Java BeanInstantiationException:无法实例化bean类

我在Tomcat7上执行SpringMVC应用程序时遇到问题

这是我的DSLRServletController：

 import main.java.com.springapp.mvc.dao.DSLRDAO;
    import main.java.com.springapp.mvc.model.DSLR;
    import main.java.com.springapp.mvc.pckg.DSLRForm;
    import main.java.com.springapp.mvc.pckg.DSLRValidaor;
    import org.apache.log4j.Logger;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.Model;
    import org.springframework.web.bind.annotation.ModelAttribute;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RequestParam;

    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    import java.util.*;

    @Controller
    public class DSLRServletController extends HttpServlet {
        static Logger logger = Logger.getLogger(DSLRServletController.class);

        private DSLRDAO dslrDAO;

       /* request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html; charset=utf-8");
        List list = getActions(request, response);
        response.setContentType("text/html; charset=UTF-8");*/

        //@Autowired // need?
        public DSLRServletController() {
            this.dslrDAO = new DSLRDAO();
        }

        public void init() {logger.error("DSLRServlet.init(): just started"); }
        /*
                /s                                    GET
                /s?id=1                               GET
                /s?action=save                        POST
                /dslrservice?id=1&tm=<timestamp>      GET
         */
    @RequestMapping(value = "/s", method = RequestMethod.GET)
    public String showHTMLResponse(@ModelAttribute("dslrs") DSLR dslrs[],
                                   @ModelAttribute("dslr") DSLR dslr,
                                   @ModelAttribute("dslrErrors") HashMap dslrErrors,
                                   @ModelAttribute ("dslrform") DSLRForm dslrForm,
                                   @RequestParam("id") String paramId,
                                   @RequestParam("action") String paramAction,
                                   Model model){

        if(paramId == null || paramId.equals("")){
            //show_all_dslrs
            dslrs = getAllDslrs();    // DSLR adslrs[] -> to MODEL; HOW?
            //getServletConfig().getServletContext().getRequestDispatcher("/dslrs.jsp").forward(request, response);
           return "dslrs";
        }else{
            //show_this_dslr;
            HashMap<String,Object> dslrHashMap = getDSLRById(paramId);
            dslr = (DSLR) dslrHashMap.get("dslr");
            dslrForm = (DSLRForm)dslrHashMap.get("dslrForm");
            dslrErrors = (HashMap)dslrHashMap.get("dslrErrors");

                if(dslr != null){
    //                getServletConfig().getServletContext().getRequestDispatcher("/dslr.jsp").forward(request, response);
                    return "dslr";
                }

                else{
    //                getServletConfig().getServletContext().getRequestDispatcher("/error.jsp").forward(request, response);
                    return "error";
                }


        }
    }

    @RequestMapping(value = "/s", method = RequestMethod.POST)
    public String showHTMLResponsePOST(@ModelAttribute("dslrs") DSLR dslrs[],
                                   @ModelAttribute("dslrErrors") HashMap<?,?> dslrErrors,
                                   @ModelAttribute ("dslrform") DSLRForm dslrForm,

                                   @RequestParam("id") String paramId,
                                   @RequestParam("action") String paramAction,
                                   @RequestParam("dslr_model") String paramModel,
                                   @RequestParam("price") String paramPrice,
                                   @RequestParam("description") String paramDescription,
                                   Model model){
        int iStatusCode = 0;
        if(paramAction.equals("save") )
            iStatusCode = saveDSLR(paramId, paramModel, paramPrice, paramDescription, dslrErrors, dslrForm);    // POST

        return "dslrs";

    }

        private int saveDSLR(String paramId,
                             String paramModel,
                             String paramPrice,
                             String paramDescription,
                             HashMap<?,?> context_dslrErrors,
                             DSLRForm context_dslrForm
                             ) {
            int byte0 = 1;
            try {

                DSLRValidaor dslrValidaor = new DSLRValidaor();

                DSLRForm dslrForm = new DSLRForm();
                dslrForm.setDslrId(paramId);
                dslrForm.setModel(paramModel);
                dslrForm.setPrice(paramPrice);
                dslrForm.setDescription(paramDescription);

                HashMap hashmap = dslrValidaor.Validate(dslrForm);
                if(hashmap.size() > 0) {
                    context_dslrForm = dslrForm;
                    context_dslrErrors = hashmap;
                    byte0 = -1;
                } else{
                    DSLRDAO planedao = new DSLRDAO();
                    DSLR dslr = new DSLR();
                    dslr.setDslrId(Integer.parseInt(paramId));
                    dslr.setModel(paramModel);
                    dslr.setPrice(Integer.parseInt(paramPrice));
                    dslr.setDescription(paramDescription);
                    planedao.update(dslr);
                }
            }
            catch(Exception exception)
            {
                logger.error((new StringBuilder()).append("DSLRServlet.saveDSLR():").append(exception.getMessage()).toString());
                byte0 = -1;
            }
            return byte0;

        }

        private DSLR[] getAllDslrs(){
            DSLR adslrs[] = null;
            try
            {
                DSLRDAO DSLRDAO = new DSLRDAO();
                adslrs = (DSLR[])DSLRDAO.findAll();
            }
            catch(Exception exception)
            {
                logger.error((new StringBuilder()).append("PlaneServlet.getAllPlanes():").append(exception.getMessage()).toString());
            }
    //        request.setAttribute("dslrs", adslrs);
            return adslrs;
        }

        private HashMap<String, Object> getDSLRById(String s)
        {
            HashMap<String,Object> map = new HashMap<String, Object>();

            DSLR dslr = null;
            try {
                int i = Integer.parseInt(s);
                DSLRDAO DSLRDAO = new DSLRDAO();
                dslr = (DSLR)DSLRDAO.findById(i);

                DSLRForm dslrForm = new DSLRForm();
                dslrForm.setDslrId(Integer.toString(dslr.getDslrId()));
                dslrForm.setModel(dslr.getModel());
                dslrForm.setPrice(Integer.toString(dslr.getPrice()));
                dslrForm.setDescription(dslr.getDescription());


                map.put("dslr", dslr);
                map.put("dslrform", dslrForm);
                map.put("dslrErrors", new HashMap());

    //            request.setAttribute("dslrform", dslrForm);
    //            HashMap hashmap = new HashMap();
    //            request.setAttribute("dslrErrors", hashmap);
            }
            catch(Exception exception)
            {
                logger.error((new StringBuilder()).append("DSLRServlet.getDSLRById():").append(exception.getMessage()).toString());
            }
            return map;
        }
    }

import main.java.com.springapp.mvc.dao.DSLRDAO；
导入main.java.com.springapp.mvc.model.DSLR；
导入main.java.com.springapp.mvc.pckg.DSLRForm；
导入main.java.com.springapp.mvc.pckg.dslvalidaor；
导入org.apache.log4j.Logger；
导入org.springframework.beans.factory.annotation.Autowired；
导入org.springframework.stereotype.Controller；
导入org.springframework.ui.Model；
导入org.springframework.web.bind.annotation.ModelAttribute；
导入org.springframework.web.bind.annotation.RequestMapping；
导入org.springframework.web.bind.annotation.RequestMethod；
导入org.springframework.web.bind.annotation.RequestParam；
导入javax.servlet.ServletException；
导入javax.servlet.http.HttpServlet；
导入javax.servlet.http.HttpServletRequest；
导入javax.servlet.http.HttpServletResponse；
导入java.io.IOException；
导入java.util.*；
@控制器
公共类DSLRServletController扩展HttpServlet{
静态记录器Logger=Logger.getLogger（DSLRServletController.class）；
私家私房；
/*setCharacterEncoding（“UTF-8”）；
setContentType（“text/html；charset=utf-8”）；
列表=获取操作（请求、响应）；
setContentType（“text/html；charset=UTF-8”）*/
//@自动连线//需要吗？
公共DSLRServletController（）{
this.dslrDAO=新的dslrDAO（）；
}
public void init（）{logger.error（“DSLRServlet.init（）：刚刚启动”）；}
/*
/让我们
/s？id=1
/s？操作=保存帖子
/dslrservice？id=1&tm=GET
*/
@RequestMapping（value=“/s”，method=RequestMethod.GET）
公共字符串showHTMLResponse（@ModelAttribute（“dslrs”）DSLR dslrs[]，
@ModelAttribute（“dslr”）dslr dslr，
@ModelAttribute（“dslrErrors”）哈希映射dslrErrors，
@ModelAttribute（“dslrform”）dslrform dslrform，
@RequestParam（“id”）字符串paramId，
@RequestParam（“action”）字符串paramAction，
（模型）{
if（paramId==null | | paramId.equals（“”）{
//显示所有单反相机
dslrs=getAllDslrs（）；//DSLR adslrs[]->要建模；如何建模？
//getServletConfig（）.getServletContext（）.getRequestDispatcher（“/dslrs.jsp”）.forward（请求，响应）；
返回“数码单反”；
}否则{
//显示此单反；
HashMap dslrHashMap=getDSLRById（paramId）；
dslr=（dslr）dslrHashMap.get（“dslr”）；
dslrForm=（dslrForm）dslrHashMap.get（“dslrForm”）；
dslrErrors=（HashMap）dslrHashMap.get（“dslrErrors”）；
如果（dslr！=null）{
//getServletConfig（）.getServletContext（）.getRequestDispatcher（“/dslr.jsp”）.forward（请求，响应）；
返回“dslr”；
}
否则{
//getServletConfig（）.getServletContext（）.getRequestDispatcher（“/error.jsp”）.forward（请求，响应）；
返回“错误”；
}
}
}
@RequestMapping（value=“/s”，method=RequestMethod.POST）
公共字符串showHTMLResponsePOST（@ModelAttribute（“dslrs”）DSLR dslrs[]，
@ModelAttribute（“dslrErrors”）哈希映射dslrErrors，
@ModelAttribute（“dslrform”）dslrform dslrform，
@RequestParam（“id”）字符串paramId，
@RequestParam（“action”）字符串paramAction，
@RequestParam（“dslr_模型”）字符串参数模型，
@RequestParam（“价格”）字符串paramPrice，
@RequestParam（“描述”）字符串paramDescription，
（模型）{
int iStatusCode=0；
if（paramAction.equals（“保存”））
iStatusCode=saveDSLR（paramId、paramModel、paramPrice、paramDescription、dslrErrors、dslrForm）；//POST
返回“数码单反”；
}
私有int saveDSLR（字符串参数，
字符串参数模型，
字符串价格，
字符串参数说明，
HashMap上下文错误，
DSLRForm上下文\u DSLRForm
) {
int字节0=1；
试一试{
DSLRValidaor DSLRValidaor=新的DSLRValidaor（）；
DSLRForm DSLRForm=新的DSLRForm（）；
setDslrId（paramId）；
dslrForm.setModel（paramModel）；
dslrForm.setPrice（参数价格）；
dslrForm.setDescription（paramDescription）；
HashMap HashMap=dslrValidaor.Validate（dslrForm）；
if（hashmap.size（）>0）{
上下文_dslrForm=dslrForm；
context_dslrErrors=hashmap；
字节0=-1；
}否则{
DSLRDAO planedao=新的DSLRDAO（）；
单反单反=新单反（）；
setdsrid（Integer.parseInt（paramId））；
dslr.setModel（paramModel）；
dslr.setPrice（Integer.parseInt（paramPrice））；
dslr.setDescription（参数描述）；
planedao.update（单反）；
}
}
捕获（异常）
{
记录器错误（（新Stri
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="
   http://www.springframework.org/schema/beans     
   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
   http://www.springframework.org/schema/context 
   http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <context:component-scan base-package="main.java.com.springapp.mvc" />

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/pages/" />
        <property name="suffix" value=".jsp" />
    </bean>

    <!--<bean name="/s" class="main.java.com.springapp.mvc.controller.DSLRServletController"/>-->

</beans>

package main.java.com.springapp.mvc.dao;

import main.java.com.springapp.mvc.model.DSLR;
import main.java.com.springapp.mvc.util.DbUtil;
import org.apache.log4j.Logger;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class DSLRDAO {

    Connection connection = null;
//    static Logger logger = Logger.getLogger(ttu/idu0200/db/PlaneDAO);
    public DSLRDAO() {
        connection = DbUtil.getConnection();
    }

    public DSLR[] findAll() {
//        connection = DbUtil.getConnection();
        List<DSLR> dslrs = new ArrayList<DSLR>();
        try {
            Statement statement = connection.createStatement();
            ResultSet rs = statement.executeQuery("select * from DSLR");
            while (rs.next()) {
                DSLR dslr = new DSLR();
                dslr.setDslrId(rs.getInt("dslrid"));
                dslr.setModel(rs.getString("model"));
                dslr.setPrice(rs.getInt("price"));
                dslr.setDescription(rs.getString("description"));
                dslrs.add(dslr);
            }
        } catch (SQLException exception) {
            Logger.getLogger(DSLRDAO.class).error((new StringBuilder()).append("DSLRDAO:").append(exception.getMessage()).toString());
        }finally {
//            DbUtil.close();
        }

        return dslrs.toArray(new DSLR[dslrs.size()]);
    }

    public DSLR findById(int dslrId){
//        connection = DbUtil.getConnection();
        DSLR dslr = new DSLR();

        try{
            PreparedStatement preparedStatement = connection.prepareStatement("select * from DSLR where dslrid=?");
            preparedStatement.setInt(1, dslrId);
            ResultSet resultSet = preparedStatement.executeQuery();

            if(resultSet.next()){
                dslr.setDslrId(resultSet.getInt("dslrid"));
                dslr.setModel(resultSet.getString("model"));
                dslr.setPrice(resultSet.getInt("price"));
                dslr.setDescription(resultSet.getString("description"));
            }
        } catch (SQLException exception) {
            Logger.getLogger(DSLRDAO.class).error((new StringBuilder()).append("DSLRDAO:").append(exception.getMessage()).toString());
        } finally {
//            DbUtil.close();
//            connection = null;
        }
        return dslr;
    }
    public void update(DSLR dslr){
//        connection = DbUtil.getConnection();
     try{
         PreparedStatement preparedStatement  =
                 connection.prepareStatement("update dslr set model=?, price=?, description=?" + " where dslrid=?");

         preparedStatement.setString(1, dslr.getModel());
         preparedStatement.setInt(2, dslr.getPrice());
         preparedStatement.setString(3, dslr.getDescription());
         preparedStatement.setInt(4, dslr.getDslrId());

         preparedStatement.executeUpdate();

     } catch (SQLException exception) {
         Logger.getLogger(DSLRDAO.class).error((new StringBuilder()).append("DSLRDAO:").append(exception.getMessage()).toString());
     } finally {
//        DbUtil.close();
//        connection = null;
     }

    }
}

<web-app version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

    <display-name>Spring MVC Application</display-name>

    <servlet>
        <servlet-name>mvc-dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>mvc-dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

HTTP Status 500 - Request processing failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [[Lmain.java.com.springapp.mvc.model.DSLR;]: No default constructor found; nested exception is java.lang.NoSuchMethodException: [Lmain.java.com.springapp.mvc.model.DSLR;.<init>()

type Exception report

message Request processing failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [[Lmain.java.com.springapp.mvc.model.DSLR;]: No default constructor found; nested exception is java.lang.NoSuchMethodException: [Lmain.java.com.springapp.mvc.model.DSLR;.<init>()

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [[Lmain.java.com.springapp.mvc.model.DSLR;]: No default constructor found; nested exception is java.lang.NoSuchMethodException: [Lmain.java.com.springapp.mvc.model.DSLR;.<init>()
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:927)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:811)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:620)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:796)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause

org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [[Lmain.java.com.springapp.mvc.model.DSLR;]: No default constructor found; nested exception is java.lang.NoSuchMethodException: [Lmain.java.com.springapp.mvc.model.DSLR;.<init>()
    org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:108)
    org.springframework.web.bind.annotation.support.HandlerMethodInvoker.resolveModelAttribute(HandlerMethodInvoker.java:770)
    org.springframework.web.bind.annotation.support.HandlerMethodInvoker.resolveHandlerArguments(HandlerMethodInvoker.java:363)
    org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:171)
    org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:439)
    org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:427)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:915)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:811)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:620)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:796)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause

java.lang.NoSuchMethodException: [Lmain.java.com.springapp.mvc.model.DSLR;.<init>()
    java.lang.Class.getConstructor0(Class.java:2810)
    java.lang.Class.getDeclaredConstructor(Class.java:2053)
    org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:105)
    org.springframework.web.bind.annotation.support.HandlerMethodInvoker.resolveModelAttribute(HandlerMethodInvoker.java:770)
    org.springframework.web.bind.annotation.support.HandlerMethodInvoker.resolveHandlerArguments(HandlerMethodInvoker.java:363)
    org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:171)
    org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:439)
    org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:427)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:915)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:811)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:620)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:796)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

<bean name="s" class="main.java.com.springapp.mvc.controller.DSLRServletController"/>
<property name="dslrDAO" ref="dslrDAO" />
</bean>

org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [[Lmain.java.com.springapp.mvc.model.DSLR;]: No default constructor found; nested exception is java.lang.NoSuchMethodException: [Lmain.java.com.springapp.mvc.model.DSLR;.<init>()
    org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:108)
    org.springframework.web.bind.annotation.support.HandlerMethodInvoker.resolveModelAttribute(HandlerMethodInvoker.java:770)
    org.springframework.web.bind.annotation.support.HandlerMethodInvoker.resolveHandlerArguments(HandlerMethodInvoker.java:363)