kona/src/org/feistymeow/system/RegistryEditor.java

   1 \r
   2 package org.feistymeow.system;\r
   3 \r
   4 import java.io.*;\r
   5 \r
   6 /*\r
   7  * this class supports reading and setting values in the Windows registry.\r
   8  * \r
   9  * some example code came from http://www.rgagnon.com/javadetails/java-0480.html\r
  10  * @author Chris Koeritz\r
  11  */\r
  12 public class RegistryEditor {\r
  13 \r
  14         // the values below can be used for the expected type in the registry calls.\r
  15         public static final String STRING_TYPE = "REG_SZ";\r
  16         public static final String DOUBLEWORD_TYPE = "REG_DWORD";  \r
  17 \r
  18         // looks up the key provided in the registry and returns true if the key seems to exist.\r
  19         // this is just a check for presence; it could have no subkeys or values under it, but it at\r
  20         // least seems to be there.\r
  21         public static boolean checkKey(String keyName) {\r
  22                 try {\r
  23                         // make a command to run in windows that will query the value.\r
  24                         StringBuilder command = new StringBuilder(QUERY_COMMAND);\r
  25                         command.append("\"");\r
  26                         command.append(keyName);\r
  27                         command.append("\"");\r
  28                         // start the command running and trap its output.\r
  29                         Process process = Runtime.getRuntime().exec(command.toString());\r
  30                         StreamReader reader = new StreamReader(process.getInputStream());\r
  31                         reader.start();\r
  32                         process.waitFor();  // let the system call finish up.\r
  33                         reader.join();  // let the stream reader finish also.\r
  34                         return process.exitValue() == 0;\r
  35                 } catch (Exception e) {\r
  36                         return false;\r
  37                 }\r
  38         }\r
  39 \r
  40         // retrieves the key provided from the registry and selects out the value requested.\r
  41         // it is necessary to know the expected type, such as REG_SZ or REG_DWORD.\r
  42         // the value is always returned as a string and needs to be cast to different types as appropriate.\r
  43         public static String getValue(String keyName, String valueName, String typeExpected) {\r
  44                 try {\r
  45                         // make a command to run in windows that will query the value.\r
  46                         StringBuilder command = new StringBuilder(QUERY_COMMAND);\r
  47                         command.append("\"");\r
  48                         command.append(keyName);\r
  49                         command.append("\"");\r
  50                         command.append(VALUE_FLAG); \r
  51                         command.append(valueName);\r
  52                         // start the command running and trap its output.\r
  53                         Process process = Runtime.getRuntime().exec(command.toString());\r
  54                         StreamReader reader = new StreamReader(process.getInputStream());\r
  55                         reader.start();\r
  56                         process.waitFor();  // let the system call finish up.\r
  57                         reader.join();  // let the stream reader finish also.\r
  58                         // now grab the results from running the command and extract the answer.\r
  59                         String result = reader.getResult();\r
  60                         int p = result.indexOf(typeExpected);\r
  61                         if (p == -1) return null;\r
  62                         // return the result with the stuff before the type chopped off.\r
  63                         return result.substring(p + typeExpected.length()).trim();\r
  64                 } catch (Exception e) {\r
  65                         return null;\r
  66                 }\r
  67         }\r
  68 \r
  69         // makes a change to the specified "keyName" value called "valueName".  the old value will be replaced\r
  70         // with the "newValue" provided.  the key and the value do not have to exist prior to the call, but if\r
  71         // they already did exist, they'll be updated.\r
  72         public static boolean setValue(String keyName, String valueName, String typeExpected, String newValue) {\r
  73                 try {\r
  74                         // make a command to run in windows that will set the value.\r
  75                         StringBuilder command = new StringBuilder(SET_COMMAND);\r
  76                         command.append("\"");\r
  77                         command.append(keyName);\r
  78                         command.append("\"");\r
  79                         command.append(VALUE_FLAG); \r
  80                         command.append(valueName);\r
  81                         command.append(TYPE_FLAG);\r
  82                         command.append(typeExpected);\r
  83                         command.append(FORCE_FLAG);\r
  84                         command.append(DATA_FLAG);\r
  85                         command.append(newValue);\r
  86                         //System.out.println("command to run: " + command);\r
  87                         // start the command running and trap its output.\r
  88                         Process process = Runtime.getRuntime().exec(command.toString());\r
  89                         StreamReader reader = new StreamReader(process.getInputStream());\r
  90                         reader.start();\r
  91                         process.waitFor();  // let the system call finish up.\r
  92                         reader.join();  // let the stream reader finish also.\r
  93                         return (process.exitValue() == 0);  // zero exit is a success.\r
  94                 } catch (Exception e) {\r
  95                         return false;\r
  96                 }\r
  97         }\r
  98 \r
  99         // removes the "valueName" value from the key "keyName".  true is returned on success.\r
 100         public static boolean deleteValue(String keyName, String valueName) {\r
 101                 try {\r
 102                         // make a command to run in windows that will set the value.\r
 103                         StringBuilder command = new StringBuilder(DELETE_COMMAND);\r
 104                         command.append("\"");\r
 105                         command.append(keyName);\r
 106                         command.append("\"");\r
 107                         command.append(VALUE_FLAG);\r
 108                         command.append(valueName);\r
 109                         command.append(FORCE_FLAG);\r
 110                         //System.out.println("command to run: " + command);\r
 111                         // start the command running and trap its output.\r
 112                         Process process = Runtime.getRuntime().exec(command.toString());\r
 113                         StreamReader reader = new StreamReader(process.getInputStream());\r
 114                         reader.start();\r
 115                         process.waitFor();  // let the system call finish up.\r
 116                         reader.join();  // let the stream reader finish also.\r
 117                         return (process.exitValue() == 0);  // zero exit is a success.\r
 118                 } catch (Exception e) {\r
 119                         return false;\r
 120                 }\r
 121         }       \r
 122 \r
 123         // removes the entire key "keyName" from the registry.  true is returned on success.\r
 124         public static boolean deleteKey(String keyName) {\r
 125                 try {\r
 126                         // make a command to run in windows that will set the value.\r
 127                         StringBuilder command = new StringBuilder(DELETE_COMMAND);\r
 128                         command.append("\"");\r
 129                         command.append(keyName);\r
 130                         command.append("\"");\r
 131                         command.append(FORCE_FLAG);\r
 132                         //System.out.println("command to run: " + command);\r
 133                         // start the command running and trap its output.\r
 134                         Process process = Runtime.getRuntime().exec(command.toString());\r
 135                         StreamReader reader = new StreamReader(process.getInputStream());\r
 136                         reader.start();\r
 137                         process.waitFor();  // let the system call finish up.\r
 138                         reader.join();  // let the stream reader finish also.\r
 139                         return (process.exitValue() == 0);  // zero exit is a success.\r
 140                 } catch (Exception e) {\r
 141                         return false;\r
 142                 }\r
 143         }\r
 144 \r
 145         // constants used in the registry code for talking to windows' reg application.\r
 146         private static final String QUERY_COMMAND = "reg query ";\r
 147         private static final String VALUE_FLAG = " /v ";\r
 148 \r
 149         private static final String SET_COMMAND = "reg add ";\r
 150         private static final String TYPE_FLAG = " /t ";\r
 151         private static final String DATA_FLAG = " /d ";\r
 152         private static final String FORCE_FLAG = " /f ";\r
 153 \r
 154         private static final String DELETE_COMMAND = "reg delete ";\r
 155 \r
 156         // wrapper class for stream reading came from web example mentioned above. \r
 157         static class StreamReader extends Thread {\r
 158                 private InputStream is;\r
 159                 private StringWriter sw;\r
 160 \r
 161                 StreamReader(InputStream is) {\r
 162                         this.is = is;\r
 163                         sw = new StringWriter();\r
 164                 }\r
 165 \r
 166                 public void run() {\r
 167                         int c;\r
 168                         try {\r
 169                                 while ((c = is.read()) != -1) sw.write(c);\r
 170                         } catch (IOException e) { /*nothing*/ }\r
 171                 }\r
 172 \r
 173                 String getResult() { return sw.toString(); }\r
 174         }\r
 175 }\r