如何改进从 Socket 读取 XML 的方式
How can I improve how I read XML from Socket
我正在开发一个 Java 客户端,它通过套接字和 sends/receives XML 消息连接到服务器。我知道消息的模式是什么。我目前正在使用它,但感觉很乱,我还没有测试它以了解它如何处理一次从服务器发送的多个 XML。
代码如下:
private static BufferedReader socketIn;
private static PrintWriter socketOut;
private static final String SERVICES_FILE = "/etc/services";
public static void main(String[] args) {
int port = getServicePortByName("Service1", "tcp");
try {
logger.info("Creating socket port with ip: " + InetAddress.getLocalHost() + " and port: " + port);
Socket socket = new Socket(InetAddress.getLocalHost(), port);
socketOut = new PrintWriter(socket.getOutputStream(), true);
String message = createMessageXML("LOGIN");
socketOut.println(message);
socketIn = new BufferedReader(new InputStreamReader(socket.getInputStream()));
StringBuilder inputLine = new StringBuilder();
String tmp;
while (true) {
//loop to keep listening/parsing
while(socketIn.ready()) {
tmp = socketIn.readLine();
inputLine.append(tmp);
}
if(inputLine.length() > 0) {
parseReceivedMessage(inputLine.toString());
}
inputLine.replace(0, inputLine.length(), "");
}
} catch (UnknownHostException ex) {
Logger.getLogger(TestClient.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(TestClient.class.getName()).log(Level.SEVERE, null, ex);
}
}
parseReceivedMessage 方法只接收一个字符串并将其转换为文档对象。我的问题是,是否有比使用 StringBuilder 更好或更简洁的方法来执行此操作?我最初想将 InputStream 传递给 DOM 构建器解析方法。
我看到了一些使用 ByteArray 流的示例,但我遇到了一些问题。如果有任何需要澄清的地方,请告诉我。
ready()
不是消息结束的有效测试。完全摆脱那个 StringBuilder
和 readLine()
调用,将输入流直接传递给 DOM 解析器。
我强烈建议您围绕 XML 消息设计一个框架协议。在每个 XML 消息前加上一个长度值,指定要传输的字节数,然后发送 XML 本身(以字节为单位,而不是字符)。接收方然后可以读取长度,然后读取指定数量的字节并将它们传递给 XML 解析器,然后读取下一个长度,依此类推。例如:
private static DataInputStream socketIn;
private static DataOutputStream socketOut;
private static final String SERVICES_FILE = "/etc/services";
public static void main(String[] args) {
int port = getServicePortByName("Service1", "tcp");
try {
logger.info("Creating socket port with ip: " + InetAddress.getLocalHost() + " and port: " + port);
Socket socket = new Socket(InetAddress.getLocalHost(), port);
socketIn = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
socketOut = new DataOutputStream(new BufferedOutputStream(socket.getOutputStream()));
byte[] message = createMessageXML("LOGIN");
socketOut.writeInt(message.length());
socketOut.write(message, 0, message.length());
int len = socketIn.readInt();
if (len > 0)
{
message = new byte[len];
socketIn.readFully(message);
parseReceivedMessage(message);
}
} catch (UnknownHostException ex) {
Logger.getLogger(TestClient.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(TestClient.class.getName()).log(Level.SEVERE, null, ex);
}
}
我正在开发一个 Java 客户端,它通过套接字和 sends/receives XML 消息连接到服务器。我知道消息的模式是什么。我目前正在使用它,但感觉很乱,我还没有测试它以了解它如何处理一次从服务器发送的多个 XML。
代码如下:
private static BufferedReader socketIn;
private static PrintWriter socketOut;
private static final String SERVICES_FILE = "/etc/services";
public static void main(String[] args) {
int port = getServicePortByName("Service1", "tcp");
try {
logger.info("Creating socket port with ip: " + InetAddress.getLocalHost() + " and port: " + port);
Socket socket = new Socket(InetAddress.getLocalHost(), port);
socketOut = new PrintWriter(socket.getOutputStream(), true);
String message = createMessageXML("LOGIN");
socketOut.println(message);
socketIn = new BufferedReader(new InputStreamReader(socket.getInputStream()));
StringBuilder inputLine = new StringBuilder();
String tmp;
while (true) {
//loop to keep listening/parsing
while(socketIn.ready()) {
tmp = socketIn.readLine();
inputLine.append(tmp);
}
if(inputLine.length() > 0) {
parseReceivedMessage(inputLine.toString());
}
inputLine.replace(0, inputLine.length(), "");
}
} catch (UnknownHostException ex) {
Logger.getLogger(TestClient.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(TestClient.class.getName()).log(Level.SEVERE, null, ex);
}
}
parseReceivedMessage 方法只接收一个字符串并将其转换为文档对象。我的问题是,是否有比使用 StringBuilder 更好或更简洁的方法来执行此操作?我最初想将 InputStream 传递给 DOM 构建器解析方法。 我看到了一些使用 ByteArray 流的示例,但我遇到了一些问题。如果有任何需要澄清的地方,请告诉我。
ready()
不是消息结束的有效测试。完全摆脱那个 StringBuilder
和 readLine()
调用,将输入流直接传递给 DOM 解析器。
我强烈建议您围绕 XML 消息设计一个框架协议。在每个 XML 消息前加上一个长度值,指定要传输的字节数,然后发送 XML 本身(以字节为单位,而不是字符)。接收方然后可以读取长度,然后读取指定数量的字节并将它们传递给 XML 解析器,然后读取下一个长度,依此类推。例如:
private static DataInputStream socketIn;
private static DataOutputStream socketOut;
private static final String SERVICES_FILE = "/etc/services";
public static void main(String[] args) {
int port = getServicePortByName("Service1", "tcp");
try {
logger.info("Creating socket port with ip: " + InetAddress.getLocalHost() + " and port: " + port);
Socket socket = new Socket(InetAddress.getLocalHost(), port);
socketIn = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
socketOut = new DataOutputStream(new BufferedOutputStream(socket.getOutputStream()));
byte[] message = createMessageXML("LOGIN");
socketOut.writeInt(message.length());
socketOut.write(message, 0, message.length());
int len = socketIn.readInt();
if (len > 0)
{
message = new byte[len];
socketIn.readFully(message);
parseReceivedMessage(message);
}
} catch (UnknownHostException ex) {
Logger.getLogger(TestClient.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(TestClient.class.getName()).log(Level.SEVERE, null, ex);
}
}