jar包添加了,数据库连接也修改好了,请大师指教还需要改什么?
private static final String DRIVER="com.microsoft.sqlserver.jdbc.SQLServerDriver";
private static final String URL="jdbc:sqlserver://localhost:1433;databasename=shopping";
private static final String USERNAME="sa";
private static final String PASSWORD="123";
错误如下
org.apache.jasper.JasperException: An exception occurred processing JSP page /welcome.jsp at line 2623: </head>
24:
25: <body>
26: <jsp:forward page="IndexServlet"></jsp:forward>
27: </body>
28: </html>
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:510)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
com.xasxt.shopping.util.EncodingFilter.doFilter(EncodingFilter.java:26)
root causejava.lang.NullPointerException
com.xasxt.shopping.dao.BaseDao.execQuery(BaseDao.java:46)
com.xasxt.shopping.dao.impl.AfficheDaoImpl.getAll(AfficheDaoImpl.java:48)
com.xasxt.shopping.biz.impl.AfficheBizImpl.getAll(AfficheBizImpl.java:29)
com.xasxt.shopping.servlet.IndexServlet.doPost(IndexServlet.java:38)
com.xasxt.shopping.servlet.IndexServlet.doGet(IndexServlet.java:30)
javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.runtime.PageContextImpl.doForward(PageContextImpl.java:706)
org.apache.jasper.runtime.PageContextImpl.forward(PageContextImpl.java:677)
org.apache.jsp.welcome_jsp._jspService(welcome_jsp.java:85)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
com.xasxt.shopping.util.EncodingFilter.doFilter(EncodingFilter.java:26)
private static final String DRIVER="com.microsoft.sqlserver.jdbc.SQLServerDriver";
private static final String URL="jdbc:sqlserver://localhost:1433;databasename=shopping";
private static final String USERNAME="sa";
private static final String PASSWORD="123";
错误如下
org.apache.jasper.JasperException: An exception occurred processing JSP page /welcome.jsp at line 2623: </head>
24:
25: <body>
26: <jsp:forward page="IndexServlet"></jsp:forward>
27: </body>
28: </html>
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:510)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
com.xasxt.shopping.util.EncodingFilter.doFilter(EncodingFilter.java:26)
root causejava.lang.NullPointerException
com.xasxt.shopping.dao.BaseDao.execQuery(BaseDao.java:46)
com.xasxt.shopping.dao.impl.AfficheDaoImpl.getAll(AfficheDaoImpl.java:48)
com.xasxt.shopping.biz.impl.AfficheBizImpl.getAll(AfficheBizImpl.java:29)
com.xasxt.shopping.servlet.IndexServlet.doPost(IndexServlet.java:38)
com.xasxt.shopping.servlet.IndexServlet.doGet(IndexServlet.java:30)
javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.runtime.PageContextImpl.doForward(PageContextImpl.java:706)
org.apache.jasper.runtime.PageContextImpl.forward(PageContextImpl.java:677)
org.apache.jsp.welcome_jsp._jspService(welcome_jsp.java:85)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
com.xasxt.shopping.util.EncodingFilter.doFilter(EncodingFilter.java:26)
import java.sql.*;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;public class BaseDao {
//private static final String DRIVER="com.mysql.jdbc.Driver";
private static final String DRIVER="com.microsoft.sqlserver.jdbc.SQLServerDriver";
//private static final String URL="jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=UTF-8";
private static final String URL="jdbc:sqlserver://localhost:1433;databasename=shopping";
// private static final String USERNAME="root";
//private static final String PASSWORD="root";
private static final String USERNAME="sa";
private static final String PASSWORD="123";
private Connection conn;
private PreparedStatement psmt;
public ResultSet rs;
public void getConn(){
try {
Class.forName(DRIVER);
conn = DriverManager.getConnection(URL,USERNAME, PASSWORD);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
}
public void closeAll(){
try {
if(rs!=null)rs.close();
if(psmt!=null)psmt.close();
if(conn!=null)conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
public ResultSet execQuery(String sql,String[] params){
getConn();
try {
psmt = conn.prepareStatement(sql);
if(params!=null&¶ms.length>0){
for (int i = 0; i < params.length; i++) {
psmt.setString(i+1, params[i]);
}
}
rs = psmt.executeQuery();
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}
public int execUpdate(String sql,String[] params){
int count=0;
getConn();
try {
psmt = conn.prepareStatement(sql);
if(params!=null&¶ms.length>0){
for (int i = 0; i < params.length; i++) {
psmt.setString(i+1, params[i]);
}
}
count = psmt.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}finally{
this.closeAll();
}
return count;
}
}
import java.sql.*;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;public class BaseDao {
//private static final String DRIVER="com.mysql.jdbc.Driver";
private static final String DRIVER="com.microsoft.sqlserver.jdbc.SQLServerDriver";
//private static final String URL="jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=UTF-8";
private static final String URL="jdbc:sqlserver://localhost:1433;databasename=shopping";
// private static final String USERNAME="root";
//private static final String PASSWORD="root";
private static final String USERNAME="sa";
private static final String PASSWORD="123";
private Connection conn;
private PreparedStatement psmt;
public ResultSet rs;
public void getConn(){
try {
Class.forName(DRIVER);
conn = DriverManager.getConnection(URL,USERNAME, PASSWORD);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
}
public void closeAll(){
try {
if(rs!=null)rs.close();
if(psmt!=null)psmt.close();
if(conn!=null)conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
public ResultSet execQuery(String sql,String[] params){
getConn();
try {
psmt = conn.prepareStatement(sql);
if(params!=null&¶ms.length>0){
for (int i = 0; i < params.length; i++) {
psmt.setString(i+1, params[i]);
}
}
rs = psmt.executeQuery();
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}
public int execUpdate(String sql,String[] params){
int count=0;
getConn();
try {
psmt = conn.prepareStatement(sql);
if(params!=null&¶ms.length>0){
for (int i = 0; i < params.length; i++) {
psmt.setString(i+1, params[i]);
}
}
count = psmt.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}finally{
this.closeAll();
}
return count;
}
}
BaseDao.java:46行在哪个位置
psmt = conn.prepareStatement(sql);