05 Январь, 2010

tomcat datasource native connection

Sometimes need use native db connection.
For example, to correct the following exception:

java.lang.ClassCastException: org.apache.tomcat.dbcp.dbcp.PoolingDataSource cannot be cast to oracle.jdbc.OracleConnection


  private String datasource = "java:comp/env/jdbc/mydb";

  private DataSource getDataSource() {
    InitialContext ctx;
    try {
      ctx = new InitialContext();
      BasicDataSource ds = (BasicDataSource) ctx.lookup(datasource);
      ds.setAccessToUnderlyingConnectionAllowed(true);
      return ds;
    } catch (NamingException e) {
      throw new RuntimeException(e);
    }
  }

  private Connection getNativeConnection(Connection connection) {
    return ((DelegatingConnection) connection).getInnermostDelegate();
  }

  public void doIt() {
    Connection connection = null;
    try {
      connection = getDataSource().getConnection();
      Connection nativeConnection = getNativeConnection(connection);
      doSomethingWithNativeConnection(nativeConnection);
    } catch (SQLException e) {
      throw new RuntimeException(e);
    } finally {
      if (connection != null) {
        try {
          connection.close();
        } catch (SQLException e) {
          e.printStackTrace();
        }
      }
    }

  }

  private void doSomethingWithNativeConnection(Connection connection) {
    System.out.println(connection.getClass());
    /*- for oracle will be print:
     class oracle.jdbc.driver.T4CConnection
     */
    // ...
  }

For example context.xml below:


<Resource name="jdbc/mydb" auth="Container" type="javax.sql.DataSource"
maxActive="10" maxIdle="10" maxWait="10000" username="user" password="password"
driverClassName="oracle.jdbc.OracleDriver" url="jdbc:oracle:thin:@localhost:1521:orasid"
validationQuery="select 1 from dual" />

hibernate sequence generator

ru.olimpiks.MySequenceGenerator.java


public class MySequenceGenerator implements IdentifierGenerator {
  public static final String QUERY_NAME = "MySequence.newId";

  public Serializable generate(SessionImplementor session, Object object)
      throws HibernateException {

    Long id = null;
    Connection connection = session.connection();

    try {
      PreparedStatement preparedStatement = connection.prepareStatement(session
          .getNamedQuery(QUERY_NAME).getQueryString());

      ResultSet resultSet = preparedStatement.executeQuery();
      if (resultSet.next()) {
        id = resultSet.getLong(1);
      }
    } catch (SQLException e) {
      e.printStackTrace();
    }
    return id;
  }
}

hbm.xml


...
<sql-query name="MySequence.newId">
 <return-scalar column="id" type="long" />
 <![CDATA[
  select
   seq_my.NEXTVAL id
  from
   dual
 ]]>
</sql-query>
...

ru.olimpiks.MyEntity.java


@Entity
@Table(name = "MY_TABLE")
public class MyEntity implements java.io.Serializable {

  private Long id;

  @Id
  @Column(name = "ID")
  @GeneratedValue(generator = "my_id")
  @GenericGenerator(name = "my_id", strategy = "ru.olimpiks.MySequenceGenerator")
  public Long getId() {
    return this.id;
  }

  public void setId(Long id) {
    this.id = id;
  }
  // ...
}

02 Январь, 2010

1. create oracle types


CREATE OR REPLACE TYPE qwerty_element_t AS OBJECT
(str VARCHAR2(10)
,num number
,str_big clob
,dt date
);
/
CREATE OR REPLACE TYPE qwerty_tt AS TABLE OF qwerty_element_t;
/
CREATE OR REPLACE TYPE qwerty_t AS OBJECT
(id VARCHAR2(1000)
,element qwerty_element_t
,elements qwerty_tt
);
/
create or replace
function getQwertyAsXml(p_id varchar2) return clob as
       v_qwerty        qwerty_t;
       v_xml           XMLTYPE;
begin
       -- init object instance
       v_qwerty := ...;
       --convert object to xml
       v_xml := XMLTYPE (v_qwerty);
       -- xml to clob
       return v_xml.getClobVal();
end;
/

2. oracle type to xsd

OracleType2XSD.groovy


class OracleType2XSD {
 static String clob2String(java.sql.Clob clob) {/*...*/}
 static Sql getSql() {/*...*/}
 static String oracleType2XSD(Sql sql, String oracleType, String rootTag) {
  String res
  sql.call("""{ ${Sql.CLOB} = call dbms_xmlschema.generateSchema(
   user,
   ${Sql.VARCHAR(oracleType)},
   ${Sql.VARCHAR(rootTag)},
   TRUE,FALSE,TRUE
   ).getClobVal() }""") { xsd ->
    res = clob2String(xsd)
  }
  res
 }
 static void main(args) {
  new File('qwerty.xsd').withWriter { 
    it << oracleType2XSD(getSql(), 'QWERTY_T', 'qwerty') 
  }
 }
}

execute


set CLASSPATH=...
java -cp %CLASSPATH% groovy.lang.GroovyShell OracleType2XSD.groovy

product qwerty.xsd


<?xml version="1.0"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xdb="http://xmlns.oracle.com/xdb"
  xsi:schemaLocation="http://xmlns.oracle.com/xdb http://xmlns.oracle.com/xdb/XDBSchema.xsd">
  <xsd:element name="qwerty" type="QWERTY_TType" />
  <xsd:complexType name="QWERTY_TType">
    <xsd:sequence>
      <xsd:element name="ID">
        <xsd:simpleType>
          <xsd:restriction base="xsd:string">
            <xsd:maxLength value="1000" />
          </xsd:restriction>
        </xsd:simpleType>
      </xsd:element>
      <xsd:element name="INNER" type="QWERTY_INNER_TType" />
    </xsd:sequence>
  </xsd:complexType>
  <xsd:complexType name="QWERTY_INNER_TType">
    <xsd:sequence>
      <xsd:element name="STR">
        <xsd:simpleType>
          <xsd:restriction base="xsd:string">
            <xsd:maxLength value="10" />
          </xsd:restriction>
        </xsd:simpleType>
      </xsd:element>
      <xsd:element name="NUM" type="xsd:double" />
      <xsd:element name="STR_BIG" type="xsd:string" />
      <xsd:element name="DT" type="xsd:date" />
    </xsd:sequence>
  </xsd:complexType>
</xsd:schema>

3. xsd to java beans

execute


%JAVA_HOME%/bin/xjc qwerty.xsd -p ru.olimpiks.oracle.model

product java beans:

ru.olimpiks.oracle.model.QWERTYELEMENTTType.java


@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "QWERTY_ELEMENT_TType", propOrder = {
   "str",
   "num",
   "strbig",
   "dt"
})
public class QWERTYELEMENTTType {
   @XmlElement(name = "STR", required = true)
   protected String str;
   @XmlElement(name = "NUM")
   protected double num;
   @XmlElement(name = "STR_BIG", required = true)
   protected String strbig;
   @XmlElement(name = "DT", required = true)
   @XmlSchemaType(name = "date")
   protected XMLGregorianCalendar dt;
       //...setters and getters
}

ru.olimpiks.oracle.model.QWERTYTType.java


@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "QWERTY_TType", propOrder = {
   "id",
   "element",
   "elements"
})
@XmlRootElement(name="qwerty")//!!!to further correct unmarshall object, you must add this line
public class QWERTYTType {
   @XmlElement(name = "ID", required = true)
   protected String id;
   @XmlElement(name = "ELEMENT", required = true)
   protected QWERTYELEMENTTType element;
   @XmlElement(name = "ELEMENTS")
   protected List<QWERTYELEMENTTType> elements;
       //...setters and getters
}

4. oracle type to java object with jaxb (groovy example)


static QWERTYTType getQwerty(Sql sql, String id) {
 String res
 sql.call("""{ ${Sql.CLOB} = call getQwertyAsXml(${Sql.VARCHAR(id)}) }""") { p_res ->
  res = clob2String(p_res)
 }
 JAXBContext context = JAXBContext.newInstance(QWERTYTType.class);
 Unmarshaller u = context.createUnmarshaller();
 return (QWERTYTType)u.unmarshal(new java.io.StringReader(res));        
}

Can't register Tomcat as Windows service on some computers, under Java6

source...

jdk1.6.0_12
apache-tomcat-6.0.20
Windows Server 2003 R2


...
[2009-12-15 19:05:16] [info] Procrun (2.0.4.0) started
[2009-12-15 19:05:16] [info] Running Service...
[2009-12-15 19:05:16] [info] Starting service...
[2009-12-15 19:05:16] [174  javajni.c] [error] The specified module could not be found.
[2009-12-15 19:05:16] [994  prunsrv.c] [error] Failed creating java d:\dev\jdk1.6.0_12\jre\bin\server\jvm.dll
[2009-12-15 19:05:16] [1269 prunsrv.c] [error] ServiceStart returned 1
[2009-12-15 19:05:16] [info] Run service finished.
[2009-12-15 19:05:16] [info] Procrun finished.
...

For fix it:


copy %JAVA_HOME%/bin/msvcr71.dll %CATALINA_HOME%/bin

olimpiks project