SpringMvc执行过程

2023-08-02 20:02:40

--Test过程：

1. 先执行各种 Filter

2. HttpServlet.service(ServletRequest req, ServletResponse res)

3. HttpServlet.service(HttpServletRequest req, HttpServletResponse resp) 根据 Method做分发。以下是POST流程

4. FrameworkServlet.doPost(HttpServletRequest request, HttpServletResponse response) -> processRequest -> doService -> doDispatch

5. org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handle -> handlerInternal -> invokeHandlerMethod -> invokeHandle -> invokeForRequest ->

6. InvocableHandlerMethod.doInvoke

7. 到了Action方法

--Post 带参数详细过程

http://blog.csdn.net/fytain/article/details/43918609

问题：

像普通函数那样定义action。从 request.body 里的 JSON 串中取出某个属性值。

先解析!

1. 各种Filter

2. /org/apache/catalina/core/ApplicationFilterChain.java 中 internalDoFilter ，servlet.service

3. /javax/servlet/http/HttpServlet.java . service

4. HttpServlet.service(HttpServletRequest req, HttpServletResponse resp) 根据 Method做分发。以下是POST流程

5. FrameworkServlet.doPost(HttpServletRequest request, HttpServletResponse response) -> processRequest -> doService -> doDispatch

6.org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handle -> handlerInternal -> invokeHandlerMethod -> invokeHandle -> invokeForRequest

7. 在 /org/springframework/web/method/support/InvocableHandlerMethod.java 的 invokeForRequest 方法中：

getMethodArgumentValues(request, mavContainer , 变参 provideArgs) 获取参数

之后调用 doInvoke(args)

　 getMethodArgumentValue方法：

/**

     * Get the method argument values for the current request.

     */

    private Object[] getMethodArgumentValues(NativeWebRequest request, ModelAndViewContainer mavContainer,

            Object... providedArgs) throws Exception {

        MethodParameter[] parameters = getMethodParameters();

        Object[] args = new Object[parameters.length];

        for (int i = 0; i < parameters.length; i++) {

            MethodParameter parameter = parameters[i];

            parameter.initParameterNameDiscovery(this.parameterNameDiscoverer);

            args[i] = resolveProvidedArgument(parameter, providedArgs);

            if (args[i] != null) {

                continue;

            }

            if (this.argumentResolvers.supportsParameter(parameter)) {

                try {

                    args[i] = this.argumentResolvers.resolveArgument(

                            parameter, mavContainer, request, this.dataBinderFactory);

                    continue;

                }

                catch (Exception ex) {

                    if (logger.isDebugEnabled()) {

                        logger.debug(getArgumentResolutionErrorMessage("Failed to resolve", i), ex);

                    }

                    throw ex;

                }

            }

            if (args[i] == null) {

                throw new IllegalStateException("Could not resolve method parameter at index " +

                        parameter.getParameterIndex() + " in " + parameter.getMethod().toGenericString() +

                        ": " + getArgumentResolutionErrorMessage("No suitable resolver for", i));

            }

        }

        return args;

    }

重点：

　　1. this.argumentResolvers.supportsParameter

　　2. this.argumentResolvers.resolveArgument ，如下：

@Override

    public final Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer,

            NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {

        NamedValueInfo namedValueInfo = getNamedValueInfo(parameter);

        MethodParameter nestedParameter = parameter.nestedIfOptional();

        Object resolvedName = resolveStringValue(namedValueInfo.name);

        if (resolvedName == null) {

            throw new IllegalArgumentException(

                    "Specified name must not resolve to null: [" + namedValueInfo.name + "]");

        }

        Object arg = resolveName(resolvedName.toString(), nestedParameter, webRequest);

        if (arg == null) {

            if (namedValueInfo.defaultValue != null) {

                arg = resolveStringValue(namedValueInfo.defaultValue);

            }

            else if (namedValueInfo.required && !nestedParameter.isOptional()) {

                handleMissingValue(namedValueInfo.name, nestedParameter, webRequest);

            }

            arg = handleNullValue(namedValueInfo.name, arg, nestedParameter.getNestedParameterType());

        }

        else if ("".equals(arg) && namedValueInfo.defaultValue != null) {

            arg = resolveStringValue(namedValueInfo.defaultValue);

        }

        if (binderFactory != null) {

            WebDataBinder binder = binderFactory.createBinder(webRequest, null, namedValueInfo.name);

            try {

                arg = binder.convertIfNecessary(arg, parameter.getParameterType(), parameter);

            }

            catch (ConversionNotSupportedException ex) {

                throw new MethodArgumentConversionNotSupportedException(arg, ex.getRequiredType(),

                        namedValueInfo.name, parameter, ex.getCause());

            }

            catch (TypeMismatchException ex) {

                throw new MethodArgumentTypeMismatchException(arg, ex.getRequiredType(),

                        namedValueInfo.name, parameter, ex.getCause());

            }

        }

        handleResolvedValue(arg, namedValueInfo.name, parameter, mavContainer, webRequest);

        return arg;

    }

在 resolveArgument 方法过程中，先执行 resolveName，再执行 handleResolvedValue

@Override

    protected Object resolveName(String name, MethodParameter parameter, NativeWebRequest request) throws Exception {

        HttpServletRequest servletRequest = request.getNativeRequest(HttpServletRequest.class);

        MultipartHttpServletRequest multipartRequest =

                WebUtils.getNativeRequest(servletRequest, MultipartHttpServletRequest.class);

        Object mpArg = MultipartResolutionDelegate.resolveMultipartArgument(name, parameter, servletRequest);

        if (mpArg != MultipartResolutionDelegate.UNRESOLVABLE) {

            return mpArg;

        }

        Object arg = null;

        if (multipartRequest != null) {

            List<MultipartFile> files = multipartRequest.getFiles(name);

            if (!files.isEmpty()) {

                arg = (files.size() == 1 ? files.get(0) : files);

            }

        }

        if (arg == null) {

            String[] paramValues = request.getParameterValues(name);

            if (paramValues != null) {

                arg = (paramValues.length == 1 ? paramValues[0] : paramValues);

            }

        }

        return arg;

    }

解决方式：

package pzx.base.config

import org.springframework.context.annotation.Bean

import org.springframework.context.annotation.Configuration

import org.springframework.web.servlet.HandlerInterceptor

import org.springframework.web.servlet.config.annotation.InterceptorRegistry

import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter

import java.util.ArrayList

import org.springframework.boot.web.servlet.FilterRegistrationBean

import org.springframework.boot.web.servlet.ServletRegistrationBean

import pzx.web.sys.AuthImageServlet

import javax.servlet.MultipartConfigElement

import org.springframework.beans.factory.annotation.Autowired

import org.springframework.core.MethodParameter

import org.springframework.core.env.Environment

import org.springframework.http.HttpInputMessage

import org.springframework.http.HttpOutputMessage

import org.springframework.http.MediaType

import org.springframework.http.converter.HttpMessageConverter

import org.springframework.web.bind.support.WebDataBinderFactory

import org.springframework.web.context.request.NativeWebRequest

import org.springframework.web.method.support.HandlerMethodArgumentResolver

import org.springframework.web.method.support.HandlerMethodReturnValueHandler

import org.springframework.web.method.support.ModelAndViewContainer

import pzx.base.comm.JsonMap

import pzx.base.extend.FromJson

import pzx.base.extend.ToJson

import java.nio.charset.Charset

import javax.servlet.http.HttpServletRequest

import javax.servlet.http.HttpServletRequestWrapper

/**

 * Created by udi on 2017.3.11.

 */

@Configuration

open class MyWebMvcConfig : WebMvcConfigurerAdapter() {

    @Bean

    open fun filterRegistrationBean(): FilterRegistrationBean {

        val registrationBean = FilterRegistrationBean()

        val httpBasicFilter = MyAllFilter()

        registrationBean.filter = httpBasicFilter

        val urlPatterns = ArrayList<String>()

        urlPatterns.add("/*")

        urlPatterns.add("/**")

        registrationBean.urlPatterns = urlPatterns

        return registrationBean

    }

    override fun addInterceptors(registry: InterceptorRegistry?) {

        if (registry == null) return

        registry.addInterceptor(MySessionFilter())

                .addPathPatterns("/*")

                .addPathPatterns("/**")

                .excludePathPatterns("/hi")

                .excludePathPatterns("/open/**")

                .excludePathPatterns("/oh")

                .excludePathPatterns("/doc")

                .excludePathPatterns("/error")

                .excludePathPatterns("/login")

                .excludePathPatterns("/registe")

                .excludePathPatterns("/swagger-resources/**")

                .excludePathPatterns("/v2/**")

    }

    @Bean

    fun RegisteAuthImageServlet(): ServletRegistrationBean {

        var registration = ServletRegistrationBean(AuthImageServlet())

        registration.isEnabled = true

        registration.addUrlMappings("/open/getValidateCodeImage")

        return registration

    }

    class RequestJsonResolver : HandlerMethodArgumentResolver {

        //只认是否包含。

        override fun supportsParameter(parameter: MethodParameter?): Boolean {

            if (parameter!!.parameterName == null) return false;

            if (HttpContext.request is MyHttpRequestWrapper) return false;

            return (HttpContext.request as MyHttpRequestWrapper).json.containsKey(parameter.parameterName)

        }

        override fun resolveArgument(parameter: MethodParameter?, mavContainer: ModelAndViewContainer?, webRequest: NativeWebRequest?, binderFactory: WebDataBinderFactory?): Any {

            var request = webRequest!!.nativeRequest as MyHttpRequestWrapper;

            if (parameter!!.parameterName == null) {

                throw Error("${request.requestURI} 找不到 ${parameter!!.parameterName}");

            }

            var map = request.json;//String(request!!.inputStream.readBytes(), Charset.defaultCharset()).FromJson<JsonMap>();

            if (map.containsKey(parameter!!.parameterName)) {

                return map.get(parameter!!.parameterName)!!;

            }

            return parameter!!.parameterType.newInstance();

        }

    }

    override fun addArgumentResolvers(argumentResolvers: MutableList<HandlerMethodArgumentResolver>?) {

        argumentResolvers?.add(RequestJsonResolver())

        super.addArgumentResolvers(argumentResolvers)

    }

}

如何接收Map数据：

http://www.codes51.com/article/detail_114729.html
调试发现： SpringMvc可以接收 LinkedHashMap<String, String> , Map<String,String> ，但不能接收继承 LinkedHashMap 的数据类型。也不能接收 HashMap 。

估计是这帮SB把代码又写死了。

Model绑定

http://*.com/questions/12893566/passing-multiple-variables-in-requestbody-to-a-spring-mvc-controller-using-ajax

https://www.oschina.net/question/227902_162591

<mvc:annotation-driven>

    <mvc:argument-resolvers>

        <beans:bean class="com.redcollar.bl.commons.extension.JsonArgumentResolver" />

    </mvc:argument-resolvers>

</mvc:annotation-driven>

对应的SpringBoot，就是

@Configuration
+

WebMvcConfigurerAdapter

教程：http://starscream.iteye.com/blog/1098880

码农公寓

--Test过程：

--Post 带参数 详细过程

Model绑定

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--Post 带参数详细过程