java fileupload上传附件到服务器，可携带参数（简单易用）可跨域，看这篇就够了_业界新闻

发布时间:2024-07-19 07:04

阅读量:3

@SuppressWarnings(“unchecked”)

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException

{

int state = 0;

DiskFileItemFactory factory = new DiskFileItemFactory();

factory.setSizeThreshold(4096);

request.setCharacterEncoding(“GBK”);

response.setContentType(“text/html;charset=UTF-8”);

PrintWriter out = response.getWriter();

ServletFileUpload upload = new ServletFileUpload(factory);

upload.setSizeMax(1024 * 1024 * 10);

//上传文件流

try

{

String a = “”;

String b = “”;

HashMap fileMap = new HashMap();

boolean isMultipart = ServletFileUpload.isMultipartContent(request);

if (isMultipart)

{

try

{

List items = upload.parseRequest(request);

Iterator iter = items.iterator();

while (iter.hasNext())

{

FileItem item = (FileItem) iter.next();

if (item.isFormField())

{

//普通文本信息处理

String paramName = item.getFieldName();

String paramValue = item.getString();

if (“a”.equals(paramName))

a = paramValue;

else if (“b”.equals(paramName))

b = paramValue;

}

else

{

//上传文件信息处理

String fileName = item.getName();

// String fileExt = this.getFileExt(fileName);

String path = “/filetest”;

InputStream is = item.getInputStream();

FileOutputStream fos = new FileOutputStream(path+“/”+ fileName);

int index = 0;

while((index=is.read())!=-1){

fos.write(index);

}

is.close();

fos.close();

item.delete();

//处理自己的业务

System.out.println(“a==”+a);

System.out.println(“b==”+b);

//设置成功

state=1;

}

catch (FileUploadException e)

{

e.printStackTrace();

}

if (state > 0)

out.write(“{‘result’:‘true’,‘message’:‘上传成功’}”);

out.flush();

}

catch (Exception e)

{

//out.write(“0”);

out.write(“{‘result’:‘false’,‘message’:‘文件上传出现未知错误!’}”);

out.flush();

out.close();

//释放IO资源

}

/**

获取后缀名
@param vo

private String getFileExt(String fileName) throws Exception

{

String value = new String();

int start = 0;

int end = 0;

if (fileName == null)

return null;

start = fileName.lastIndexOf(‘.’) + 1;

end = fileName.length();

value = fileName.substring(start, end);

if (fileName.lastIndexOf(‘.’) > 0)

return value;

else

return “”;

}

其中处理文本信息的代码：

处理附件的代码：

接下来是客户端调用代码：

============

package com.file;

import java.io.BufferedReader;

import java.io.DataOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.net.HttpURLConnection;

import java.net.URL;

import java.util.HashMap;

import java.util.Map;

public class FileUpLoadUtil

{

/**

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 访问的服务器URL
@param params 普通参数
@param files 文件参数
@return
@throws IOException

public static String post(String actionUrl, Map<String, String> params, String[] filePathList) 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”;

String result = “”;

URL uri = new URL(actionUrl);

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

conn.setReadTimeout(10 * 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”, CHARSET);

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 (filePathList != null)

{

for (String filePath : filePathList)

{

File file = new File(filePath);

StringBuilder sb1 = new StringBuilder();

sb1.append(PREFIX);

sb1.append(BOUNDARY);

sb1.append(LINEND);

sb1.append(“Content-Disposition: form-data; name=“file”; filename=”" + file.getName() + “”" + LINEND);

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

sb1.append(LINEND);

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

InputStream is = new FileInputStream(file);

byte[] buffer = new byte[1024 * 3];

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();

int responseCode = conn.getResponseCode();

if (HttpURLConnection.HTTP_OK == responseCode)

{

StringBuffer returnInfo = new StringBuffer();

String readLine;

BufferedReader responseReader;

responseReader = new BufferedReader(new InputStreamReader(conn.getInputStream(),“UTF-8”));

while ((readLine = responseReader.readLine()) != null)

{

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