ODCItableDescripte在Java存储过程中的实现

目前的问题是第二部分

我在Oracle SQL中实现了一个集合类型，它实际上被定义为一个类型和该类型的表

CREATE TYPE row_type AS OBJECT
(
  C1 VARCHAR2(50),
  C2 VARCHAR2(50),
  C3 VARCHAR2(50)
);
/

CREATE TYPE row_type_set AS TABLE OF row_type;

此外，我还将ODCI类型及其实现定义为数据库中的Java存储过程：

SQL:

CREATE OR REPLACE TYPE ODCIImpl AS OBJECT (
  key INTEGER,

  STATIC FUNCTION ODCITableStart(sctx OUT ODCIImpl, cur SYS_REFCURSOR)
    RETURN NUMBER
    AS LANGUAGE JAVA
    NAME 'ODCIImpl.ODCITableStart(oracle.sql.STRUCT[], java.sql.ResultSet) return java.math.BigDecimal',

  MEMBER FUNCTION ODCITableFetch(self IN OUT ODCIImpl, nrows IN NUMBER,
                                 outSet OUT row_type_set) RETURN NUMBER
    AS LANGUAGE JAVA
    NAME 'ODCIImpl.ODCITableFetch(java.math.BigDecimal, oracle.sql.ARRAY[]) return java.math.BigDecimal',

  MEMBER FUNCTION ODCITableClose(self IN ODCIImpl) RETURN NUMBER
    AS LANGUAGE JAVA
    NAME 'ODCIImpl.ODCITableClose() return java.math.BigDecimal'

);
/

import java.io.*;
import java.util.*;
import oracle.sql.*;
import java.sql.*;
import java.math.BigDecimal;
import oracle.CartridgeServices.*;

// stored context type

public class StoredCtx
{
  ResultSet rset;
  public StoredCtx(ResultSet rs) { rset=rs; }
}

// implementation type

public class ODCIImpl implements SQLData 
{
  private BigDecimal key;

  final static BigDecimal SUCCESS = new BigDecimal(0);
  final static BigDecimal ERROR = new BigDecimal(1);
  final static int MAX_COLUMNS = 3;

  // Implement SQLData interface.

  String sql_type;
  public String getSQLTypeName() throws SQLException 
  {
    return sql_type;
  }

  public void readSQL(SQLInput stream, String typeName) throws SQLException 
  {
    sql_type = typeName;
    key = stream.readBigDecimal();
  }

  public void writeSQL(SQLOutput stream) throws SQLException 
  {
    stream.writeBigDecimal(key);
  }

  // type methods implementing ODCITable interface

  static public BigDecimal ODCITableStart(STRUCT[] sctx,ResultSet rset)
    throws SQLException 
  {
    Connection conn = DriverManager.getConnection("jdbc:default:connection:");

    // create a stored context and store the result set in it
    StoredCtx ctx=new StoredCtx(rset);

    // register stored context with cartridge services
    int key;
    try {
      key = ContextManager.setContext(ctx);
    } catch (CountException ce) {
      return ERROR;
    }

    // create a ODCIImpl instance and store the key in it
    Object[] impAttr = new Object[1];
    impAttr[0] = new BigDecimal(key); 
    StructDescriptor sd = new StructDescriptor("ODCIIMPL",conn);
    sctx[0] = new STRUCT(sd,conn,impAttr);

    return SUCCESS;
  }

  public BigDecimal ODCITableFetch(BigDecimal nrows, ARRAY[] outSet)
    throws SQLException 
  {
    Connection conn = DriverManager.getConnection("jdbc:default:connection:");

    // retrieve stored context using the key
    StoredCtx ctx;
    try {
      ctx=(StoredCtx)ContextManager.getContext(key.intValue());
    } catch (InvalidKeyException ik ) {
      return ERROR;
    }

    // get the nrows parameter, but return up to 10 rows
    int nrowsval = nrows.intValue();

    // create a vector for the fetched rows
    Vector v = new Vector(nrowsval);
    int i=0;

    StructDescriptor outDesc = 
      StructDescriptor.createDescriptor("ROW_TYPE", conn);
    Object[] out_attr = new Object[MAX_COLUMNS];

    ResultSetMetaData rsmd = ctx.rset.getMetaData();
    int columnsNumber = rsmd.getColumnCount();

    while(nrowsval>0 && ctx.rset.next()){
        for(int j = 0; j < columnsNumber; j++) {
            if(j == MAX_COLUMNS)
                break;
            out_attr[j] = (Object)ctx.rset.getString(j+1);
        }
      v.add((Object)new STRUCT(outDesc, conn, out_attr));
      i+=1;
      nrowsval-=1;
    }

    // return if no rows found
    if(i==0) return SUCCESS;

    // create the output ARRAY using the vector
    Object out_arr[] = v.toArray();
    ArrayDescriptor ad = new ArrayDescriptor("ROW_TYPE_SET",conn);
    outSet[0] = new ARRAY(ad,conn,out_arr);

    return SUCCESS;
  }

  public BigDecimal ODCITableClose() throws SQLException {

    // retrieve stored context using the key, and remove from ContextManager
    StoredCtx ctx;
    try {
      ctx=(StoredCtx)ContextManager.clearContext(key.intValue());
    } catch (InvalidKeyException ik ) {
      return ERROR;
    }

    // close the result set
    Statement stmt = ctx.rset.getStatement();
    ctx.rset.close();
    if(stmt!=null) stmt.close();

    return SUCCESS;
  }

}

Java存储过程：

CREATE OR REPLACE TYPE ODCIImpl AS OBJECT (
  key INTEGER,

  STATIC FUNCTION ODCITableStart(sctx OUT ODCIImpl, cur SYS_REFCURSOR)
    RETURN NUMBER
    AS LANGUAGE JAVA
    NAME 'ODCIImpl.ODCITableStart(oracle.sql.STRUCT[], java.sql.ResultSet) return java.math.BigDecimal',

  MEMBER FUNCTION ODCITableFetch(self IN OUT ODCIImpl, nrows IN NUMBER,
                                 outSet OUT row_type_set) RETURN NUMBER
    AS LANGUAGE JAVA
    NAME 'ODCIImpl.ODCITableFetch(java.math.BigDecimal, oracle.sql.ARRAY[]) return java.math.BigDecimal',

  MEMBER FUNCTION ODCITableClose(self IN ODCIImpl) RETURN NUMBER
    AS LANGUAGE JAVA
    NAME 'ODCIImpl.ODCITableClose() return java.math.BigDecimal'

);
/

import java.io.*;
import java.util.*;
import oracle.sql.*;
import java.sql.*;
import java.math.BigDecimal;
import oracle.CartridgeServices.*;

// stored context type

public class StoredCtx
{
  ResultSet rset;
  public StoredCtx(ResultSet rs) { rset=rs; }
}

// implementation type

public class ODCIImpl implements SQLData 
{
  private BigDecimal key;

  final static BigDecimal SUCCESS = new BigDecimal(0);
  final static BigDecimal ERROR = new BigDecimal(1);
  final static int MAX_COLUMNS = 3;

  // Implement SQLData interface.

  String sql_type;
  public String getSQLTypeName() throws SQLException 
  {
    return sql_type;
  }

  public void readSQL(SQLInput stream, String typeName) throws SQLException 
  {
    sql_type = typeName;
    key = stream.readBigDecimal();
  }

  public void writeSQL(SQLOutput stream) throws SQLException 
  {
    stream.writeBigDecimal(key);
  }

  // type methods implementing ODCITable interface

  static public BigDecimal ODCITableStart(STRUCT[] sctx,ResultSet rset)
    throws SQLException 
  {
    Connection conn = DriverManager.getConnection("jdbc:default:connection:");

    // create a stored context and store the result set in it
    StoredCtx ctx=new StoredCtx(rset);

    // register stored context with cartridge services
    int key;
    try {
      key = ContextManager.setContext(ctx);
    } catch (CountException ce) {
      return ERROR;
    }

    // create a ODCIImpl instance and store the key in it
    Object[] impAttr = new Object[1];
    impAttr[0] = new BigDecimal(key); 
    StructDescriptor sd = new StructDescriptor("ODCIIMPL",conn);
    sctx[0] = new STRUCT(sd,conn,impAttr);

    return SUCCESS;
  }

  public BigDecimal ODCITableFetch(BigDecimal nrows, ARRAY[] outSet)
    throws SQLException 
  {
    Connection conn = DriverManager.getConnection("jdbc:default:connection:");

    // retrieve stored context using the key
    StoredCtx ctx;
    try {
      ctx=(StoredCtx)ContextManager.getContext(key.intValue());
    } catch (InvalidKeyException ik ) {
      return ERROR;
    }

    // get the nrows parameter, but return up to 10 rows
    int nrowsval = nrows.intValue();

    // create a vector for the fetched rows
    Vector v = new Vector(nrowsval);
    int i=0;

    StructDescriptor outDesc = 
      StructDescriptor.createDescriptor("ROW_TYPE", conn);
    Object[] out_attr = new Object[MAX_COLUMNS];

    ResultSetMetaData rsmd = ctx.rset.getMetaData();
    int columnsNumber = rsmd.getColumnCount();

    while(nrowsval>0 && ctx.rset.next()){
        for(int j = 0; j < columnsNumber; j++) {
            if(j == MAX_COLUMNS)
                break;
            out_attr[j] = (Object)ctx.rset.getString(j+1);
        }
      v.add((Object)new STRUCT(outDesc, conn, out_attr));
      i+=1;
      nrowsval-=1;
    }

    // return if no rows found
    if(i==0) return SUCCESS;

    // create the output ARRAY using the vector
    Object out_arr[] = v.toArray();
    ArrayDescriptor ad = new ArrayDescriptor("ROW_TYPE_SET",conn);
    outSet[0] = new ARRAY(ad,conn,out_arr);

    return SUCCESS;
  }

  public BigDecimal ODCITableClose() throws SQLException {

    // retrieve stored context using the key, and remove from ContextManager
    StoredCtx ctx;
    try {
      ctx=(StoredCtx)ContextManager.clearContext(key.intValue());
    } catch (InvalidKeyException ik ) {
      return ERROR;
    }

    // close the result set
    Statement stmt = ctx.rset.getStatement();
    ctx.rset.close();
    if(stmt!=null) stmt.close();

    return SUCCESS;
  }

}

我现在的问题是我们如何在Java存储过程中实现ODCItableDescripte方法，以便在模拟表中输出任何数据类型？首先，这有可能吗？在和的Oracle文档中，我似乎没有找到任何与此相关的信息

如果有可能的话，可以自我解释，我们不再需要前面提到的集合类型。模拟表的大小和数据类型应与我们要从中选择信息的表相同