用Java实现可保存状态的数据库生成XML树（7）

用Java实现可保存状态的数据库生成XML树（7）

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--- 用Java实现可保存状态的数据库生成XML树（7） (http://www.webasp.net/article/7/6978.htm)

-- 作者：未知
-- 发布日期： 2003-07-26

6.3.源码
6.3.1.ResultEdit SessionBean源码和相关文件
1.远程接口文件,ResultEdit.java
package com.sitechasia.ejb;

import java.rmi.*;
import javax.ejb.*;
import java.io.*;

import javax.sql.RowSet;
import java.sql.SQLException;

public interface ResultEdit extends EJBObject {

    public RowSet getRowSet() throws RemoteException , SQLException ;

        public RowSet setRowSet(String sqlExp) throws RemoteException , SQLException ;
}

2.Home接口文件 ResultEditHome.java
package com.sitechasia.ejb;

import java.rmi.*;
import javax.ejb.*;
import java.io.*;

import java.util.HashMap;

public interface ResultEditHome extends EJBHome {
  public ResultEdit create() throws RemoteException, CreateException;
  public ResultEdit create(HashMap startingCart) throws RemoteException, CreateException;

}

3.Bean类 ResultEditBean.java
package com.sitechasia.ejb;

import java.rmi.*;
import javax.ejb.*;
import java.io.*;

import java.sql.*;
import javax.sql.*;
import sun.jdbc.rowset.*;

import javax.sql.DataSource;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

import java.util.HashMap;

public class ResultEditBean implements SessionBean {
    private SessionContext sessionContext;
    public int id;
    public String name;
        private CachedRowSet crset=null;

        private HashMap cart;

        private Context ctx = null;
        private DataSource ds = null;

        public ResultEditBean() {
            cart = new HashMap();
        }

        public void ejbCreate() {
            try {
                cart = new HashMap();
                ctx = new InitialContext();
                        ds = (DataSource)ctx.lookup("java:comp/env/imis");
                }
                catch (Exception e) {
                    System.out.println("ejbCreate failed:"+e.getMessage());
                    e.printStackTrace();
                }
        }

        public void ejbCreate(HashMap starting) {
            try {
                cart = (HashMap) starting.clone();
                ctx = new InitialContext();
                        ds = (DataSource)ctx.lookup("java:comp/env/imis");
                }
                catch (Exception e) {
                    System.out.println("ejbCreate failed:"+e.getMessage());
                    e.printStackTrace();
                }
        }

        public void ejbRemove() throws RemoteException {
        }
        public void ejbActivate() throws RemoteException {
        }
        public void ejbPassivate() throws RemoteException {
        }
        public void setSessionContext(SessionContext sessionContext) throws RemoteException {
            this.sessionContext = sessionContext;
        }
        public RowSet getRowSet() throws SQLException {
            return crset;
        }
        public RowSet setRowSet(String sqlExp) throws SQLException {
            Connection con = null;
            try {
                con = ds.getConnection();
                Statement stmt = con.createStatement();
                ResultSet rs =  stmt.executeQuery(sqlExp);
                CachedRowSet t_crset = new CachedRowSet();
                t_crset.populate(rs);
                rs.close();
                stmt.close();
                crset = t_crset;
                return t_crset;
            }
            finally {
                if (con != null) con.close();
            }
        }
}

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