/*
* Copyright 2002-2013 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 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.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.*;
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.annotation.RequestParamMethodArgumentResolver;
import org.springframework.web.method.support.CompositeUriComponentsContributor;
import org.springframework.web.servlet.DispatcherServlet;
import org.springframework.web.servlet.support.ServletUriComponentsBuilder;
import org.springframework.web.util.UriComponents;
import org.springframework.web.util.UriComponentsBuilder;
import javax.servlet.http.HttpServletRequest;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
/**
* 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 CompositeUriComponentsContributor defaultUriComponentsContributor;
private static final PathMatcher pathMatcher = new AntPathMatcher();
private static final ParameterNameDiscoverer parameterNameDiscoverer = new DefaultParameterNameDiscoverer();
private final static ObjenesisStd objenesis = new ObjenesisStd(true);
private static Log logger = LogFactory.getLog(MvcUriComponentsBuilder.class);
static {
defaultUriComponentsContributor = new CompositeUriComponentsContributor(
Arrays.<Object>asList(
new PathVariableMethodArgumentResolver(),
new RequestParamMethodArgumentResolver(null, false)));
}
/**
* Create a {@link UriComponentsBuilder} by pointing to a controller class. The
* resulting builder contains the current request information up to and including
* the Servlet mapping plus any type-level request mapping. If the controller
* contains multiple mappings, the first one is used.
*
* @param controllerType the controller to create a URI for
* @return a UriComponentsBuilder instance
*/
public static UriComponentsBuilder fromController(Class<?> controllerType) {
String mapping = getTypeRequestMapping(controllerType);
return ServletUriComponentsBuilder.fromCurrentServletMapping().path(mapping);
}
/**
* Create a {@link UriComponentsBuilder} by pointing to a controller method and
* providing method argument values. The method is matched based on the provided
* method name and the number of argument values. If that results in a clash
* (i.e. overloaded methods with the same number of parameters), use
* {@link #fromMethod(java.lang.reflect.Method, Object...)} instead.
* <p>The argument values are used to prepare the URI for example expanding
* path variables, or adding query parameters. Any other arguments not
* relevant to the URI can be provided as {@literal null} and will be ignored.
* <p>Additional (custom) argument types can be supported through an implementation
* of {@link org.springframework.web.method.support.UriComponentsContributor}.
*
* @param controllerType the target controller type
* @param methodName the target method name
* @param argumentValues argument values matching to method parameters
* @return a UriComponentsBuilder instance
*/
public static UriComponentsBuilder fromMethodName(Class<?> controllerType,
String methodName, Object... argumentValues) {
Method match = null;
for (Method method : controllerType.getDeclaredMethods()) {
if ((method.getParameterTypes().length == argumentValues.length) && method.getName().equals(methodName)) {
if (match != null) {
throw new IllegalStateException("Found two methods named '" + methodName
+ "' having " + 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 fromMethod(match, argumentValues);
}
/**
* Create a {@link UriComponentsBuilder} by pointing to a controller method and
* providing method argument values. The method argument values are used to
* prepare the URI for example expanding path variables, or adding request
* parameters. Any other arguments not relevant to the URL can be provided as
* {@literal null} and will be ignored.
* <p>Additional (custom) argument types can be supported through an implementation
* of {@link org.springframework.web.method.support.UriComponentsContributor}.
*
* @param method the target controller method
* @param argumentValues argument values matching to method parameters
* @return a UriComponentsBuilder instance
*/
public static UriComponentsBuilder fromMethod(Method method, Object... argumentValues) {
UriComponentsBuilder builder = ServletUriComponentsBuilder.newInstance().path(getMethodRequestMapping(method));
UriComponents uriComponents = applyContributors(builder, method, argumentValues);
String typePath = getTypeRequestMapping(method.getDeclaringClass());
String methodPath = uriComponents.getPath();
String path = pathMatcher.combine(typePath, methodPath);
return ServletUriComponentsBuilder.fromCurrentServletMapping().path(
path).queryParams(uriComponents.getQueryParams());
}
/**
* Create a {@link UriComponents} by invoking a method on a "mock" controller, similar
* to how test frameworks provide mock objects and record method invocations.
* <p>For example given this controller:
* <p/>
* <pre class="code">
* @RequestMapping("/people/{id}/addresses")
* class AddressController {
* <p/>
* @RequestMapping("/{country}")
* public HttpEntity<Void> getAddressesForCountry(@PathVariable String country) { ... }
* <p/>
* @RequestMapping(value="/", method=RequestMethod.POST)
* public void addAddress(Address address) { ... }
* }
* </pre>
* <p/>
* A "mock" controller can be used as follows:
* <p/>
* <pre>
*
* // Inline style with static import of MvcUriComponentsBuilder.mock
*
* MvcUriComponentsBuilder.fromMethodCall(
* mock(CustomerController.class).showAddresses("US")).buildAndExpand(1);
*
* // Longer style for preparing multiple URIs and for void controller methods
*
* CustomerController controller = MvcUriComponentsBuilder.mock(CustomController.class);
* controller.addAddress(null);
*
* MvcUriComponentsBuilder.fromMethodCall(controller);
*
* </pre>
* <p/>
* The above supports {@code @PathVariable} and {@code @RequestParam} method parameters.
* Any other arguments can be provided as {@literal null} and will be ignored.
* <p>Additional (custom) argument types can be supported through an implementation
* of {@link org.springframework.web.method.support.UriComponentsContributor}.
*
* @param methodInvocationInfo 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 methodInvocationInfo) {
Assert.isInstanceOf(MethodInvocationInfo.class, methodInvocationInfo);
MethodInvocationInfo info = (MethodInvocationInfo) methodInvocationInfo;
Method method = info.getControllerMethod();
Object[] argumentValues = info.getArgumentValues();
UriComponentsBuilder builder = ServletUriComponentsBuilder.newInstance().path(getMethodRequestMapping(method));
UriComponents uriComponents = applyContributors(builder, method, argumentValues);
String typeMapping = getTypeRequestMapping(method.getDeclaringClass());
String methodMapping = uriComponents.getPath();
String path = pathMatcher.combine(typeMapping, methodMapping);
return ServletUriComponentsBuilder.fromCurrentServletMapping().path(
path).queryParams(uriComponents.getQueryParams());
}
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.warn("Multiple mappings on controller " + controllerType.getName() + ", using the first one");
}
return annot.value()[0];
}
private static String getMethodRequestMapping(Method method) {
RequestMapping annot = AnnotationUtils.findAnnotation(method, RequestMapping.class);
Assert.notNull(annot, "No @RequestMapping on: " + method.toGenericString());
if (ObjectUtils.isEmpty(annot.value()) || StringUtils.isEmpty(annot.value()[0])) {
return "/";
}
if (annot.value().length > 1) {
logger.debug("Multiple mappings 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;
Assert.isTrue(paramCount == argCount, "Number of method parameters " + paramCount +
" does not match number of argument values " + argCount);
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);
}
return builder.buildAndExpand(uriVars);
}
protected static CompositeUriComponentsContributor getConfiguredUriComponentsContributor() {
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;
}
WebApplicationContext wac = (WebApplicationContext) request.getAttribute(
DispatcherServlet.WEB_APPLICATION_CONTEXT_ATTRIBUTE);
if (wac == null) {
logger.debug("No WebApplicationContext found: not in a DispatcherServlet request?");
return null;
}
try {
String beanName = MVC_URI_COMPONENTS_CONTRIBUTOR_BEAN_NAME;
return wac.getBean(beanName, CompositeUriComponentsContributor.class);
} catch (NoSuchBeanDefinitionException ex) {
if (logger.isDebugEnabled()) {
logger.debug("No CompositeUriComponentsContributor bean with name '"
+ MVC_URI_COMPONENTS_CONTRIBUTOR_BEAN_NAME + "'");
}
return null;
}
}
/**
* 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 prepare a URL to the method via
* {@link #fromMethodCall(Object)}.
* <p>This is a shorthand version of {@link #controller(Class)} intended for
* inline use as follows:
* <pre>
* UriComponentsBuilder builder = 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 prepare a URL to the method via
* {@link #fromMethodCall(Object)}.
* <p>This is a longer version of {@link #on(Class)} for use with void controller
* methods as well as for creating multiple links in succession.
* <pre>
* 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.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();
}
}