Hibernate HQL查询中的Oracle字符类型问题

Question

@Entity
@Table(name="ORG")
public class Organization  {

private String serviceName;
private String orgAcct;

     //Some other properties goes here...

@Column(name="ORG_ACCT", nullable=false, length=16)
public String getOrgAcct() {
    return this.orgAcct;
}

public void setOrgAcct(String orgAcct) {
    this.orgAcct = orgAcct;
}


@Column(name="SERVICE_NAME",nullable=true, length=16)
public String getServiceName() {
    return this.serviceName;
}

public void setServiceName(String serviceName) {
    this.serviceName = serviceName;
}

}

@Repository
@Scope("singleton") //By default scope is singleton
public class OrganizationDAOImpl implementsOrganizationDAO {

public OrganizationDAOImpl(){
}

public Organization findOrganizationByOrgAcctAndServiceName(String orgAcct,String serviceName){
    String hqlQuery = "SELECT org FROM  Organization org WHERE org.serviceName = :serName AND org.orgAcct = :orgAct";
    Query query = getCurrentSession().createQuery(hqlQuery)
        .setString("serName", serviceName)
        .setString("orgAct", orgAcct);

    Organization org =  findObject(query);
    return org;
}
 }

请帮助我解决这个问题。这里我不能将Oracle类型char更改为varchar2。我需要使用oracle char类型变量。

@EngineerDollery在抛出上面的帖子之后，我用columnDefinition修改了实体类，@column注释属性。

@Column(name="SERVICE_NAME",nullable=true,length=16,columnDefinition="CHAR")
    public String getServiceName() {
        return this.serviceName;
    }

但我仍然无法检索相应列的数据。

Answer 1

我使用OraclePreparedStatement和Hibernate UserType接口解决了这个问题。

通过扩展org.hibernate.UserType.UserType接口创建了一个新的UserType类，并提供了nullSafeSet()、nullSafeGet（）方法的实现。

nullSafeSet（）方法，我们有第一个参数为PreparedStatement，在方法内部，我将PreparedStatement转换为OraclePreparedStatement对象，并使用setFixedCHAR（）方法传递字符串值。

这里是UserType impl类的完整代码。

package nc3.jws.persistence.userType;

import java.io.Serializable;
import java.sql.PreparedStatement; 
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;

import org.apache.commons.lang.StringUtils;
import org.hibernate.type.StringType;
import org.hibernate.usertype.UserType;

/**
* 
* based on www.hibernate.org/388.html
*/

 public class OracleFixedLengthCharType implements UserType {

public OracleFixedLengthCharType() {
    System.out.println("OracleFixedLengthCharType constructor");
}

public int[] sqlTypes() {
    return new int[] { Types.CHAR };
}



public Class<String> returnedClass() {
    return String.class;
}

public boolean equals(Object x, Object y) {
    return (x == y) || (x != null && y != null && (x.equals(y)));
}

@SuppressWarnings("deprecation")
public Object nullSafeGet(ResultSet inResultSet, String[] names, Object o) throws SQLException {
    //String val = (String) Hibernate.STRING.nullSafeGet(inResultSet, names[0]);
    String val = StringType.INSTANCE.nullSafeGet(inResultSet, names[0]);
    //System.out.println("From nullSafeGet method valu is "+val);
    return val == null ? null : StringUtils.trim(val);
}


public void nullSafeSet(PreparedStatement inPreparedStatement, Object o,
        int i)
                throws SQLException {

    String val = (String) o;
    //Get the delegatingStmt object from DBCP connection pool PreparedStatement object.
    org.apache.commons.dbcp.DelegatingStatement delgatingStmt = (org.apache.commons.dbcp.DelegatingStatement)inPreparedStatement;
    //Get OraclePreparedStatement object using deletatingStatement object.

    oracle.jdbc.driver.OraclePreparedStatement oraclePreparedStmpt = (oracle.jdbc.driver.OraclePreparedStatement)delgatingStmt.getInnermostDelegate();
    //Call setFixedCHAR method, by passing string type value .
    oraclePreparedStmpt.setFixedCHAR(i, val);
}


public Object deepCopy(Object o) {
    if (o == null) {
        return null;
    }
    return new String(((String) o));
}


public boolean isMutable() {
    return false;
}

public Object assemble(Serializable cached, Object owner) {
    return cached;
}


public Serializable disassemble(Object value) {
    return (Serializable) value;
}

public Object replace(Object original, Object target, Object owner) {
    return original;
}

public int hashCode(Object obj) {
    return obj.hashCode();
}

  }

在Entity类中使用@TypeDefs批注配置了此类。

@TypeDefs({
@TypeDef(name = "fixedLengthChar", typeClass = nc3.jws.persistence.userType.OracleFixedLengthCharType.class)

}）

@Type(type="fixedLengthChar")
@Column(name="SERVICE_NAME",nullable=true,length=16)
public String getServiceName() {
    return this.serviceName;
}