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android通过servlet服务器保存文件到手机

移动开发
2023-02-17

这篇文章主要为大家详细介绍了android通过servlet服务器保存文件到手机，文中示例代码介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们可以参考一下

本文实例为大家分享了android通过servlet服务器保存文件到手机的具体代码，供大家参考，具体内容如下

服务器端：（手机和电脑连接的同一个WIFI）


package com;
 
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
 
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import sun.misc.BASE64Encoder;
 
public class download extends HttpServlet {
 
 /**
 * Constructor of the object.
 */
 public download() {
 super();
 }
 
 /**
 * Destruction of the servlet. <br>
 */
 public void destroy() {
 super.destroy(); // Just puts "destroy" string in log
 // Put your code here
 }
 
 /**
 * The doGet method of the servlet. <br>
 *
 * This method is called when a form has its tag value method equals to get.
 * 
 * @param request the request send by the client to the server
 * @param response the response send by the server to the client
 * @throws ServletException if an error occurred
 * @throws IOException if an error occurred
 */
 public void doGet(HttpServletRequest request, HttpServletResponse response)
 throws ServletException, IOException {
 
// response.setContentType("text/html");
// PrintWriter out = response.getWriter();
// out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
// out.println("<HTML>");
// out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
// out.println(" <BODY>");
// out.print(" This is ");
// out.print(this.getClass());
// out.println(", using the GET method");
// out.println(" </BODY>");
// out.println("</HTML>");
// out.flush();
// out.close();
 doPost(request, response);
 
 }
 
 /**
 * The doPost method of the servlet. <br>
 *
 * This method is called when a form has its tag value method equals to post.
 * 
 * @param request the request send by the client to the server
 * @param response the response send by the server to the client
 * @throws ServletException if an error occurred
 * @throws IOException if an error occurred
 */
 public void doPost(HttpServletRequest request, HttpServletResponse response)
 throws ServletException, IOException {
 
 response.setContentType("text/html");
 //request.setCharacterEncoding("utf-8");////这句至关重要，不然中文的文件名称显示乱码
 PrintWriter out = response.getWriter();
// out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
// out.println("<HTML>");
// out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
// out.println(" <BODY>");
// out.print(" This is ");
// out.print(this.getClass());
// out.println(", using the POST method");
// out.println(" </BODY>");
// out.println("</HTML>");
 out.print(GetImageStr());///输出文件的字符串
 out.flush();
 out.close();
 
 
 
 }
 
 /**
 * Initialization of the servlet. <br>
 *
 * @throws ServletException if an error occurs
 */
 public void init() throws ServletException {
 // Put your code here
 }
 public static String GetImageStr() 
 {//将图片文件转化为字节数组字符串，并对其进行Base64编码处理 
 // String imgFile = "d://test.jpg";//待处理的图片 
 
 //String imgFile="F://upload//1.jpg";////可以
 // String imgFile="F://upload//软工大作业.ppt";////可以
 String imgFile="F://upload//爱的勇气.mp3";//不可以
 // String imgFile="F://upload//upload.rar";//可以
 InputStream in = null; 
 byte[] data = null; 
 //读取图片字节数组 
 try 
 { 
 in = new FileInputStream(imgFile); 
 data = new byte[in.available()]; 
 in.read(data); 
 in.close(); 
 } 
 catch (IOException e) 
 { 
 e.printStackTrace(); 
 } 
 //对字节数组Base64编码 
 BASE64Encoder encoder = new BASE64Encoder(); 
 return encoder.encode(data);//返回Base64编码过的字节数组字符串 
 } ///GetImageStr 
}

手机端：


package com.example.getfile_2;
 
import java.io.FileOutputStream;
import java.io.OutputStream;
 
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.util.EntityUtils;
 
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
 
public class MainActivity extends Activity {
 
 private static final int REQUEST_TIMEOUT = 5 * 1000;// 设置请求超时10秒钟
 private static final int SO_TIMEOUT = 10*60 * 1000; // 设置请求超时时间10秒钟
 private static final int LOGIN_OK = 1;
 private Button button1, button2;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 button1 = (Button) findViewById(R.id.button1);
 
 button2 = (Button) findViewById(R.id.button2);
 
 button1.setOnClickListener(new OnClickListener() {
 
 @Override
 public void onClick(View v) {
 // TODO 自动生成的方法存根
 Log.i("button1", "button1");
 fun_HttpPost();
 
 }
 });
 }
 
 public void fun_HttpPost() {
 new Thread(new Runnable() {
 @Override
 public void run() {
 // TODO 自动生成的方法存根
 String urlStr = "http://192.168.0.102:8080/download/servlet/download";
 HttpPost request = new HttpPost(urlStr);
 
 try {
 HttpClient client = getHttpClient();
 // 执行请求返回相应
 HttpResponse response = client.execute(request);
 // 判断是否请求成功
 if (response.getStatusLine().getStatusCode() == 200) {
 // 获得响应信息
 String responseMessage = EntityUtils.toString(response
 .getEntity());
 Log.i("responseMessage", responseMessage + ",长度："
 + responseMessage.length());
 GenerateImage(responseMessage);
 Log.i("生成成功", "生成成功");
 }
 } catch (Exception e) {
 e.printStackTrace();
 }
 
 }// //run()
 }).start();
 }// /fun_register()
 
 //base64字符串转化成图片 
 public static boolean GenerateImage(String imgStr) 
 { //对字节数组字符串进行Base64解码并生成图片 
 if (imgStr == null) //图像数据为空 
 return false; 
 Decoder.BASE64Decoder decoder = new Decoder.BASE64Decoder(); 
 try 
 { 
 //Base64解码 
 byte[] b = decoder.decodeBuffer(imgStr); 
 for(int i=0;i<b.length;++i) 
 { 
 if(b[i]<0) 
 {//调整异常数据 
 b[i]+=256; 
 } 
 } 
 //生成jpeg图片 
 // String imgFilePath = "d://222.jpg";//新生成的图片 
 // String imgFilePath = "F://upload//1_2.jpg";///可以
 //String imgFilePath = "F://upload//软工大作业_2.ppt";//可以
// String imgFilePath="F://upload//upload_2.rar";
 // String imgFilePath="/sdcard/1spray/1_2.jpg";//可以
 // String imgFilePath = "/sdcard/1spray/软工大作业_2.ppt";//可以
 String imgFilePath ="/sdcard/1spray/爱的勇气_2.mp3";//9M不行了？？？？？
 OutputStream out = new FileOutputStream(imgFilePath); 
 out.write(b); 
 out.flush(); 
 out.close(); 
 return true; 
 } 
 catch (Exception e) 
 { 
 return false; 
 } 
 } 
 // 初始化HttpClient，并设置超时
 public HttpClient getHttpClient() {
 BasicHttpParams httpParams = new BasicHttpParams();
 HttpConnectionParams.setConnectionTimeout(httpParams, REQUEST_TIMEOUT);
 HttpConnectionParams.setSoTimeout(httpParams, SO_TIMEOUT);
 HttpClient client = new DefaultHttpClient(httpParams);
 return client;
 }// /public HttpClient getHttpClient()
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context="${relativePackage}.${activityClass}" >
 
 <TextView
 android:id="@+id/textView1"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="@string/hello_world" />
 
 <Button
 android:id="@+id/button1"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_below="@+id/textView1"
 android:layout_marginLeft="25dp"
 android:layout_marginTop="142dp"
 android:layout_toRightOf="@+id/textView1"
 android:text="ButtonPost" />
 
 <Button
 android:id="@+id/button2"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_alignLeft="@+id/button1"
 android:layout_below="@+id/button1"
 android:layout_marginTop="34dp"
 android:text="ButtonGet" />
 
</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="com.example.getfile_2"
 android:versionCode="1"
 android:versionName="1.0" >
 
 <uses-sdk
 android:minSdkVersion="15"
 android:targetSdkVersion="16" />
 <!-- 使用网络功能所需权限 -->
 <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 <uses-permission android:name="android.permission.INTERNET" />
 <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
 <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
 <!-- SDK离线地图和cache功能需要读写外部存储器 -->
 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 
 <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" /> 
 <application
 android:allowBackup="true"
 android:icon="@drawable/ic_launcher"
 android:label="@string/app_name"
 android:theme="@style/AppTheme" >
 <activity
 android:name=".MainActivity"
 android:label="@string/app_name" >
 <intent-filter>
 <action android:name="android.intent.action.MAIN" />
 
 <category android:name="android.intent.category.LAUNCHER" />
 </intent-filter>
 </activity>
 </application>
</manifest>

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本文标题为：android通过servlet服务器保存文件到手机

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