标签:des c style class blog code
细化一下AccountService接口方法
AccountService.java
这里我把注解@Transactional调整到了具体的方法上,也就是说这样写的话,凡是加入注解的标注的方法都属于事务配置!
Account
register(Account
account);用做用户注册作用!
@Transactional(readOnly =
true)只读属性
@Transactional(readOnly = false, rollbackFor
=
DataAccessException.class)只读关闭,遇到DataAccessException异常回滚!如果不对异常进行处理,该异常将一直向上层抛出,直至抛出到页面!
如果你的Eclipse集成了SpringIDE,你可以观察一下这时的xml配置文件和AccoutServiceImpl.java的变化!
这次,来个用户注册功能演示,故意在某个位置制造一个异常,看看是否正常回滚!
先看注册控制器
RegisterController.java
@InitBinder用于表单自定义属性绑定。这里我们要求输入一个日期格式的生日。
@RequestMapping(method
= RequestMethod.GET)用于初始化页面。
@RequestMapping(method =
RequestMethod.POST)用于提交页面。
再看注册页面
register.jsp
这里我用了一个JavaScript日期控制标签:
使用起来就像是这样:
非常好用!!!
当然,你完全可以使用JE上的那个JS控件!
接下来稍微调整一下AccountService接口及其实现AccountServiceImpl
AccountService.java
为了在插入一条记录后获得当前用户的主键,我们还得这么玩!
的确有点雷人~
从架构考虑,这是符合业务要求的实现!如果用iBatis或者Hibernate,这个问题就有数据库一次IO处理完成了!
再看看AccountDao接口及其实现AccountDaoImpl
AccountDao.java
AccountDaoImpl.java
来个注册演示!
注册:
信息展示:
来制造一起事故!
先看看数据库目前的状况!
在AccountDaoImpl中来个破坏!![]()
我们强行在执行完Insert语句后抛出DataAccessException异常(RecoverableDataAccessException)!
来个注册试试!

Spring的@RequestBody非常牛x,可以将提交的json直接转换成POJO对象。
正好今天有这样的需求,使用一下,结果一直报415,十分头疼。
HTTP 415 错误 – 不支持的媒体类型(Unsupported media type)
我的angularJs是这样写的
$http({method: "POST",
url: url;
headers: {‘Content-type‘: ‘application/json;charset=UTF-8‘},
data: scope.$modelValue})
.success(function(data, status) {
// success handle code
})
.error(function(data, status) {
// error handle code
});
url与scope.$modelValue都是项目中的代码,在这里占个坑,scope.$modelValue是一个js对象,会被angularJs转换成json字符串,
反复看angularJs的文档,又抓包分析,确认js没有问题。
在网上一查貌似是Spring的问题,有的网友说需要在*-servlet.xml中增加<mvc:annotation-driven />,一看我的项目没加,立刻加上。
当然还需要加上mvc的xml命名空间,否则该配置无法解析。
xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd"
<mvc:annotation-driven />会自动注册DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter两个bean
AnnotationMethodHandlerAdapter将会初始化7个转换器,可以通过调用AnnotationMethodHandlerAdapter的getMessageConverts()方法来获取转换器的一个集合 List<HttpMessageConverter>
ByteArrayHttpMessageConverter
StringHttpMessageConverter
ResourceHttpMessageConverter
SourceHttpMessageConverter
XmlAwareFormHttpMessageConverter
Jaxb2RootElementHttpMessageConverter
MappingJacksonHttpMessageConverter
对于json的解析就是通过MappingJacksonHttpMessageConverter转换器完成的。
只添加<mvc:annotation-driven />还不行,需要在classpath环境中能找到Jackson包,用maven配置如下
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>1.9.8</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
至此问题解决,附上Spring代码
@RequestMapping(value = "/testjson", method = RequestMethod.POST, consumes = "application/json") @ResponseBody public void testJson(@RequestBody JsonInfo jsonInfo, HttpServletRequest request, HttpServletResponse response) { //handle jsonInfo object instance }
从下文得到帮助,对作者表示感谢:)
http://snowolf.iteye.com/blog/1628861





接上一篇文章,对@RequestMapping进行地址映射讲解之后,该篇主要讲解request 数据到handler method 参数数据的绑定所用到的注解和什么情形下使用;
handler method 参数绑定常用的注解,我们根据他们处理的Request的不同内容部分分为四类:(主要讲解常用类型)
A、处理requet uri 部分(这里指uri template中variable,不含queryString部分)的注解: @PathVariable;
B、处理request header部分的注解: @RequestHeader, @CookieValue;
C、处理request body部分的注解:@RequestParam, @RequestBody;
D、处理attribute类型是注解: @SessionAttributes, @ModelAttribute;
当使用@RequestMapping URI template 样式映射时, 即 someUrl/{paramId}, 这时的paramId可通过 @Pathvariable注解绑定它传过来的值到方法的参数上。
示例代码:
@Controller @RequestMapping("/owners/{ownerId}") public class RelativePathUriTemplateController { @RequestMapping("/pets/{petId}") public void findPet(@PathVariable String ownerId, @PathVariable String petId, Model model) { // implementation omitted } }
上面代码把URI template 中变量 ownerId的值和petId的值,绑定到方法的参数上。若方法参数名称和需要绑定的uri
template中变量名称不一致,需要在@PathVariable("name")指定uri template中的名称。
@RequestHeader 注解,可以把Request请求header部分的值绑定到方法的参数上。
示例代码:
这是一个Request 的header部分:
Host localhost:8080 Accept text/html,application/xhtml+xml,application/xml;q=0.9 Accept-Language fr,en-gb;q=0.7,en;q=0.3 Accept-Encoding gzip,deflate Accept-Charset ISO-8859-1,utf-8;q=0.7,*;q=0.7 Keep-Alive 300
@RequestMapping("/displayHeaderInfo.do")
public void displayHeaderInfo(@RequestHeader("Accept-Encoding") String encoding,
@RequestHeader("Keep-Alive") long keepAlive) {
//...
}
上面的代码,把request header部分的 Accept-Encoding的值,绑定到参数encoding上了, Keep-Alive header的值绑定到参数keepAlive上。
@CookieValue 可以把Request header中关于cookie的值绑定到方法的参数上。
例如有如下Cookie值:
JSESSIONID=415A4AC178C59DACE0B2C9CA727CDD84
参数绑定的代码:
@RequestMapping("/displayHeaderInfo.do")
public void displayHeaderInfo(@CookieValue("JSESSIONID") String cookie) {
//...
}
即把JSESSIONID的值绑定到参数cookie上。
@RequestParam
A) 常用来处理简单类型的绑定,通过Request.getParameter() 获取的String可直接转换为简单类型的情况( String--> 简单类型的转换操作由ConversionService配置的转换器来完成);因为使用request.getParameter()方式获取参数,所以可以处理get 方式中queryString的值,也可以处理post方式中 body data的值;
B)用来处理Content-Type: 为 application/x-www-form-urlencoded编码的内容,提交方式GET、POST;
C) 该注解有两个属性: value、required; value用来指定要传入值的id名称,required用来指示参数是否必须绑定;
示例代码:
@Controller @RequestMapping("/pets") @SessionAttributes("pet") public class EditPetForm { // ... @RequestMapping(method = RequestMethod.GET) public String setupForm(@RequestParam("petId") int petId, ModelMap model) { Pet pet = this.clinic.loadPet(petId); model.addAttribute("pet", pet); return "petForm"; } // ...
@RequestBody
该注解常用来处理Content-Type: 不是application/x-www-form-urlencoded编码的内容,例如application/json,
application/xml等;
它是通过使用HandlerAdapter 配置的HttpMessageConverters来解析post data
body,然后绑定到相应的bean上的。
因为配置有FormHttpMessageConverter,所以也可以用来处理 application/x-www-form-urlencoded的内容,处理完的结果放在一个MultiValueMap<String,
String>里,这种情况在某些特殊需求下使用,详情查看FormHttpMessageConverter api;
示例代码:
@RequestMapping(value = "/something", method = RequestMethod.PUT) public void handle(@RequestBody String body, Writer writer) throws IOException { writer.write(body); }
@SessionAttributes:
该注解用来绑定HttpSession中的attribute对象的值,便于在方法中的参数里使用。
该注解有value、types两个属性,可以通过名字和类型指定要使用的attribute 对象;
示例代码:
@Controller @RequestMapping("/editPet.do") @SessionAttributes("pet") public class EditPetForm { // ... }
@ModelAttribute
该注解有两个用法,一个是用于方法上,一个是用于参数上;
用于方法上时: 通常用来在处理@RequestMapping之前,为请求绑定需要从后台查询的model;
用于参数上时: 用来通过名称对应,把相应名称的值绑定到注解的参数bean上;要绑定的值来源于:
A) @SessionAttributes 启用的attribute 对象上;
B) @ModelAttribute 用于方法上时指定的model对象;
C) 上述两种情况都没有时,new一个需要绑定的bean对象,然后把request中按名称对应的方式把值绑定到bean中。
用到方法上@ModelAttribute的示例代码:
// Add one attribute // The return value of the method is added to the model under the name "account" // You can customize the name via @ModelAttribute("myAccount") @ModelAttribute public Account addAccount(@RequestParam String number) { return accountManager.findAccount(number); }
这种方式实际的效果就是在调用@RequestMapping的方法之前,为request对象的model里put(“account”, Account);
用在参数上的@ModelAttribute示例代码:
@RequestMapping(value="/owners/{ownerId}/pets/{petId}/edit", method = RequestMethod.POST)
public String processSubmit(@ModelAttribute Pet pet) {
}
首先查询
@SessionAttributes有无绑定的Pet对象,若没有则查询@ModelAttribute方法层面上是否绑定了Pet对象,若没有则将URI
template中的值按对应的名称绑定到Pet对象的各属性上。
通过分析AnnotationMethodHandlerAdapter和RequestMappingHandlerAdapter的源代码发现,方法的参数在不给定参数的情况下:
若要绑定的对象时简单类型: 调用@RequestParam来处理的。
若要绑定的对象时复杂类型: 调用@ModelAttribute来处理的。
这里的简单类型指java的原始类型(boolean, int 等)、原始类型对象(Boolean, Int等)、String、Date等ConversionService里可以直接String转换成目标对象的类型;
下面贴出AnnotationMethodHandlerAdapter中绑定参数的部分源代码:
private Object[] resolveHandlerArguments(Method handlerMethod, Object handler, NativeWebRequest webRequest, ExtendedModelMap implicitModel) throws Exception { Class[] paramTypes = handlerMethod.getParameterTypes(); Object[] args = new Object[paramTypes.length]; for (int i = 0; i < args.length; i++) { MethodParameter methodParam = new MethodParameter(handlerMethod, i); methodParam.initParameterNameDiscovery(this.parameterNameDiscoverer); GenericTypeResolver.resolveParameterType(methodParam, handler.getClass()); String paramName = null; String headerName = null; boolean requestBodyFound = false; String cookieName = null; String pathVarName = null; String attrName = null; boolean required = false; String defaultValue = null; boolean validate = false; Object[] validationHints = null; int annotationsFound = 0; Annotation[] paramAnns = methodParam.getParameterAnnotations(); for (Annotation paramAnn : paramAnns) { if (RequestParam.class.isInstance(paramAnn)) { RequestParam requestParam = (RequestParam) paramAnn; paramName = requestParam.value(); required = requestParam.required(); defaultValue = parseDefaultValueAttribute(requestParam.defaultValue()); annotationsFound++; } else if (RequestHeader.class.isInstance(paramAnn)) { RequestHeader requestHeader = (RequestHeader) paramAnn; headerName = requestHeader.value(); required = requestHeader.required(); defaultValue = parseDefaultValueAttribute(requestHeader.defaultValue()); annotationsFound++; } else if (RequestBody.class.isInstance(paramAnn)) { requestBodyFound = true; annotationsFound++; } else if (CookieValue.class.isInstance(paramAnn)) { CookieValue cookieValue = (CookieValue) paramAnn; cookieName = cookieValue.value(); required = cookieValue.required(); defaultValue = parseDefaultValueAttribute(cookieValue.defaultValue()); annotationsFound++; } else if (PathVariable.class.isInstance(paramAnn)) { PathVariable pathVar = (PathVariable) paramAnn; pathVarName = pathVar.value(); annotationsFound++; } else if (ModelAttribute.class.isInstance(paramAnn)) { ModelAttribute attr = (ModelAttribute) paramAnn; attrName = attr.value(); annotationsFound++; } else if (Value.class.isInstance(paramAnn)) { defaultValue = ((Value) paramAnn).value(); } else if (paramAnn.annotationType().getSimpleName().startsWith("Valid")) { validate = true; Object value = AnnotationUtils.getValue(paramAnn); validationHints = (value instanceof Object[] ? (Object[]) value : new Object[] {value}); } } if (annotationsFound > 1) { throw new IllegalStateException("Handler parameter annotations are exclusive choices - " + "do not specify more than one such annotation on the same parameter: " + handlerMethod); } if (annotationsFound == 0) {// 若没有发现注解 Object argValue = resolveCommonArgument(methodParam, webRequest); //判断WebRquest是否可赋值给参数 if (argValue != WebArgumentResolver.UNRESOLVED) { args[i] = argValue; } else if (defaultValue != null) { args[i] = resolveDefaultValue(defaultValue); } else { Class<?> paramType = methodParam.getParameterType(); if (Model.class.isAssignableFrom(paramType) || Map.class.isAssignableFrom(paramType)) { if (!paramType.isAssignableFrom(implicitModel.getClass())) { throw new IllegalStateException("Argument [" + paramType.getSimpleName() + "] is of type " + "Model or Map but is not assignable from the actual model. You may need to switch " + "newer MVC infrastructure classes to use this argument."); } args[i] = implicitModel; } else if (SessionStatus.class.isAssignableFrom(paramType)) { args[i] = this.sessionStatus; } else if (HttpEntity.class.isAssignableFrom(paramType)) { args[i] = resolveHttpEntityRequest(methodParam, webRequest); } else if (Errors.class.isAssignableFrom(paramType)) { throw new IllegalStateException("Errors/BindingResult argument declared " + "without preceding model attribute. Check your handler method signature!"); } else if (BeanUtils.isSimpleProperty(paramType)) {// 判断是否参数类型是否是简单类型,若是在使用@RequestParam方式来处理,否则使用@ModelAttribute方式处理 paramName = ""; } else { attrName = ""; } } } if (paramName != null) { args[i] = resolveRequestParam(paramName, required, defaultValue, methodParam, webRequest, handler); } else if (headerName != null) { args[i] = resolveRequestHeader(headerName, required, defaultValue, methodParam, webRequest, handler); } else if (requestBodyFound) { args[i] = resolveRequestBody(methodParam, webRequest, handler); } else if (cookieName != null) { args[i] = resolveCookieValue(cookieName, required, defaultValue, methodParam, webRequest, handler); } else if (pathVarName != null) { args[i] = resolvePathVariable(pathVarName, methodParam, webRequest, handler); } else if (attrName != null) { WebDataBinder binder = resolveModelAttribute(attrName, methodParam, implicitModel, webRequest, handler); boolean assignBindingResult = (args.length > i + 1 && Errors.class.isAssignableFrom(paramTypes[i + 1])); if (binder.getTarget() != null) { doBind(binder, webRequest, validate, validationHints, !assignBindingResult); } args[i] = binder.getTarget(); if (assignBindingResult) { args[i + 1] = binder.getBindingResult(); i++; } implicitModel.putAll(binder.getBindingResult().getModel()); } } return args; }
RequestMappingHandlerAdapter中使用的参数绑定,代码稍微有些不同,有兴趣的同仁可以分析下,最后处理的结果都是一样的。
示例:
@RequestMapping ({"/", "/home"})
public String showHomePage(String key){
logger.debug("key="+key);
return "home";
}
这种情况下,就调用默认的@RequestParam来处理。
@RequestMapping (method = RequestMethod.POST) public String doRegister(User user){ if(logger.isDebugEnabled()){ logger.debug("process url[/user], method[post] in "+getClass()); logger.debug(user); } return "user"; }
这种情况下,就调用@ModelAttribute来处理
作用:
i) 该注解用于读取Request请求的body部分数据,使用系统默认配置的HttpMessageConverter进行解析,然后把相应的数据绑定到要返回的对象上;
ii) 再把HttpMessageConverter返回的对象数据绑定到 controller中方法的参数上。
使用时机:
A) GET、POST方式提时, 根据request header Content-Type的值来判断:
B) PUT方式提交时, 根据request header Content-Type的值来判断:
说明:request的body部分的数据编码格式由header部分的Content-Type指定;
作用:
该注解用于将Controller的方法返回的对象,通过适当的HttpMessageConverter转换为指定格式后,写入到Response对象的body数据区。
使用时机:
返回的数据不是html标签的页面,而是其他某种格式的数据时(如json、xml等)使用;
<span style="font-family:Microsoft YaHei;">/** * Strategy interface that specifies a converter that can convert from and to HTTP requests and responses. * * @author Arjen Poutsma * @author Juergen Hoeller * @since 3.0 */ public interface HttpMessageConverter<T> { /** * Indicates whether the given class can be read by this converter. * @param clazz the class to test for readability * @param mediaType the media type to read, can be {@code null} if not specified. * Typically the value of a {@code Content-Type} header. * @return {@code true} if readable; {@code false} otherwise */ boolean canRead(Class<?> clazz, MediaType mediaType); /** * Indicates whether the given class can be written by this converter. * @param clazz the class to test for writability * @param mediaType the media type to write, can be {@code null} if not specified. * Typically the value of an {@code Accept} header. * @return {@code true} if writable; {@code false} otherwise */ boolean canWrite(Class<?> clazz, MediaType mediaType); /** * Return the list of {@link MediaType} objects supported by this converter. * @return the list of supported media types */ List<MediaType> getSupportedMediaTypes(); /** * Read an object of the given type form the given input message, and returns it. * @param clazz the type of object to return. This type must have previously been passed to the * {@link #canRead canRead} method of this interface, which must have returned {@code true}. * @param inputMessage the HTTP input message to read from * @return the converted object * @throws IOException in case of I/O errors * @throws HttpMessageNotReadableException in case of conversion errors */ T read(Class<? extends T> clazz, HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException; /** * Write an given object to the given output message. * @param t the object to write to the output message. The type of this object must have previously been * passed to the {@link #canWrite canWrite} method of this interface, which must have returned {@code true}. * @param contentType the content type to use when writing. May be {@code null} to indicate that the * default content type of the converter must be used. If not {@code null}, this media type must have * previously been passed to the {@link #canWrite canWrite} method of this interface, which must have * returned {@code true}. * @param outputMessage the message to write to * @throws IOException in case of I/O errors * @throws HttpMessageNotWritableException in case of conversion errors */ void write(T t, MediaType contentType, HttpOutputMessage outputMessage) throws IOException, HttpMessageNotWritableException; } </span>
该接口定义了四个方法,分别是读取数据时的 canRead(), read() 和 写入数据时的canWrite(), write()方法。
在使用 <mvc:annotation-driven />标签配置时,默认配置了RequestMappingHandlerAdapter(注意是RequestMappingHandlerAdapter不是AnnotationMethodHandlerAdapter,详情查看Spring
3.1 document “16.14 Configuring Spring
MVC”章节),并为他配置了一下默认的HttpMessageConverter:
ByteArrayHttpMessageConverter converts byte arrays. StringHttpMessageConverter converts strings. ResourceHttpMessageConverter converts to/from org.springframework.core.io.Resource for all media types. SourceHttpMessageConverter converts to/from a javax.xml.transform.Source. FormHttpMessageConverter converts form data to/from a MultiValueMap<String, String>. Jaxb2RootElementHttpMessageConverter converts Java objects to/from XML — added if JAXB2 is present on the classpath. MappingJacksonHttpMessageConverter converts to/from JSON — added if Jackson is present on the classpath. AtomFeedHttpMessageConverter converts Atom feeds — added if Rome is present on the classpath. RssChannelHttpMessageConverter converts RSS feeds — added if Rome is present on the classpath.
ByteArrayHttpMessageConverter:
负责读取二进制格式的数据和写出二进制格式的数据;
StringHttpMessageConverter:
负责读取字符串格式的数据和写出二进制格式的数据;
ResourceHttpMessageConverter:负责读取资源文件和写出资源文件数据;
FormHttpMessageConverter: 负责读取form提交的数据(能读取的数据格式为 application/x-www-form-urlencoded,不能读取multipart/form-data格式数据);负责写入application/x-www-from-urlencoded和multipart/form-data格式的数据;
MappingJacksonHttpMessageConverter: 负责读取和写入json格式的数据;
SouceHttpMessageConverter: 负责读取和写入 xml 中javax.xml.transform.Source定义的数据;
Jaxb2RootElementHttpMessageConverter: 负责读取和写入xml 标签格式的数据;
AtomFeedHttpMessageConverter: 负责读取和写入Atom格式的数据;
RssChannelHttpMessageConverter: 负责读取和写入RSS格式的数据;
当使用@RequestBody和@ResponseBody注解时,RequestMappingHandlerAdapter就使用它们来进行读取或者写入相应格式的数据。
@RequestBody注解时: 根据Request对象header部分的Content-Type类型,逐一匹配合适的HttpMessageConverter来读取数据;
spring 3.1源代码如下:
private Object readWithMessageConverters(MethodParameter methodParam, HttpInputMessage inputMessage, Class paramType) throws Exception { MediaType contentType = inputMessage.getHeaders().getContentType(); if (contentType == null) { StringBuilder builder = new StringBuilder(ClassUtils.getShortName(methodParam.getParameterType())); String paramName = methodParam.getParameterName(); if (paramName != null) { builder.append(‘ ‘); builder.append(paramName); } throw new HttpMediaTypeNotSupportedException( "Cannot extract parameter (" + builder.toString() + "): no Content-Type found"); } List<MediaType> allSupportedMediaTypes = new ArrayList<MediaType>(); if (this.messageConverters != null) { for (HttpMessageConverter<?> messageConverter : this.messageConverters) { allSupportedMediaTypes.addAll(messageConverter.getSupportedMediaTypes()); if (messageConverter.canRead(paramType, contentType)) { if (logger.isDebugEnabled()) { logger.debug("Reading [" + paramType.getName() + "] as \"" + contentType +"\" using [" + messageConverter + "]"); } return messageConverter.read(paramType, inputMessage); } } } throw new HttpMediaTypeNotSupportedException(contentType, allSupportedMediaTypes); }
@ResponseBody注解时: 根据Request对象header部分的Accept属性(逗号分隔),逐一按accept中的类型,去遍历找到能处理的HttpMessageConverter;
源代码如下:
private void writeWithMessageConverters(Object returnValue, HttpInputMessage inputMessage, HttpOutputMessage outputMessage) throws IOException, HttpMediaTypeNotAcceptableException { List<MediaType> acceptedMediaTypes = inputMessage.getHeaders().getAccept(); if (acceptedMediaTypes.isEmpty()) { acceptedMediaTypes = Collections.singletonList(MediaType.ALL); } MediaType.sortByQualityValue(acceptedMediaTypes); Class<?> returnValueType = returnValue.getClass(); List<MediaType> allSupportedMediaTypes = new ArrayList<MediaType>(); if (getMessageConverters() != null) { for (MediaType acceptedMediaType : acceptedMediaTypes) { for (HttpMessageConverter messageConverter : getMessageConverters()) { if (messageConverter.canWrite(returnValueType, acceptedMediaType)) { messageConverter.write(returnValue, acceptedMediaType, outputMessage); if (logger.isDebugEnabled()) { MediaType contentType = outputMessage.getHeaders().getContentType(); if (contentType == null) { contentType = acceptedMediaType; } logger.debug("Written [" + returnValue + "] as \"" + contentType + "\" using [" + messageConverter + "]"); } this.responseArgumentUsed = true; return; } } } for (HttpMessageConverter messageConverter : messageConverters) { allSupportedMediaTypes.addAll(messageConverter.getSupportedMediaTypes()); } } throw new HttpMediaTypeNotAcceptableException(allSupportedMediaTypes); }
MappingJacksonHttpMessageConverter 调用了 objectMapper.writeValue(OutputStream stream, Object)方法,使用@ResponseBody注解返回的对象就传入Object参数内。若返回的对象为已经格式化好的json串时,不使用@RequestBody注解,而应该这样处理:
1、response.setContentType("application/json; charset=UTF-8");2、response.getWriter().print(jsonStr);
直接输出到body区,然后的视图为void。
前段时间项目中用到了RESTful模式来开发程序,但是当用POST、PUT模式提交数据时,发现服务器端接受不到提交的数据(服务器端参数绑定没有加任何注解),查看了提交方式为application/json, 而且服务器端通过request.getReader() 打出的数据里确实存在浏览器提交的数据。为了找出原因,便对参数绑定(@RequestParam、 @RequestBody、 @RequestHeader 、 @PathVariable)进行了研究,同时也看了一下HttpMessageConverter的相关内容,在此一并总结。
@RequestMapping
RequestMapping是一个用来处理请求地址映射的注解,可用于类或方法上。用于类上,表示类中的所有响应请求的方法都是以该地址作为父路径。
RequestMapping注解有六个属性,下面我们把她分成三类进行说明。
value: 指定请求的实际地址,指定的地址可以是URI Template 模式(后面将会说明);
method: 指定请求的method类型, GET、POST、PUT、DELETE等;
consumes: 指定处理请求的提交内容类型(Content-Type),例如application/json, text/html;
produces: 指定返回的内容类型,仅当request请求头中的(Accept)类型中包含该指定类型才返回;
params: 指定request中必须包含某些参数值是,才让该方法处理。
headers: 指定request中必须包含某些指定的header值,才能让该方法处理请求。
默认RequestMapping("....str...")即为value的值;
@Controller @RequestMapping("/appointments") public class AppointmentsController { private AppointmentBook appointmentBook; @Autowired public AppointmentsController(AppointmentBook appointmentBook) { this.appointmentBook = appointmentBook; } @RequestMapping(method = RequestMethod.GET) public Map<String, Appointment> get() { return appointmentBook.getAppointmentsForToday(); } @RequestMapping(value="/{day}", method = RequestMethod.GET) public Map<String, Appointment> getForDay(@PathVariable @DateTimeFormat(iso=ISO.DATE) Date day, Model model) { return appointmentBook.getAppointmentsForDay(day); } @RequestMapping(value="/new", method = RequestMethod.GET) public AppointmentForm getNewForm() { return new AppointmentForm(); } @RequestMapping(method = RequestMethod.POST) public String add(@Valid AppointmentForm appointment, BindingResult result) { if (result.hasErrors()) { return "appointments/new"; } appointmentBook.addAppointment(appointment); return "redirect:/appointments"; } }
value的uri值为以下三类:
A) 可以指定为普通的具体值;
B) 可以指定为含有某变量的一类值(URI Template Patterns with Path Variables);
C) 可以指定为含正则表达式的一类值( URI Template Patterns with Regular Expressions);
example B)
@RequestMapping(value="/owners/{ownerId}", method=RequestMethod.GET)
public String findOwner(@PathVariable String ownerId, Model model) {
Owner owner = ownerService.findOwner(ownerId);
model.addAttribute("owner", owner);
return "displayOwner";
}
example C)
@RequestMapping("/spring-web/{symbolicName:[a-z-]+}-{version:\d\.\d\.\d}.{extension:\.[a-z]}")
public void handle(@PathVariable String version, @PathVariable String extension) {
// ...
}
}
cousumes的样例:
@Controller @RequestMapping(value = "/pets", method = RequestMethod.POST, consumes="application/json") public void addPet(@RequestBody Pet pet, Model model) { // implementation omitted }
方法仅处理request Content-Type为“application/json”类型的请求。
produces的样例:
@Controller @RequestMapping(value = "/pets/{petId}", method = RequestMethod.GET, produces="application/json") @ResponseBody public Pet getPet(@PathVariable String petId, Model model) { // implementation omitted }
方法仅处理request请求中Accept头中包含了"application/json"的请求,同时暗示了返回的内容类型为application/json;
params的样例:
@Controller @RequestMapping("/owners/{ownerId}") public class RelativePathUriTemplateController { @RequestMapping(value = "/pets/{petId}", method = RequestMethod.GET, params="myParam=myValue") public void findPet(@PathVariable String ownerId, @PathVariable String petId, Model model) { // implementation omitted } }
仅处理请求中包含了名为“myParam”,值为“myValue”的请求;
headers的样例:
@Controller @RequestMapping("/owners/{ownerId}") public class RelativePathUriTemplateController { @RequestMapping(value = "/pets", method = RequestMethod.GET, headers="Referer=http://www.ifeng.com/") public void findPet(@PathVariable String ownerId, @PathVariable String petId, Model model) { // implementation omitted } }
仅处理request的header中包含了指定“Refer”请求头和对应值为“http://www.ifeng.com/”的请求;
Rest介绍
/blog/1 HTTP GET => 得到id = 1的blog
/blog/1 HTTP DELETE => 删除 id = 1的blog
/blog/1 HTTP PUT => 更新id = 1的blog
/blog HTTP POST => 新增BLOG
以下详细解一下spring rest使用.
首先,我们带着如下两个问题查看本文。
1.如何在java构造没有扩展名的RESTful url,如 /forms/1,而不是 /forms/1.do
2.浏览器的form标签不支持提交delete,put请求,如何曲线解决
springmvc rest 实现
springmvc的resturl是通过@RequestMapping 及@PathVariable
annotation提供的,
通过如@RequestMapping(value="/blog
/{id}",method=RequestMethod.DELETE)即可处理/blog/1 的delete请求.
@RequestMapping(value="/blog/{id}",method=RequestMethod.DELETE)
public ModelAndView delete(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) {
blogManager.removeById(id);
return new ModelAndView(LIST_ACTION);
}@RequestMapping @PathVariable如果URL中带参数,则配合使用,如
@RequestMapping(value="/blog/{blogId}/message/{msgId}",method=RequestMethod.DELETE)
public ModelAndView delete(@PathVariable("blogId") Long blogId,@PathVariable("msgId") Long msgId,HttpServletRequest request,HttpServletResponse response) {
}
1.springmvc web.xml配置
<!-- 该servlet为tomcat,jetty等容器提供,将静态资源映射从/改为/static/目录,如原来访问 http://localhost/foo.css ,现在http://localhost/static/foo.css -->
<servlet-mapping>
<servlet-name>default</servlet-name>
<url-pattern>/static/*</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<!-- URL重写filter,用于将访问静态资源http://localhost/foo.css 转为http://localhost/static/foo.css -->
<filter>
<filter-name>UrlRewriteFilter</filter-name>
<filter-class>org.tuckey.web.filters.urlrewrite.UrlRewriteFilter</filter-class>
<init-param>
<param-name>confReloadCheckInterval</param-name>
<param-value>60</param-value>
</init-param>
<init-param>
<param-name>logLevel</param-name>
<param-value>DEBUG</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>UrlRewriteFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- 覆盖default servlet的/, springmvc servlet将处理原来处理静态资源的映射 -->
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<!-- 浏览器不支持put,delete等method,由该filter将/blog?_method=delete转换为标准的http delete方法 -->
<filter>
<filter-name>HiddenHttpMethodFilter</filter-name>
<filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>HiddenHttpMethodFilter</filter-name>
<servlet-name>springmvc</servlet-name>
</filter-mapping>
2.webapp/WEB-INF/springmvc-servlet.xml配置,使用如下两个class激活@RequestMapping annotation
<bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping"/>
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/> 
3.Controller编写
/**
* @RequestMapping("/userinfo") 具有层次关系,方法级的将在类一级@RequestMapping之一,
* 如下面示例, 访问方法级别的@RequestMapping("/new"),则URL为 /userinfo/new
*/
@Controller
@RequestMapping("/userinfo")
public class UserInfoController extends BaseSpringController{
//默认多列排序,example: username desc,createTime asc
protected static final String DEFAULT_SORT_COLUMNS = null;
private UserInfoManager userInfoManager;
private final String LIST_ACTION = "redirect:/userinfo";
/**
* 通过spring自动注入
**/
public void setUserInfoManager(UserInfoManager manager) {
this.userInfoManager = manager;
}
/** 列表 */
@RequestMapping
public ModelAndView index(HttpServletRequest request,HttpServletResponse response,UserInfo userInfo) {
PageRequest<Map> pageRequest = newPageRequest(request,DEFAULT_SORT_COLUMNS);
//pageRequest.getFilters(); //add custom filters 
Page page = this.userInfoManager.findByPageRequest(pageRequest);
savePage(page,pageRequest,request);
return new ModelAndView("/userinfo/list","userInfo",userInfo);
}
/** 进入新增 */
@RequestMapping(value="/new")
public ModelAndView _new(HttpServletRequest request,HttpServletResponse response,UserInfo userInfo) throws Exception {
return new ModelAndView("/userinfo/new","userInfo",userInfo);
}
/** 显示 */
@RequestMapping(value="/{id}")
public ModelAndView show(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) throws Exception {
UserInfo userInfo = (UserInfo)userInfoManager.getById(id);
return new ModelAndView("/userinfo/show","userInfo",userInfo);
}
/** 编辑 */
@RequestMapping(value="/{id}/edit")
public ModelAndView edit(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) throws Exception {
UserInfo userInfo = (UserInfo)userInfoManager.getById(id);
return new ModelAndView("/userinfo/edit","userInfo",userInfo);
}
/** 保存新增 */
@RequestMapping(method=RequestMethod.POST)
public ModelAndView create(HttpServletRequest request,HttpServletResponse response,UserInfo userInfo) throws Exception {
userInfoManager.save(userInfo);
return new ModelAndView(LIST_ACTION);
}
/** 保存更新 */
@RequestMapping(value="/{id}",method=RequestMethod.PUT)
public ModelAndView update(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) throws Exception {
UserInfo userInfo = (UserInfo)userInfoManager.getById(id);
bind(request,userInfo);
userInfoManager.update(userInfo);
return new ModelAndView(LIST_ACTION);
}
/** 删除 */
@RequestMapping(value="/{id}",method=RequestMethod.DELETE)
public ModelAndView delete(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) {
userInfoManager.removeById(id);
return new ModelAndView(LIST_ACTION);
}
/** 批量删除 */
@RequestMapping(method=RequestMethod.DELETE)
public ModelAndView batchDelete(HttpServletRequest request,HttpServletResponse response) {
String[] items = request.getParameterValues("items");
for(int i = 0; i < items.length; i++) {
java.lang.Long id = new java.lang.Long(items[i]);
userInfoManager.removeById(id);
}
return new ModelAndView(LIST_ACTION);
}
}
/userinfo => index()
/userinfo/new => _new()
/userinfo/{id} => show()
/userinfo/{id}/edit => edit()
/userinfo POST => create()
/userinfo/{id} PUT => update()
/userinfo/{id} DELETE => delete()
/userinfo DELETE => batchDelete()
注(不使用 /userinfo/add
=> add() 方法是由于add这个方法会被maxthon浏览器当做广告链接过滤掉,因为包含ad字符)
4.jsp 编写
<form:form action="${ctx}/userinfo${userInfo.userId}" method="put">
</form:form>
生成的html内容如下, 生成一个hidden的_method=put,并于web.xml中的HiddenHttpMethodFilter配合使用,在服务端将post请求改为put请求
<form id="userInfo" action="/springmvc_rest_demo/userinfo/2" method="post">
<input type="hidden" name="_method" value="put"/>
</form>
另外一种方法是你可以使用ajax发送put,delete请求.
5.静态资源的URL重写
如上我们描述,现因为将default servlet映射至/static/的子目录,现我们访问静态资源将会带一个/static/前缀.
如 /foo.gif, 现在访问该文件将是 /static/foo.gif.
那如何避免这个前缀呢,那就是应用URL rewrite,现我们使用 http://tuckey.org/urlrewrite/, 重写规则如下
<urlrewrite>
<!-- 访问jsp及jspx将不rewrite url,其它.js,.css,.gif等将重写,如 /foo.gif => /static/foo.gif -->
<rule>
<condition operator="notequal" next="and" type="request-uri">.*.jsp</condition>
<condition operator="notequal" next="and" type="request-uri">.*.jspx</condition>
<from>^(/.*\..*)$</from>
<to>/static$1</to>
</rule>
</urlrewrite>
----------------------------------------------------
这里访问WEB-INF目录下的页面,这个还不知道有没有类似struts2那样的通配符来可以访问不同的action,不同的method,不同的页面,用户则很爽,有的话求告知,而且我还有一个问题就是配置了如下的配置,但却访问不到静态资源,望解答!!-----访问路径:http://localhost:8080/Springmvc3/images/4.jpg
好了,其他不说了,看如下:
配置视图解析器
package com.tgb.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import com.tgb.entity.User;
@Controller
@RequestMapping("/test")
//这里也可以写成@RequestMapping("/test.do")也可以不写,因为在web.xml中配置了*.do
public class TestController {
@RequestMapping(params="method=addUser")
public String addUser(User user){
System.out.println("dddddddddd");
return "success";
}
@RequestMapping(value="/test0")//默认为get方式
public String test0(){
System.out.println("访问路径:test/test0.do");
return "success";
}
@RequestMapping(value="/test1",method=RequestMethod.POST)
public String test1(String sex){
System.out.println(sex);
System.out.println("访问路径为:test/test1.do,而且是get方式______"+sex);
return "success";
}
@RequestMapping(value="/test2",method=RequestMethod.GET,params="param=test2")
public String test2(){
System.out.println("访问路径为:test/test1.do?param=test2,而且是get方式");
return "success";
}
//REST风格的参数
@RequestMapping(value="/test3/{name}")
public String test3(@PathVariable String name){//形参和接收参数的名称一致
System.out.println(name);
System.out.println("访问路径为:test/test3/zhangsan.do");
System.out.println("看这里的访问路径,直接就将‘zhangsan’这个参数值就传递给了@RequestMapping(value=\"/test3/{name}\")中的name参数名,可随意命名参数名称,");
return "success";
}
@RequestMapping(value="/test5/{name}")
public String test5(@PathVariable("name")String rename){//形参和接收参数的名称不一致
System.out.println(rename);
System.out.println("访问路径为:test/test5/zhangsan.do");
System.out.println("看这里的访问路径,直接就将‘zhangsan’这个参数值就传递给了@RequestMapping(value=\"/test5/{name}\")中的name参数名,可随意命名参数名称," +
"然后后面的@PathVariable(\"name\")中的name名称要和上面的那个name保持一致,然后把此name绑定到形参rename");
return "success";
}
@RequestMapping(value="/test4/{sex}/{sno}")
//这里我写成@RequestMapping(value="test4/{sex}/{sno}")也是可以滴
public String test4(@PathVariable("sex")String sex,@PathVariable("sno")String sno){
System.out.println(sex);
System.err.println(sno);
System.out.println("访问路径:test/test4/male/10506.do");
return "success";
}
//支持正则
@RequestMapping(value="/test6/{textualPart:[a-z-]+}.{numericPart:[\\d]+}")
public String test6(@PathVariable String textualPart,@PathVariable String numericPart){
System.out.println(textualPart);//输出sometxt
System.out.println(numericPart);//输出123
System.out.println("访问路径:test/test6/sometxt.123.do");
return "success";
}
//访问WEB-INF下的views文件中的不同目录的页面,这里访问的是user目录下的,不知道其他有什么好的办法没
@RequestMapping(value="/test7")
public String test7(){
System.out.println("访问路径:test/test7.do");
return "user/success";
}
}
标签:des c style class blog code
原文地址:http://www.cnblogs.com/steven9801/p/3762468.html