java httpclient 上传文件 服务器 servlet 接收

1、新建一个普通的java项目，然后新建个包和类，代码如下：

package com.busymonkey;

import java.io.File;
import java.io.IOException;

import org.apache.http.HttpEntity;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class HttpClientUtile {
public static void main(String[] args) throws ClientProtocolException,
IOException {
args = new String[] { "D:\\test.exe" };
if (args.length != 1) {
System.out.println("File path not given");
System.exit(1);
}
CloseableHttpClient httpclient = HttpClients.createDefault();
try {
HttpPost httppost = new HttpPost(
"http://localhost:8080/servlet/Servlet");

FileBody bin = new FileBody(new File(args[0]));
StringBody comment = new StringBody("A binary file of some kind",
ContentType.TEXT_PLAIN);

HttpEntity reqEntity = MultipartEntityBuilder.create()
.addPart("bin", bin).addPart("comment", comment).build();

httppost.setEntity(reqEntity);

System.out.println("executing request " + httppost.getRequestLine());
CloseableHttpResponse response = httpclient.execute(httppost);
try {
System.out.println("----------------------------------------");
System.out.println(response.getStatusLine());
HttpEntity resEntity = response.getEntity();
if (resEntity != null) {
System.out.println("Response content length: "
+ resEntity.getContentLength());
System.out.println(EntityUtils.toString(resEntity));
}
EntityUtils.consume(resEntity);
} finally {
response.close();
}
} finally {
httpclient.close();
}
}
}

需要的包（解压后全部拷贝肯定能用）下载地址：点击打开链接 点击打开链接 点击打开链接

2、首先要有tomcat的运行环境，与eclipse的关联看文章：点击打开链接

然后新建一个动态web项目，并且在项目源文件下新建一个servlet，这样web.xml文件里面应该能自动生成一些映射配置，然后servlet的代码（服务器）如下：

package com.busymonkey;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUpload;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.RequestContext;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.fileupload.servlet.ServletRequestContext;

public class Servlet extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
private static final long FILE_MAX_SIZE = 1024 * 1024 * 200;
private static final String FILE_SAVE_PATH = "D:\\temp\\";

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
System.out.println("do get");
}

@Override
protected void doPost(HttpServletRequest request, HttpServletResponse resp)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
RequestContext req = new ServletRequestContext(request);
if (FileUpload.isMultipartContent(req)) {
DiskFileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload fileUpload = new ServletFileUpload(factory);
fileUpload.setHeaderEncoding("UTF-8");
fileUpload.setFileSizeMax(FILE_MAX_SIZE);
List<FileItem> items = new ArrayList<FileItem>();
try {
items = fileUpload.parseRequest(request);
} catch (FileUploadException e) {
e.printStackTrace();
}
Iterator<FileItem> 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 (Exception e) {
e.printStackTrace();
}
} else {
System.out.println("no file choosen or empty file");
}
}
}
}
}
}

需要用到的包（最好直接放到tomcat部署环境的lib文件夹下，不用每次拷贝）下载地址：点击打开链接 点击打开链接

3、最后建立好待上传的文件和用于接收的文件夹，路径自己可以在程序里修改，然后先运行服务器端，再运行java 应用程序。

4、注意：如果提示 404 首先检查项目路径下的build目录有没有生成class文件。