/*
* 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 org.jboss.errai.codegen.BlockStatement;
import org.jboss.errai.codegen.BooleanOperator;
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.ObjectBuilder;
import org.jboss.errai.codegen.meta.MetaClass;
import org.jboss.errai.codegen.meta.MetaClassFactory;
import org.jboss.errai.codegen.util.Stmt;
import org.jboss.errai.common.client.api.interceptor.InterceptedCall;
import org.jboss.errai.common.client.framework.CallContextStatus;
import org.jboss.errai.config.rebind.ProxyUtil;
import org.jboss.errai.enterprise.client.jaxrs.ResponseDemarshallingCallback;
import org.jboss.errai.enterprise.client.jaxrs.api.interceptor.RestCallContext;
import com.google.gwt.http.client.RequestBuilder;
import com.google.gwt.http.client.URL;
import com.google.gwt.user.client.Cookies;
/**
* 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 declaringClass;
private final JaxrsResourceMethod resourceMethod;
private final BlockBuilder<?> methodBlock;
private final List<Statement> parameters;
public JaxrsProxyMethodGenerator(final ClassStructureBuilder<?> classBuilder, final JaxrsResourceMethod resourceMethod) {
this.declaringClass = classBuilder.getClassDefinition();
this.resourceMethod = resourceMethod;
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));
if (resourceMethod.getMethod().isAnnotationPresent(InterceptedCall.class) ||
resourceMethod.getMethod().getDeclaringClass().isAnnotationPresent(InterceptedCall.class)) {
methodBlock.append(generateInterceptorLogic());
}
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);
// 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)) {
if (i++ > 0)
urlBuilder = urlBuilder.invoke(APPEND, "&");
urlBuilder = urlBuilder.invoke(APPEND, queryParamName).invoke(APPEND, "=")
.invoke(APPEND, encodeQuery(marshal(queryParam)));
}
}
}
if (urlBuilder != null)
block.addStatement(urlBuilder);
return block;
}
/**
* 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(Cookies.class, "setCookie", cookieName, marshal(cookieParam)))
.finish();
block.addStatement(setCookie);
}
}
return block.isEmpty() ? null : block;
}
/**
* Generated the logic required to make this proxy method interceptable.
*
* @return statement representing the interceptor logic.
*/
private Statement generateInterceptorLogic() {
JaxrsResourceMethodParameters jaxrsParams =
JaxrsResourceMethodParameters.fromMethod(resourceMethod.getMethod(), "parameters");
InterceptedCall interceptedCall = resourceMethod.getMethod().getAnnotation(InterceptedCall.class);
if (interceptedCall == null) {
interceptedCall = resourceMethod.getMethod().getDeclaringClass().getAnnotation(InterceptedCall.class);
}
Statement callContext =
ProxyUtil.generateProxyMethodCallContext(RestCallContext.class, declaringClass,
resourceMethod.getMethod(), generateInterceptedRequest(), interceptedCall)
.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((Object[]) interceptedCall.value())))
.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;
}
/**
* Generate 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();
}
}