/src/main/java/xjt/ws/core/ServiceInvokeServlet.java

package xjt.ws.core;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import org.springframework.web.multipart.MultipartException;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;

import xjt.ws.invoker.ServiceInvoker;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;

/**
 * Web服务调用的Servlet入口<br>
 * @author huzq
 * @author xjt
 */
public class ServiceInvokeServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	private static final Logger logger = LoggerFactory.getLogger(ServiceInvokeServlet.class);
	private ServiceInvoker serviceInvoker;
	private String encoding = "utf-8";
	public void init(ServletConfig config) throws ServletException {
		super.init(config);
		initServiceInvoker();
	}
	/*
	 *调用指定服务名的服务方法 
	 */
	protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		req.setCharacterEncoding(encoding);
		logger.debug("请求编码:"+req.getCharacterEncoding());
		ServiceRequest serviceRequest = buildServiceRequest(req, resp);
		logger.debug("调用服务：" + serviceRequest);
		ServiceResponse serviceResponse = new ServiceResponse();
		try {
			this.serviceInvoker.invoke(serviceRequest,serviceResponse);
		}catch (Throwable t) {
			while(t.getCause()!=null){
				t = t.getCause();
			}
			logger.error("服务异常：", t);
			serviceResponse.setErrorInfo(t);
		}
		if(serviceResponse.isCached()){
			resp.reset();
			resp.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
		}else if (serviceResponse.isBinary()) {
			printBinary(resp, serviceResponse);
		} else {
			if (serviceResponse.isSuccess()) {
				printSuccess(resp, serviceResponse.getResults(),serviceResponse.getLastModifiedTime());
			} else {
				printError(resp, serviceResponse.getErrors(), serviceResponse.getErrorDetails());
			}
		}

	}

	/**
	 * 输出二进制数据
	 * 
	 * @param resp
	 * @param serviceResp
	 * @throws IOException
	 */
	private void printBinary(HttpServletResponse resp, ServiceResponse serviceResp) throws IOException {
		resp.reset();
		ResponseFile file = serviceResp.getResponseFile();
		if (file == null) {
			printError(resp, "服务返回的文件流为空");
			return;
		}
		String fileName = file.getFileName();		
		if (StringUtils.isNotEmpty(fileName)) {
			fileName = URLEncoder.encode(fileName,this.encoding);
			logger.debug("filename:"+fileName);
			resp.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
			resp.setHeader(ServiceResponse.RESPONSE_HEADER_FILE_NAME, fileName);
		}
		if (file.getLength() > 0) {
			resp.setContentLength((int)file.getLength());
			resp.setHeader(ServiceResponse.RESPONSE_HEADER_FILE_SIZE, file.getLength()+"");
		}
		if (serviceResp.getLastModifiedTime()!=null){
			resp.setHeader(ServiceResponse.RESPONSE_HEADER_LAST_MODIFIED_TIME, serviceResp.getLastModifiedTime());
		}else if (file.getLastModifiedTime() > 0) {
			resp.setHeader(ServiceResponse.RESPONSE_HEADER_LAST_MODIFIED_TIME, file.getLastModifiedTime() + "");
		}
		
		if(file.getPages()!=null){
			resp.setHeader(ServiceResponse.RESPONSE_HEADER_PAGES, file.getPages()+"");
		}
		resp.setContentType("application/octet-stream;charset="+encoding);
		if (file.getInputStream() != null) {
			ServletOutputStream os = null;
			InputStream is = null;
			try{
				is = file.getInputStream();
				os = resp.getOutputStream();
				IOUtils.copy(is, os);
			}finally{
				if(is!=null) {
					is.close();
				}
				if(os!=null){
					os.close();
				}
			}
		} else {
			printError(resp, "服务返回的文件流为空");
		}
		resp.flushBuffer();

	}

	/**
	 * 输出成功的结果
	 * 
	 * @param resp
	 * @param results
	 * @throws IOException
	 */
	private void printSuccess(HttpServletResponse resp, Object results,String lastModifedTime) throws IOException {
		printText(resp, true, results, null, null,lastModifedTime);
	}

	/**
	 * 输出错误信息
	 * 
	 * @param resp
	 * @param errors
	 * @throws IOException
	 */
	private void printError(HttpServletResponse resp, String errors) throws IOException {
		printText(resp, false, null, errors, null,null);
	}

	/**
	 * 输出错误信息
	 * 
	 * @param resp
	 * @param errors
	 * @param errorDetails
	 * @throws IOException
	 */
	private void printError(HttpServletResponse resp, String errors, String errorDetails) throws IOException {
		printText(resp, false, null, errors, errorDetails,null);
	}

	/**
	 * 输出文本信息
	 * 
	 * @param resp
	 * @param results
	 * @param success
	 * @throws IOException
	 */
	private void printText(HttpServletResponse resp, boolean success, Object results, String errors, String errorDetails,String lastModifiedTime)
			throws IOException {
		resp.reset();
		HashMap<Object,Object> resultMap = new HashMap<Object,Object>();
		if (success) {
			resp.setStatus(HttpServletResponse.SC_OK);
			if (results != null) {
				resultMap.put(ServiceResponse.RESULTS_PARAM_RESULTS, results);
			}
		} else {
			resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
			resultMap.put(ServiceResponse.RESULTS_PARAM_ERRORS, errors);
			resultMap.put(ServiceResponse.RESULT_PARAM_ERROR_DETAILS, errorDetails);
		}
		resp.setContentType("application/json;charset="+encoding);
		if(lastModifiedTime!=null){
			resp.setHeader(ServiceResponse.RESPONSE_HEADER_LAST_MODIFIED_TIME, lastModifiedTime);
		}
		PrintWriter out = resp.getWriter();
		out.print(JSON.toJSONString(resultMap));
		resp.flushBuffer();
		out.close();
	}

	/**
	 * 构造服务请求
	 * 
	 * @param req
	 * @param resp
	 * @return
	 * @throws MultipartException
	 * @throws IOException
	 * @throws ServletException
	 */
	private ServiceRequest buildServiceRequest(HttpServletRequest req, HttpServletResponse resp)
			throws MultipartException, IOException, ServletException {
		CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver(getServletContext());
		boolean isMultiPart = multipartResolver.isMultipart(req);
		logger.debug("multipart:" + isMultiPart);
		//MultipartFile[] files = null;
		Map<String,MultipartFile> fileMap = null;
		if (isMultiPart) {
			MultipartHttpServletRequest request = multipartResolver.resolveMultipart(req);
			fileMap = request.getFileMap();
			//files = (MultipartFile[]) fileMap.values().toArray(new MultipartFile[0]);
			req = request;
		}
		String service = StringUtils.trim(req.getParameter(ServiceRequest.POST_PARAM_SERVICE));
		if (StringUtils.isEmpty(service)) {
			printError(resp, "service参数不能为空");
			throw new ServletException("service参数不能为空");
		}
		String serviceName = service.substring(0, service.lastIndexOf("."));
		String methodName = service.substring(service.lastIndexOf(".") + 1, service.length());
		String headerString = req.getParameter(ServiceRequest.POST_PARAM_HEADER);
		String paramString = req.getParameter(ServiceRequest.POST_PARAM_PARAMS);
		logger.debug("header:" + headerString);
		logger.debug("param:" + paramString);
		JSONObject headers = null;
		if (StringUtils.isNotEmpty(headerString)) {
			headers = JSON.parseObject(headerString);
		}
		JSONObject params = null;
		if (StringUtils.isNotEmpty(paramString)) {
			params = JSON.parseObject(paramString);
		}
		return new ServiceRequest(req, service, serviceName, methodName, headers, params, isMultiPart, fileMap);
	}
	private void initServiceInvoker() throws ServletException {
		WebApplicationContext applicationContext = WebApplicationContextUtils
				.getWebApplicationContext(getServletContext());
		if (applicationContext == null) {
			throw new ServletException("不能获取到Spring上下文");
		}
		this.serviceInvoker = applicationContext.getBean("serviceInvoker", ServiceInvoker.class);
	}
}