我想在打印出数据库web中的所有内容,代码如下(已添加jdbc驱动包) 一个与数据库连接的javabean DBcon.java
package mypack;import java.sql.Connection;
import java.sql.DriverManager;public class DBcon {
public Connection conn=null;
public Connection getConnection()
{
String Driver="com.mysql.jdbc.Driver";
String Url="jdbc:mysql://localhost:3306/test";
//System.out.println("建立连接");
try{
Class.forName(Driver); /* 加载驱动 */
/* 连接数据库*/
conn=DriverManager.getConnection( Url,"root","1234");
//System.out.println("success");
}catch(Exception e)
{
System.out.println("runtime");
//throw new RuntimeException(e);
e.printStackTrace();
}
return conn;
}
public static void main(String args[])
{
DBcon con=new DBcon();
con.getConnection();
}}
一个用户属性的Javabean People.javapackage mypack;public class People { String name;
String hometown; //户籍
String local; //高校所在地
String university; //就读高校
String highschool; //曾读高中
String major; //专业
String grade; //年纪
public void setName(String name)
{
this.name=name;
}
public String getName()
{
return name;
}
public void setHometown(String hometown)
{
this.hometown=hometown;
}
public String getHometown()
{
return hometown;
}
public void setLocal(String local)
{
this.local=local;
}
public String getLocal()
{
return local;
}
public void setUniversity(String university)
{
this.university=university;
}
public String getUniversity()
{
return university;
}
public void setHighschool(String highschool)
{
this.highschool=highschool;
}
public String getHighschool()
{
return highschool;
}
public void setMajor(String major)
{
this.major=major;
}
public String getMajor()
{
return major;
}
public void setGrade(String grade)
{
this.grade=grade;
}
public String getGrade()
{
return grade;
}
}一个访问数据库得到所有数据的javabean Getall.javapackage mypack;import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;public class Getall {
People[] sb;
int num;
public Getall()
{
num=0;
sb= new People[100];
}
public void loop()
{ DBcon db=new DBcon();
Connection conn=db.getConnection();
PreparedStatement pstmt;
String sql="select * from web ";
ResultSet rs;
try{
pstmt=conn.prepareStatement(sql);
rs=pstmt.executeQuery();
while(rs.next()){
sb[num].setName(rs.getString("name"));
sb[num].setHometown(rs.getString("hometown"));
sb[num].setLocal(rs.getString("local"));
sb[num].setUniversity(rs.getString("university"));
sb[num].setHighschool(rs.getString("highschool"));
sb[num].setMajor(rs.getString("major"));
sb[num].setGrade(rs.getString("grade"));
System.out.println("name:"+sb[num].getName());
num++;
}
}catch(Exception e){
e.printStackTrace();
}
}
}最后一个简单的jsp页面 index.jsp<%@ page language="java" contentType="text/html; charset=GBK"%>
<%@ page import="mypack.Getall" %>
<%@ page import="mypack.DBcon" %><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Hello</title>
</head>
<body>
<%
Getall pp=new Getall();
pp.loop();
%>
Hello!
</body>
</html>但部署好后(确认部署没有问题),tomcat报错
2012-5-18 18:16:29 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet [jsp] in context with path [/test] threw exception [Unable to compile class for JSP: An error occurred at line: 15 in the generated java file
Only a type can be imported. mypack.DBcon resolves to a packageStacktrace:] with root cause
org.apache.jasper.JasperException: Unable to compile class for JSP: An error occurred at line: 15 in the generated java file
Only a type can be imported. mypack.DBcon resolves to a packageStacktrace:
at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:102)
at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:331)
at org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:469)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:378)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:353)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:340)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:646)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:357)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)哪位牛人帮忙看一下哪里出了问题,不胜感激!
package mypack;import java.sql.Connection;
import java.sql.DriverManager;public class DBcon {
public Connection conn=null;
public Connection getConnection()
{
String Driver="com.mysql.jdbc.Driver";
String Url="jdbc:mysql://localhost:3306/test";
//System.out.println("建立连接");
try{
Class.forName(Driver); /* 加载驱动 */
/* 连接数据库*/
conn=DriverManager.getConnection( Url,"root","1234");
//System.out.println("success");
}catch(Exception e)
{
System.out.println("runtime");
//throw new RuntimeException(e);
e.printStackTrace();
}
return conn;
}
public static void main(String args[])
{
DBcon con=new DBcon();
con.getConnection();
}}
一个用户属性的Javabean People.javapackage mypack;public class People { String name;
String hometown; //户籍
String local; //高校所在地
String university; //就读高校
String highschool; //曾读高中
String major; //专业
String grade; //年纪
public void setName(String name)
{
this.name=name;
}
public String getName()
{
return name;
}
public void setHometown(String hometown)
{
this.hometown=hometown;
}
public String getHometown()
{
return hometown;
}
public void setLocal(String local)
{
this.local=local;
}
public String getLocal()
{
return local;
}
public void setUniversity(String university)
{
this.university=university;
}
public String getUniversity()
{
return university;
}
public void setHighschool(String highschool)
{
this.highschool=highschool;
}
public String getHighschool()
{
return highschool;
}
public void setMajor(String major)
{
this.major=major;
}
public String getMajor()
{
return major;
}
public void setGrade(String grade)
{
this.grade=grade;
}
public String getGrade()
{
return grade;
}
}一个访问数据库得到所有数据的javabean Getall.javapackage mypack;import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;public class Getall {
People[] sb;
int num;
public Getall()
{
num=0;
sb= new People[100];
}
public void loop()
{ DBcon db=new DBcon();
Connection conn=db.getConnection();
PreparedStatement pstmt;
String sql="select * from web ";
ResultSet rs;
try{
pstmt=conn.prepareStatement(sql);
rs=pstmt.executeQuery();
while(rs.next()){
sb[num].setName(rs.getString("name"));
sb[num].setHometown(rs.getString("hometown"));
sb[num].setLocal(rs.getString("local"));
sb[num].setUniversity(rs.getString("university"));
sb[num].setHighschool(rs.getString("highschool"));
sb[num].setMajor(rs.getString("major"));
sb[num].setGrade(rs.getString("grade"));
System.out.println("name:"+sb[num].getName());
num++;
}
}catch(Exception e){
e.printStackTrace();
}
}
}最后一个简单的jsp页面 index.jsp<%@ page language="java" contentType="text/html; charset=GBK"%>
<%@ page import="mypack.Getall" %>
<%@ page import="mypack.DBcon" %><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Hello</title>
</head>
<body>
<%
Getall pp=new Getall();
pp.loop();
%>
Hello!
</body>
</html>但部署好后(确认部署没有问题),tomcat报错
2012-5-18 18:16:29 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet [jsp] in context with path [/test] threw exception [Unable to compile class for JSP: An error occurred at line: 15 in the generated java file
Only a type can be imported. mypack.DBcon resolves to a packageStacktrace:] with root cause
org.apache.jasper.JasperException: Unable to compile class for JSP: An error occurred at line: 15 in the generated java file
Only a type can be imported. mypack.DBcon resolves to a packageStacktrace:
at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:102)
at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:331)
at org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:469)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:378)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:353)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:340)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:646)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:357)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)哪位牛人帮忙看一下哪里出了问题,不胜感激!
<%@ page import="mypack.DBcon" %>
应该是导入没有成功,页面要加相对路径
Only a type can be imported. mypack.DBcon resolves to a package
Only a type can be imported. mypack.DBcon resolves to a package
从代码来看,你那个类有没有单独运行过。有没有什么问题。会不会是包的问题。可能是你有些包没引入