1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
|
/*
* @author Savitha
* @version 1.0
*
* Development Environment : Oracle JDeveloper 10g
* Name of the Application : ClobManipulationIn10g.java
* Creation/Modification History :
*
* Savitha 17-Mar-2004 Created.
*/
// Java SQL classes
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
// Oracle JDBC driver class
import oracle.jdbc.OracleDriver;
// Java IO classes
import java.io.IOException;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
//Java Util classes
import java.util.Properties;
/**
* This class demonstrates the Oracle JDBC 10g enhanced features for inserting
* and retrieving CLOB data from the database. Using the new features, large
* data of more than 32765 bytes can be inserted into the database using the
* existing PreparedStatement.setString() and PreparedStatement.getString()
* methods.
*/
public class ClobManipulationIn10g {
/* Database Connection object */
private Connection conn = null;
/* Variables to hold database details */
private String url = null;
private String user = null;
private String password = null;
// Create a property object to hold the username, password and
// the new property SetBigStringTryClob.
private Properties props = new Properties();
/* String to hold file name */
private String fileName = null;
/**
* Default Constructor to instantiate and get a handle to class methods
* and variables.
*/
public ClobManipulationIn10g(String fileName) {
this.fileName = fileName;
}
/**
* Main runnable class.
*/
public static void main(String[] args) throws SQLException {
// Instantiate the main class.
ClobManipulationIn10g clobManipulationIn10g =
new ClobManipulationIn10g("test.xml");
// Load the Oracle JDBC driver class.
DriverManager.registerDriver(new OracleDriver());
// Load the database details into the variables.
String dbUrl = "jdbc:oracle:thin:@127.0.0.1:1521:xe";
clobManipulationIn10g.url = dbUrl;
// Replace the username where the table 'clob_tab' was created.
clobManipulationIn10g.user = "user";
// Replace the password of the username.
clobManipulationIn10g.password = "pwd";
// Populate the property object to hold the username, password and
// the new property 'SetBigStringTryClob' which is set to true. Setting
// this property allows inserting of large data using the existing
// setString() method, to a CLOB column in the database.
clobManipulationIn10g.props.put("user", clobManipulationIn10g.user );
clobManipulationIn10g.props.put("password", clobManipulationIn10g.password);
clobManipulationIn10g.props.put("SetBigStringTryClob", "true");
// Check if the table 'CLOB_TAB' is present in the database.
clobManipulationIn10g.checkTables();
// Call the methods to insert and select CLOB from the database.
clobManipulationIn10g.insertClob();
// clobManipulationIn10g.selectClob();
System.out.println("END...");
}
/*
* This method will insert the data into a CLOB column in the database.
* Oracle JDBC 10g has enhanced the existing PreparedStatement.setString()
* method for setting the data more than 32765 bytes. So, using setString(),
* it is now easy to insert CLOB data into the database directly.
*/
private void insertClob() throws SQLException {
// Create a PreparedStatement object.
PreparedStatement pstmt = null;
try {
// Create the database connection, if it is closed.
if ((conn==null)||conn.isClosed()){
// Connect to the database.
conn = DriverManager.getConnection( this.url, this.props );
}
// Create SQL query to insert data into the CLOB column in the database.
String sql ="INSERT INTO RECEPTION_TMP (NUM_ENR,DAT_REC,CONTENU) VALUES (?,?,?)";
// Read a big file(larger than 32765 bytes)
String str = this.readFile();
// Create the OraclePreparedStatement object
pstmt = conn.prepareStatement(sql);
// Use the same setString() method which is enhanced to insert
// the CLOB data. The string data is automatically transformed into a
// clob and inserted into the database column. Make sure that the
// Connection property - 'SetBigStringTryClob' is set to true for
// the insert to happen.
pstmt.setString(1,"str");
pstmt.setDate(2,null);
pstmt.setString(3,str);
// Execute the PreparedStatement
pstmt.executeUpdate();
} catch (SQLException sqlex) {
sqlex.printStackTrace();
// Catch Exceptions and display messages accordingly.
System.out.println("SQLException while connecting and inserting into " +
"the database table: " + sqlex.toString());
} catch (Exception ex) {
System.out.println("Exception while connecting and inserting into the" +
" database table: " + ex.toString());
} finally {
// Close the Statement and the connection objects.
if (pstmt!=null) pstmt.close();
if (conn!=null) conn.close();
}
}
/*
* This method reads the CLOB data from the database by using getString()
* method.
*/
private void selectClob() throws SQLException {
// Create a PreparedStatement object
PreparedStatement pstmt = null;
// Create a ResultSet to hold the records retrieved.
ResultSet rset = null;
try {
// Create the database connection, if it is closed.
if ((conn==null)||conn.isClosed()){
// Connect to the database.
conn = DriverManager.getConnection( this.url, this.props );
}
// Create SQL query statement to retrieve records having CLOB data from
// the database.
String sqlCall = "SELECT clob_col FROM clob_tab";
pstmt= conn.prepareStatement(sqlCall);
// Execute the PrepareStatement
rset = pstmt.executeQuery();
String clobVal = null;
// Get the CLOB value from the resultset
while (rset.next()) {
clobVal = rset.getString(1);
System.out.println("CLOB length: "+clobVal.length());
}
} catch (SQLException sqlex) {
// Catch Exceptions and display messages accordingly.
System.out.println("SQLException while connecting and querying the " +
"database table: " + sqlex.toString());
} catch (Exception ex) {
System.out.println("Exception while connecting and querying the " +
"database table: " + ex.toString());
} finally {
// Close the resultset, statement and the connection objects.
if (rset !=null) rset.close();
if (pstmt!=null) pstmt.close();
if (conn!=null) conn.close();
}
}
/**
* Method to check if the table ('CLOB_TAB') exists in the database; if not
* then it is created.
*
* Table Name: CLOB_TAB
* Column Name Type
* -----------------------------------
* col_col CLOB
*/
private void checkTables() {
Statement stmt = null;
ResultSet rset = null;
try {
// Create the database connection, if it is closed.
if ((conn==null)||conn.isClosed()){
// Connect to the database.
conn = DriverManager.getConnection( this.url, this.props );
}
// Create Statement object
stmt = conn.createStatement();
// Check if the table is present
rset = stmt.executeQuery(" SELECT table_name FROM user_tables "+
" WHERE table_name = 'CLOB_TAB' ");
// If the table is not present, then create the table.
if (!rset.next()) {
// Table does not exist, create it
stmt.executeUpdate(" CREATE TABLE clob_tab(clob_col CLOB)");
}
} catch (SQLException sqlEx) {
System.out.println("Could not create table clob_tab : "
+sqlEx.toString());
} finally {
try {
if( rset != null ) rset.close();
if( stmt != null ) stmt.close();
if (conn!=null) conn.close();
} catch(SQLException ex) {
System.out.println("Could not close objects in checkTables method : "
+ex.toString());
}
}
}
/*
* This method reads the specified text file and, returns the content
* as a string.
*/
private String readFile()
throws FileNotFoundException, IOException{
// Read the file whose content has to be passed as String
BufferedReader br = new BufferedReader(new FileReader(fileName));
String nextLine = "";
StringBuffer sb = new StringBuffer();
while ((nextLine = br.readLine()) != null) {
sb.append(nextLine);
}
// Convert the content into to a string
String clobData = sb.toString();
// Return the data.
return clobData;
}
} |
Probléme insertion d'un CLOB
Répondre avec citation
Partager