java - Restartability for access to the database -

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i'm trying access oracle database, see code below.

the problem database cluster db if 1 down, can access other. has problem staying on 1 node possible me update java code , if fails check again until connection has been established?

i'm using properties-file insert credential database. when connection has been established query entered , result returned.

public static string connectdb(string configfile, string query) throws filenotfoundexception, ioexception, sqlexception, classnotfoundexception{     properties p = new properties();     p.load(new fileinputstream(configfile));      string servername = (p.getproperty("rms_dbservername"));     string portnumber = (p.getproperty("rms_portnumber"));     string sid = (p.getproperty("rms_sid"));     string url = "jdbc:oracle:thin:@//" + servername + ":" + portnumber + "/" + sid;     string username = (p.getproperty("rms_username"));     string password = (p.getproperty("rms_password"));      class.forname("oracle.jdbc.driver.oracledriver");     sleep(10);     connection connection = drivermanager.getconnection(url,username,password);     sleep(5);     string setr = null;     try {               statement stmt = connection.createstatement();         try {             resultset rset = stmt.executequery(query);             try {                     while(rset.next())                        setr = rset.getstring(1);                     return setr;               }                     {                 try {                      rset.close();                  }                  catch (exception ignore) {}             }         }          {             try {                  stmt.close();              }              catch (exception ignore) {}         }     }      {         try {              connection.close();          }          catch (exception ignore) {}     } }

i'm not sure understand you, java.​sql.​drivermanager throws sqlexception "if database access error occurs". can sth like:

public static string connectdb(string configfile, string query)      try{       connection connection = drivermanager.getconnection(url,username,password);     } catch (sqlexception ex) {      sleep(10);      connectdb(configfile,query); // try connect again     }

or sth like:

//dbprefix put before name of every property associated given node in config file. public static string connectdb(string configfile, string dbprefix, string query) ... { ...     string servername = (p.getproperty(dbprefix + "rms_dbservername"));         string portnumber = (p.getproperty(dbprefix + "rms_portnumber"));         string sid = (p.getproperty(dbprefix + "rms_sid"));         string url = "jdbc:oracle:thin:@//" + servername + ":" + portnumber + "/" + sid;         string username = (p.getproperty(dbprefix + "rms_username"));         string password = (p.getproperty(dbprefix + "rms_password")); ...          try{           connection connection = drivermanager.getconnection(url,username,password);         } catch (sqlexception ex) {          sleep(10);          connectdb(configfile,dbprefix,query); // try connect again, use different node         }

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