谁能给我一个jsp连mysql的实例?

Question

Connection conn=null;
Statement stmt=null;
ResultSet rs=null;
try {
Class.forName("org.gjt.mm.mysql.Driver");
String url="jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=gb2312";
String user="root";
String pass="";
conn=DriverManager.getConnection(url,user,pass);
out.println("congraturation!");
stmt=conn.createStatement(java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE,java.sql.ResultSet.CONCUR_READ_ONLY); 
rs=stmt.executeQuery("select * from bbs1");
while(rs.next()) {
out.println(rs.getString(1)+"<br>");
}
} catch(Exception e)  {
out.println(e.toString());
} finally {
}

Answer 1

连接CLASS:
package db;import java.util.*;
import java.sql.*;
import java.io.*;public class DbConnection{
Connection conn = null;
Statement stmt = null;
ResultSet rset = null; public DbConnection(){
} /************************************************
 * openConnection
 * read file "db.txt"
************************************************/
public boolean openConnection(){
Properties prop = new Properties();
try{
InputStream is = getClass().getResourceAsStream("db.txt");
prop.load(is);
if(is != null) is.close();
}catch(IOException e){
System.out.println("[DbConnection] Open db.txt File, Error!");
} String jdbc = prop.getProperty("driver");
String uri = prop.getProperty("url");
try{
Class.forName(jdbc).newInstance();
}catch(ClassNotFoundException e){
System.out.println("JDBC login, Error!@" + e.getMessage());
return false;
}catch (Exception e){
System.err.println("Unable to load driver!");
                        e.printStackTrace();
                }
try{
this.conn = DriverManager.getConnection (uri);
}catch(SQLException e){
System.out.println("Generate Connection, Error!" + e.getMessage());
return false;
}
return true; }
/*************************************************
 * executeQuery and executeUpdate
 * query and update DB
*************************************************/
public ResultSet executeQuery(String query) throws SQLException{
stmt = conn.createStatement();
rset = stmt.executeQuery(query);
return rset;
} public void executeUpdate(String query) throws SQLException{
stmt = conn.createStatement();
stmt.executeUpdate(query);
if(stmt != null) stmt.close();
} public void close() throws SQLException{
if(conn != null) conn.close();
if(rset != null) rset.close();
if(stmt != null) stmt.close();
} protected void finalize() throws Throwable{
close();
} public static void main(String[] args){
//Design for test purpose.
DbConnection dc = new DbConnection();
System.out.println(dc.openConnection());
}}
DB.TXT:
driver=org.gjt.mm.mysql.Driver
url=jdbc:mysql://192.168.3.160:3306/bbs?user=root&password=&useUnicode=true&characterEncoding=8859_1当然需要在WEB-INF下的LIB中加入mysql_comp.jar驱动程序。

Answer 2

谢谢了，
可以连接了，
不过可以再问一个问题吗？
我现在将数据库连接部份做成一个类，而且纺译成为一个.java文件，那这个文件该放在什么地方啊？
我直接放在下面然给我的错误提示是：org.apache.jasper.JasperException: Unable to compile class for JSPAn error occurred at line: -1 in the jsp file: nullGenerated servlet error:
    [javac] Since fork is true, ignoring compiler setting.
    [javac] Compiling 1 source file
    [javac] Since fork is true, ignoring compiler setting.
    [javac] C:\Tomcat 4.1\work\Standalone\localhost\_\liuyanben\ly_jsp.java:53: cannot resolve symbol
    [javac] symbol  : class jdbc  
    [javac] location: package wu
    [javac]       wu.jdbc wu = null;
    [javac]         ^
    [javac] C:\Tomcat 4.1\work\Standalone\localhost\_\liuyanben\ly_jsp.java:55: cannot resolve symbol
    [javac] symbol  : class jdbc  
    [javac] location: package wu
    [javac]         wu = (wu.jdbc) pageContext.getAttribute("wu", PageContext.PAGE_SCOPE);
    [javac]                 ^
    [javac] C:\Tomcat 4.1\work\Standalone\localhost\_\liuyanben\ly_jsp.java:58: cannot resolve symbol
    [javac] symbol  : class jdbc  
    [javac] location: package wu
    [javac]             wu = (wu.jdbc) java.beans.Beans.instantiate(this.getClass().getClassLoader(), "wu.jdbc");
    [javac]                     ^
    [javac] 3 errors at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:130)
at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:293)
at org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:353)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:370)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:473)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:190)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2415)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:223)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:594)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:392)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:565)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:619)
at java.lang.Thread.run(Thread.java:484)怎么办？谢谢！