Java操做DB2 XML數據實踐

Java操做DB2 XML數據實踐

 

自學了90分鐘的DB2 XQuery，還不很熟悉，就要在項目中用了，內心很不踏實，仍是先跑個CRUD的Demo看看，以避免走彎路。

 

代碼很粗糙，主要目的是看看JDBC是否能很好的執行這種新SQL，呵呵。

 

另外，在此以前，看到Oracle老大已經開始實現一個操做XML數據的規範，目前尚未正式出臺，但願Sun能儘快跟進，將標準的API接口定出來，以支持廣大的Java社區。項目有期限，咱們也沒時間等Sun給咱們作好任何東西，本身動手實現吧。

 

下面是我作的一個Demo，但願能給正在研究這一塊的朋友一點參考，XQuery SQL代碼參考了DB2官方文檔。

 

1、實現一個簡單的數據庫工具

import java.sql.*;

/**
* 簡單的數據鏈接工具
* File: DBUtils.java
* User: leizhimin
* Date: 2008-3-18 15:19:12
*/
public class DBUtils {
     public static final String url = "jdbc:db2://192.168.3.143:50000/lavasoft";
    public static final String username = "lavasoft";
    public static final String password = "lavasoftdb2";
    public static final String driverClassName = "com.ibm.db2.jcc.DB2Driver";

    /**
     * 獲取數據庫鏈接Connection
     *
     * @return 數據庫鏈接Connection
     */
    public static Connection makeConnection() {
        Connection conn = null;
        try {
            Class.forName(driverClassName);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        try {
            conn = DriverManager.getConnection(url, username, password);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }

    public static void main(String args[]) {
        testConnection();
    }

    /**
     * 測試鏈接方法
     */
    public static void testConnection() {
        Connection conn = makeConnection();
        try {
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT * FROM DM_HYML");
            while (rs.next()) {
                String s1 = rs.getString(1);
                String s2 = rs.getString(2);
                System.out.println(s1 + s2);
            }
            rs.close();
            stmt.close();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

 

2、寫一個簡單的測試類執行各類XQuery SQL

 

import com.topsoft.icib.common.utils.DBUtils;

import java.sql.*;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.IOException;

/**
* DB2 XML數據操做測試
* File: TestXMLDAO.java
* User: leizhimin
* Date: 2008-3-18 16:33:51
*/
public class TestDB2XML {

     /**
     * 預刪除表Customer
     *
     * @throws SQLException
     */
     public static void testDropXMLTable() throws SQLException {
        String drop_sql = "DROP TABLE Customer";
        Connection conn = DBUtils.makeConnection();
        Statement stmt = conn.createStatement();
        stmt.executeUpdate(drop_sql);
        stmt.close();
        conn.close();
    }

     /**
     * 建立表
     *
     * @throws SQLException
     */
     public static void testCreateXMLTable() throws SQLException {
        String ct_sql = "CREATE TABLE Customer (Cid BIGINT NOT NULL PRIMARY KEY, Info XML)";
        Connection conn = DBUtils.makeConnection();
        Statement stmt = conn.createStatement();
        stmt.executeUpdate(ct_sql);
        stmt.close();
        conn.close();
    }

     /**
     * 插入數據
     *
     * @throws SQLException
     * @throws IOException
     */
     public static void testInsertXMLTable() throws SQLException, IOException {
        String xml = "<customerinfo xmlns=\"http://posample.org\" Cid=\"1000\">\n" +
                "<name>Robert Shoemaker</name>\n" +
                "<addr country=\"Canada\">\n" +
                "<street>1596 Baseline</street>\n" +
                "<city>zhengzhou</city>\n" +
                "<prov-state>Ontario</prov-state>\n" +
                "<pcode-zip>N8X 7F8</pcode-zip>\n" +
                "</addr>\n" +
                "<phone type=\"work\">905-555-2937</phone>\n" +
                "</customerinfo>";
        String ins_sql = "INSERT INTO CUSTOMER (CID, INFO) VALUES (1000, ?)";
        Connection conn = DBUtils.makeConnection();
        conn.setAutoCommit(false);
        PreparedStatement pstmt = conn.prepareStatement(ins_sql);
        byte[] b = xml.getBytes();
        InputStream ins = new ByteArrayInputStream(b);
        pstmt.setBinaryStream(1, ins, b.length);
        pstmt.executeUpdate();
        conn.commit();
        ins.close();
        pstmt.close();
        conn.close();
    }

    /**
     * XQuery查詢數據
     *
     * @throws SQLException
     */
    public static void testQueryXMLTable() throws SQLException {
        String query_sql = "SELECT XMLQUERY (\n" +
                "'declare default element namespace \"http://posample.org\";\n" +
                "for $d in $doc/customerinfo\n" +
                "return <out>{$d/name}</out>'\n" +
                "passing INFO as \"doc\")\n" +
                "FROM Customer as c\n" +
                "WHERE XMLEXISTS ('declare default element namespace \"http://posample.org\";\n" +
                "$i/customerinfo/addr[city=\"zhengzhou\"]' passing c.INFO as \"i\")";
        Connection conn = DBUtils.makeConnection();
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery(query_sql);
        StringBuffer xmls = new StringBuffer();
        while (rs.next()) {
            xmls.append(rs.getString(1)).append("\n");
        }
        System.out.println(xmls.toString());
        stmt.close();
        conn.close();
    }

    /**
     * XQuery更新數據
     *
     * @throws SQLException
     * @throws IOException
     */
    public static void testUpdateXMLTable() throws SQLException, IOException {
        String xml = "<customerinfo xmlns=\"http://posample.org\" Cid=\"1002\">\n" +
                "<name>Jim Noodle</name>\n" +
                "<addr country=\"Canada\">\n" +
                "<street>1150 Maple Drive</street>\n" +
                "<city>Newtown</city>\n" +
                "<prov-state>Ontario</prov-state>\n" +
                "<pcode-zip>Z9Z 2P2</pcode-zip>\n" +
                "</addr>\n" +
                "<phone type=\"work\">905-555-7258</phone>\n" +
                "</customerinfo>";
        String up_sql = "UPDATE customer SET info =?" +
                "WHERE XMLEXISTS (\n" +
                "'declare default element namespace \"http://posample.org\";\n" +
                "$doc/customerinfo[@Cid = 1000]'\n" +
                "passing INFO as \"doc\")";

        Connection conn = DBUtils.makeConnection();
        conn.setAutoCommit(false);
        PreparedStatement pstmt = conn.prepareStatement(up_sql);
        byte[] b = xml.getBytes();
        InputStream ins = new ByteArrayInputStream(b);
        pstmt.setBinaryStream(1, ins, b.length);
        pstmt.executeUpdate();
        conn.commit();
        ins.close();
        pstmt.close();
        conn.close();
    }

    /**
     * 查詢xml列數據，用於驗證
     *
     * @throws SQLException
     */
    public static void testQueryXMLColumn() throws SQLException {
        String query_sql = "SELECT INFO FROM Customer";
        Connection conn = DBUtils.makeConnection();
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery(query_sql);
        StringBuffer xmls = new StringBuffer();
        while (rs.next()) {
            xmls.append(rs.getString(1)).append("\n");
        }
        System.out.println(xmls.toString());
        stmt.close();
        conn.close();
    }

    /**
     * 測試入口，方法組調用
     *
     * @param rags
     * @throws Exception
     */
    public static void main(String rags[]) throws Exception {
        testDropXMLTable();
        testCreateXMLTable();
        testInsertXMLTable();
        testQueryXMLTable();
        testUpdateXMLTable();
        testQueryXMLColumn();
    }
}

 

3、運行結果

 

< out xmlns ="http://posample.org" > < name >Robert Shoemaker </ name > </ out >

< customerinfo xmlns ="http://posample.org" Cid ="1002" > < name >Jim Noodle </ name > < addr country ="Canada" > < street >1150 Maple Drive </ street > < city >Newtown </ city > < prov-state >Ontario </ prov-state > < pcode-zip >Z9Z 2P2 </ pcode-zip > </ addr > < phone type ="work" >905-555-7258 </ phone > </ customerinfo >


Process finished with exit code 0

 

呵呵，終於看到運行結果了。。。