目标
Demo是通过Java ServerSocket 和 Socket 通信实现客户端发送消息和发送文件到服务器,服务器接收到消息和文件，并且实现解决inputStream.read()的阻塞问题思路。
服务器端
创建ServerSocket服务器
serverSocket = new ServerSocket(port);//首先创建一个服务端口
//等待客户端的连接请求
socket = serverSocket.accept();
等待Socket客户端连接
//等待客户端的连接请求
socket = serverSocket.accept();
final String socketAddress = socket.getRemoteSocketAddress().toString();
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(ServerActivity.this, "成功建立与客户端的连接 : " + socketAddress, Toast.LENGTH_SHORT).show();
Log.i("Lin", "成功建立与客户端的连接 : " + socketAddress);
}
});
接收Socket客户端信息
为了防止接收消息时，服务器inputStream.read()读取消息时产生阻塞，以换行符("\n")结束inputStream.read()
byte[] bytes = new byte[1];
StringBuilder info = new StringBuilder();
while (inputStream.read(bytes) != -1) {
String str = new String(bytes);
if (str.equals("\n")) {
break;
}
info.append(new String(bytes));
}
final String finalInfo = info.toString();
Log.i("Lin", "text = " + finalInfo);
runOnUiThread(new Runnable() {
@Override
public void run() {
mEtReceive.setText(mEtReceive.getText().toString() + socketAddress + " : " + finalInfo + "\n");
}
});
接收Socket客户端文件
为了防止接收消息时，服务器inputStream.read()接受文件时产生阻塞，以文件MD5校验码进行校验，从而结束inputStream.read()
byte[] remote = new byte[32];
String md5 = "";
if (inputStream.read(remote) != -1) {
md5 = nullOfString(new String(remote));
}
final String root = Environment.getExternalStorageDirectory().getPath();
Log.i("Lin", root);
byte[] inputByte = new byte[1024 * 1024];
int len = 0;
long fileSize = 0;
DataInputStream dis = new DataInputStream(inputStream);
// 文件名和长度
String fileName = dis.readUTF();
final long fileLength = dis.readLong();
Log.i("Lin", "fileName = " + fileName);
Log.i("Lin", "fileLength = " + fileLength);
mPath = root + "/ECG/" + fileName;
File file = new File(root + "/ECG/");
if (!file.exists()) file.mkdir();
file = new File(mPath);
FileOutputStream fileOutputStream = new FileOutputStream(file);
String fileMD5 = nullOfString(getFileMD5(new File(mPath)));
while (!md5.equals(fileMD5) && (len = dis.read(inputByte, 0, inputByte.length)) > 0) {
fileSize += len;
fileOutputStream.write(inputByte, 0, len);
fileOutputStream.flush();
fileMD5 = nullOfString(getFileMD5(new File(mPath)));
Log.i("Lin", "md5 = " + md5 + " file = " + fileMD5);
Log.i("Lin", "fileLength = " + fileLength + " fileSize = " + fileSize + " " + (fileSize * 100 / fileLength) + "%")
;
final long finalFileSize = fileSize;
runOnUiThread(new Runnable() {
@Override
public void run() {
mProgressDialog.setMessage((finalFileSize * 100 / fileLength) + "%");
mProgressDialog.show();
}
});
if (md5.equals(fileMD5)) {
fileOutputStream.close();
runOnUiThread(new Runnable() {
@Override
public void run() {
mProgressDialog.hide();
}
});
}
}
Log.i("Lin", "md52 = " + md5 + " file2 = " + getFileMD5(file));
fileMD5 = nullOfString(getFileMD5(new File(mPath)));
Log.i("Lin", "file = " + fileMD5);
final String finalFileMD = fileMD5;
final String finalMd = md5;
runOnUiThread(new Runnable() {
@Override
public void run() {
mEtReceive.setText(mEtReceive.getText().toString() + "文件路径：" + mPath + "\n");
mEtReceive.setText(mEtReceive.getText().toString() + "file = " + finalFileMD + "\n");
mEtReceive.setText(mEtReceive.getText().toString() + "text = " + finalMd + "\n");
}
});
客户端
创建Socket客户端
连接ServerSocket服务器
socket = new Socket();
socket.connect(new InetSocketAddress(ip, port));
//ip= 服务器ip
//port= 服务器端口
向ServerSocket服务器发送消息
try {
if (socket == null) return;
OutputStream om = socket.getOutputStream();
om.write(Constant.SERVER_TEXT.getBytes());
om.write(returnServer.getBytes());
om.write("\n".getBytes());//[10]
om.flush();
} catch (Exception e) {
e.printStackTrace();
Log.i("Lin", e.toString());
}
为了防止发送消息时，服务器inputStream.read()读取消息时产生阻塞，客户端以换行符结束发送(om.write("\n".getBytes());)
向ServerSocket服务器发送文件
File file = new File(finalImagePath);
if (file.exists()) {
final String fileMD5 = nullOfString(getFileMD5(file));
OutputStream outputStream = socket.getOutputStream();
runOnUiThread(new Runnable() {
@Override
public void run() {
mEtReceive.setText(mEtReceive.getText().toString() + "file = " + fileMD5 + "\n");
}
});
FileInputStream fileInputStream = new FileInputStream(file);
outputStream.write(Constant.SERVER_FILE.getBytes());
outputStream.flush();
outputStream.write(fileMD5.getBytes());
outputStream.flush();
DataOutputStream dis = new DataOutputStream(outputStream);
// 文件名和长度
dis.writeUTF(file.getName());
dis.flush();
dis.writeLong(file.length());
dis.flush();
byte[] buffer = new byte[1024 * 1024];
int len = 0;
while ((len = fileInputStream.read(buffer, 0, buffer.length)) > 0) {
dis.write(buffer, 0, len);
dis.flush();
}
fileInputStream.close();
Log.i("Lin", "传输成功");
}
为了防止发送文件时，服务器inputStream.read()接受文件时产生阻塞，客户端先向服务器发送文件MD5校验码再发送文件，服务器对接收文件进行校验从而结束inputStream.read()阻塞。
Demo中发送格式
字符：SERVER_TEXT + 字符 + 换行符（\n）
文件：SERVER_FILE + 文件MD5校验码 + 文件
获取文件MD5
private static String getFileMD5(File file) {
if (!file.isFile()) {
return null;
}
MessageDigest digest;
FileInputStream in;
try {
byte[] buffer = new byte[1024];
int len;
digest = MessageDigest.getInstance("MD5");
in = new FileInputStream(file);
while ((len = in.read(buffer, 0, 1024)) != -1) {
digest.update(buffer, 0, len);
}
in.close();
BigInteger bigInt = new BigInteger(1, digest.digest());
return bigInt.toString(16);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
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