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1
8
9 package mx4j.tools.remote.caucho;
10
11 import java.io.BufferedInputStream  ;
12 import java.io.BufferedOutputStream ;
13 import java.io.IOException ;
14 import java.io.InputStream ;
15 import java.io.OutputStream ;
16 import java.lang.reflect.InvocationTargetException ;
17 import java.lang.reflect.Method ;
18 import java.util.HashMap ;
19 import java.util.Map ;
20
21 import javax.servlet.ServletException ;
22 import javax.servlet.http.HttpServlet ;
23 import javax.servlet.http.HttpServletRequest ;
24 import javax.servlet.http.HttpServletResponse ;
25
26 import mx4j.tools.remote.http.HTTPConnection;
27
28
31 public abstract class CauchoServlet extends HttpServlet
32 {
33 private Map methods;
34
35 public void init() throws ServletException
36 {
37 methods = new HashMap ();
38 mapMethods(HTTPConnection.class, methods);
39 }
40
41 protected void mapMethods(Class cls, Map methods)
42 {
43 Method [] mthds = cls.getMethods();
44 for (int i = 0; i < mthds.length; ++i)
45 {
46 Method mthd = mthds[i];
47 String key = mangleMethodName(mthd);
48 methods.put(key, mthd);
49 }
50 }
51
52 protected Method findMethod(String methodName)
53 {
54 return (Method ) methods.get(methodName);
55 }
56
57 protected String mangleMethodName(Method method)
58 {
59 return CauchoService.mangleMethodName(method);
60 }
61
62 protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException , IOException
63 {
64 if (!"POST".equalsIgnoreCase(request.getMethod())) throw new ServletException ("Caucho protocol requires POST");
65
66 BufferedInputStream is = new BufferedInputStream (request.getInputStream(), 48);
67 CauchoInput input = createCauchoInput(is);
68 BufferedOutputStream bos = new BufferedOutputStream (response.getOutputStream(), 48);
69 CauchoOutput output = createCauchoOutput(bos);
70
71 invoke(request, input, output);
72
73 bos.flush();
74 }
75
76 protected abstract CauchoInput createCauchoInput(InputStream stream);
77
78 protected abstract CauchoOutput createCauchoOutput(OutputStream stream);
79
80 protected abstract Object getService();
81
82 protected void invoke(HttpServletRequest request, CauchoInput input, CauchoOutput output) throws IOException
83 {
84 input.startCall();
85 Map headers = readHeaders(input);
86 String methodName = input.readMethod();
87 Method method = findMethod(methodName);
88 if (method == null)
89 {
90 output.startReply();
91 NoSuchMethodException x = new NoSuchMethodException (methodName);
92 output.writeFault(x);
93 output.completeReply();
94 } else
95 {
96 Object [] values = readArguments(input, method);
97 input.completeCall();
98
99 Object result = null;
100 try
101 {
102 result = invoke(request.getRequestURL().toString(), getService(), method, headers, values);
103 } catch (Throwable x)
104 {
105 output.startReply();
106 output.writeFault(x);
107 output.completeReply();
108 return;
109 }
110 output.startReply();
111 output.writeObject(result);
112 output.completeReply();
113 }
114 }
115
116 protected Map readHeaders(CauchoInput input) throws IOException
117 {
118 Map headers = new HashMap ();
119 String header = null;
120 while ((header = input.readHeader()) != null) headers.put(header, input.readObject(null));
121 return headers;
122 }
123
124 protected Object [] readArguments(CauchoInput input, Method method) throws IOException
125 {
126 Class [] types = method.getParameterTypes();
127 Object [] values = new Object [types.length];
128 for (int i = 0; i < types.length; ++i) values[i] = input.readObject(types[i]);
129 return values;
130 }
131
132 protected Object invoke(String url, Object target, Method method, Map headers, Object [] values) throws Exception
133 {
134 if (target == null) throw new IOException ("Service is not available");
135 String connectionId = (String ) headers.get(CauchoService.CONNECTION_ID_HEADER_NAME);
136 CauchoService.setConnectionContext(url, connectionId);
137 try
138 {
139 return method.invoke(target, values);
140 } catch (InvocationTargetException x)
141 {
142 Throwable t = x.getTargetException();
143 if (t instanceof Exception ) throw (Exception ) t;
144 throw (Error ) t;
145 } finally
146 {
147 CauchoService.resetConnectionContext();
148 }
149 }
150 }
151 |
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