菜鸟求教!servlet一调用dao就报错

java阿俊 2018-02-04 07:02:57
工具类DBUtil用的连接池,换了普通连接方法报ClassNotFount写了个main方法测了下正常,可以取到数据库的东西
确定就是在MainServlet的25行出的错,一注释就不报错了

public class test {

       //测试类,测试正常

    public static void main(String []args) {

        CostDao dao=new CostDao();

        List<Cost> list=dao.findAll();

        System.out.println(list);

    }

}

public class CostDao implements Serializable {

 

    public List<Cost> findAll() {

        try {

            Connection conn = 

                DBUtil.getConnection();

            String sql = 

                "select * from cost "

                + "order by cost_id";

            Statement smt = 

                conn.createStatement();

            ResultSet rs = smt.executeQuery(sql);

            List<Cost> list = new ArrayList<Cost>();

            while(rs.next()) {

                Cost c = new Cost();

                c.setCostId(rs.getInt("cost_id"));

                c.setName(rs.getString("name"));

                c.setBaseDuration(rs.getInt("base_duration"));

                c.setBaseCost(rs.getDouble("base_cost"));

                c.setUnitCost(rs.getDouble("unit_cost"));

                c.setStatus(rs.getString("status"));

                c.setDescr(rs.getString("descr"));

                c.setCreatime(rs.getTimestamp("creatime"));

                c.setStartime(rs.getTimestamp("startime"));

                c.setCostType(rs.getString("cost_type"));

                list.add(c);

            }

            return list;

        } catch (ClassNotFoundException e) {

            e.printStackTrace();

            throw new RuntimeException(

                "找不到驱动类",e);

        } catch (SQLException e) {

            e.printStackTrace();

            throw new RuntimeException(

                "查询资费失败",e);

        } finally {

            DBUtil.closeConnection();

        }

    }

     

     

}

public class MainServlet extends HttpServlet {

 

    @Override

    protected void service(

        HttpServletRequest req, 

        HttpServletResponse res) 

        throws ServletException, IOException {

        //获取并判断访问路径

        String path = req.getServletPath();

        if("/findCost.do".equals(path)) {

            findCost(req,res);

        } else {

            throw new RuntimeException("查无此页");

        }

    }

     

    //查询资费

    protected void findCost(

        HttpServletRequest req, 

        HttpServletResponse res) 

        throws ServletException, IOException {

        //查询所有资费

        CostDao dao = new CostDao();

                

               //就是在这出的错,把findAll一注释就不报错了,jsp正常

        List<Cost> list = dao.findAll();

        //转发至jsp

        req.setAttribute("costs", list);

        //当前:/netctoss/findCost.do

        //目标:/netctoss/WEB-INF/cost/find.jsp

        req.getRequestDispatcher

            ("WEB-INF/cost/find.jsp").forward(req, res);

    }

 

}


<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

  <modelVersion>4.0.0</modelVersion>

  <groupId>cn.tedu</groupId>

  <artifactId>netctoss</artifactId>

  <version>0.0.1-SNAPSHOT</version>

  <packaging>war</packaging>

  

  <dependencies>

  	<dependency>

	  <groupId>javaee</groupId>

	  <artifactId>javaee-api</artifactId>

	  <version>5</version>

	</dependency>

	<dependency>

	  <groupId>jstl</groupId>

	  <artifactId>jstl</artifactId>

	  <version>1.2</version>

	</dependency>  	

  	<dependency>

  		<groupId>commons-dbcp</groupId>

  		<artifactId>commons-dbcp</artifactId>

  		<version>1.4</version>

  	</dependency>

  </dependencies>  

</project>

org.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class 'oracle.jdbc.driver.OracleDriver'

	at org.apache.commons.dbcp.BasicDataSource.createConnectionFactory(BasicDataSource.java:1429)

	at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1371)

	at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)

	at util.DBUtil.getConnection(DBUtil.java:65)

	at dao.CostDao.findAll(CostDao.java:19)

	at web.MainServlet.findCost(MainServlet.java:37)

	at web.MainServlet.service(MainServlet.java:24)

	at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)

	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)

	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)

	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)

	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)

	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)

	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)

	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)

	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)

	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)

	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)

	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)

Caused by: java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver

	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1856)

	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1705)

	at org.apache.commons.dbcp.BasicDataSource.createConnectionFactory(BasicDataSource.java:1420)

	... 27 more

二月 04, 2018 6:58:14 下午 org.apache.catalina.core.StandardWrapperValve invoke

严重: Servlet.service() for servlet [main] in context with path [/asd] threw exception

java.lang.RuntimeException: 查询资费失败

	at dao.CostDao.findAll(CostDao.java:48)

	at web.MainServlet.findCost(MainServlet.java:37)

	at web.MainServlet.service(MainServlet.java:24)

	at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)

	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)

	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)

	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)

	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)

	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)

	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)

	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)

	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)

	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)

	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)

	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)

Caused by: org.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class 'oracle.jdbc.driver.OracleDriver'

	at org.apache.commons.dbcp.BasicDataSource.createConnectionFactory(BasicDataSource.java:1429)

	at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1371)

	at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)

	at util.DBUtil.getConnection(DBUtil.java:65)

	at dao.CostDao.findAll(CostDao.java:19)

	... 23 more

Caused by: java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver

	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1856)

	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1705)

	at org.apache.commons.dbcp.BasicDataSource.createConnectionFactory(BasicDataSource.java:1420)

	... 27 more


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java阿俊 2018-02-05
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找到原因了,jar包是手动导的,Tomcat的lib没有手动导入jar包
qq_39546305 2018-02-05
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对,缺少驱动 jar
遥远的想念 2018-02-05
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Caused by: java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver 缺少依赖的数据库驱动。所以你dao层去查数据库的时候就报错了，把相应的依赖jar引入项目就好了
gyz_?? 2018-02-04
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把oracle的驱动<dependency> 进入进去
tianfang 2018-02-04
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org.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class 'oracle.jdbc.driver.OracleDriver' 缺少jar包了
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