/*
* Copyright 2011 JBoss, by Red Hat, Inc
*
* 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.jboss.errai.enterprise.rebind;
import static org.jboss.errai.enterprise.rebind.TypeMarshaller.demarshal;
import static org.jboss.errai.enterprise.rebind.TypeMarshaller.marshal;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import javax.ws.rs.QueryParam;
import org.jboss.errai.codegen.BlockStatement;
import org.jboss.errai.codegen.BooleanOperator;
import org.jboss.errai.codegen.Cast;
import org.jboss.errai.codegen.DefParameters;
import org.jboss.errai.codegen.Parameter;
import org.jboss.errai.codegen.Statement;
import org.jboss.errai.codegen.StringStatement;
import org.jboss.errai.codegen.Variable;
import org.jboss.errai.codegen.builder.BlockBuilder;
import org.jboss.errai.codegen.builder.ClassStructureBuilder;
import org.jboss.errai.codegen.builder.ContextualStatementBuilder;
import org.jboss.errai.codegen.builder.impl.BooleanExpressionBuilder;
import org.jboss.errai.codegen.builder.impl.ObjectBuilder;
import org.jboss.errai.codegen.exception.GenerationException;
import org.jboss.errai.codegen.meta.MetaClass;
import org.jboss.errai.codegen.meta.MetaClassFactory;
import org.jboss.errai.codegen.meta.MetaParameterizedType;
import org.jboss.errai.codegen.meta.MetaType;
import org.jboss.errai.codegen.util.If;
import org.jboss.errai.codegen.util.ProxyUtil;
import org.jboss.errai.codegen.util.ProxyUtil.InterceptorProvider;
import org.jboss.errai.codegen.util.Stmt;
import org.jboss.errai.common.client.api.ErrorCallback;
import org.jboss.errai.common.client.api.RemoteCallback;
import org.jboss.errai.common.client.framework.CallContextStatus;
import org.jboss.errai.enterprise.client.jaxrs.ResponseDemarshallingCallback;
import org.jboss.errai.enterprise.client.jaxrs.api.ResponseCallback;
import org.jboss.errai.enterprise.client.jaxrs.api.RestClient;
import org.jboss.errai.enterprise.client.jaxrs.api.interceptor.RestCallContext;
import org.jboss.errai.enterprise.rebind.TypeMarshaller.PrimitiveTypeMarshaller;
import com.google.gwt.core.ext.GeneratorContext;
import com.google.gwt.http.client.RequestBuilder;
import com.google.gwt.http.client.Response;
import com.google.gwt.http.client.URL;
/**
* Generates a JAX-RS remote proxy method.
*
* @author Christian Sadilek <csadilek@redhat.com>
*/
public class JaxrsProxyMethodGenerator {
private static final String APPEND = "append";
private final MetaClass remote;
private final MetaClass declaringClass;
private final JaxrsResourceMethod resourceMethod;
private final BlockBuilder<?> methodBlock;
private final List<Statement> parameters;
private final InterceptorProvider interceptorProvider;
private final GeneratorContext context;
public JaxrsProxyMethodGenerator(final MetaClass remote,
final ClassStructureBuilder<?> classBuilder,
final JaxrsResourceMethod resourceMethod,
final InterceptorProvider interceptorProvider,
final GeneratorContext context) {
this.remote = remote;
this.declaringClass = classBuilder.getClassDefinition();
this.resourceMethod = resourceMethod;
this.interceptorProvider = interceptorProvider;
this.context = context;
Parameter[] parms = DefParameters.from(resourceMethod.getMethod()).getParameters().toArray(new Parameter[0]);
Parameter[] finalParms = new Parameter[parms.length];
parameters = new ArrayList<Statement>();
for (int i = 0; i < parms.length; i++) {
finalParms[i] = Parameter.of(parms[i].getType(), parms[i].getName(), true);
parameters.add(Stmt.loadVariable(parms[i].getName()));
}
this.methodBlock = classBuilder.publicMethod(resourceMethod.getMethod().getReturnType(),
resourceMethod.getMethod().getName(), finalParms);
}
public void generate() {
if (resourceMethod.getHttpMethod() != null) {
JaxrsResourceMethodParameters jaxrsParams = resourceMethod.getParameters();
methodBlock.append(generateUrl(jaxrsParams));
methodBlock.append(generateRequestBuilder());
methodBlock.append(generateHeaders(jaxrsParams));
List<Class<?>> interceptors = interceptorProvider.getInterceptors(remote, resourceMethod.getMethod());
if (!interceptors.isEmpty()) {
methodBlock.append(generateInterceptorLogic(interceptors));
}
else {
methodBlock.append(generateRequest());
}
}
generateReturnStatement();
}
/**
* Generates a {@link StringBuilder} constructing the request URL based on the method parameters
* annotated with JAX-RS annotations.
*
* @param params
* the resource method's parameters
* @return the URL statement
*/
private Statement generateUrl(final JaxrsResourceMethodParameters params) {
BlockStatement block = new BlockStatement();
block.addStatement(Stmt.declareVariable("url", StringBuilder.class,
Stmt.newObject(StringBuilder.class, new StringStatement("getBaseUrl()"))));
// construct path using @PathParams and @MatrixParams
String path = resourceMethod.getPath();
ContextualStatementBuilder pathValue = Stmt.loadLiteral(path);
for (String pathParamName : JaxrsResourceMethodParameters.getPathParameterNames(path)) {
String pathParamId = pathParamName;
if (pathParamName.contains(":")) {
pathParamId = pathParamName.split(":")[0];
}
Statement pathParam = marshal(params.getPathParameter(pathParamId));
if (params.needsEncoding(pathParamId)) {
pathParam = encodePath(pathParam);
}
pathValue = pathValue.invoke("replace", "{" + pathParamName + "}", pathParam);
}
if (params.getMatrixParameters() != null) {
for (String matrixParamName : params.getMatrixParameters().keySet()) {
pathValue = pathValue.invoke("concat", ";" + matrixParamName + "=")
.invoke("concat", encodePath(marshal(params.getMatrixParameter(matrixParamName))));
}
}
ContextualStatementBuilder urlBuilder = Stmt.loadVariable("url").invoke(APPEND, pathValue);
block.addStatement(urlBuilder);
// construct query using @QueryParams
if (params.getQueryParameters() != null) {
urlBuilder = urlBuilder.invoke(APPEND, "?");
int i = 0;
for (String queryParamName : params.getQueryParameters().keySet()) {
for (Statement queryParam : params.getQueryParameters(queryParamName)) {
MetaClass queryParamType = queryParam.getType();
if (isListOrSet(queryParamType)) {
MetaClass paramType = assertValidCollectionParam(queryParamType, queryParamName, QueryParam.class);
ContextualStatementBuilder listParam = (queryParam instanceof Parameter) ?
Stmt.loadVariable(((Parameter) queryParam).getName()) : Stmt.nestedCall(queryParam);
block.addStatement(listParam.foreach("p")
.append(If.not(Stmt.loadVariable("url").invoke("toString").invoke("endsWith", "?"))
.append(Stmt.loadVariable("url").invoke(APPEND, "&")).finish())
.append(Stmt.loadVariable("url").invoke(APPEND, queryParamName).invoke(APPEND, "=")
.invoke(APPEND, encodeQuery(marshal(paramType, Stmt.loadVariable("p")))))
.finish()
);
}
else {
if (i++ > 0) {
urlBuilder = urlBuilder.invoke(APPEND, "&");
}
urlBuilder = urlBuilder.invoke(APPEND, queryParamName).invoke(APPEND, "=")
.invoke(APPEND, encodeQuery(marshal(queryParam)));
}
}
}
}
return block;
}
/**
* Checks if the provided type is a {@link List} or {@link Set}.
*
* @param paramType
* the type to check
* @return true if the type can be assigned to a List or Set, otherwise false.
*/
private boolean isListOrSet(MetaClass paramType) {
return paramType.isAssignableTo(List.class) || paramType.isAssignableTo(Set.class);
}
/**
* Asserts that the provided type is a valid collection type for JAX-RS resource parameters.
*
* @param paramType
* the provided type.
* @param paramName
* the name of the resource parameter for error reporting.
* @param jaxrsParamType
* the JAX-RS resource parameter type for error reporting.
*
* @return the element type.
* @throws GenerationException
* if the type parameters of the collection type are invalid for JAX-RS resource
* parameters.
*/
private MetaClass assertValidCollectionParam(MetaClass paramType, String paramName, Class<?> jaxrsParamType) {
MetaParameterizedType queryParamPType = paramType.getParameterizedType();
MetaType[] typeParams = (queryParamPType != null) ? queryParamPType.getTypeParameters() : null;
if (typeParams != null && typeParams.length == 1 && typeParams[0] instanceof MetaClass
&& PrimitiveTypeMarshaller.canHandle((MetaClass) typeParams[0], "text/plain")) {
return (MetaClass) typeParams[0];
}
else {
throw new GenerationException(
"Unsupported type parameter found on " + jaxrsParamType.getSimpleName() + " with name "
+ paramName + " in method " + resourceMethod.getMethod() +
" (check the JavaDocs of " + jaxrsParamType.getName() + " for details!)");
}
}
/**
* Generates the declaration for a new {@link RequestBuilder} instance, initialized with the
* generated URL {@link #generateUrl(JaxrsResourceMethodParameters)}
*
* @return the RequestBuilder statement
*/
private Statement generateRequestBuilder() {
Statement requestBuilder =
Stmt.declareVariable("requestBuilder", RequestBuilder.class,
Stmt.newObject(RequestBuilder.class)
.withParameters(resourceMethod.getHttpMethod(), Stmt.loadVariable("url").invoke("toString")));
return requestBuilder;
}
/**
* Generates calls to set the appropriate headers on the generated {@link RequestBuilder} (see
* {@link #generateRequestBuilder()}) based on the method parameters annotated with JAX-RS
* annotations.
*
* @param params
* the resource method's parameters
* @return a block statement with the corresponding calls to
* {@link RequestBuilder#setHeader(String, String)}
*/
private Statement generateHeaders(final JaxrsResourceMethodParameters params) {
BlockStatement block = new BlockStatement();
// set headers based on method and class
for (String key : resourceMethod.getHeaders().keySet()) {
block.addStatement(Stmt.loadVariable("requestBuilder").invoke("setHeader", key,
resourceMethod.getHeaders().get(key)));
}
// set headers based on @HeaderParams
if (params.getHeaderParameters() != null) {
for (String headerParamName : params.getHeaderParameters().keySet()) {
ContextualStatementBuilder headerValueBuilder = Stmt.nestedCall(Stmt.newObject(StringBuilder.class));
int i = 0;
for (Statement headerParam : params.getHeaderParameters(headerParamName)) {
if (i++ > 0) {
headerValueBuilder = headerValueBuilder.invoke(APPEND, ",");
}
headerValueBuilder = headerValueBuilder.invoke(APPEND, marshal(headerParam));
}
block.addStatement(Stmt.loadVariable("requestBuilder").invoke("setHeader", headerParamName,
headerValueBuilder.invoke("toString")));
}
}
// set cookies based on @CookieParams
if (params.getCookieParameters() != null) {
for (String cookieName : params.getCookieParameters().keySet()) {
Statement cookieParam = params.getCookieParameters().get(cookieName).get(0);
ContextualStatementBuilder setCookie = (cookieParam instanceof Parameter) ?
Stmt.loadVariable(((Parameter) cookieParam).getName()) :
Stmt.nestedCall(cookieParam);
setCookie.if_(BooleanOperator.NotEquals, null)
.append(Stmt.invokeStatic(RestClient.class, "setCookie", cookieName, marshal(cookieParam)))
.finish();
block.addStatement(setCookie);
}
}
return block.isEmpty() ? null : block;
}
/**
* Generates the logic required to make this proxy method interceptable.
*
* @param interceptors
* @return statement representing the interceptor logic.
*/
private Statement generateInterceptorLogic(List<Class<?>> interceptors) {
JaxrsResourceMethodParameters jaxrsParams =
JaxrsResourceMethodParameters.fromMethod(resourceMethod.getMethod(), "parameters");
Statement callContext =
ProxyUtil.generateProxyMethodCallContext(context, RestCallContext.class, declaringClass,
resourceMethod.getMethod(), generateInterceptedRequest(), interceptors)
.publicOverridesMethod("proceed", Parameter.of(ResponseCallback.class, "interceptorCallback", true))
.append(Stmt.declareVariable(RemoteCallback.class).asFinal().named("providedCallback").initializeWith(
Stmt.loadStatic(declaringClass, "this").loadField("remoteCallback")))
.append(
Stmt.loadVariable("remoteCallback").assignValue(Stmt.newObject(ResponseCallback.class).extend()
.publicOverridesMethod("callback", Parameter.of(Response.class, "response"))
.append(Stmt.declareVariable(ResponseCallback.class).named("intCallback")
.initializeWith(Stmt.loadVariable("interceptorCallback")))
.append(StringStatement.of("setResult(response)"))
.append(Stmt.loadVariable("intCallback").invoke("callback",
Cast.to(Response.class, StringStatement.of("getResult()", Object.class))))
.append(Stmt.loadVariable("providedCallback").invoke("callback",
StringStatement.of("getResult()", Object.class)))
.finish()
.finish())
)
.append(Stmt.loadVariable("this").invoke("proceed"))
.finish()
.publicOverridesMethod("proceed", Parameter.of(ResponseCallback.class, "interceptorCallback", true),
Parameter.of(ErrorCallback.class, "interceptorErrorCallback", true))
.append(
Stmt.declareVariable(ErrorCallback.class).asFinal().named("providedErrorCallback").initializeWith(
Stmt.loadStatic(declaringClass, "this").loadField("errorCallback")))
.append(
Stmt.loadVariable("errorCallback").assignValue(Stmt.newObject(ErrorCallback.class).extend()
.publicOverridesMethod("error", Parameter.of(Object.class, "message"),
Parameter.of(Throwable.class, "throwable"))
.append(
Stmt.loadVariable("interceptorErrorCallback").invoke("error", Variable.get("message"),
Variable.get("throwable")))
.append(
Stmt.if_(
BooleanExpressionBuilder.create(
StringStatement.of("getResult()", Object.class), BooleanOperator.NotEquals, Stmt
.loadLiteral(null)))
.append(
Stmt.loadVariable("remoteCallback").invoke("callback",
StringStatement.of("getResult()", Object.class)))
.append(Stmt.load(false).returnValue())
.finish()
.elseif_(
BooleanExpressionBuilder.create(
Stmt.loadVariable("providedErrorCallback"), BooleanOperator.NotEquals, Stmt
.loadLiteral(null)))
.append(
Stmt.nestedCall(
Stmt.loadVariable("providedErrorCallback").invoke("error",
Variable.get("message"),
Variable.get("throwable")))
.returnValue())
.finish())
.append(Stmt.load(true).returnValue())
.finish()
.finish())
)
.append(Stmt.loadVariable("this").invoke("proceed", Variable.get("interceptorCallback")))
.finish()
.publicOverridesMethod("setParameters", Parameter.of(Object[].class, "parameters"))
.append(new StringStatement("super.setParameters(parameters)"))
.append(generateUrl(jaxrsParams))
.append(generateRequestBuilder())
.append(generateHeaders(jaxrsParams))
.append(new StringStatement("setRequestBuilder(requestBuilder)"))
.finish()
.finish();
return Stmt.try_()
.append(
Stmt.declareVariable(CallContextStatus.class).asFinal().named("status").initializeWith(
Stmt.newObject(CallContextStatus.class).withParameters(interceptors.toArray())))
.append(
Stmt.declareVariable(RestCallContext.class).asFinal().named("callContext")
.initializeWith(callContext))
.append(
Stmt.loadVariable("callContext").invoke("setRequestBuilder", Variable.get("requestBuilder")))
.append(
Stmt.loadVariable("callContext").invoke("setParameters",
Stmt.newArray(Object.class).initialize(parameters.toArray())))
.append(
Stmt.loadVariable("callContext").invoke("proceed"))
.finish()
.catch_(Throwable.class, "throwable")
.append(
Stmt.loadStatic(declaringClass, "this").invoke("handleError", Variable.get("throwable"), null, null))
.finish();
}
/**
* Generates the call to
* {@link RequestBuilder#sendRequest(String, com.google.gwt.http.client.RequestCallback)} for
* interceptable methods.
*
* @return statement representing the request
*/
private Statement generateInterceptedRequest() {
return generateRequest(
Stmt.nestedCall(new StringStatement("getRequestBuilder()", MetaClassFactory.get(RequestBuilder.class))),
Stmt.loadStatic(declaringClass, "this"));
}
/**
* Generates the call to
* {@link RequestBuilder#sendRequest(String, com.google.gwt.http.client.RequestCallback)} for
* non-interceptable methods.
*
* @return statement representing the request
*/
private Statement generateRequest() {
return generateRequest(Stmt.loadVariable("requestBuilder"), Stmt.loadVariable("this"));
}
/**
* Generates the call to
* {@link RequestBuilder#sendRequest(String, com.google.gwt.http.client.RequestCallback)} for
* proxy methods.
*
* @return statement representing the request
*/
private Statement generateRequest(final ContextualStatementBuilder requestBuilder,
final ContextualStatementBuilder proxy) {
Statement sendRequest = null;
if (resourceMethod.getParameters().getEntityParameter() == null) {
sendRequest = proxy.invoke("sendRequest", requestBuilder, null, responseDemarshallingCallback());
}
else {
Statement body = marshal(resourceMethod.getParameters().getEntityParameter(),
resourceMethod.getContentTypeHeader());
sendRequest = proxy.invoke("sendRequest", requestBuilder, body, responseDemarshallingCallback());
}
return sendRequest;
}
/**
* Generates an anonymous implementation/instance of {@link ResponseDemarshallingCallback} that
* will handle the demarshalling of the HTTP response.
*
* @return statement representing the {@link ResponseDemarshallingCallback}.
*/
private Statement responseDemarshallingCallback() {
Statement result = Stmt.load(null);
if (!resourceMethod.getMethod().getReturnType().equals(MetaClassFactory.get(void.class))) {
result = demarshal(
resourceMethod.getMethod().getReturnType(),
Stmt.loadVariable("response"),
resourceMethod.getAcceptHeader());
}
return ObjectBuilder
.newInstanceOf(ResponseDemarshallingCallback.class)
.extend()
.publicOverridesMethod("demarshallResponse", Parameter.of(String.class, "response"))
.append(Stmt.nestedCall(result).returnValue())
.finish()
.finish();
}
/**
* Adds path encoding to the provided statement
*
* @param s
* the statement representing an HTTP path that should be encoded
* @return statement with path encoding
*/
private Statement encodePath(Statement s) {
return Stmt.invokeStatic(URL.class, "encodePathSegment", s);
}
/**
* Adds query parameter encoding to the provided statement
*
* @param s
* the statement representing an HTTP query that should be encoded
* @return statement with query param encoding
*/
private Statement encodeQuery(Statement s) {
return Stmt.invokeStatic(URL.class, "encodeQueryString", s);
}
/**
* Generates the return statement of this proxy method if required. If the proxy method returns
* void, it will just finish the method block.
*/
private void generateReturnStatement() {
Statement returnStatement = ProxyUtil.generateProxyMethodReturnStatement(resourceMethod.getMethod());
if (returnStatement != null) {
methodBlock.append(returnStatement);
}
methodBlock.finish();
}
}