代码
package util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class DBUtil {
private String driver;
private String url;
private String username;
private String password;
private Connection con;
private PreparedStatement pstmt;
private ResultSet rs;
public void setDriver(String driver){
this.driver=driver;
}
public void setUrl(String url){
this.url=url;
}
public void setUsername(String username){
this.username=username;
}
public void setPassword(String password){
this.password=password;
}
public DBUtil(){
driver="com.microsoft.jdbc.sqlserver.SQLServerDriver";
url="jdbc:sqlserver://127.0.0.1:1433;databaseName=yyghxt";
username="sa";
password="123456";
}
private Connection getConnection() throws SQLException{
try{
Class.forName(driver);
con=DriverManager.getConnection(url,username,password);
}catch(ClassNotFoundException e){
e.printStackTrace();
}
return con;
}
private PreparedStatement getPrepareStatement(String sql){
try{
pstmt=getConnection().prepareStatement(sql);
}catch(SQLException e){
e.printStackTrace();
}
return pstmt;
}
private void setParams(String sql,String[]params){
pstmt=this.getPrepareStatement(sql);
for(int i=0;i<params.length;i++)
try{
pstmt.setString(i+1, params[i]);
}catch(SQLException e){
e.printStackTrace();
}
}
public List getList(String sql,String[]params){
List list=new ArrayList();
try{
this.setParams(sql, params);
ResultSet rs=pstmt.executeQuery();
ResultSetMetaData rsmd= rs.getMetaData();
while(rs.next()){
Map m=new HashMap();
for(int i=1;i<=rsmd.getColumnCount();i++){
String colName=rsmd.getColumnName(i);
m.put(colName,rs.getString(colName));
}
list.add(m);
}
}catch(SQLException e){
e.printStackTrace();
}finally{
close();
}
return list;
}
public Map getMap(String sql,String[]params){
List list=getList(sql,params);
if(list.isEmpty())
return null;
else
return(Map)list.get(0);
}
public int update(String sql,String[]params){
int recNo=0;
try{
setParams(sql,params);
recNo=pstmt.executeUpdate();
}catch(Exception e){
e.printStackTrace();
}finally{
close();
}
return recNo;
}
private void close(){
try{
if(rs!=null)
rs.close();
if(pstmt!=null)
pstmt.close();
if(con!=null)
con.close();
}catch(SQLException e){
}
}
}
报错信息
java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC]Unable to connect. Invalid URL.
at com.microsoft.jdbc.base.BaseExceptions.createException(Unknown Source)
at com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
at com.microsoft.jdbc.base.BaseDriver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at util.DBUtil.getConnection(DBUtil.java:45)
at util.DBUtil.getPrepareStatement(DBUtil.java:56)
at util.DBUtil.setParams(DBUtil.java:66)
at util.DBUtil.getList(DBUtil.java:80)
at util.DBUtil.getMap(DBUtil.java:99)
at beans.UserInfo.checkName(UserInfo.java:52)
at servlet.userInfoController.doPost(userInfoController.java:34)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
六月 09, 2017 10:29:44 上午 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet [userInfoController] in context with path [/yyghxt] threw exception
java.lang.NullPointerException
at util.DBUtil.setParams(DBUtil.java:70)
at util.DBUtil.getList(DBUtil.java:80)
at util.DBUtil.getMap(DBUtil.java:99)
at beans.UserInfo.checkName(UserInfo.java:52)
at servlet.userInfoController.doPost(userInfoController.java:34)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
