/*
* Copyright 2002-2014 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.web.servlet.mvc.method.annotation;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import org.aopalliance.intercept.MethodInterceptor;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.aop.framework.ProxyFactory;
import org.springframework.aop.target.EmptyTargetSource;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.NoUniqueBeanDefinitionException;
import org.springframework.cglib.core.SpringNamingPolicy;
import org.springframework.cglib.proxy.Callback;
import org.springframework.cglib.proxy.Enhancer;
import org.springframework.cglib.proxy.Factory;
import org.springframework.cglib.proxy.MethodProxy;
import org.springframework.core.DefaultParameterNameDiscoverer;
import org.springframework.core.MethodParameter;
import org.springframework.core.ParameterNameDiscoverer;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.objenesis.ObjenesisStd;
import org.springframework.util.AntPathMatcher;
import org.springframework.util.Assert;
import org.springframework.util.ObjectUtils;
import org.springframework.util.PathMatcher;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.method.annotation.RequestParamMethodArgumentResolver;
import org.springframework.web.method.support.CompositeUriComponentsContributor;
import org.springframework.web.servlet.DispatcherServlet;
import org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping;
import org.springframework.web.servlet.support.ServletUriComponentsBuilder;
import org.springframework.web.util.UriComponents;
import org.springframework.web.util.UriComponentsBuilder;
/**
* A UriComponentsBuilder that helps to build URIs to Spring MVC controllers
* and methods from their request mappings.
*
* @author Oliver Gierke
* @author Rossen Stoyanchev
* @since 4.0
*/
public class MvcUriComponentsBuilder extends UriComponentsBuilder {
/**
* Well-known name for the {@link CompositeUriComponentsContributor} object in the bean factory.
*/
public static final String MVC_URI_COMPONENTS_CONTRIBUTOR_BEAN_NAME = "mvcUriComponentsContributor";
private static final Log logger = LogFactory.getLog(MvcUriComponentsBuilder.class);
private static final ObjenesisStd objenesis = new ObjenesisStd(true);
private static final PathMatcher pathMatcher = new AntPathMatcher();
private static final ParameterNameDiscoverer parameterNameDiscoverer = new DefaultParameterNameDiscoverer();
private static final CompositeUriComponentsContributor defaultUriComponentsContributor;
static {
defaultUriComponentsContributor = new CompositeUriComponentsContributor(
new PathVariableMethodArgumentResolver(), new RequestParamMethodArgumentResolver(false));
}
/**
* Create a {@link UriComponentsBuilder} from the mapping of a controller class
* and current request information including Servlet mapping. If the controller
* contains multiple mappings, only the first one is used.
* @param controllerType the controller to build a URI for
* @return a UriComponentsBuilder instance (never {@code null})
*/
public static UriComponentsBuilder fromController(Class<?> controllerType) {
String mapping = getTypeRequestMapping(controllerType);
return ServletUriComponentsBuilder.fromCurrentServletMapping().path(mapping);
}
private static String getTypeRequestMapping(Class<?> controllerType) {
Assert.notNull(controllerType, "'controllerType' must not be null");
RequestMapping annot = AnnotationUtils.findAnnotation(controllerType, RequestMapping.class);
if (annot == null || ObjectUtils.isEmpty(annot.value()) || StringUtils.isEmpty(annot.value()[0])) {
return "/";
}
if (annot.value().length > 1 && logger.isWarnEnabled()) {
logger.warn("Multiple paths on controller " + controllerType.getName() + ", using first one");
}
return annot.value()[0];
}
/**
* Create a {@link UriComponentsBuilder} from the mapping of a controller
* method and an array of method argument values. This method delegates
* to {@link #fromMethod(java.lang.reflect.Method, Object...)}.
* @param controllerType the controller
* @param methodName the method name
* @param argumentValues the argument values
* @return a UriComponentsBuilder instance, never {@code null}
* @throws IllegalArgumentException if there is no matching or
* if there is more than one matching method
*/
public static UriComponentsBuilder fromMethodName(Class<?> controllerType, String methodName, Object... argumentValues) {
Method method = getMethod(controllerType, methodName, argumentValues);
return fromMethod(method, argumentValues);
}
private static Method getMethod(Class<?> controllerType, String methodName, Object... argumentValues) {
Method match = null;
for (Method method : controllerType.getDeclaredMethods()) {
if (method.getName().equals(methodName) && method.getParameterTypes().length == argumentValues.length) {
if (match != null) {
throw new IllegalArgumentException("Found two methods named '" + methodName + "' having " +
Arrays.asList(argumentValues) + " arguments, controller " + controllerType.getName());
}
match = method;
}
}
if (match == null) {
throw new IllegalArgumentException("No method '" + methodName + "' with " + argumentValues.length +
" parameters found in " + controllerType.getName());
}
return match;
}
/**
* Create a {@link UriComponentsBuilder} by invoking a "mock" controller method.
* The controller method and the supplied argument values are then used to
* delegate to {@link #fromMethod(java.lang.reflect.Method, Object...)}.
* <p>For example, given this controller:
* <pre class="code">
* @RequestMapping("/people/{id}/addresses")
* class AddressController {
*
* @RequestMapping("/{country}")
* public HttpEntity<Void> getAddressesForCountry(@PathVariable String country) { ... }
*
* @RequestMapping(value="/", method=RequestMethod.POST)
* public void addAddress(Address address) { ... }
* }
* </pre>
* A UriComponentsBuilder can be created:
* <pre class="code">
* // Inline style with static import of "MvcUriComponentsBuilder.on"
*
* MvcUriComponentsBuilder.fromMethodCall(
* on(CustomerController.class).showAddresses("US")).buildAndExpand(1);
*
* // Longer form useful for repeated invocation (and void controller methods)
*
* CustomerController controller = MvcUriComponentsBuilder.on(CustomController.class);
* controller.addAddress(null);
* builder = MvcUriComponentsBuilder.fromMethodCall(controller);
* controller.getAddressesForCountry("US")
* builder = MvcUriComponentsBuilder.fromMethodCall(controller);
* </pre>
* @param invocationInfo either the value returned from a "mock" controller
* invocation or the "mock" controller itself after an invocation
* @return a UriComponents instance
*/
public static UriComponentsBuilder fromMethodCall(Object invocationInfo) {
Assert.isInstanceOf(MethodInvocationInfo.class, invocationInfo);
MethodInvocationInfo info = (MethodInvocationInfo) invocationInfo;
return fromMethod(info.getControllerMethod(), info.getArgumentValues());
}
/**
* Create a URL from the name of a Spring MVC controller method's request mapping.
*
* <p>The configured
* {@link org.springframework.web.servlet.handler.HandlerMethodMappingNamingStrategy
* HandlerMethodMappingNamingStrategy} determines the names of controller
* method request mappings at startup. By default all mappings are assigned
* a name based on the capital letters of the class name, followed by "#" as
* separator, and then the method name. For example "PC#getPerson"
* for a class named PersonController with method getPerson. In case the
* naming convention does not produce unique results, an explicit name may
* be assigned through the name attribute of the {@code @RequestMapping}
* annotation.
*
* <p>This is aimed primarily for use in view rendering technologies and EL
* expressions. The Spring URL tag library registers this method as a function
* called "mvcUrl".
*
* <p>For example, given this controller:
* <pre class="code">
* @RequestMapping("/people")
* class PersonController {
*
* @RequestMapping("/{id}")
* public HttpEntity<Void> getPerson(@PathVariable String id) { ... }
*
* }
* </pre>
*
* A JSP can prepare a URL to the controller method as follows:
*
* <pre class="code">
* <%@ taglib uri="http://www.springframework.org/tags" prefix="s" %>
*
* <a href="${s:mvcUrl('PC#getPerson').arg(0,"123").build()}">Get Person</a>
* </pre>
*
* <p>Note that it's not necessary to specify all arguments. Only the ones
* required to prepare the URL, mainly {@code @RequestParam} and {@code @PathVariable}).
*
* @param mappingName the mapping name
* @return a builder to to prepare the URI String
* @throws IllegalArgumentException if the mapping name is not found or
* if there is no unique match
* @since 4.1
*/
public static MethodArgumentBuilder fromMappingName(String mappingName) {
RequestMappingInfoHandlerMapping handlerMapping = getRequestMappingInfoHandlerMapping();
List<HandlerMethod> handlerMethods = handlerMapping.getHandlerMethodsForMappingName(mappingName);
if (handlerMethods == null) {
throw new IllegalArgumentException("Mapping mappingName not found: " + mappingName);
}
if (handlerMethods.size() != 1) {
throw new IllegalArgumentException(
"No unique match for mapping mappingName " + mappingName + ": " + handlerMethods);
}
return new MethodArgumentBuilder(handlerMethods.get(0).getMethod());
}
/**
* Create a {@link UriComponentsBuilder} from the mapping of a controller method
* and an array of method argument values. The array of values must match the
* signature of the controller method. Values for {@code @RequestParam} and
* {@code @PathVariable} are used for building the URI (via implementations of
* {@link org.springframework.web.method.support.UriComponentsContributor})
* while remaining argument values are ignored and can be {@code null}.
* @param method the controller method
* @param argumentValues argument values for the controller method
* @return a UriComponentsBuilder instance, never {@code null}
*/
public static UriComponentsBuilder fromMethod(Method method, Object... argumentValues) {
String typePath = getTypeRequestMapping(method.getDeclaringClass());
String methodPath = getMethodRequestMapping(method);
String path = pathMatcher.combine(typePath, methodPath);
UriComponentsBuilder builder = ServletUriComponentsBuilder.fromCurrentServletMapping().path(path);
UriComponents uriComponents = applyContributors(builder, method, argumentValues);
return ServletUriComponentsBuilder.newInstance().uriComponents(uriComponents);
}
private static String getMethodRequestMapping(Method method) {
RequestMapping annot = AnnotationUtils.findAnnotation(method, RequestMapping.class);
if (annot == null) {
throw new IllegalArgumentException("No @RequestMapping on: " + method.toGenericString());
}
if (ObjectUtils.isEmpty(annot.value()) || StringUtils.isEmpty(annot.value()[0])) {
return "/";
}
if (annot.value().length > 1 && logger.isWarnEnabled()) {
logger.warn("Multiple paths on method " + method.toGenericString() + ", using first one");
}
return annot.value()[0];
}
private static UriComponents applyContributors(UriComponentsBuilder builder, Method method, Object... args) {
CompositeUriComponentsContributor contributor = getConfiguredUriComponentsContributor();
if (contributor == null) {
logger.debug("Using default CompositeUriComponentsContributor");
contributor = defaultUriComponentsContributor;
}
int paramCount = method.getParameterTypes().length;
int argCount = args.length;
if (paramCount != argCount) {
throw new IllegalArgumentException("Number of method parameters " + paramCount +
" does not match number of argument values " + argCount);
}
final Map<String, Object> uriVars = new HashMap<String, Object>();
for (int i = 0; i < paramCount; i++) {
MethodParameter param = new MethodParameter(method, i);
param.initParameterNameDiscovery(parameterNameDiscoverer);
contributor.contributeMethodArgument(param, args[i], builder, uriVars);
}
// We may not have all URI var values, expand only what we have
return builder.build().expand(new UriComponents.UriTemplateVariables() {
@Override
public Object getValue(String name) {
return uriVars.containsKey(name) ? uriVars.get(name) : UriComponents.UriTemplateVariables.SKIP_VALUE;
}
});
}
protected static CompositeUriComponentsContributor getConfiguredUriComponentsContributor() {
WebApplicationContext wac = getWebApplicationContext();
if (wac == null) {
return null;
}
try {
return wac.getBean(MVC_URI_COMPONENTS_CONTRIBUTOR_BEAN_NAME, CompositeUriComponentsContributor.class);
}
catch (NoSuchBeanDefinitionException ex) {
if (logger.isDebugEnabled()) {
logger.debug("No CompositeUriComponentsContributor bean with name '" +
MVC_URI_COMPONENTS_CONTRIBUTOR_BEAN_NAME + "'");
}
return null;
}
}
protected static RequestMappingInfoHandlerMapping getRequestMappingInfoHandlerMapping() {
WebApplicationContext wac = getWebApplicationContext();
Assert.notNull(wac, "Cannot lookup handler method mappings without WebApplicationContext");
try {
return wac.getBean(RequestMappingInfoHandlerMapping.class);
}
catch (NoUniqueBeanDefinitionException ex) {
throw new IllegalStateException("More than one RequestMappingInfoHandlerMapping beans found", ex);
}
catch (NoSuchBeanDefinitionException ex) {
throw new IllegalStateException("No RequestMappingInfoHandlerMapping bean", ex);
}
}
private static WebApplicationContext getWebApplicationContext() {
RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
if (requestAttributes == null) {
logger.debug("No request bound to the current thread: is DispatcherSerlvet used?");
return null;
}
HttpServletRequest request = ((ServletRequestAttributes) requestAttributes).getRequest();
if (request == null) {
logger.debug("Request bound to current thread is not an HttpServletRequest");
return null;
}
String attributeName = DispatcherServlet.WEB_APPLICATION_CONTEXT_ATTRIBUTE;
WebApplicationContext wac = (WebApplicationContext) request.getAttribute(attributeName);
if (wac == null) {
logger.debug("No WebApplicationContext found: not in a DispatcherServlet request?");
return null;
}
return wac;
}
/**
* Return a "mock" controller instance. When an {@code @RequestMapping} method
* on the controller is invoked, the supplied argument values are remembered
* and the result can then be used to create a {@code UriComponentsBuilder}
* via {@link #fromMethodCall(Object)}.
* <p>
* Note that this is a shorthand version of {@link #controller(Class)} intended
* for inline use (with a static import), for example:
* <pre class="code">
* MvcUriComponentsBuilder.fromMethodCall(on(FooController.class).getFoo(1)).build();
* </pre>
* @param controllerType the target controller
*/
public static <T> T on(Class<T> controllerType) {
return controller(controllerType);
}
/**
* Return a "mock" controller instance. When an {@code @RequestMapping} method
* on the controller is invoked, the supplied argument values are remembered
* and the result can then be used to create {@code UriComponentsBuilder} via
* {@link #fromMethodCall(Object)}.
* <p>
* This is a longer version of {@link #on(Class)}. It is needed with controller
* methods returning void as well for repeated invocations.
* <pre class="code">
* FooController fooController = controller(FooController.class);
*
* fooController.saveFoo(1, null);
* builder = MvcUriComponentsBuilder.fromMethodCall(fooController);
*
* fooController.saveFoo(2, null);
* builder = MvcUriComponentsBuilder.fromMethodCall(fooController);
* </pre>
* @param controllerType the target controller
*/
public static <T> T controller(Class<T> controllerType) {
Assert.notNull(controllerType, "'controllerType' must not be null");
return initProxy(controllerType, new ControllerMethodInvocationInterceptor());
}
@SuppressWarnings("unchecked")
private static <T> T initProxy(Class<?> type, ControllerMethodInvocationInterceptor interceptor) {
if (type.isInterface()) {
ProxyFactory factory = new ProxyFactory(EmptyTargetSource.INSTANCE);
factory.addInterface(type);
factory.addInterface(MethodInvocationInfo.class);
factory.addAdvice(interceptor);
return (T) factory.getProxy();
}
else {
Enhancer enhancer = new Enhancer();
enhancer.setSuperclass(type);
enhancer.setInterfaces(new Class<?>[] {MethodInvocationInfo.class});
enhancer.setNamingPolicy(SpringNamingPolicy.INSTANCE);
enhancer.setCallbackType(org.springframework.cglib.proxy.MethodInterceptor.class);
Factory factory = (Factory) objenesis.newInstance(enhancer.createClass());
factory.setCallbacks(new Callback[] {interceptor});
return (T) factory;
}
}
private static class ControllerMethodInvocationInterceptor
implements org.springframework.cglib.proxy.MethodInterceptor, MethodInterceptor {
private static final Method getControllerMethod =
ReflectionUtils.findMethod(MethodInvocationInfo.class, "getControllerMethod");
private static final Method getArgumentValues =
ReflectionUtils.findMethod(MethodInvocationInfo.class, "getArgumentValues");
private Method controllerMethod;
private Object[] argumentValues;
@Override
public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) {
if (getControllerMethod.equals(method)) {
return this.controllerMethod;
}
else if (getArgumentValues.equals(method)) {
return this.argumentValues;
}
else if (ReflectionUtils.isObjectMethod(method)) {
return ReflectionUtils.invokeMethod(method, obj, args);
}
else {
this.controllerMethod = method;
this.argumentValues = args;
Class<?> returnType = method.getReturnType();
return (void.class.equals(returnType) ? null : returnType.cast(initProxy(returnType, this)));
}
}
@Override
public Object invoke(org.aopalliance.intercept.MethodInvocation inv) throws Throwable {
return intercept(inv.getThis(), inv.getMethod(), inv.getArguments(), null);
}
}
public interface MethodInvocationInfo {
Method getControllerMethod();
Object[] getArgumentValues();
}
public static class MethodArgumentBuilder {
private final Method method;
private final Object[] argumentValues;
public MethodArgumentBuilder(Method method) {
Assert.notNull(method, "'method' is required");
this.method = method;
this.argumentValues = new Object[method.getParameterTypes().length];
for (int i = 0; i < this.argumentValues.length; i++) {
this.argumentValues[i] = null;
}
}
public MethodArgumentBuilder arg(int index, Object value) {
this.argumentValues[index] = value;
return this;
}
public String build() {
return MvcUriComponentsBuilder.fromMethod(this.method, this.argumentValues)
.build(false).encode().toUriString();
}
public String buildAndExpand(Object... uriVariables) {
return MvcUriComponentsBuilder.fromMethod(this.method, this.argumentValues)
.build(false).expand(uriVariables).encode().toString();
}
}
}