NCC的http接口實現方案（無session訪問）

NCC的http接口實現方案

一. 功能描述

在實際應用中，開發雙方希望無session訪問接口，使用nccloud的restful風格的action無法滿足業務要求，需要開發一套支持無session訪問的接口訪問方式。由於嘗試使用NC6系列開發webservise的方式行不通，所以可以參照以下介紹的方式開發接口，如有問題，可在以下的方式上進行優化。
此處我設置的url-patten是*.ws，例如我請求的url是http://localhost:80/nccloud/web/hrwa/kpiassign/action/PlanDataReqAction.ws ，那麼我這個請求的後端對應的類是nccloud.web.hrwa.kpiassign.action.PlanDataReqAction。需要注意的是，請求的Header必須包括Host，如圖：

二. 實現方式

1. 編寫filter攔截器，可根據需求加入一些攔截功能

package nccloud.framework.core;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import nccloud.framework.core.env.Locator;
import nccloud.framework.core.log.ILog;
import nccloud.framework.core.log.ILogFactory;
import nccloud.framework.web.action.entry.Result;
public class PlatformInterfaceFilter implements Filter {
	public PlatformInterfaceFilter() {
	}
	public void destroy() {
	}
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws UnsupportedEncodingException {
		ILog logger = ((ILogFactory) Locator.find(ILogFactory.class)).getLog("nccloud");
		HttpServletRequest req = (HttpServletRequest) request;
		HttpServletResponse res = (HttpServletResponse) response;
		try {
			// start攔截器攔截操作
			// end攔截器攔截操作
			chain.doFilter(req, res);
		} catch (Exception e) {
			String msg = URLEncoder.encode(e.getMessage(), "UTF-8");
			res.setHeader("EXCEPTION", msg);
			res.setStatus(500);
			logger.error(e);
		}
	}
	public void init(FilterConfig arg0) throws ServletException {
	}
}

2. 編寫請求入口servlet，所以滿足url-patten的都會進到這個請求，url-patten在web.xml中配置

package nccloud.framework.core;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import nc.vo.ml.NCLangRes4VoTransl;
import nccloud.framework.core.json.IJson;
import nccloud.framework.core.log.Log;
import nccloud.framework.web.action.entry.Dispatcher;
import nccloud.framework.web.action.entry.Result;
import nccloud.framework.web.container.GZip;
import nccloud.framework.web.container.HttpOperator;
import nccloud.framework.web.json.JsonFactory;
import org.apache.commons.lang3.StringUtils;
public class PlatformInterfaceController extends HttpServlet {
	private static final long serialVersionUID = -832392821095654820L;
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		req.getParameter("data");
		HttpServletRequest request = req;
		String uri = request.getRequestURI();
		if (StringUtils.isNotEmpty(uri)) {
			String className = uri.replaceAll("/", ".").replaceAll(".ws", "");
			className = className.substring(1, className.length());
			try {
				Class clz = Class.forName(className);
				// 根據URI生成處理類
				IInterfaceAction ta = (IInterfaceAction) clz.newInstance();
				Object value = ta.execute(req);
				Result result = new Result();
				result.setData(value);
				if (result != null) {
					IJson gson = JsonFactory.create();
					resp.getWriter().write(gson.toJson(result));
				}
			} catch (Exception e) {
				resp.getWriter().write(getErrorMsg(e));
			}
		}
	}
	private void writeJson(String json, HttpServletResponse resp) {
		try {
			GZip zip = new GZip();
			json = zip.zip(json);
			resp.getWriter().write(json);
		} catch (Exception ex) {
			Log.error(ex);
		}

	}
	private void writeJson(Result result, HttpServletResponse resp) {
		String json = null;
		try {
			IJson gson = JsonFactory.create();
			json = gson.toJson(result);
			GZip zip = new GZip();
			json = zip.zip(json);
			resp.getWriter().write(gson.toJson(json));
		} catch (Exception ex) {
			Log.error(ex);
		}

	}
	public String getErrorMsg(Exception ex) {
		String stack = getStackTrace(ex);
		StringBuilder sb = new StringBuilder();
		sb.append("{");
		sb.append("  \"data\": null,");
		sb.append("  \"error\": {");
		sb.append("    \"exceptionClass\":");
		sb.append("\"");
		sb.append(ex.getClass().getName());
		sb.append("\"");
		sb.append(",");
		sb.append(NCLangRes4VoTransl.getNCLangRes().getStrByID("1501001_0", "01501001-0199"));
		sb.append("    \"stack\":\"");
		sb.append(stack);
		sb.append("\",");
		sb.append("    \"status\": 500");
		sb.append("  },");
		sb.append("  \"success\": false");
		sb.append("}");
		return sb.toString();
	}
	private String getStackTrace(Throwable th) {
		StringWriter sw = new StringWriter();
		PrintWriter pw = new PrintWriter(sw, true);
		th.printStackTrace(pw);
		return sw.getBuffer().toString();
	}
}

3. 將以上的filter和servlet配置到web.xml中，web.xml的路徑爲：ncchome\hotwebs\nccloud\WEB-INF\web.xml

<!--PlatformInterfaceFilter -->
<filter>
	<filter-name>PlatformInterfaceFilter</filter-name>
	<filter-class>nccloud.framework.core.PlatformInterfaceFilter</filter-class>
</filter>
<filter-mapping>
	<filter-name>PlatformInterfaceFilter</filter-name>
	<url-pattern>*.ws</url-pattern>
</filter-mapping>
<!--PlatformInterfaceFilter -->
<!--PlatformInterfaceController -->
<servlet>
	<servlet-name>PlatformInterfaceController</servlet-name>
	<servlet-class>nccloud.framework.core.PlatformInterfaceController</servlet-class>
	<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
	<servlet-name>PlatformInterfaceController</servlet-name>
	<url-pattern>*.ws</url-pattern>
</servlet-mapping>
<!--PlatformInterfaceController -->

配置完成後編寫一個接口規範，之後所有的類似請求都必須實現這個接口

package nccloud.framework.core;
import javax.servlet.http.HttpServletRequest;
public abstract interface IInterfaceAction {
	public abstract Object execute(HttpServletRequest req);
}

4. 實現示例

package nccloud.web.hrwa.kpiassign.action;
import java.io.BufferedReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import nc.bs.framework.common.NCLocator;
import nc.bs.logging.Logger;
import nc.itf.uap.IUAPQueryBS;
import nccloud.framework.core.IInterfaceAction;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
public class TestAction implements IInterfaceAction {
	private String param;
	public String getParam(HttpServletRequest req) {
		param = "";
        try {
			BufferedReader reader = req.getReader();
			String line;
			while ((line = reader.readLine()) != null){
				param = param.concat(line);
			}
		} catch (IOException e1) {
			Logger.error(e1);
			e1.printStackTrace();
		}
		return param;
	}
	@Override
	public Object execute(HttpServletRequest req, HttpServletResponse resp) {
		String param = getParam(req);
		JSONObject paramJson = JSON.parseObject(param);
		IUAPQueryBS queryBS = NCLocator.getInstance().lookup(IUAPQueryBS.class);
		String optType = paramJson.getString("optType");
		List<Map<String, Object>> mapList = new ArrayList<>();
		return mapList;
	}
}

注意：此處數據處理需用IUAPQueryBS接口和IVOPersistence接口操作數據，用其他接口可能會導致token is null的錯誤