Android中发送Http请求实例（包括文件上传、servlet接收）

摘自：http://www.eoeandroid.com/thread-22679-1-1.html

前天开始要准备实现手机端往服务器传参数，还要能传附件，找了不少文章和资料，现在总结一下分享分享：代码中的catch什么的就省略了，尝试了图片、txt、xml是没问题的.. 各位 尽情拍砖吧。
发完发现代码部分的格式……这个编辑器不太会用，怎么感觉把换行都去掉了,处理好换行缩进也……
首先我是写了个java工程测试发送post请求：可以包含文本参数和文件参数****************************************************

1. /**
2. * 通过http协议提交数据到服务端，实现表单提交功能，包括上传文件
3. * @param actionUrl 上传路径
4. * @param params 请求参数 key为参数名,value为参数值
5. * @param file 上传文件
6. */
7. public static void postMultiParams(String actionUrl, Map<String, String> params, FormBean[] files) {
8. try {
9. PostMethod post = new PostMethod(actionUrl);
10. List<art> formParams = new ArrayList<art>();
11. for(Map.Entry<String, String> entry : params.entrySet()){
12. formParams.add(new StringPart(entry.getKey(), entry.getValue()));
13. }
14. if(files!=null)
15. for(FormBean file : files){
16. //filename为在服务端接收时希望保存成的文件名，filepath是本地文件路径(包括了源文件名)，filebean中就包含了这俩属性
17. formParams.add(new FilePart("file", file.getFilename(), new File(file.getFilepath())));
18. }
19. Part[] parts = new Part[formParams.size()];
20. Iterator<art> pit = formParams.iterator();
21. int i=0;
22. while(pit.hasNext()){
23. parts[i++] = pit.next();
24. }
25. //如果出现乱码可以尝试一下方式
26. //StringPart sp = new StringPart("TEXT", "testValue", "GB2312"); 
27. //FilePart fp = new FilePart("file", "test.txt", new File("./temp/test.txt"), null, "GB2312"
28. //postMethod.getParams().setContentCharset("GB2312");
29. MultipartRequestEntity mrp = new MultipartRequestEntity(parts, post.getParams());
30. post.setRequestEntity(mrp);
31. //execute post method
32. HttpClient client = new HttpClient();
33. int code = client.executeMethod(post);
34. System.out.println(code);
35. } catch ...
36. }

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通过以上代码可以成功的模拟java客户端发送post请求，服务端也能接收并保存文件 java端测试的main方法：

1. public static void main(String[] args){
2. String actionUrl = "http://192.168.0.123:8080/WSserver/androidUploadServlet";
3. Map<String, String> strParams = new HashMap<String, String>();
4. strParams.put("paramOne", "valueOne");
5. strParams.put("paramTwo", "valueTwo");
6. FormBean[] files = new FormBean[]{new FormBean("dest1.xml", "F:/testpostsrc/main.xml")};
7. HttpTool.postMultiParams(actionUrl,strParams,files);
8. }

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本以为大功告成了，结果一移植到android工程中，编译是没有问题的。 但是运行时抛了异常 先是说找不到PostMethod类，org.apache.commons.httpclient.methods.PostMethod这个类绝对是有包含的； 还有个异常就是VerifyError。 开发中有几次碰到这个异常都束手无策，觉得是SDK不兼容还是怎么地，哪位知道可得跟我说说～～ 于是看网上有直接分析http request的内容构建post请求的，也有找到带上传文件的，拿下来运行老是有些问题，便直接通过运行上面的java工程发送的post请求，在servlet中打印出请求内容，然后对照着拼接字符串和流终于给实现了！代码如下： ***********************************************************

1. /**
2. * 通过拼接的方式构造请求内容，实现参数传输以及文件传输
3. * @param actionUrl
4. * @param params
5. * @param files
6. * @return
7. * @throws IOException
8. */
9. public static String post(String actionUrl, Map<String, String> params,
10. Map<String, File> files) throws IOException {
11. String BOUNDARY = java.util.UUID.randomUUID().toString();
12. String PREFIX = "--" , LINEND = "\r\n";
13. String MULTIPART_FROM_DATA = "multipart/form-data";
14. String CHARSET = "UTF-8";
15. URL uri = new URL(actionUrl);
16. HttpURLConnection conn = (HttpURLConnection) uri.openConnection();
17. conn.setReadTimeout(5 * 1000); // 缓存的最长时间
18. conn.setDoInput(true);// 允许输入
19. conn.setDoOutput(true);// 允许输出
20. conn.setUseCaches(false); // 不允许使用缓存
21. conn.setRequestMethod("POST");
22. conn.setRequestProperty("connection", "keep-alive");
23. conn.setRequestProperty("Charsert", "UTF-8");
24. conn.setRequestProperty("Content-Type", MULTIPART_FROM_DATA + ";boundary=" + BOUNDARY);
25. // 首先组拼文本类型的参数
26. StringBuilder sb = new StringBuilder();
27. for (Map.Entry<String, String> entry : params.entrySet()) {
28. sb.append(PREFIX);
29. sb.append(BOUNDARY);
30. sb.append(LINEND);
31. sb.append("Content-Disposition: form-data; name=\"" + entry.getKey() + "\"" + LINEND);
32. sb.append("Content-Type: text/plain; charset=" + CHARSET+LINEND);
33. sb.append("Content-Transfer-Encoding: 8bit" + LINEND);
34. sb.append(LINEND);
35. sb.append(entry.getValue());
36. sb.append(LINEND);
37. }
38. DataOutputStream outStream = new DataOutputStream(conn.getOutputStream());
39. outStream.write(sb.toString().getBytes());
40. // 发送文件数据
41. if(files!=null)
42. for (Map.Entry<String, File> file: files.entrySet()) {
43. StringBuilder sb1 = new StringBuilder();
44. sb1.append(PREFIX);
45. sb1.append(BOUNDARY);
46. sb1.append(LINEND);
47. sb1.append("Content-Disposition: form-data; name=\"file\"; filename=\""+file.getKey()+"\""+LINEND);
48. sb1.append("Content-Type: application/octet-stream; charset="+CHARSET+LINEND);
49. sb1.append(LINEND);
50. outStream.write(sb1.toString().getBytes());
51. InputStream is = new FileInputStream(file.getValue());
52. byte[] buffer = new byte[1024];
53. int len = 0;
54. while ((len = is.read(buffer)) != -1) {
55. outStream.write(buffer, 0, len);
56. }
57. is.close();
58. outStream.write(LINEND.getBytes());
59. }
60. //请求结束标志
61. byte[] end_data = (PREFIX + BOUNDARY + PREFIX + LINEND).getBytes();
62. outStream.write(end_data);
63. outStream.flush();
64. // 得到响应码
65. int res = conn.getResponseCode();
66. if (res == 200) {
67. InputStream in = conn.getInputStream();
68. int ch;
69. StringBuilder sb2 = new StringBuilder();
70. while ((ch = in.read()) != -1) {
71. sb2.append((char) ch);
72. }
73. }
74. outStream.close();
75. conn.disconnect();
76. return in.toString();
77. }

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********************** button响应中的代码： **********************

1. public void onClick(View v){
2. String actionUrl = getApplicationContext().getString(R.string.wtsb_req_upload);
3. Map<String, String> params = new HashMap<String, String>();
4. params.put("strParamName", "strParamValue");
5. Map<String, File> files = new HashMap<String, File>();
6. files.put("tempAndroid.txt", new File("/sdcard/temp.txt"));
7. try {
8. HttpTool.postMultiParams(actionUrl, params, files);
9. } catch ...

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*************************** 服务器端servlet代码： ***************************

1. public void doPost(HttpServletRequest request, HttpServletResponse response)
2. throws ServletException, IOException {
3. //print request.getInputStream to check request content
4. //HttpTool.printStreamContent(request.getInputStream());
5. RequestContext req = new ServletRequestContext(request);
6. if(FileUpload.isMultipartContent(req)){
7. DiskFileItemFactory factory = new DiskFileItemFactory();
8. ServletFileUpload fileUpload = new ServletFileUpload(factory);
9. fileUpload.setFileSizeMax(FILE_MAX_SIZE);
10. List items = new ArrayList();
11. try {
12. items = fileUpload.parseRequest(request);
13. } catch ...
14. Iterator it = items.iterator();
15. while(it.hasNext()){
16. FileItem fileItem = (FileItem)it.next();
17. if(fileItem.isFormField()){
18. System.out.println(fileItem.getFieldName()+" "+fileItem.getName()+" "+new String(fileItem.getString().getBytes("ISO-8859-1"),"GBK"));
19. } else {
20. System.out.println(fileItem.getFieldName()+" "+fileItem.getName()+" "+
21. fileItem.isInMemory()+" "+fileItem.getContentType()+" "+fileItem.getSize());
22. if(fileItem.getName()!=null && fileItem.getSize()!=0){
23. File fullFile = new File(fileItem.getName());
24. File newFile = new File(FILE_SAVE_PATH+fullFile.getName());
25. try {
26. fileItem.write(newFile);
27. } catch ...
28. } else {
29. System.out.println("no file choosen or empty file");
30. }
31. }
32. }
33. }
34. }
35. public void init() throws ServletException {
36. //读取在web.xml中配置的init-param  
37. FILE_MAX_SIZE = Long.parseLong(this.getInitParameter("file_max_size"));//上传文件大小限制 
38. FILE_SAVE_PATH = this.getInitParameter("file_save_path");//文件保存位置
39. }