch (ClassNotFoundException cnf) {
LoggerManager.writeLogWarning(cnf);
} catch (SQLException se) {
LoggerManager.writeLogWarning(se);
}
return con;
}
public int getSequenceID(String tableName, String pkid) {
int id = 0;
try {
con = getConnection();
Statement st = con.createStatement();
ResultSet rs = st.executeQuery("select max(" + pkid + ") from " + tableName);
if (rs.next()) id = rs.getInt(1);
id++;
} catch (SQLException se) {
LoggerManager.writeLogWarning(se);
try {
con.close();
} catch (SQLException se1) {
LoggerManager.writeLogWarning(se1);
} catch (Exception e) {
LoggerManager.writeLogWarning(e);
}
} catch (Exception e) {
LoggerManager.writeLogWarning(e);
try {
con.close();
} catch (SQLException se) {
LoggerManager.writeLogWarning(se);
} catch (Exception e1) {
LoggerManager.writeLogWarning(e1);
}
} finally {
try {
con.close();
} catch (SQLException se) {
LoggerManager.writeLogWarning(se);
} catch (Exception e) {
LoggerManager.writeLogWarning(e);
}
}
return id;
}
SecurityDAO.java
package com.dts.dae.dao;
import com.dts.core.dao.AbstractDataAccessObject;
import com.dts.core.util.DateWrapper;
import com.dts.core.util.LoggerManager;
import com.dts.dae.model.Profile;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Date;
public class SecurityDAO
extends AbstractDataAccessObject {
Connection con;
private String desc;
private boolean flag;
public SecurityDAO() {
con = getConnection();
}
public boolean checkPassword(Profile regbean) {
String loginid = regbean.getLoginID();
String oldpassword = regbean.getPassword();
try {
PreparedStatement pst = con.prepareStatement("select * from logindetails where password=? and loginname=?");
pst.setString(1, oldpassword);
pst.setString(2, loginid);
ResultSet rs = pst.executeQuery();
if (rs.next()) {
flag = true;
LoggerManager.writeLogInfo("Login Success");
} else {
flag = false;
}
} catch (SQLException ex) {
LoggerManager.writeLogSevere(ex);
LoggerManager.writeLogInfo("Database Connection problem");
flag = false;
}
return flag;
}
public int checkFirstLogin(String loginname) {
int fstatus = 2;
try {
con.setAutoCommit(true);
PreparedStatement pst = con.prepareStatement("select firstlogin from logindetails where loginname=?");
pst.setString(1, loginname);
ResultSet rs = pst.executeQuery();
if (rs.next()) {
fstatus = rs.getInt(1);
}
con.close();
} catch (SQLException ex) {
LoggerManager.writeLogSevere(ex);
LoggerManager.writeLogInfo("Database Connection problem");
flag = false;
}
return fstatus;
}
public String loginCheck(Profile regbean) {
String loginid = regbean.getLoginID();
String password = regbean.getPassword();
String role = "";
try {
con.setAutoCommit(true);
PreparedStatement pst = con.prepareStatement("select logintype from logindetails where password=? and loginname=? and loginstatus=1");
pst.setString(2, loginid);
pst.setString(1, password);
ResultSet rs = pst.executeQuery();
if (rs.next()) {
role = rs.getString(1);
desc = "Login Success";
} else {
flag = false;
desc = "Entered Invalid password";
}
} catch (SQLException ex) {
LoggerManager.writeLogSevere(ex);
desc = "Database Connection problem";
flag = false;
}
loginaudit(loginid, desc);
return role;
}
public void loginaudit(String loginid, String desc) {
try {
String newdate = DateWrapper.parseDate(new Date());
PreparedStatement pst = con.prepareStatement("insert into loginaudit values(?,?,?)");
pst.setString(1, loginid);
pst.setString(2, newdate);
pst.setString(3, desc);
int i = pst.executeUpdate();
if (i == 1) {
con.commit();
} else con.rollback();
con.close();
} catch (Exception e) {
try {
con.rollback();
} catch (SQLException ex) {
LoggerManager.writeLogSevere(ex);
}
e.printStackTrace();
}
}
public boolean changePassword(Profile regbean) {
String loginid = regbean.getLoginID();
String oldpassword = regbean.getPassword();
String newpassword = regbean.getNewPassword();
try {
con.setAutoCommit(false);
String newdate = DateWrapper.parseDate(new Date());
PreparedStatement pst = con.prepareStatement("UPDATE logindetails SET password=?,passmodifieddate=? WHERE loginname=? and password=?");
pst.setString(1, newpassword);
pst.setString(2, newdate);
pst.setString(3, loginid);
pst.setString(4, oldpassword);
int i = pst.executeUpdate();
if (i == 1) {
flag = true;
con.commit();
} else {
flag = false;
con.rollback();
}
con.close();
} catch (SQLException ex) {
LoggerManager.writeLogSevere(ex);
flag = false;
try {
con.rollback();
} catch (SQLException sex) {
LoggerManager.writeLogSevere(sex);
}
} catch (Exception e) {
e.printStackTrace();
flag = false;
try {
con.rollback();
} catch (SQLException sex) {
LoggerManager.writeLogSevere(sex);
}
}
return flag;
}
public boolean changeQuestion(Profile regbean) {
String loginid = regbean.getLoginID();
String password = regbean.getPassword();
int secretquestid = regbean.getSecretQuestionID();
String ownsecretquest = regbean.getOwnSecretQuestion();
String secretans = regbean.getSecretAnswer();
int i = 0;
try {
con.setAutoCommit(false);
if (checkPassword(regbean)) {
if (secretquestid == 0) {
Statement st = con.createStatement();
ResultSet rs = st.executeQuery("select (max(questionid))+1 from questionbase");
if (rs.next()) secretquestid = rs.getInt(1);
PreparedStatement pst = con.prepareStatement("INSERT INTO question_base VALUES(?,?)");
pst.setInt(1, secretquestid);
pst.setString(2, ownsecretquest);
pst.executeUpdate();
}
PreparedStatement pst = con.prepareStatement("UPDATE logindetails SET squestionid=?,sanswer=? WHERE loginname=? and password=?");
pst.setInt(1, secretquestid);
pst.setString(2, secretans);
pst.setString(3, loginid);
pst.setString(4, password);
i = pst.executeUpdate();
if (i == 1) {
flag = true;
con.commit();
} else {
flag = false;
con.rollback();
}
}
con.close();
} catch (SQLException ex) {
LoggerManager.writeLogSevere(ex);
flag = false;
try {
con.rollback();
} catch (SQLException sex) {
LoggerManager.writeLogSevere(sex);
}
} catch (Exception e) {
LoggerManager.writeLogSevere(e);
flag = false;
try {
con.rollback();
} catch (SQLException sex) {
LoggerManager.writeLogSevere(sex);
}
}
return flag;
}
public String recoverPasswordByExistQuestion(Profile regbean) {
String loginid = regbean.getLoginID();
int secretquestid = regbean.getSecretQuestionID();
String secretans = regbean.getSecretAnswer();
String password;
try {
con.setAutoCommit(true);
PreparedStatement pst = con.prepareStatement("SELECT password FROM logindetails WHERE loginname=? and squestionid=? and sanswer=?");
pst.setString(1, loginid);
pst.setInt(2, secretquestid);
pst.setString(3, secretans);
ResultSet rs = pst.executeQuery();
if (rs.next()) {
password = rs.getString(1);
} else password = "";
con.close();
} catch (SQLException ex) {
LoggerManager.writeLogSevere(ex);
password = "";
} catch (Exception e) {
LoggerManager.writeLogSevere(e);
password = "";
}
return password;
}
public String recoverPasswordByOWNQuestion(Profile regbean) {
String loginid = regbean.getLoginID();
String ownsecretquest = regbean.getOwnSecretQuestion();
String secretans = regbean.getSecretAnswer();
String password;
try {
con.setAutoCommit(true);
PreparedStatement pst = con.prepareStatement("SELECT password FROM logindetails WHERE loginname=? and squestionid=(select questionid from questionbase where questiondetails=?) and sanswer=?");
pst.setString(1, loginid);
pst.setString(2, ownsecretquest);
pst.setString(3, secretans);
ResultSet rs = pst.executeQuery();
if (rs.next()) {
password = rs.getString(1);
} else password = "";
con.close();
} catch (SQLException ex) {
LoggerManager.writeLogSevere(ex);
password = "";
} catch (Exception e) {
LoggerManager.writeLogSevere(e);
password = "";
}
return password;
}
在SecurityDAO.java中，我在con.setAutoCommit（true）获得nullpointerexception;
答案 0 :(得分：0)
您shadowing变量con。取代
Connection con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","Bug","dog567");
与
con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","Bug","dog567");
con方法的范围返回变量，请在try-catch块之前或声明getConnection