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. }