How to Convert Java List or ArrayList into ResultSet
At this project i found an obstacle, which i need to convert a reporting module from fetching data from database into fetching data from Webservices. At first I think it was easy, I just fetch strings from Webservice, and put it in a bean or in a map and put it all in an ArrayList, just like JasperReport. But I forgot, this isn’t JasperReport I’m using, I’m using bloody hell CrystalReport. And my Crystal-Report-calling method only accepting ResultSet for parameter, so somehow I need to convert strings from webservice into ResultSet.
My idea is adding strings from webservices into an ArrayList<Object> and adding this ArrayList into ArrayList<ArrayList<Object>> and converting it into rows of ResultSet. And im using MockRunner library to help me. This is how I do it :
I create a class to convert a list into result set
package com.edw.rs;
import com.mockrunner.mock.jdbc.MockResultSet;
import java.sql.ResultSet;
import java.util.List;
/**
*
* @author edw
*/
public class MyResultSet {
public ResultSet getResultSet(List<String> headers, List<List<Object>> data) throws Exception {
// validation
if (headers == null || data == null) {
throw new Exception("null parameters");
}
if (headers.size() != data.size()) {
throw new Exception("parameters size are not equals");
}
// create a mock result set
MockResultSet mockResultSet = new MockResultSet("myResultSet");
// add header
for (String string : headers) {
mockResultSet.addColumn(string);
}
// add data
for (List<Object> list : data) {
mockResultSet.addRow(list);
}
return mockResultSet;
}
}
and i tested it with my junit class
package com.edw.rs.test;
import com.edw.rs.MyResultSet;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
import org.apache.log4j.Logger;
import org.junit.Test;
/**
*
* @author edw
*/
public class MyResultSetTest {
private Logger logger = Logger.getLogger(MyResultSetTest.class);
public MyResultSetTest() {
}
@Test
public void testMyResultSet() throws Exception {
MyResultSet myResultSet = new MyResultSet();
List<String> headers = new ArrayList<String>();
headers.add("id");
headers.add("name");
headers.add("salary");
headers.add("age");
List<List<Object>> data = new ArrayList<List<Object>>();
for (int i = 0; i < 4; i++) {
List<Object> objects = new ArrayList<Object>();
objects.add(new Integer(i));
objects.add("name " + i);
objects.add(new Double(i));
objects.add(new Integer(20 + i));
data.add(objects);
}
ResultSet rs = myResultSet.getResultSet(headers, data);
while (rs.next()) {
logger.debug(rs.getString("id"));
logger.debug(rs.getString(2));
logger.debug(rs.getDouble("salary"));
logger.debug(rs.getInt(4));
logger.debug("------------------------");
}
}
}
this is the result on my IDE console
2010-08-18 18:13:09,112 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:42 - 0 2010-08-18 18:13:09,131 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:43 - name 0 2010-08-18 18:13:09,132 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:44 - 0.0 2010-08-18 18:13:09,132 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:45 - 20 2010-08-18 18:13:09,133 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:46 - ------------------------ 2010-08-18 18:13:09,133 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:42 - 1 2010-08-18 18:13:09,189 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:43 - name 1 2010-08-18 18:13:09,189 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:44 - 1.0 2010-08-18 18:13:09,189 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:45 - 21 2010-08-18 18:13:09,190 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:46 - ------------------------ 2010-08-18 18:13:09,190 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:42 - 2 2010-08-18 18:13:09,191 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:43 - name 2 2010-08-18 18:13:09,218 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:44 - 2.0 2010-08-18 18:13:09,219 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:45 - 22 2010-08-18 18:13:09,219 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:46 - ------------------------ 2010-08-18 18:13:09,219 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:42 - 3 2010-08-18 18:13:09,220 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:43 - name 3 2010-08-18 18:13:09,225 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:44 - 3.0 2010-08-18 18:13:09,226 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:45 - 23 2010-08-18 18:13:09,226 [MyResultSetTest] DEBUG com.edw.rs.test.MyResultSetTest:46 - ------------------------
this is my project structure, FYI im using Netbeans 6.9.
all i can say is, Thank You mockrunner, you saved my life.
