mysql,tomcat连接池配置及jsp测试疑问

fantasyginge · 发表于 2005-8-1 02:43:41

按照一些资料我先修改了
$CATALINA_HOME/conf/server.xml

找到配置context的地方，添加了如下元素：

<Context path="/DBTest" docBase="E:\eclipse\workspace\DBTest\work"
   debug="5" reloadable="true" crossContext="true">

<Logger className="org.apache.catalina.logger.FileLogger"
         prefix="localhost_DBTest_log." suffix=".txt"
         timestamp="true"/>

<Resource name="jdbc/TestDB"
            auth="Container"
            type="javax.sql.DataSource"/>

<ResourceParams name="jdbc/TestDB">
<parameter>
   <name>factory</name>
   <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
</parameter>


      <parameter>
   <name>maxActive</name>
   <value>100</value>
   </parameter>


      <parameter>
   <name>maxIdle</name>
   <value>30</value>
</parameter>


      <parameter>
   <name>maxWait</name>
   <value>10000</value>
</parameter>


<parameter>
<name>username</name>
<value>root</value>
</parameter>
<parameter>
<name>password</name>
<value>16357336</value>
</parameter>

      <parameter>
   <name>driverClassName</name>
   <value>com.mysql.jdbc.Driver</value>
</parameter>


      <parameter>
   <name>url</name>
   <value>jdbc:mysql://localhost:1433;databasename=student</value>
</parameter>
</ResourceParams>

</Context>

能够正常启动tomcat服务器。

之后我利用eclipse新增一个名为DBTest的tomcat project，编写了web.xml
其内容如下：
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_4.dtd">
<web-app>
<description>MySql DB Test App</description>
<resource-ref>
   <description>DB Connection</description>
   <res-ref-name>jdbc/TestDB</res-ref-name>
   <res-type>javax.sql.DataSource</res-type>
   <res-auth>Container</res-auth>
</resource-ref>
</web-app>

接着写了一个名字叫test.jsp的文件。文件内容如下：
<%@page contentType="text/html" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>

<head>
<title>JSP Page</title>\n\
</head>

<body bgcolor="#FFFFFF">

<%@ page import="javax.naming.*"%>
<%@ page import="javax.sql.*"%>
<%@ page import="java.sql.*"%>
<%
      InitialContext ctx=new javax.naming.InitialContext();
      DataSource ds=(javax.sql.DataSource)ctx.lookup("java:comp/env/jdbc/TestDB");
      Connection conn=ds.getConnection();
      String sql="SELECT * FROM courses";
      Statement stmt = conn.createStatement();
      ResultSet rs=stmt.executeQuery(sql);
      while(rs.next()){
            out.print("<tr><td>"+rs.getString(1)+"</td>");
            out.print("<td>"+rs.getString(2)+"</td>");
            out.print("<td>"+rs.getString(3)+"</td>");
            out.print("<td>"+rs.getString(4)+"</td></tr>");

      }
%>

</body>

</html>

用eclipse将tomcat启动，把刚刚写的tomcat project部署。
打开浏览器输入http://localhost:8080/DBTest/test.jsp
出现了http 404 file not found错误。

总结过程：
1，修改了server.xml
2,建立一个名为DBTest的tomcat project
2，新建web.xml文件
4，新建test.jsp文件

问题：
   1，serverl.xml有错误吗？还是web.xml有错误，还是两者都有？
   2，怎么会出现http 404错误的？

fantasyginge · 发表于 2005-8-1 02:50:19

图像处的文字应为
冒号:和comp

eTony · 发表于 2005-8-1 03:00:23

404 :未找到请求资源,

确认访问的资源书写正确

fantasyginge · 发表于 2005-8-3 14:01:42

书写格式没有问题
后来修改jsp测试文件重新测试时
说can't load driver class，
后来就把server.xml改了
改着改着问题就解决了

修改地方有：
1，server.xml
<Logger className="org.apache.catalina.logger.FileLogger"
directory="logs" prefix="localhost_log." suffix=".txt" timestamp="true" />


<Context path="/DataSourceTest" reloadable="true"
docBase="C:\Documents and Settings\ginge\workspace\DataSourceTest"
workDir="C:\Documents and Settings\ginge\workspace\DataSourceTest\work">


<Resource name="jdbc/TestDataSource" auth="Container"
type="javax.sql.DataSource" maxActive="100" maxIdle="30"
maxWait="10000" username="root" password="16357336"
driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/student?autoReconnect=true" />

2，修改了测试用的JSP文件：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ page
import="javax.naming.*,java.io.*,javax.sql.*,java.sql.*"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://" + request.getServerName()
+ ":" + request.getServerPort() + path + "/";
%>
<%@ page contentType="text/html; charset=GBK"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

<title>My JSP 'dbtest.jsp' starting page</title>

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">


</head>

<body>
This is my JSP page.
<br>

<h1>test Tomcat</h1>
<%Context initCtx = null;
DataSource ds = null;
Context envCtx = null;
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;

try {
initCtx = new InitialContext();
envCtx = (Context) initCtx.lookup("java:comp/env");

} catch (Exception x) {
x.printStackTrace();
if (envCtx == null)
System.out.println("envCtx is null");
}

try {
ds = (DataSource) envCtx.lookup("jdbc/TestDataSource");
} catch (Exception p) {
p.printStackTrace();
if (ds == null) {
PrintWriter pw = response.getWriter();
pw.println("<h2>Can't not create Connection</h2>");
}
}
System.out.println("before getting connection!");

try {
conn = ds.getConnection();
if (conn == null) {
PrintWriter pw = response.getWriter();
pw.println("<h2>Can't not create Connection</h2>");
}
out.println("data from database:<br>");
stmt = conn.createStatement();
rs = stmt.executeQuery("select * from courses");
} catch (Exception e) {
e.printStackTrace();
System.out.println("before while loop");
}

%>
<TABLE>
<%try {
while (rs.next()) {
out.print("<tr><td>" + rs.getString(1) + "</td>");
out.print("<td>" + rs.getString(2) + "</td>");
out.print("<td>" + rs.getString(3) + "</td>");
out.print("<td>" + rs.getString(4) + "</td></tr>");

}
} catch (Exception b) {
b.printStackTrace();
System.out.println("in while loop");
}

%>
<%try {
rs.close();
stmt.close();
} catch (Exception c) {
c.printStackTrace();
System.out.println("try to close statement");
rs.close();
stmt.close();
} finally {
}

%>
<
</body>
</html>

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