dubbo系列 - telnet
Dubbo服务器判断如果接受到的请求时候String类型时，会调到TelnetHandlerAdapter#telnet。
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
| public class TelnetHandlerAdapter extends ChannelHandlerAdapter implements TelnetHandler {
private final ExtensionLoader<TelnetHandler> extensionLoader = ExtensionLoader.getExtensionLoader(TelnetHandler.class);
@Override
public String telnet(Channel channel, String message) throws RemotingException {
String prompt = channel.getUrl().getParameterAndDecoded(Constants.PROMPT_KEY, Constants.DEFAULT_PROMPT);
boolean noprompt = message.contains("--no-prompt");
message = message.replace("--no-prompt", "");
StringBuilder buf = new StringBuilder();
message = message.trim();
String command;
if (message.length() > 0) {
int i = message.indexOf(' ');
if (i > 0) {
command = message.substring(0, i).trim();
message = message.substring(i + 1).trim();
} else {
command = message;
message = "";
}
} else {
command = "";
}
if (command.length() > 0) {
if (extensionLoader.hasExtension(command)) {
if (commandEnabled(channel.getUrl(), command)) {
try {
String result = extensionLoader.getExtension(command).telnet(channel, message);
if (result == null) {
return null;
}
buf.append(result);
} catch (Throwable t) {
buf.append(t.getMessage());
}
} else {
buf.append("Command: ");
buf.append(command);
buf.append(" disabled");
}
} else {
buf.append("Unsupported command: ");
buf.append(command);
}
}
if (buf.length() > 0) {
buf.append("\r\n");
}
if (prompt != null && prompt.length() > 0 && !noprompt) {
buf.append(prompt);
}
return buf.toString();
}
private boolean commandEnabled(URL url, String command) {
boolean commandEnable = false;
String supportCommands = url.getParameter(Constants.TELNET);
if (StringUtils.isEmpty(supportCommands)) {
commandEnable = true;
} else {
String[] commands = Constants.COMMA_SPLIT_PATTERN.split(supportCommands);
for (String c : commands) {
if (command.equals(c)) {
commandEnable = true;
break;
}
}
}
return commandEnable;
}
}
|
TelnetHandlerAdapter解析命令，然后通过SPI来调到具体的TelnetHandler实现类。
通过SPI的配置文件可以知道Dubbo一共有12个TelnetHandler扩展：
clear=com.alibaba.dubbo.remoting.telnet.support.command.ClearTelnetHandler
exit=com.alibaba.dubbo.remoting.telnet.support.command.ExitTelnetHandler
help=com.alibaba.dubbo.remoting.telnet.support.command.HelpTelnetHandler
status=com.alibaba.dubbo.remoting.telnet.support.command.StatusTelnetHandler
log=com.alibaba.dubbo.remoting.telnet.support.command.LogTelnetHandler
ls=com.alibaba.dubbo.rpc.protocol.dubbo.telnet.ListTelnetHandler
ps=com.alibaba.dubbo.rpc.protocol.dubbo.telnet.PortTelnetHandler
cd=com.alibaba.dubbo.rpc.protocol.dubbo.telnet.ChangeTelnetHandler
pwd=com.alibaba.dubbo.rpc.protocol.dubbo.telnet.CurrentTelnetHandler
invoke=com.alibaba.dubbo.rpc.protocol.dubbo.telnet.InvokeTelnetHandler
trace=com.alibaba.dubbo.rpc.protocol.dubbo.telnet.TraceTelnetHandler
count=com.alibaba.dubbo.rpc.protocol.dubbo.telnet.CountTelnetHandler
看一下ListTelnetHandler的实现：
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
| @Activate
@Help(parameter = "[-l] [service]", summary = "List services and methods.", detail = "List services and methods.")
public class ListTelnetHandler implements TelnetHandler {
@Override
public String telnet(Channel channel, String message) {
StringBuilder buf = new StringBuilder();
String service = null;
boolean detail = false;
if (message.length() > 0) {
String[] parts = message.split("\\s+");
for (String part : parts) {
if ("-l".equals(part)) {
detail = true;
} else {
if (service != null && service.length() > 0) {
return "Invaild parameter " + part;
}
service = part;
}
}
} else {
service = (String) channel.getAttribute(ChangeTelnetHandler.SERVICE_KEY);
if (service != null && service.length() > 0) {
buf.append("Use default service " + service + ".\r\n");
}
}
if (service == null || service.length() == 0) {
for (Exporter<?> exporter : DubboProtocol.getDubboProtocol().getExporters()) {
if (buf.length() > 0) {
buf.append("\r\n");
}
buf.append(exporter.getInvoker().getInterface().getName());
if (detail) {
buf.append(" -> ");
buf.append(exporter.getInvoker().getUrl());
}
}
} else {
Invoker<?> invoker = null;
for (Exporter<?> exporter : DubboProtocol.getDubboProtocol().getExporters()) {
if (service.equals(exporter.getInvoker().getInterface().getSimpleName())
|| service.equals(exporter.getInvoker().getInterface().getName())
|| service.equals(exporter.getInvoker().getUrl().getPath())) {
invoker = exporter.getInvoker();
break;
}
}
if (invoker != null) {
Method[] methods = invoker.getInterface().getMethods();
for (Method method : methods) {
if (buf.length() > 0) {
buf.append("\r\n");
}
if (detail) {
buf.append(ReflectUtils.getName(method));
} else {
buf.append(method.getName());
}
}
} else {
buf.append("No such service " + service);
}
}
return buf.toString();
}
}
|
