阅读:8824回复:1
关于Ajax call get and post method, 和前端解决跨域
关于Ajax call的一些介绍:
1.get var urlAJAXServlet = ""; jQuery.support.cors = true; $.ajax({ url: urlAJAXServlet, type: 'GET', crossDomain: true, dataType: 'json', async: false, beforeSend: function(xhr){ xhr.setRequestHeader('Access-Control-Allow-Origin', '*'); }, success : function(data) { responseJson=data; console.log("Success: in call json service..."+JSON.stringify(responseJson)); }, error:function(XMLHttpRequest, textStatus, errorThrown){ console.log("Error: in call json service..."); console.log("Error: in call json service..."+XMLHttpRequest); console.log("Error: in call json service..."+textStatus); console.log("Error: in call json service..."+errorThrown); } }) 2. POST var requestForHost={}; var urlAJAXServlet = ""; jQuery.support.cors = true; $.ajax({ contentType:"application/json", url: urlAJAXServlet, type: 'POST', crossDomain: true, data: JSON.stringify(requestForHost), dataType: 'json', async: false, beforeSend: function(xhr){ xhr.setRequestHeader('channelId', 'MEM'); xhr.setRequestHeader('countryCode', 'SG'); xhr.setRequestHeader('Access-Control-Allow-Origin', '*'); }, success : function(data) { reponseGDTJson=data; console.log("Success: in call json service..."+JSON.stringify(reponseGDTJson)); }, error:function(XMLHttpRequest, textStatus, errorThrown){ console.log("Error: in call json service..."); console.log("Error: in call json service..."+XMLHttpRequest); console.log("Error: in call json service..."+textStatus); console.log("Error: in call json service..."+errorThrown); } }); 这样的方法也许call 本地的api没有问题,但是一旦上到环境上,我们就会面临跨域问题,解决方法 这样的我们可以在本地创建一个servlet,虽然这样有点麻烦但是还是很好用的,现在这个就是纯Jquery Ajax call, 当然你可以用SpringMVC 和Backbonds的框架来call 但是可能也会有跨域问题。这个还没有研究, 现在先说纯Jquery建立一个servlet来解决前台的跨域问题。 我们可以在本地创建一个servlet,用的是httpClients public class SBGetDatesServlet extends HttpServlet{ private static final long serialVersionUID=1L; public SBGetDatesServlet(){ super(); } protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException{ doPost(request,response); } protected void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException{ CloseableHttpClient httpClient = null; HttpPost httpPost = null; CloseableHttpResponse httpResponse = null; try { httpClient = HttpClients.createDefault(); //Start read the json String that ajax call Post Passed BufferedReader br1 = new BufferedReader(new InputStreamReader(request.getInputStream(),"utf-8")); String line = null; StringBuilder sb= new StringBuilder(); while((line = br1.readLine())!=null){ sb.append(line); } //END JSONObject json = JSONObject.fromObject(sb.toString());//Json String - > Json object httpPost = new HttpPost("https://......"); // Rest server URL StringEntity input = new StringEntity(json.toString()); input.setContentType("application/json"); // Json format httpPost.setEntity(input); httpPost.addHeader("channelId", request.getHeader("channelId")); httpPost.addHeader("countryCode", request.getHeader("countryCode")); httpPost.addHeader("Content-Type", "application/json"); httpResponse = httpClient.execute(httpPost); if (httpResponse.getStatusLine().getStatusCode() != 200) { throw new RuntimeException("Failed : HTTP error code : " + httpResponse.getStatusLine().getStatusCode()); // Error } BufferedReader br = new BufferedReader(new InputStreamReader((httpResponse.getEntity().getContent()))); String responseOut = ""; String output; // System.out.println("Output from Server .... \n");// Console log while ((output = br.readLine()) != null) { // get output System.out.println(output); responseOut += output; } Map<String, String> OutputMap = new HashMap<String, String>(); ObjectMapper mapper = new ObjectMapper(); Writer out = response.getWriter(); try { OutputMap = mapper.readValue(responseOut, new TypeReference<HashMap<String, Object>>() { }); System.out.println(OutputMap); JSONObject jsonReponse = new JSONObject(); jsonReponse.putAll(OutputMap); // System.out.println(jsonReponse.putAll(responseOut)); // out.write(jsonReponse.toString()); MemfisLogger.logMessage(MemfisLogger.DEBUG, "", "Json response " + responseOut); out.write(responseOut);//我们可以用out.write将正确的json response返回到页面上。 out.flush(); // System.out.println(OutMap); // console log } catch (Exception e) { e.printStackTrace(); } } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { try { httpResponse.close(); httpClient.close(); // close ALL } catch (Exception ex) { ex.printStackTrace(); } } } } |
|
沙发#
发布于:2018-08-25 21:50
我们还有一种方法,同样是新建一个servlet但是我们不是用httpClients, 而是用
restAccessor,但是这个需要一些版本比较高的Jar包, httpclient-4.5.2.jar httpcore-4.4.5.jar spring-beans-4.2.3.RELEASE.jar spring-core-4.2.3.RELEASE.jar spring-web-4.2.3.RELEASE.jar jackson-all-1.9.9.jar jackson-annotations-2.7.3.jar jackson-core-2.7.3.jar jackson-databind-2.7.3.jar public class SBGetDatesServlet extends HttpServlet{ private static final long serialVersionUID = 1L; private static final String HOST_NAME; private static final String PORT; private static final String PROTOCOL; static { String url = String[] sourceStrArray = url.split(":"); int length = sourceStrArray[1].length(); String hostName = sourceStrArray[1].substring(2,length); HOST_NAME=hostName; PORT=sourceStrArray[2]; PROTOCOL=sourceStrArray[0]; } public SBGetDatesServlet() { super(); // TODO Auto-generated constructor stub } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ObjectMapper mapper = new ObjectMapper(); RestAccessor restAccessor=new RestAccessor(); restAccessor.setHost(HOST_NAME); restAccessor.setPort(PORT); restAccessor.setProtocol(PROTOCOL); restAccessor.setPath(""); RestRequestObject req=new RestRequestObject(); try { BufferedReader br1 = new BufferedReader(new InputStreamReader(request.getInputStream(),"utf-8")); String line = null; StringBuilder sb= new StringBuilder(); while((line = br1.readLine())!=null){ sb.append(line); } JSONObject json = JSONObject.fromObject(sb.toString()); System.out.println("SBGetDatesServlet : doPost() : Json Object Request" + json); req.setHttpMethod(HttpMethod.POST); req.setHttpRequestHeaders(getDefaultHTTPRequestHeaders()); req.setRequestBody(sb.toString()); RestResponseObject res = restAccessor.makeRESTCall(req); System.out.println("calling makeRESTCall completed " + mapper.writeValueAsString(res)); res.getResponseBody(); JSONObject jsonRes = JSONObject.fromObject(res.getResponseBody().toString()); System.out.println("SBGetDatesServlet : doPost() : Json Object Response" + jsonRes); Writer out = response.getWriter(); out.write(res.getResponseBody().toString()); out.flush(); if (res.isSuccess()) { System.out.println("invokeCustUpdRESTService Success "); resCode = "0"; } else { resCode = "-1"; System.out.println("invokeCustUpdRESTService Failed "); if (res.getErrorResponse() != null) { System.out.println("invokeCustUpdRESTService Failed :: " + res.getErrorResponse()); } else { System.out.println("invokeCustUpdRESTService Failed - NO ESB UUID :: "); } } } catch (Exception e) { resCode = "-1"; System.out.println("invokeCustUpdRESTService || invokeCustUpdRESTService || Exception: " + e); } } private static HttpHeaders getDefaultHTTPRequestHeaders() { String methodName = "getDefaultHTTPRequestHeaders"; HttpHeaders requestHeaders = new HttpHeaders(); try { requestHeaders.add("countryCode", "SG"); requestHeaders.add("channelID", "MEM"); } catch (Exception e) { System.out.println("RESTfulServiceInvoker"+ "getDefaultHTTPRequestHeaders"+ "Exception" +e); } System.out.println("RESTfulServiceInvoker"+ "getDefaultHTTPRequestHeaders"+ "requestHeaders" +requestHeaders); return requestHeaders; } } 但是如果真正解决跨域问题还是需要后台的API端相配合的。 |
|