httpclient笔记
Jakarta的httpclient3.1是最新版本，项目中需要用程序模拟浏览器的GET和POST动作。在使用过程中遇到不少问题。
1. 带附件的POST提交
??? 最开始都是使用MultipartPostMethod这个类，现在已经废弃这个类了。API说明：Deprecated. Use MultipartRequestEntity in conjunction with PostMethod instead.?? 使用PostMethod可以实现的功能，就没有必要再弄一个MultipartPostMethod了。下面是一段最简单的示例：
PostMethod post = new PostMethod(); NameValuePair[] pairs = new NameValuePair[2]; pairs[0] = new NameValuePair("para1", "value1"); pairs[0] = new NameValuePair("para2", "value2"); post.setRequestBody(pairs); HttpClient client = new HttpClient(); try { client.executeMethod(post); } catch (HttpException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); }?
?? 这是针对一般的form形式的提交，而且这个form里面不带附件的。如果带附件，那么这种方法就不起作用，附件上传的参数和普通参数无法一同在服务器获取到。org.apache.commons.httpclient.methods.multipart 这个包就是为处理文件上传这种多形式参数的情况的。最主要的类是Part（代表一种post object），它有二个比较重要的子类：FilePart和StringPart，一个是文件的参数，另一个就是普通的文本参数。它的典型使用方法如下：
String url = "http://localhost:8080/HttpTest/Test"; PostMethod postMethod = new PostMethod(url); StringPart sp = new StringPart("TEXT", "testValue"); FilePart fp = new FilePart("file", "test.txt", new File("./temp/test.txt")); MultipartRequestEntity mrp= new MultipartRequestEntity(new Part[]{sp, fp}, postMethod .getParams()); postMethod.setRequestEntity(mrp); //执行postMethod HttpClient httpClient = new HttpClient(); try { httpClient.executeMethod(postMethod); } catch (HttpException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); }?
? ?? 在第二行PostMethod postMethod = new PostMethod();后面，有人说需要使用postMehtod.setRequestHeader("Content-type", "multipart/form-data"); Content-type的请求类型进行更改。但是我在使用过程没有加上这一句，查了一下httpCleint的默认Content-type是 application/octet-stream。应该是没有影响的。对于MIME类型的请求，httpclient建议全用 MulitPartRequestEntity进行包装，就是上面的用法。
2.? 参数中文的处理问题
??? httpclient的默认编码都是ISO-8859-1，那肯定就无法支持中文参数了。引用一下这篇文章：http://thinkbase.net/w/main/Wiki?HttpClient+POST+%E7%9A%84+UTF-8+%E7%BC%96%E7%A0%81%E9%97%AE%E9%A2%98 ，按照作者的说法，就可以正常解决中文编码的问题。其中最关键的是修改EncodingUtil这个类的一个方法实现。另外，FilePart和 StringPart的构造方法都有一个带编码指定的参数，为了减少问题的出现，建议所有的都带上统一的编码，包括 postMethod.getParams()。示例如下：
String url = "http://localhost:8080/HttpTest/Test"; PostMethod postMethod = new PostMethod(url); StringPart sp = new StringPart("TEXT", "testValue", "GB2312"); FilePart fp = new FilePart("file", "test.txt", new File("./temp/test.txt"), null, "GB2312"); postMethod.getParams().setContentCharset("GB2312"); MultipartRequestEntity mrp= new MultipartRequestEntity(new Part[]{sp, fp}, postMethod .getParams()); postMethod.setRequestEntity(mrp); //执行postMethod HttpClient httpClient = new HttpClient(); try { httpClient.executeMethod(postMethod); } catch (HttpException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); }?
不多说了，直接上示例：
A服务器：
?msURL为：http://192.168.7.203:8080
?
Java代码
1. /** 2. * 发送文件到另一台服务器B 3. * 4. * @param File file 附件 5. * @param serviceType服务类型 6. * @param spId id 7. * @return 8. */ 9. public String sendApply(File file, String serviceType, String spId) { 10. String fromAgentResult = ""; 11. HttpClient client = new HttpClient(); 12. PostMethod filePost = new PostMethod(msUrl+"?serviceType="+serviceType+"&spId="+spId+"&type=menu"); 13. // MultipartPostMethod filePost = new MultipartPostMethod(msUrl); 14. // 若上传的文件比较大 , 可在此设置最大的连接超时时间 15. client.getHttpConnectionManager(). getParams().setConnectionTimeout(8000); 16. 17. try { 18. 19. FilePart fp = new FilePart(file.getName(), file); 20. MultipartRequestEntity mrp= new MultipartRequestEntity(new Part[]{fp}, filePost.getParams()); 21. filePost.setRequestEntity(mrp); 22. 23. //使用系统提供的默认的恢复策略 24. filePost.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, 25. new DefaultHttpMethodRetryHandler()); 26. 27. int httpStat = client.executeMethod(filePost); 28. System.out.println("httpStat----"+httpStat); 29. if (!(httpStat == HttpStatus.SC_OK)) { 30. fromAgentResult = "connected fail:" + httpStat; 31. } else if (httpStat == HttpStatus.SC_OK) { 32. 33. try { 34. DocumentBuilderFactory factory = DocumentBuilderFactory 35. .newInstance(); 36. DocumentBuilder builder = factory.newDocumentBuilder(); 37. Document doc = builder 38. .parse(filePost.getResponseBodyAsStream()); 39. doc.normalize(); 40. // NodeList optypeNL= doc.getElementsByTagName("optype"); 41. NodeList resultNL = doc.getElementsByTagName("result"); 42. // fromAgentOptype= 43. // optypeNL.item(0).getFirstChild().getNodeValue(); 44. fromAgentResult = resultNL.item(0).getFirstChild() 45. .getNodeValue(); 46. System.out.println("发送请求完毕，接收状态："+fromAgentResult); 47. } catch (Exception e) { 48. e.printStackTrace(); 49. } 50. } 51. } catch (HttpException e) { 52. // TODO Auto-generated catch block 53. e.printStackTrace(); 54. } catch (IOException e) { 55. // TODO Auto-generated catch block 56. e.printStackTrace(); 57. } 58. filePost.releaseConnection(); 59. return fromAgentResult; 60. } ? 1. /** 2. * 发送文件到另一台服务器B 3. * 4. * @param File file 附件 5. * @param serviceType服务类型 6. * @param spId id 7. * @return 8. */ 9. public String sendApply(File file, String serviceType, String spId) { 10. String fromAgentResult = ""; 11. HttpClient client = new HttpClient(); 12. PostMethod filePost = new PostMethod(msUrl+"?serviceType="+serviceType+"&spId="+spId+"&type=menu"); 13. // MultipartPostMethod filePost = new MultipartPostMethod(msUrl); 14. // 若上传的文件比较大 , 可在此设置最大的连接超时时间 15. client.getHttpConnectionManager(). getParams().setConnectionTimeout(8000); 16. 17. try { 18. 19. FilePart fp = new FilePart(file.getName(), file); 20. MultipartRequestEntity mrp= new MultipartRequestEntity(new Part[]{fp}, filePost.getParams()); 21. filePost.setRequestEntity(mrp); 22. 23. //使用系统提供的默认的恢复策略 24. filePost.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, 25. new DefaultHttpMethodRetryHandler()); 26. 27. int httpStat = client.executeMethod(filePost); 28. System.out.println("httpStat----"+httpStat); 29. if (!(httpStat == HttpStatus.SC_OK)) { 30. fromAgentResult = "connected fail:" + httpStat; 31. } else if (httpStat == HttpStatus.SC_OK) { 32. 33. try { 34. DocumentBuilderFactory factory = DocumentBuilderFactory 35. .newInstance(); 36. DocumentBuilder builder = factory.newDocumentBuilder(); 37. Document doc = builder 38. .parse(filePost.getResponseBodyAsStream()); 39. doc.normalize(); 40. // NodeList optypeNL= doc.getElementsByTagName("optype"); 41. NodeList resultNL = doc.getElementsByTagName("result"); 42. // fromAgentOptype= 43. // optypeNL.item(0).getFirstChild().getNodeValue(); 44. fromAgentResult = resultNL.item(0).getFirstChild() 45. .getNodeValue(); 46. System.out.println("发送请求完毕，接收状态："+fromAgentResult); 47. } catch (Exception e) { 48. e.printStackTrace(); 49. } 50. } 51. } catch (HttpException e) { 52. // TODO Auto-generated catch block 53. e.printStackTrace(); 54. } catch (IOException e) { 55. // TODO Auto-generated catch block 56. e.printStackTrace(); 57. } 58. filePost.releaseConnection(); 59. return fromAgentResult; 60. } ?
?
B服务器接收：
?
Java代码
1. boolean bl = false; 2. System.out.println("接收文件开始--------------"); 3. String serviceType = request.getParameter("serviceType"); 4. String spId = request.getParameter("spId"); 5. String type = request.getParameter("type"); 6. if (type.equals("menu")) { 7. 8. DiskFileUpload fu = new DiskFileUpload(); 9. fu.setSizeMax(1000000); 10. 11. List fileItems; 12. 13. try { 14. fileItems = fu.parseRequest(request); 15. Iterator itr = fileItems.iterator(); 16. while (itr.hasNext()) { 17. FileItem fi = (FileItem) itr.next(); 18. 19. if (!fi.isFormField()) { 20. System.out.println("\nNAME: " + fi.getName()); 21. System.out.println("SIZE: " + fi.getSize()); 22. try { 23. String newFileName = msu.updateName(Integer 24. .parseInt(serviceType), spId); 25. System.out.println("newFileName---------------" 26. + newFileName); 27. File fNew = new File(applyFilePath, newFileName); 28. fi.write(fNew); 29. bl = msu.acceptApply(Integer.parseInt(serviceType), 30. spId, newFileName); 31. 32. System.out.println(fNew.getAbsolutePath()); 33. 34. } catch (Exception e) { 35. // TODO Auto-generated catch block 36. e.printStackTrace(); 37. } 38. } else { 39. System.out.println("Field =" + fi.getFieldName()); 40. } 41. } 42. 43. } catch (FileUploadException e1) { 44. // TODO Auto-generated catch block 45. e1.printStackTrace(); 46. } 47. } ?boolean bl = false; System.out.println("接收文件开始--------------"); String serviceType = request.getParameter("serviceType"); String spId = request.getParameter("spId"); String type = request.getParameter("type"); if (type.equals("menu")) { DiskFileUpload fu = new DiskFileUpload(); fu.setSizeMax(1000000); List fileItems; try { fileItems = fu.parseRequest(request); Iterator itr = fileItems.iterator(); while (itr.hasNext()) { FileItem fi = (FileItem) itr.next(); if (!fi.isFormField()) { System.out.println("\nNAME: " + fi.getName()); System.out.println("SIZE: " + fi.getSize()); try { String newFileName = msu.updateName(Integer .parseInt(serviceType), spId); System.out.println("newFileName---------------" + newFileName); File fNew = new File(applyFilePath, newFileName); fi.write(fNew); bl = msu.acceptApply(Integer.parseInt(serviceType), spId, newFileName); System.out.println(fNew.getAbsolutePath()); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } else { System.out.println("Field =" + fi.getFieldName()); } } } catch (FileUploadException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } }?
Java代码
?? 1. //下面是返回执行结果 ?
//下面是返回执行结果
Java代码
1. msu.responseToAS(response, bl); 2. System.out.println("接收申请处理完毕，状态：" + bl); 3. return null; msu.responseToAS(response, bl); System.out.println("接收申请处理完毕，状态：" + bl); return null;?
Java代码
?? 1. //msu.responseToAS ?
//msu.responseToAS
Java代码
public void responseToAS(HttpServletResponse response, boolean synSuccess) { 2. try { 3. PrintWriter out = response.getWriter(); 4. if (synSuccess) 5. out 6. .println("<?xml version="1.0" encoding="UTF-8"?><root><result>ok</result></root>"); 7. else 8. out 9. .println("<?xml version="1.0" encoding="UTF-8"?><root><result>fail</result></root>"); 10. } catch (IOException e) { 11. e.printStackTrace(); 12. System.out.println("responseToAS--error"); 13. } 14. } ??