Android中发送Http请求实例（包括文件上传、servlet接收）

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****************************************************

/**

* 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

* @param actionUrl 上传路径

* @param params 请求参数 key为参数名,value为参数值

* @param file 上传文件

*/

public static void postMultiParams(String actionUrl, Map<String, String> params, FormBean[] files) {

try {

PostMethod post = new PostMethod(actionUrl);

List<art> formParams = new ArrayList<art>();

for(Map.Entry<String, String> entry : params.entrySet()){

formParams.add(new StringPart(entry.getKey(), entry.getValue()));

}

if(files!=null)

for(FormBean file : files){

//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

formParams.add(new FilePart("file", file.getFilename(), new File(file.getFilepath())));

}

Part[] parts = new Part[formParams.size()];

Iterator<art> pit = formParams.iterator();

int i=0;

while(pit.hasNext()){

parts[i++] = pit.next();

}

//如果出现乱码可以尝试一下方式

//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(parts, post.getParams());

post.setRequestEntity(mrp);

//execute post method

HttpClient client = new HttpClient();

int code = client.executeMethod(post);

System.out.println(code);

} catch ...

}

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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：

public static void main(String[] args){

String actionUrl = "http://192.168.0.123:8080/WSserver/androidUploadServlet";

Map<String, String> strParams = new HashMap<String, String>();

strParams.put("paramOne", "valueOne");

strParams.put("paramTwo", "valueTwo");

FormBean[] files = new FormBean[]{new FormBean("dest1.xml", "F:/testpostsrc/main.xml")};

HttpTool.postMultiParams(actionUrl,strParams,files);

}

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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：

***********************************************************

/**

* 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

* @param actionUrl

* @param params

* @param files

* @return

* @throws IOException

*/

public static String post(String actionUrl, Map<String, String> params,

Map<String, File> files) throws IOException {

String BOUNDARY = java.util.UUID.randomUUID().toString();

String PREFIX = "--" , LINEND = "\r\n";

String MULTIPART_FROM_DATA = "multipart/form-data";

String CHARSET = "UTF-8";

URL uri = new URL(actionUrl);

HttpURLConnection conn = (HttpURLConnection) uri.openConnection();

conn.setReadTimeout(5 * 1000); // 缓存的最长时间

conn.setDoInput(true);// 允许输入

conn.setDoOutput(true);// 允许输出

conn.setUseCaches(false); // 不允许使用缓存

conn.setRequestMethod("POST");

conn.setRequestProperty("connection", "keep-alive");

conn.setRequestProperty("Charsert", "UTF-8");

conn.setRequestProperty("Content-Type", MULTIPART_FROM_DATA + ";boundary=" + BOUNDARY);

// 首先组拼文本类型的参数

StringBuilder sb = new StringBuilder();

for (Map.Entry<String, String> entry : params.entrySet()) {

sb.append(PREFIX);

sb.append(BOUNDARY);

sb.append(LINEND);

sb.append("Content-Disposition: form-data; name=\"" + entry.getKey() + "\"" + LINEND);

sb.append("Content-Type: text/plain; charset=" + CHARSET+LINEND);

sb.append("Content-Transfer-Encoding: 8bit" + LINEND);

sb.append(LINEND);

sb.append(entry.getValue());

sb.append(LINEND);

}

DataOutputStream outStream = new DataOutputStream(conn.getOutputStream());

outStream.write(sb.toString().getBytes());

// 发送文件数据

if(files!=null)

for (Map.Entry<String, File> file: files.entrySet()) {

StringBuilder sb1 = new StringBuilder();

sb1.append(PREFIX);

sb1.append(BOUNDARY);

sb1.append(LINEND);

sb1.append("Content-Disposition: form-data; name=\"file\"; filename=\""+file.getKey()+"\""+LINEND);

sb1.append("Content-Type: application/octet-stream; charset="+CHARSET+LINEND);

sb1.append(LINEND);

outStream.write(sb1.toString().getBytes());

InputStream is = new FileInputStream(file.getValue());

byte[] buffer = new byte[1024];

int len = 0;

while ((len = is.read(buffer)) != -1) {

outStream.write(buffer, 0, len);

}

is.close();

outStream.write(LINEND.getBytes());

}

//请求结束标志

byte[] end_data = (PREFIX + BOUNDARY + PREFIX + LINEND).getBytes();

outStream.write(end_data);

outStream.flush();

// 得到响应码

int res = conn.getResponseCode();

if (res == 200) {

InputStream in = conn.getInputStream();

int ch;

StringBuilder sb2 = new StringBuilder();

while ((ch = in.read()) != -1) {

sb2.append((char) ch);

}

}

outStream.close();

conn.disconnect();

return in.toString();

}

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**********************

button响应中的代码：

**********************

public void onClick(View v){

String actionUrl = getApplicationContext().getString(R.string.wtsb_req_upload);

Map<String, String> params = new HashMap<String, String>();

params.put("strParamName", "strParamValue");

Map<String, File> files = new HashMap<String, File>();

files.put("tempAndroid.txt", new File("/sdcard/temp.txt"));

try {

HttpTool.postMultiParams(actionUrl, params, files);

} catch ...

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***************************

服务器端servlet代码：

***************************

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

//print request.getInputStream to check request content

//HttpTool.printStreamContent(request.getInputStream());

RequestContext req = new ServletRequestContext(request);

if(FileUpload.isMultipartContent(req)){

DiskFileItemFactory factory = new DiskFileItemFactory();

ServletFileUpload fileUpload = new ServletFileUpload(factory);

fileUpload.setFileSizeMax(FILE_MAX_SIZE);

List items = new ArrayList();

try {

items = fileUpload.parseRequest(request);

} catch ...

Iterator it = items.iterator();

while(it.hasNext()){

FileItem fileItem = (FileItem)it.next();

if(fileItem.isFormField()){

System.out.println(fileItem.getFieldName()+" "+fileItem.getName()+" "+new String(fileItem.getString().getBytes("ISO-8859-1"),"GBK"));

} else {

System.out.println(fileItem.getFieldName()+" "+fileItem.getName()+" "+

fileItem.isInMemory()+" "+fileItem.getContentType()+" "+fileItem.getSize());

if(fileItem.getName()!=null && fileItem.getSize()!=0){

File fullFile = new File(fileItem.getName());

File newFile = new File(FILE_SAVE_PATH+fullFile.getName());

try {

fileItem.write(newFile);

} catch ...

} else {

System.out.println("no file choosen or empty file");

}

}

}

}

}

public void init() throws ServletException {

//读取在web.xml中配置的init-param

FILE_MAX_SIZE = Long.parseLong(this.getInitParameter("file_max_size"));//上传文件大小限制

FILE_SAVE_PATH = this.getInitParameter("file_save_path");//文件保存位置

}