关于这个问题的许多回复我都很紧张，很多人都说我需要使用注释，但我不认为这是问题，也许我的配置有错误。它可能在我的豆线上。我在两点 1时遇到错误。当我从userName字段中跳出时 - 因为我正在执行此时的Web服务和 2。当我点击提交按钮并发布数据时。
我正在尝试检查数据库，看看 userName 是否已经存在，所以我使用了 Web服务，所以当我跳出字段时它会检查数据库。当我将数据发布到服务器时，我也想做同样的验证，所以我再次调用相同的函数。
该函数返回布尔值。它是一个接受String userName 参数的类中的函数。也许我错误地连接了bean。如果我创建工厂Bean 并创建 applicationContext.xml 的新实例，它可以工作：
FactoryBean.java
package com.crimetrack.service;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public final class FactoryBean {
private static ClassPathXmlApplicationContext context;
private static ClassPathXmlApplicationContext getContext() {
if (context == null) {
context = new ClassPathXmlApplicationContext("applicationContext.xml");
}
return context;
}
public static OfficerRegistrationValidation getOfficerRegistrationValidation() {
return (OfficerRegistrationValidation) getContext().getBean("officerRegistrationValidation");
}
}
然后如果我使用
(FactoryBean.getOfficerRegistrationValidation().validateUserNameManager.DoesUserNameExist(officer.getUserName()) == true){
Under是我的代码和两个错误日志1.当我选中userName字段和2.当我通过提交按钮发布表单时。我希望这能很好地展示我想要实现的目标：
office_registration.jsp
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js"></script>
<style>
<%@ include file="../css/forms.css" %>
</style>
<script type="text/javascript">
<%@ include file="../js/off_reg.js"%>
$(document).ready(function(){
$('#userName').blur(function(evt){
CheckAvailability();
});
});
function CheckAvailability(){
$.ajax( {
type:'GET',
url:'validateUserName.htm',
data:{userName:$('#userName').val()},
dataType: 'json',
success:function(data) {
if (data == true){
alert("User Name Already Exists");
$("#userNameErr").text("User Name Already Exist");
}else if ($("#userName").val() == ""){
$("#userNameErr").text(" ");
}else if(data == false){
$("#userNameErr").text("User Name Valid");
}
}
});
}
</script>
<title>Officer Registration</title>
</head>
<body>
<form:form method="post" modelAttribute="officers" action="officer_registration.htm">
<ol>
<li><label>User Name</label>
<form:input path="userName"/><form:errors path="userName" id="errors"/><label id="userNameErr"></label></li>
<li><label>Password</label>
<form:password path="password"/><form:errors path="password" id="errors"/></li>
<li><label>Re-Enter Password</label>
<form:password path="password2"/><form:errors path="password2" id="errors"/></li>
<li><label>e-Mail Address</label>
<form:input path="emailAdd"/><form:errors path="emailAdd" id="errors"/></li>
<br/>
<li><input type="submit" name= "request" value="Register" />
<input type="submit" name= "request" value="Update" /></li>
</ol>
</form:form>
</body>
</html>
OfficerRegistrationValidation.java
public class OfficerRegistrationValidation implements Validator{
private final Logger logger = Logger.getLogger(getClass());
ValidateUserNameManager validateUserNameManager;
public boolean supports(Class<?> clazz) {
return Officers.class.equals(clazz);
}
public void validate(Object target, Errors errors) {
Officers officer = (Officers) target;
if (officer.getUserName() == null){
errors.rejectValue("userName", "userName.required");
}else{
String userName = officer.getUserName();
logger.info("OfficerRegistrationValidation - UserName is not null so going to check if its valid for :" + userName);
try {
logger.info("OfficerRegistrationValidation - Just before try.....catch block...userName is :" + userName);
logger.info("OfficerRegistrationValidation - about to evaluate if (validateUserNameManager.DoesUserNameExist(officer.getUserName()) == true)" );
//using a factory bean to instantiate the creation of the bean
//in some cases you want to use the existing bean and not instantiate
//if (FactoryBean.getOfficerRegistrationValidation().validateUserNameManager.DoesUserNameExist(officer.getUserName()) == true){
if (validateUserNameManager.DoesUserNameExist(officer.getUserName())== true){
errors.rejectValue("userName", "userName.exist");
}
} catch (Exception e) {
logger.info("OfficerRegistrationValidation - Error Occured When validating UserName");
logger.error("Message", e);
errors.rejectValue("userName", "userName.error");
}
}
if(officer.getPassword()== null){
errors.rejectValue("password", "password.required");
}
if(officer.getPassword2()== null){
errors.rejectValue("password2", "password2.required");
}
}
/**
* @return the validateUserNameManager
*/
public ValidateUserNameManager getValidateUserNameManager() {
logger.info("Getting - ValidateUserNameManager");
return validateUserNameManager;
}
/**
* @param validateUserNameManager the validateUserNameManager to set
*/
public void setValidateUserNameManager(
ValidateUserNameManager validateUserNameManager) {
logger.info("Setting - ValidateUserNameManager");
this.validateUserNameManager = validateUserNameManager;
}
}
ValidateUserNameManager.java
public class ValidateUserNameManager implements ValidateUserNameIFace {
public ValidateUserNameManager(){}
private OfficersDAO officerDao;
private final Logger logger = Logger.getLogger(getClass());
public boolean DoesUserNameExist(String userName) throws Exception {
logger.info("Inside ValidateUserNameManager");
try{
logger.info("ValidateUserNameManager - UserName is : " + userName);
if(officerDao.OfficerExist(userName) == true){
logger.info("ValidateUserNameManager - UserName :" + userName + " does exist");
return true;
}else{
logger.info("ValidateUserNameManager - UserName :" + userName + " does NOT exist");
return false;
}
}catch(Exception e){
logger.error("Message", e);
logger.info("ValidateUserNameManager - UserName :" + userName + " EXCEPTION OCCURED " + e.toString());
return false;
}
}
/**
* @return the officerDao
*/
public OfficersDAO getOfficerDao() {
logger.info("ValidateUserNameManager - getting officerDAO");
return officerDao;
}
/**
* @param officerdao the officerDao to set
*/
public void setOfficerDao(OfficersDAO officerDao) {
logger.info("ValidateUserNameManager - setting officerDAO");
this.officerDao = officerDao;
}
}
OfficerRegistrationController.java
@Controller
public class OfficerRegistrationController {
private final Logger logger = Logger.getLogger(getClass());
private DivisionManager divisionManager;
private PositionManager positionManager;
private GenderManager genderManager;
private Officers officer = new Officers();
private ValidateUserNameManager validateUserNameManager;
Map<String, Object> myDivision = new HashMap<String, Object>();
Map<String, Object> myPosition = new HashMap<String, Object>();
Map<String, Object> myGender = new HashMap<String, Object>();
@InitBinder("officers")
protected void initBinder(WebDataBinder binder){
//removes white spaces
binder.registerCustomEditor(String.class, new StringTrimmerEditor(true));
//formats date
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
//By passing true this will convert empty strings to null
binder.registerCustomEditor(Date.class, new CustomDateEditor(dateFormat, true));
dateFormat.setLenient(false);
logger.info("Just before initBinder");
binder.setValidator(new OfficerRegistrationValidation());
}
@RequestMapping(value="officer_registration.htm", method = RequestMethod.GET)
public ModelAndView loadPage(HttpServletRequest request,
HttpServletResponse response,@ModelAttribute Officers officer, BindingResult result, ModelMap m, Model model) throws Exception {
try{
logger.debug("In Http method for OfficerRegistrationController");
myDivision.put("divisionList", this.divisionManager.getDivisions());
myPosition.put("positionList", this.positionManager.getPositionList());
myGender.put("genderList", this.genderManager.getGenderList());
model.addAttribute("division", myDivision);
model.addAttribute("position", myPosition);
model.addAttribute("gender", myGender);
return new ModelAndView("officer_registration");
}catch(Exception e){
request.setAttribute("error",e.getMessage());
return new ModelAndView("error_page");
}
}
@RequestMapping(value="officer_registration.htm", method=RequestMethod.POST)
public ModelAndView handleRequest(@Valid @ModelAttribute Officers officer, BindingResult result, ModelMap m, Model model)throws Exception{
if(result.hasErrors()){
model.addAttribute("division", myDivision);
model.addAttribute("position", myPosition);
model.addAttribute("gender", myGender);
return new ModelAndView("officer_registration");
}else{
return null;
}
}
@RequestMapping(value="validateUserName.htm", method=RequestMethod.GET)
public @ResponseBody String validateUserName(@RequestParam String userName)throws Exception{
String results = "false";
logger.info("Inside OfficerRegistrationController");
try{
logger.info("In try ..... catch for OfficerRegistrationController");
if (validateUserNameManager.DoesUserNameExist(userName)== true){
results = "true";
return results;
}
}catch(Exception e){
logger.debug("Error in validateUserName Controller " + e.toString());
return results;
}
return results;
}
public void setDivisionManager(DivisionManager divisionManager){
this.divisionManager = divisionManager;
}
public void setPositionManager(PositionManager positionManager){
this.positionManager = positionManager;
}
public void setGenderManager(GenderManager genderManager){
this.genderManager = genderManager;
}
/**
* @return the validateUserNameManager
*/
public ValidateUserNameManager getValidateUserNameManager() {
return validateUserNameManager;
}
/**
* @param validateUserNameManager the validateUserNameManager to set
*/
public void setValidateUserNameManager(
ValidateUserNameManager validateUserNameManager) {
this.validateUserNameManager = validateUserNameManager;
}
/**
* @return the officer
*/
public Officers getOfficer() {
return officer;
}
/**
* @param officer the officer to set
*/
public void setOfficer(Officers officer) {
this.officer = officer;
}
}
crimetrack-servlet.xml中
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"..............
<!-- __________________________________________________________________________________________________ -->
<!-- Supports annotations and allows the use of @Controller, @Required, @RequestMapping -->
<context:annotation-config/>
<context:component-scan base-package="com.crimetrack" />
<!-- __________________________________________________________________________________________________ -->
<!-- Forwards requests to the "/" resource to the "login" view -->
<mvc:view-controller path="/login" view-name="login"/>
<!-- Forwards requests to the "/" resource to the "officer_registration" view -->
<mvc:view-controller path="/officer_registration" view-name="officer_registration"/>
<!-- __________________________________________________________________________________________________ -->
<!-- <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping"/> -->
<!-- Is used to process method level annotations -->
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>
<!-- __________________________________________________________________________________________________ -->
<!-- <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/> -->
<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
<property name="basename" value="messages"/>
</bean>
<!-- __________________________________________________________________________________________________ -->
<bean name="/hello.htm" class="com.crimetrack.web.CountryListController">
<property name="countryManager" ref="countryManager"/>
</bean>
<bean name="/login.htm" class="com.crimetrack.web.AuthenticationController">
<property name="authenticationManager" ref="authenticationManager"/>
</bean>
<bean name="/officer_registration.htm" class="com.crimetrack.web.OfficerRegistrationController">
<property name="divisionManager" ref="divisionManager" />
<property name="positionManager" ref="positionManager" />
<property name="genderManager" ref="genderManager"/>
</bean>
<!-- __________________________________________________________________________________________________ -->
<bean name="/validateUserName.htm" class="com.crimetrack.web.OfficerRegistrationController">
<property name="validateUserNameManager" ref="validateUserNameManager"/>
</bean>
<!-- __________________________________________________________________________________________________ -->
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"></property>
<property name="prefix" value="/WEB-INF/jsp/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
</beans>
的applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"...............
<!-- __________________________________________________________________________________________________ -->
<bean id="countryManager" class="com.crimetrack.service.CountryManager">
<property name="countryDao" ref="countryDao"/>
</bean>
<bean id="countryDao" class="com.crimetrack.jdbc.JdbcCountryDAO">
<property name="dataSource" ref="dataSource"/>
</bean>
<!-- __________________________________________________________________________________________________ -->
<bean id="authenticationManager" class="com.crimetrack.service.AuthenticationManager">
<property name="loginDao" ref="loginDao" />
</bean>
<bean id="loginDao" class="com.crimetrack.jdbc.JdbcLoginDAO">
<property name="dataSource" ref="dataSource" />
</bean>
<!-- __________________________________________________________________________________________________ -->
<bean id="divisionManager" class="com.crimetrack.service.DivisionManager">
<property name="divisionDao" ref="divisionDao"/>
</bean>
<bean id="divisionDao" class="com.crimetrack.jdbc.JdbcDivisionDAO">
<property name="dataSource" ref="dataSource"/>
</bean>
<!-- __________________________________________________________________________________________________ -->
<bean id="positionManager" class="com.crimetrack.service.PositionManager">
<property name="positionDao" ref="positionDao"/>
</bean>
<bean id="positionDao" class="com.crimetrack.jdbc.JdbcPositionDAO">
<property name="dataSource" ref="dataSource" />
</bean>
<!-- __________________________________________________________________________________________________ -->
<bean id="genderManager" class="com.crimetrack.service.GenderManager">
<property name="genderDao" ref="genderDao"/>
</bean>
<bean id="genderDao" class="com.crimetrack.jdbc.JdbcGenderDAO" >
<property name="dataSource" ref="dataSource" />
</bean>
<!-- __________________________________________________________________________________________________ -->
<bean id="officerRegistrationValidation" class="com.crimetrack.service.OfficerRegistrationValidation">
<property name="validateUserNameManager" ref="validateUserNameManager"/>
</bean>
<bean id="validateUserNameManager" class="com.crimetrack.service.ValidateUserNameManager">
<property name="officerDao" ref="officerDao"/>
</bean>
<bean id="officerDao" class="com.crimetrack.jdbc.JdbcOfficersDAO" >
<property name="dataSource" ref="dataSource" />
</bean>
<!-- __________________________________________________________________________________________________ -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="${jdbc.driverClassName}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
<!-- __________________________________________________________________________________________________ -->
<bean id="propertyConfigurer"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath:jdbc.properties</value>
</list>
</property>
</bean>
<!-- __________________________________________________________________________________________________ -->
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
</bean>
</beans>
1。选项卡超出用户名字段时的错误日志
1882370 [http-8084-1] DEBUG org.springframework.web.bind.annotation.support.HandlerMethodInvoker - Invoking request handler method: public java.lang.String com.crimetrack.web.OfficerRegistrationController.validateUserName(java.lang.String) throws java.lang.Exception
1882370 [http-8084-1] INFO com.crimetrack.web.OfficerRegistrationController - Inside OfficerRegistrationController
1882370 [http-8084-1] INFO com.crimetrack.web.OfficerRegistrationController - In try ..... catch for OfficerRegistrationController
1882370 [http-8084-1] INFO com.crimetrack.service.ValidateUserNameManager - Inside ValidateUserNameManager
1882370 [http-8084-1] INFO com.crimetrack.service.ValidateUserNameManager - ValidateUserNameManager - UserName is : admin
1882371 [http-8084-1] ERROR com.crimetrack.service.ValidateUserNameManager - Message
java.lang.NullPointerException
at com.crimetrack.service.ValidateUserNameManager.DoesUserNameExist(ValidateUserNameManager.java:26)
at com.crimetrack.web.OfficerRegistrationController.validateUserName(OfficerRegistrationController.java:140)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:436)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:424)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
1882371 [http-8084-1] INFO com.crimetrack.service.ValidateUserNameManager - ValidateUserNameManager - UserName :admin EXCEPTION OCCURED java.lang.NullPointerException
2.表单POST到控制器时的错误日志：
1135560 [http-8084-1] DEBUG org.springframework.beans.TypeConverterDelegate - Converting String to [class java.lang.String] using property editor [org.springframework.beans.propertyeditors.StringTrimmerEditor@1983ad7]
1135560 [http-8084-1] INFO com.crimetrack.service.OfficerRegistrationValidation - OfficerRegistrationValidation - UserName is not null so going to check if its valid for :admin
1135560 [http-8084-1] INFO com.crimetrack.service.OfficerRegistrationValidation - OfficerRegistrationValidation - Just before try.....catch block...userName is :admin
1135560 [http-8084-1] INFO com.crimetrack.service.OfficerRegistrationValidation - OfficerRegistrationValidation - about to evaluate if (validateUserNameManager.DoesUserNameExist(officer.getUserName()) == true)
1135560 [http-8084-1] INFO com.crimetrack.service.OfficerRegistrationValidation - OfficerRegistrationValidation - Error Occured When validating UserName
1135561 [http-8084-1] ERROR com.crimetrack.service.OfficerRegistrationValidation - Message
java.lang.NullPointerException
at com.crimetrack.service.OfficerRegistrationValidation.validate(OfficerRegistrationValidation.java:61)
at org.springframework.validation.DataBinder.validate(DataBinder.java:725)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.doBind(HandlerMethodInvoker.java:815)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.resolveHandlerArguments(HandlerMethodInvoker.java:367)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:171)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:436)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:424)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
答案 0 :(得分：2)
当您在控制器new OfficerRegistrationValidation()中执行initBinder时，会得到一个validateUserNameManager为空的实例，因此是NPE。
Spring不会为你自动“填充”类字段，你需要要求它。
此外，您的控制器似乎会在字段（类级别）上存储每个用户的内容，但如果两个用户要求同一页面会怎么样。
我会建议这样的事情：
@Controller
public class OfficerRegistrationController {
private final Logger logger = Logger.getLogger(getClass());
@Autowire // tells spring to populates that for us.
private DivisionManager divisionManager;
@Autowire
private PositionManager positionManager;
@Autowire
private GenderManager genderManager;
@Autowire
private OfficerRegistrationValidation officerRegistrationValidation;
@InitBinder("officers")
protected void initBinder(WebDataBinder binder){
//removes white spaces
binder.registerCustomEditor(String.class, new StringTrimmerEditor(true));
//formats date
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
//By passing true this will convert empty strings to null
binder.registerCustomEditor(Date.class, new CustomDateEditor(dateFormat, true));
dateFormat.setLenient(false);
logger.info("Just before initBinder");
binder.setValidator(officerRegistrationValidation);
}
@RequestMapping(value="officer_registration.htm", method = RequestMethod.GET)
public ModelAndView loadPage(HttpServletRequest request, HttpServletResponse response,@ModelAttribute Officers officer, BindingResult result, ModelMap m, Model model) throws Exception {
// ...
}
@RequestMapping(value="officer_registration.htm", method=RequestMethod.POST)
public ModelAndView handleRequest(@Valid @ModelAttribute Officers officer, BindingResult result, ModelMap m, Model model) throws Exception{
// ...
}
@RequestMapping(value="validateUserName.htm", method=RequestMethod.GET)
public @ResponseBody String validateUserName(@RequestParam String userName) throws Exception{
// ...
}
}
@Component
public class OfficerRegistrationValidation implements Validator {
private final Logger logger = Logger.getLogger(getClass());
@Autowire
ValidateUserNameManager validateUserNameManager;
public boolean supports(Class<?> clazz) {
return Officers.class.equals(clazz);
}
public void validate(Object target, Errors errors) {
// ...
}
}
@Service
public class ValidateUserNameManager implements ValidateUserNameIFace {
private final Logger logger = Logger.getLogger(getClass());
@Autowire
private OfficersDAO officerDao;
public boolean doesUserNameExist(String userName) throws Exception {
// ...
}
}
@Repository
public class OfficersDAO {
// ...
}
注意类上的@Component，@Service，@Repository，这告诉spring在上下文启动时为这些类创建一个bean（参见<context:annotation-config/>和{{1 } docs）。
<context:component-scan base-package="..." />告诉spring尝试将带注释的字段与一个现有bean匹配（使用它的类型）。
整个想法是有三层：控制器，服务和daos;
我也建议一些好读:)：