1    package classUtils.pack.util.jdbc; 
2     
3    import java.net.InetAddress; 
4    import java.util.Properties; 
5    import java.util.Set; 
6     
7    import classUtils.pack.util.SymbolTable; 
8    import classUtils.pack.util.SymbolTable.UndefinedSymbolException; 
9     
10   /** 
11    * A base class for template JDBC URL templates. 
12    * <p> 
13    * This class must be provided with a template at construction (containing symbols are 
14    * defined in the <tt>$(<i>symbol</i>);</tt> form), then the corresponding values 
15    * must be filled in and a propre JDBC url can be obtained by {@link #getURL() getURL()}. 
16    * <p> 
17    * The following symbols: 
18    * <p> 
19    * <table border align=center> 
20    * <tr><td><b>subprotocol</b></td><td>the subprotocol, usually identifying a JDBC driver</td></tr> 
21    * <tr><td><b>host</b></td><td>the datbase host name</td></tr> 
22    * <tr><td><b>port</b></td><td>the datbase port</td></tr> 
23    * <tr><td><b>database</b></td><td>the datbase name</td></tr> 
24    * <tr><td><b>schema</b></td><td>the schema name</td></tr> 
25    * <tr><td><b>user</b></td><td>the username for connecting</td></tr> 
26    * <tr><td><b>password</b></td><td>the password for connecting</td></tr> 
27    * </table> 
28    * <p> 
29    * are directly supported. However, arbitrary symbols can be present in the template 
30    * and their values defined by {@link #setSymbolValue(java.lang.String, java.lang.String)  
31    * setSymbolValue()}. 
32    * <p> 
33    * All the relative setters are <b>protected</b>. A subclass defines which symbol to  
34    * expose publicly, simply by overriding one of the set<i>Symbol</i> methods with  
35    * <b>public</b> visibility an whose body just invokes the corresponding method in this class. 
36    * @author Cristiano Sadun 
37    */ 
38   public class JdbcURL { 
39        
40       private SymbolTable symbolTable; 
41       private String template; 
42       private Properties connectionProperties; 
43       private Set symbols; 
44            
45       private JdbcURL(String template, Properties connectionProperties) { 
46           this.template=template; 
47           if (!template.startsWith("jdbc:")) throw new IllegalArgumentException("The given template is not a JDBC url"); 
48           this.symbols=createSymbolsFromTemplate(template); 
49               this.connectionProperties=connectionProperties; 
50           this.symbolTable=new SymbolTable(); 
51       } 
52        
53       /** 
54        * Create a jdbc URL object using a given template 
55        */ 
56       protected JdbcURL(String template) { 
57           this(template, new Properties()); 
58       } 
59        
60       /** 
61        * Used to define a symbol in the template. 
62        * <p> 
63        * The symbol <i>must</i> be used in the template passed at construction. 
64        */      
65       protected void setSymbolValue(String symbol, String value) { 
66           if (! symbols.contains(symbol)) { 
67               throw new IllegalStateException("No "+symbol+" defined in the JDBC url template"); 
68           } 
69           symbolTable.defineSymbol(symbol, value); 
70       } 
71    
72       /** 
73        * Define the standard "subprotocol" symbol. 
74        */  
75       protected void setSubprotocol(String subprotocol) { 
76           setSymbolValue("subprotocol", subprotocol); 
77       } 
78    
79    
80       /** 
81        * Define the standard "database" symbol. 
82        */  
83       protected void setDatabase(String database) { 
84           setSymbolValue("database", database); 
85       } 
86        
87       /** 
88        * Define the standard "port" symbol. 
89        */  
90       protected void setPort(String port) { 
91           setSymbolValue("port", port); 
92       } 
93        
94       /** 
95        * Define the standard "port" symbol. 
96        */      
97       protected void setPort(int port) { 
98           setPort(String.valueOf(port)); 
99       } 
100       
101      /** 
102       * Define the standard "host" symbol. 
103       */      
104      protected void setHost(String host) { 
105          setSymbolValue("host", host); 
106      } 
107       
108      /** 
109       * Define the standard "host" symbol. 
110       */      
111      protected void setHost(InetAddress host) { 
112          setSymbolValue("host", host.getHostAddress()); 
113      } 
114       
115      /** 
116       * Define the standard "schema" symbol. 
117       */      
118      protected void setSchema(String schema) { 
119          setSymbolValue("schemaw", schema); 
120      } 
121       
122      /** 
123       * Define the standard "user" symbol. 
124       */      
125      protected void setUser(String username) { 
126          setSymbolValue("user", username); 
127      }    
128       
129      /** 
130       * Define the standard "password" symbol. 
131       */      
132      protected void setPassword(String password) { 
133          setSymbolValue("password", password); 
134      }    
135       
136      /** 
137       * Return the URL - substituting values to template symbols. 
138       * @return the final JDBC URL 
139       * @exception IllegalStateException if a symbol in the template is not defined 
140       */ 
141      public final String getURL() { 
142          try { 
143              return symbolTable.evaluate(template); 
144          } catch(SymbolTable.UndefinedSymbolException e) { 
145              throw new IllegalStateException("template symbol "+e.getSymbolName()+" has not been defined"); 
146          } 
147      } 
148   
149      /** 
150       * Method createSymbolsFromTemplate. 
151       */ 
152      private static Set createSymbolsFromTemplate(String template) { 
153          SymbolTable st = new SymbolTable(); 
154          st.setBehaviourOnUndefinedSymbol(st.RETURN_SYMBOL_ON_UNDEFINED_SYMBOL); 
155          st.evaluate(template); 
156          return st.getUndefinedSymbolsForLastEvaluation(); 
157      } 
158  } 
159