Android TCP 文件客户端与服务器DEMO介绍
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2023-11-21 23:50:28
主要功能是:
1、tcp服务器提供文件下载服务,服务器支持多线程。
2、tcp client从服务器上下载指定的文件,client也支持多线程。
首先是服务器,服务器...
主要功能是:
1、tcp服务器提供文件下载服务,服务器支持多线程。
2、tcp client从服务器上下载指定的文件,client也支持多线程。
首先是服务器,服务器是在pc机上,java运行环境,主要参考网上的代码,自己做了支持多线程处理,代码如下:
复制代码 代码如下:
//file:downloadserver.java
import java.net.*;
import java.io.*;
class serveronedownload extends thread {
private socket socket = null;
private string downloadroot = null;
private static final int buffer = 8 * 1024;
public serveronedownload(socket socket, string downloadroot) {
super();
this.socket = socket;
this.downloadroot = downloadroot;
start();
}
// 检查文件是否真实存在,核对下载密码,若文件不存在或密码错误,则返回-1,否则返回文件长度
// 此处只要密码不为空就认为是正确的
private long getfilelength(string filename, string password) {
// 若文件名或密码为null,则返回-1
if ((filename == null) || (password == null))
return -1;
// 若文件名或密码长度为0,则返回-1
if ((filename.length() == 0) || (password.length() == 0))
return -1;
string filepath = downloadroot + filename; // 生成完整文件路径
system.out.println("downloadserver getfilelength----->" + filepath);
file file = new file(filepath);
// 若文件不存在,则返回-1
if (!file.exists())
return -1;
return file.length(); // 返回文件长度
}
// 用指定输出流发送指定文件
private void sendfile(dataoutputstream out, string filename)
throws exception {
string filepath = downloadroot + filename; // 生成完整文件路径
// 创建与该文件关联的文件输入流
fileinputstream in = new fileinputstream(filepath);
system.out.println("downloadserver sendfile----->" + filepath);
byte[] buf = new byte[buffer];
int len;
// 反复读取该文件中的内容,直到读到的长度为-1
while ((len = in.read(buf)) >= 0) {
out.write(buf, 0, len); // 将读到的数据,按读到的长度写入输出流
out.flush();
}
out.close();
in.close();
}
// 提供下载服务
public void download() throws ioexception {
system.out.println("启动下载... ");
system.out.println("downloadserver currentthread--->"
+ currentthread().getname());
system.out.println("downloadserver currentthread--->"
+ currentthread().getid());
// 获取socket的输入流并包装成bufferedreader
bufferedreader in = new bufferedreader(new inputstreamreader(
socket.getinputstream()));
// 获取socket的输出流并包装成dataoutputstream
dataoutputstream out = new dataoutputstream(socket.getoutputstream());
try {
string parameterstring = in.readline(); // 接收下载请求参数
// 下载请求参数字符串为自定义的格式,由下载文件相对于下载根目录的路径和
// 下载密码组成,两者间以字符 "@ "分隔,此处按 "@ "分割下载请求参数字符串
string[] parameter = parameterstring.split("@ ");
string filename = parameter[0]; // 获取相对文件路径
string password = parameter[1]; // 获取下载密码
// 打印请求下载相关信息
system.out.print(socket.getinetaddress().gethostaddress()
+ "提出下载请求, ");
system.out.println("请求下载文件: " + filename);
// 检查文件是否真实存在,核对下载密码,获取文件长度
long len = getfilelength(filename, password);
system.out.println("download filename----->" + filename);
system.out.println("download password----->" + password);
out.writelong(len); // 向客户端返回文件大小
out.flush();
// 若获取的文件长度大于等于0,则允许下载,否则拒绝下载
if (len >= 0) {
system.out.println("允许下载 ");
system.out.println("正在下载文件 " + filename + "... ");
sendfile(out, filename); // 向客户端发送文件
system.out.println(filename +": "+"下载完毕 ");
} else {
system.out.println("下载文件不存在或密码错误,拒绝下载! ");
}
} catch (exception e) {
system.out.println(e.tostring());
} finally {
socket.close(); // 关闭socket
}
}
@override
public void run() {
try {
download();
} catch (ioexception e) {
// todo auto-generated catch block
e.printstacktrace();
}
// todo auto-generated method stub
super.run();
}
}
public class downloadserver {
private final static int port = 65525;
private static string root = "c:// "; // 下载根目录
public static void main(string[] args) throws ioexception {
string temp = null;
// 监听端口
try {
// 包装标准输入为bufferedreader
bufferedreader systemin = new bufferedreader(new inputstreamreader(
system.in));
while (true) {
system.out.print("请输入下载服务器的下载根目录: ");
root = systemin.readline().trim(); // 从标准输入读取下载根目录
file file = new file(root);
// 若该目录确实存在且为目录,则跳出循环
if ((file.exists()) && (file.isdirectory())) {
temp = root.substring(root.length() - 1, root.length());
if (!temp.equals("//"))
root += "//";
}
break;
}
} catch (exception e) {
system.out.println(e.tostring());
}
serversocket serversocket = new serversocket(port);
system.out.println("server start...");
try {
while (true) {
socket socket = serversocket.accept();
new serveronedownload(socket, root);
}
} finally {
serversocket.close();
}
}
}
file download client
client输入ip和文件名即可直接从服务器上下载,还是看代码。
复制代码 代码如下:
//file:downloadclient.java
package org.piaozhiye.study;
import java.io.ioexception;
import java.net.socket;
import android.app.activity;
import android.os.bundle;
import android.view.view;
import android.widget.button;
import android.widget.edittext;
public class downloadclient extends activity {
private button download = null;
private edittext et_serverip = null;
private edittext et_filename= null;
private string downloadfile = null;
private final static int port = 65525;
private final static string defaultip = "192.168.0.100";
private static string serverip = null;
private socket socket;
/** called when the activity is first created. */
@override
public void oncreate(bundle savedinstancestate) {
super.oncreate(savedinstancestate);
setcontentview(r.layout.main);
download = (button)findviewbyid(r.id.download);
et_serverip= (edittext)findviewbyid(r.id.et_serverip);
et_filename = (edittext)findviewbyid(r.id.et_filename);
et_serverip.settext("192.168.0.100");
download.setonclicklistener(new view.onclicklistener() {
@override
public void onclick(view v) {
serverip = et_serverip.gettext().tostring();
if(serverip == null){
serverip = defaultip;
}
system.out.println("downloadclient serverip--->" + serverip );
system.out.println("downloadclient mainthread--->" + thread.currentthread().getid() );
try{
socket = new socket(serverip, port);
}catch(ioexception e){
}
downloadfile = et_filename.gettext().tostring();
thread downfilethread = new thread(new downfilethread(socket, downloadfile));
downfilethread.start();
system.out.println("downloadclient downloadfile--->" + downloadfile );
}
});
}
}
file:downfilethread.java
复制代码 代码如下:
package org.piaozhiye.study;
import java.io.bufferedinputstream;
import java.io.datainputstream;
import java.io.fileoutputstream;
import java.io.ioexception;
import java.io.outputstreamwriter;
import java.io.printwriter;
import java.net.socket;
public class downfilethread extends thread {
private socket socket;
private string downloadfile;
private final static int buffer = 8 * 1024;
public downfilethread(socket socket, string downloadfile) {
super();
this.socket = socket;
this.downloadfile = downloadfile;
}
public socket getsocket() {
return socket;
}
public void setsocket(socket socket) {
this.socket = socket;
}
public string getdownloadfile() {
return downloadfile;
}
public void setdownloadfile(string downloadfile) {
this.downloadfile = downloadfile;
}
// 向服务器提出下载请求,返回下载文件的大小
private long request(string filename, string password) throws ioexception {
// 获取socket的输入流并包装成datainputstream
datainputstream in = new datainputstream(socket.getinputstream());
// 获取socket的输出流并包装成printwriter
printwriter out = new printwriter(new outputstreamwriter(
socket.getoutputstream()));
// 生成下载请求字符串
string requeststring = filename + "@ " + password;
out.println(requeststring); // 发出下载请求
out.flush();
return in.readlong(); // 接收并返回下载文件长度
}
// 接收并保存文件
private void receivefile(string localfile) throws exception {
// 获取socket的输入流并包装成bufferedinputstream
bufferedinputstream in = new bufferedinputstream(
socket.getinputstream());
// 获取与指定本地文件关联的文件输出流
fileoutputstream out = new fileoutputstream(localfile);
byte[] buf = new byte[buffer];
int len;
// 反复读取该文件中的内容,直到读到的长度为-1
while ((len = in.read(buf)) >= 0) {
out.write(buf, 0, len); // 将读到的数据,按读到的长度写入输出流
out.flush();
}
out.close();
in.close();
}
// 从服务器下载文件
public void download(string downloadfile) throws exception {
try {
string password = "password";
// string downloadfile ="imissyou.mp3";
string localpath = "/sdcard/";
string localfile = localpath + downloadfile;
long filelength = request(downloadfile, password);
// 若获取的文件长度大于等于0,说明允许下载,否则说明拒绝下载
if (filelength >= 0) {
system.out.println("filelength: " + filelength + " b");
system.out.println("downing...");
receivefile(localfile); // 从服务器接收文件并保存至本地文件
system.out.println("file:" + downloadfile + " had save to "
+ localfile);
} else {
system.out.println("download " + downloadfile + " error! ");
}
} catch (ioexception e) {
system.out.println(e.tostring());
} finally {
socket.close(); // 关闭socket
}
}
@override
public void run() {
system.out.println("downfilethread currentthread--->"
+ downfilethread.currentthread().getid());
// todo auto-generated method stub
try {
download(downloadfile);
} catch (exception e) {
// todo auto-generated catch block
e.printstacktrace();
}
super.run();
}
}
layout.xml
复制代码 代码如下:
<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<textview
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingleft="10dp"
android:paddingright="10dp"
android:paddingtop="5dp"
android:paddingbottom="5dp"
android:text="服务器ip:"
/>
<edittext
android:id="@+id/et_serverip"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingleft="10dp"
android:paddingright="10dp"
android:paddingtop="5dp"
android:paddingbottom="5dp"
/>
<textview
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingleft="10dp"
android:paddingright="10dp"
android:paddingtop="5dp"
android:paddingbottom="5dp"
android:text="下载文件名:"
/>
<edittext
android:id="@+id/et_filename"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingleft="10dp"
android:paddingright="10dp"
android:paddingtop="5dp"
android:paddingbottom="5dp"
/>
<button
android:id="@+id/download"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="download"
/>
</linearlayout>
同时别忘了权限:
<uses-permission android:name="android.permission.internet" />