AbstractDataFieldMaxValueIncrementer


1   /*
2    * Copyright 2002-2005 the original author or authors.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.springframework.jdbc.support.incrementer;
18  
19  import javax.sql.DataSource  ;
20  
21  import org.springframework.beans.factory.InitializingBean;
22  import org.springframework.dao.DataAccessException;
23  
24  /**
25   * Implementation of DataFieldMaxValueIncrementer that delegates
26   * to a single getNextKey template method that returns a long.
27   * Uses longs for String values, padding with zeroes if required.
28   *
29   * @author Dmitriy Kopylenko
30   * @author Juergen Hoeller
31   * @author Jean-Pierre Pawlak
32   */
33  public abstract class AbstractDataFieldMaxValueIncrementer implements DataFieldMaxValueIncrementer, InitializingBean {
34  
35      private DataSource   dataSource;
36  
37      /** The name of the sequence/table containing the sequence */
38      private String   incrementerName;
39  
40      /** The length to which a string result should be pre-pended with zeroes */
41      protected int paddingLength = 0;
42  
43  
44      /**
45       * Set the data source to retrieve the value from.
46       */
47      public void setDataSource(DataSource   dataSource) {
48          this.dataSource = dataSource;
49      }
50  
51      /**
52       * Return the data source to retrieve the value from.
53       */
54      public DataSource   getDataSource() {
55          return this.dataSource;
56      }
57  
58      /**
59       * Set the name of the sequence/table.
60       */
61      public void setIncrementerName(String   incrementerName) {
62          this.incrementerName = incrementerName;
63      }
64  
65      /**
66       * Return the name of the sequence/table.
67       */
68      public String   getIncrementerName() {
69          return this.incrementerName;
70      }
71  
72      /**
73       * Set the padding length, i.e. the length to which a string result
74       * should be pre-pended with zeroes.
75       */
76      public void setPaddingLength(int paddingLength) {
77          this.paddingLength = paddingLength;
78      }
79  
80      /**
81       * Return the padding length for String values.
82       */
83      public int getPaddingLength() {
84          return paddingLength;
85      }
86  
87      public void afterPropertiesSet() {
88          if (this.dataSource == null) {
89              throw new IllegalArgumentException  ("dataSource is required");
90          }
91          if (this.incrementerName == null) {
92              throw new IllegalArgumentException  ("incrementerName is required");
93          }
94      }
95  
96  
97      public int nextIntValue() throws DataAccessException {
98          return (int) getNextKey();
99      }
100 
101     public long nextLongValue() throws DataAccessException {
102         return getNextKey();
103     }
104 
105     public String   nextStringValue() throws DataAccessException {
106         String   s = Long.toString(getNextKey());
107         int len = s.length();
108         if (len < this.paddingLength) {
109             StringBuffer   buf = new StringBuffer  (this.paddingLength);
110             for (int i = 0; i < this.paddingLength - len; i++) {
111                 buf.append('0');
112             }
113             buf.append(s);
114             s = buf.toString();
115         }
116         return s;
117     }
118 
119     /**
120      * Determine the next key to use, as a long.
121      * @return the key to use as a long. It will eventually be converted later
122      * in another format by the public concrete methods of this class.
123      */
124     protected abstract long getNextKey();
125 
126 }
127
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