有关java中数据的问题
package com.struts2.dao;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
import com.struts2.bean.userInfo;
import com.struts2.db.DBConnection;
public class userDao {
private Connection conn;
private Statement stmt;
private ResultSet rs;
private DBConnection db;
public userDao()throws Exception{
db = new DBConnection();
}
public boolean doCheckUser(userInfo user) throws Exception{
String sql = "select * from users where username = '" + user.getUsername()+"' and userpwd = '" + user.getUserpwd() +"'";
System.out.println(sql);
conn = db.getConnection();
stmt = conn.createStatement();
rs = stmt.executeQuery(sql);
int count = 0;
while(rs.next()){
count++;
}
rs.close();
stmt.close();
db.closeConn();
return count==1? true : false;
}
public List<userInfo> doGetAll() throws Exception{
List <userInfo> list = new ArrayList<userInfo>();
String sql = "select * from users";
conn = db.getConnection();
stmt = conn.createStatement();
rs = stmt.executeQuery(sql);
System.out.println(sql);
while(rs.next()){
userInfo user = new userInfo();
user.setId(String.valueOf(rs.getInt(1)));
user.setUsername(rs.getString(2));
user.setUserpwd(rs.getString(3));
list.add(user);
}
rs.close();
stmt.close();
db.closeConn();
return list;
}
}
在运行时报
HTTP Status 500 -
--------------------------------------------
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC]Object has been closed.
com.microsoft.jdbc.base.BaseExceptions.createException(Unknown Source)
com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
com.microsoft.jdbc.base.BaseConnection.validateClosedState(Unknown Source)
com.microsoft.jdbc.base.BaseConnection.createStatement(Unknown Source)
com.microsoft.jdbc.base.BaseConnection.createStatement(Unknown Source)
com.struts2.dao.userDao.doGetAll(userDao.java:47)
com.struts2.action.LoginAction.execute(LoginAction.java:33)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:597)
com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:452)
com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:291)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:254)
com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:176)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:263)
org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:133)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:190)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:142)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:166)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:190)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:485)
org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:395)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.29 logs.
这样的错误，各位大侠帮忙指导一下！！
[解决办法]
com.struts2.db.DBConnection这个类是你自己写的，还是struts2里面自带的？
如果是你自己写的，你贴下这个类的代码
还有，提醒楼主Java命名规范所有类的首字母都要大写，你这里面的类有不符合规范的
------解决方案--------------------
导致这个错误的原因是，createStatement()方法被调用时，你的connection已经被关闭了。
或许是你的
db.getConnection()和
db.closeConn();
方法对于connection的创建和close有错误。
关闭和获取的是同一个connection
我的异常网推荐解决方案：The server encountered an internal error () that prevented it from fulfilling this request.,http://www.myexception.cn/java-web/317.html
