JDBC获取数据库信息

当同一个项目部署到不同数据库环境时，程序中涉及sql语句执行时，由于各种数据库的差异，可能会产生异常。则就需要获取数据库信息做适当处理。
  1 public class DBUtils {
  2     private static Log logger = LogFactory.getLog(DBUtils.class);
  3 
  4     private static String dbName;
  5 
  6     private static final String DBTYPE_DB2 = "DB2";
  7 
  8     private static final String DBTYPE_SYBASE = "Sybase";
  9 
 10     private static final String DBTYPE_ORACLE = "Oracle";
 11 
 12     private static final String DBTYPE_SQLSERVER = "SqlServer";
 13 
 14     private static final String DBTYPE_MYSQL = "MySQL";
 15 
 16 /*    private static Cache dbTypeJudgeCache = DBCache.DBTypeJudgeCache;*/
 17 
 18     private static String getDatabaseProductName() {
 19         WebApplicationContext webContext = (WebApplicationContext)ComponentFactory.getApplicationContext();
 20         DataSource ds = (DataSource) webContext.getBean("dataSource");
 21         if (dbName != null) {
 22             return dbName;
 23         }
 24         Connection con = null;
 25         try {
 26             con = DataSourceUtils.getConnection(ds);
 27         } catch (DataAccessException ex) {
 28             logger.error("获取数据库连接失败", ex);
 29         }
 30 
 31         if (con != null) {
 32             try {
 33                 DatabaseMetaData dbmd = con.getMetaData();
 34                 if (dbmd != null) {
 35                     dbName = dbmd.getDatabaseProductName();
 36                     if (dbName != null && dbName.startsWith("DB2/")) {
 37                         dbName = DBUtils.DBTYPE_DB2;
 38                     } else if (dbName != null && dbName.startsWith("Oracle")) {
 39                         dbName = DBUtils.DBTYPE_ORACLE;
 40                     } else if (dbName != null
 41                             && dbName.startsWith("Microsoft SQL Server")) {
 42                         dbName = DBUtils.DBTYPE_SQLSERVER;
 43                     } else if (dbName != null
 44                             && (dbName.equals("Adaptive Server Enterprise") || dbName
 45                                     .equals("Adaptive Server Anywhere"))) {
 46                         dbName = DBUtils.DBTYPE_SYBASE;
 47                     } else if (dbName != null && dbName.startsWith("MySQL")) {
 48                         dbName = DBUtils.DBTYPE_MYSQL;
 49                     }
 50                 } else {
 51                     logger.warn("获取数据库类型出错");
 52                 }
 53             } catch (SQLException se) {
 54                 logger.error("获取数据库类型出错", se);
 55             } finally {
 56                 DataSourceUtils.closeConnectionIfNecessary(con, ds);
 57             }
 58         }
 59         return dbName;
 60     }
 61 
 62     private static String getDbType() {
 63         String dbType = null;
 64         try {
 65             dbType = DBUtils.getDatabaseProductName();
 66         } catch (Exception e) {
 67             // 异常不处理;
 68         }
 69         if (dbType == null) {
 70             dbType = "";
 71         } else {
 72             dbType = dbType.trim();
 73         }
 74         return dbType;
 75     }
 76 
 77     // 下面四个方法最好能有更好的办法使每次进来的时候只比较一次，不用每次进来都比较
 78     public static boolean dbTypeIsDB2() {
 79         Boolean is_db2 = new Boolean(false);
 80         logger.debug("使用CACHE前 " + is_db2);
 81         is_db2 = new Boolean(DBUtils.getDbType().equalsIgnoreCase(DBUtils.DBTYPE_DB2));
 82         return is_db2.booleanValue();
 83     }
 84 
 85     public static boolean dbTypeIsORACLE() {
 86         Boolean is_oracle = new Boolean(false);
 87         is_oracle = new Boolean(DBUtils.getDbType().equalsIgnoreCase(DBUtils.DBTYPE_ORACLE));
 88         return is_oracle.booleanValue();
 89     }
 90 
 91     public static boolean dbTypeIsSYBASE() {
 92         Boolean is_sybase = new Boolean(false);
 93         is_sybase = new Boolean(DBUtils.getDbType().equalsIgnoreCase(DBUtils.DBTYPE_SYBASE));
 94         return is_sybase.booleanValue();
 95     }
 96 
 97     public static boolean dbTypeIsSQLSERVER() {
 98         Boolean is_sqlserver = new Boolean(false);
 99         is_sqlserver = new Boolean(DBUtils.getDbType().equalsIgnoreCase(DBUtils.DBTYPE_SQLSERVER));
100         return is_sqlserver.booleanValue();
101     }
102 
103     public static boolean dbTypeIsMYSQL() {
104         Boolean is_mysql = new Boolean(false);
105         is_mysql = new Boolean(DBUtils.getDbType().equalsIgnoreCase(DBUtils.DBTYPE_MYSQL));
106         return is_mysql.booleanValue();
107     }
108 }