3 import java.io.IOException;
4 import java.nio.ByteBuffer;
5 import java.util.Arrays;
6 import java.util.ArrayList;
7 import java.util.HashMap;
11 import java.lang.reflect.*;
14 /** Class IoTRMIObject is a class that stores info of an object.
16 * It stores object ID, methods, method ID, method's signature
18 * This class also receive calls from different objects as they
19 * ask to execute certain methods remotely. This will have the
20 * execution result (return value) sent back to
22 * @author Rahmadi Trimananda <rtrimana @ uci.edu>
26 public class IoTRMIObject {
31 private List<String> listMethodId2Sign; // List of method signature (we use list index as method Id)
32 private IoTRMIUtil rmiUtil;
33 private IoTSocketServer rmiServer;
34 private byte[] methodBytes;
40 public IoTRMIObject(int _port) throws
41 ClassNotFoundException, InstantiationException,
42 IllegalAccessException, IOException {
44 rmiUtil = new IoTRMIUtil();
46 rmiServer = new IoTSocketServer(_port);
52 * getMethodBytes() waits for method transmission in bytes
54 public byte[] getMethodBytes() throws IOException {
56 // Receive method info
57 methodBytes = rmiServer.receiveBytes(methodBytes);
58 System.out.println("Method: " + Arrays.toString(methodBytes));
64 * getObjectId() gets object Id from bytes
66 public int getObjectId() {
68 // Get object Id bytes
69 byte[] objectIdBytes = new byte[IoTRMIUtil.OBJECT_ID_LEN];
70 System.arraycopy(methodBytes, 0, objectIdBytes, 0, IoTRMIUtil.OBJECT_ID_LEN);
72 int objectId = IoTRMIUtil.byteArrayToInt(objectIdBytes);
78 * static version of getObjectId()
80 public static int getObjectId(byte[] methodBytes) {
82 // Get object Id bytes
83 byte[] objectIdBytes = new byte[IoTRMIUtil.OBJECT_ID_LEN];
84 System.arraycopy(methodBytes, 0, objectIdBytes, 0, IoTRMIUtil.OBJECT_ID_LEN);
86 int objectId = IoTRMIUtil.byteArrayToInt(objectIdBytes);
92 * setMethodBytes() sets bytes for method
94 public void setMethodBytes(byte[] _methodBytes) throws IOException {
97 methodBytes = _methodBytes;
102 * getMethodId() gets method Id from bytes
104 public int getMethodId() {
106 // Get method Id bytes
107 byte[] methodIdBytes = new byte[IoTRMIUtil.METHOD_ID_LEN];
108 // Method Id is positioned after object Id in the byte array
109 System.arraycopy(methodBytes, IoTRMIUtil.OBJECT_ID_LEN, methodIdBytes, 0, IoTRMIUtil.METHOD_ID_LEN);
111 int methodId = IoTRMIUtil.byteArrayToInt(methodIdBytes);
118 * getMethodParams() gets method params based on byte array received
120 * Basically this is the format of a method in bytes:
121 * 1) 32-bit value of object ID
122 * 2) 32-bit value of method ID
123 * 3) m parameters with n-bit value each (m x n-bit)
124 * For the parameters that don't have definite length,
125 * we need to extract the length from a preceding 32-bit
126 * field in front of it.
128 * For primitive objects:
129 * | 32-bit object ID | 32-bit method ID | m-bit actual data (fixed length) | ...
131 * For string, arrays, and non-primitive objects:
132 * | 32-bit object ID | 32-bit method ID | 32-bit length | n-bit actual data | ...
135 public Object[] getMethodParams(Class<?>[] arrCls, Class<?>[] arrGenKeyCls, Class<?>[] arrGenValCls) {
137 // Byte scanning position
138 int pos = IoTRMIUtil.OBJECT_ID_LEN + IoTRMIUtil.METHOD_ID_LEN;
139 Object[] paramObj = new Object[arrCls.length];
140 for (int i=0; i < arrCls.length; i++) {
142 String paramType = arrCls[i].getSimpleName();
143 int paramSize = rmiUtil.getTypeSize(paramType);
144 // Get the 32-bit field in the byte array to get the actual
145 // length (this is a param with indefinite length)
146 if (paramSize == -1) {
147 byte[] bytPrmLen = new byte[IoTRMIUtil.PARAM_LEN];
148 System.arraycopy(methodBytes, pos, bytPrmLen, 0, IoTRMIUtil.PARAM_LEN);
149 pos = pos + IoTRMIUtil.PARAM_LEN;
150 paramSize = IoTRMIUtil.byteArrayToInt(bytPrmLen);
152 byte[] paramBytes = new byte[paramSize];
153 System.arraycopy(methodBytes, pos, paramBytes, 0, paramSize);
154 pos = pos + paramSize;
155 paramObj[i] = IoTRMIUtil.getParamObject(arrCls[i], arrGenKeyCls[i],
156 arrGenValCls[i], paramBytes);
164 * sendReturnObj() sends back return Object to client
166 public void sendReturnObj(Object retObj) throws IOException {
168 // Send back return value
169 byte[] retObjBytes = IoTRMIUtil.getObjectBytes(retObj);
170 rmiServer.sendBytes(retObjBytes);