package org.jrest4guice.rest;
import java.lang.reflect.Method;
import java.util.List;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.jrest4guice.client.ModelMap;
import org.jrest4guice.commons.collections.MapHelper;
import org.jrest4guice.commons.lang.ClassUtils;
import org.jrest4guice.guice.GuiceContext;
import org.jrest4guice.rest.annotations.HttpMethodType;
import org.jrest4guice.rest.annotations.MimeType;
import org.jrest4guice.rest.annotations.RESTful;
import org.jrest4guice.rest.exception.RestMethodNotFoundException;
import org.jrest4guice.rest.helper.JRest4GuiceHelper;
import org.jrest4guice.rest.helper.JRestGuiceProcessorHelper;
import org.jrest4guice.rest.helper.RequestHelper;
import org.jrest4guice.rest.helper.ServiceHelper;
/**
*
* @author <a href="mailto:zhangyouqun@gmail.com">cnoss (QQ:86895156)</a>
*
*/
@SuppressWarnings("unchecked")
public class JRest4GuiceProcessor {
private String charset;
private String urlPrefix;
private JRestGuiceProcessorHelper helper;
public JRest4GuiceProcessor() {
this.helper = new JRestGuiceProcessorHelper();
}
public JRest4GuiceProcessor setUrlPrefix(String urlPrefix) {
this.urlPrefix = urlPrefix;
return this;
}
/**
* 处理来自客户端的请求
*
* @param servletReqest
* @param servletResponse
*/
public void process(ServletRequest servletReqest,
ServletResponse servletResponse) throws Throwable {
HttpServletRequest request = (HttpServletRequest) servletReqest;
HttpServletResponse response = (HttpServletResponse) servletResponse;
// 获取字符编码
this.charset = request.getCharacterEncoding();
if (this.charset == null || charset.trim().equals("")) {
this.charset = "UTF-8";
try {
request.setCharacterEncoding(charset);
} catch (Exception e) {
}
}
this.helper.setCharset(this.charset);
String contentType = RequestHelper.getContentType(request);
if (!contentType.equals(MimeType.CONTENT_OF_MULTIPART_FORM_DATA) && request.getContentLength() > JRest4GuiceHelper
.getMaxBodyPayloadSize()) {
this.helper.writeErrorMessage(new Exception("body的大小超过最大许可范围: "
+ JRest4GuiceHelper.getMaxBodyPayloadSize()));
return;
}
String uri = request.getRequestURI();
String original_url = uri;
String contextPath = request.getContextPath();
if (!contextPath.trim().equals("/") && uri.startsWith(contextPath)) {
uri = uri.substring(contextPath.length());
}
if (this.urlPrefix != null)
uri = uri.replace(this.urlPrefix, "");
// ==================================================================
// 处理html不支持put/delete方法的情况下通过在url中补!update与!delete
// ==================================================================
HttpMethodType method_type = null;
if (uri.indexOf("!update") != -1) {
method_type = HttpMethodType.PUT;
}
if (uri.indexOf("!delete") != -1) {
method_type = HttpMethodType.DELETE;
}
if (method_type == null) {
if (uri.indexOf("!") != -1) {
method_type = HttpMethodType.ACTION;
}
}
if (method_type != null) {
uri = uri.substring(0,uri.lastIndexOf("!"));
}
// ==================================================================
String method = request.getMethod();
// 针对Get类型的资源做Cache检查
if (RESTful.METHOD_OF_GET.equalsIgnoreCase(method)) {
if (this.helper.checkResourceCache(request, response, uri))
return;
}
ModelMap<String, String> params = RestContextManager.getContext()
.getModelMap();
try {
int index = uri.indexOf(RESTful.REMOTE_SERVICE_PREFIX);
if (index != -1) {
// 以远程服务方式调用的处理
this.processRemoteCall(request, original_url, params);
} else {
// 以普通方式调用的处理
this.processNormalCall(request, uri, original_url, method_type,
method, params);
}
} catch (RestMethodNotFoundException e) {
this.helper.writeRestServiceNotFoundMessage(request, original_url);
}
}
/**
* 处理普通方式的调用
*
* @param request
* @param uri
* @param original_url
* @param method_type
* @param method
* @param params
* @throws Throwable
*/
private void processNormalCall(HttpServletRequest request, String uri,
String original_url, HttpMethodType method_type, String method,
ModelMap<String, String> params) throws Throwable {
// 从REST资源注册表中查找此URI对应的资源
Service service = ServiceHelper.getInstance().lookupResource(uri);
if (service != null) {
RestContextManager.setCurrentRestUri(uri);
ServiceExecutor exec = GuiceContext.getInstance().getBean(
ServiceExecutor.class);
// 填充参数
this.helper.fillParameters(request, params);
// 根据不同的请求方法调用REST对象的不同方法
exec.execute(service, method_type == null ? this.helper
.getHttpMethodType(method) : method_type, charset, false);
} else {
this.helper.writeRestServiceNotFoundMessage(request, original_url);
}
}
/**
* 处理以远程方式进行的调用（实现对分布式资源的调用）
*
* @param request
* @param original_url
* @param params
* @throws Throwable
*/
private void processRemoteCall(HttpServletRequest request,
String original_url, ModelMap<String, String> params)
throws Throwable {
int index;
String serviceName = request
.getParameter(RESTful.REMOTE_SERVICE_NAME_KEY);
String methodIndex = request
.getParameter(RESTful.REMOTE_SERVICE_METHOD_INDEX_KEY);
Class<?> clazz = ServiceHelper.getInstance().getRemoteService(
serviceName);
if (clazz != null) {
index = Integer.parseInt(methodIndex);
List<Method> methods = ClassUtils.getSortedMethodList(clazz);
Service service = new Service(GuiceContext.getInstance().getBean(
clazz), new MapHelper().put(HttpMethodType.POST, methods.get(index)).toMap());
ServiceExecutor exec = GuiceContext.getInstance().getBean(
ServiceExecutor.class);
// 填充参数
this.helper.fillParameters(request, params);
// 根据不同的请求方法调用REST对象的不同方法
exec.execute(service, this.helper
.getHttpMethodType(RESTful.METHOD_OF_POST), charset, true);
} else {
this.helper.writeRestServiceNotFoundMessage(request, original_url);
}
}
}