java鏈接oracle並load sql從xml執行查詢

在ETL的時候，鏈接oracle並load sql執行是基礎操做，須要注意的是記得執行結束後記得關閉connection, 現記錄一下：

其中xml文件：

<?xml version="1.0" encoding="GB2312"?>
<SQLSTRING>

<Products>
select carname
from tb_info_car
where CARCODE = ?
ORDER BY carname
</Products>

</SQLSTRING>

其中須要傳參數使用?佔位

java代碼：

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Iterator;
import java.util.List;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.*;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;

import oracle.jdbc.OracleDriver;

import org.apache.log4j.Logger;

public class SqlLoaderFromXML {

static Logger logger = Logger.getLogger(SqlLoaderFromXML.class);
private static String sqlPath = "./OracleSQL/";
private static String sqlFile = sqlPath + "Car.xml";
private static Connection DBConn = null;

private static final String DEDICATED_CONNECTION_STR = "jdbc:oracle:thin:@(description=(address=(host=#IP)(protocol=tcp)(port=#PORT))(connect_data=(service_name=#SID)(SERVER = DEDICATED)))";

public static String loadSqlFromXml(String xmlFile, String xpath) throws FileNotFoundException, DocumentException {

InputStream input = new FileInputStream(xmlFile);
SAXReader saxReader = new SAXReader(false);
Document sqlDoc = saxReader.read(input);
Node node = sqlDoc.selectSingleNode(xpath);
return node.getText();

}

public static Connection getConnection(String ip,String port, String dbName, String userName,
String password) throws SQLException {
DriverManager.registerDriver(new OracleDriver());

String connStr = "";
connStr = SqlLoaderFromXML.DEDICATED_CONNECTION_STR;

connStr = connStr.replaceAll("#IP", ip);
connStr = connStr.replaceAll("#SID", dbName);
connStr = connStr.replaceAll("#PORT", port);
return DriverManager.getConnection(connStr, userName, password);
}

public static void DBConnect() throws Exception {

DBConn = getConnection(IP,port,dbname,username,password);
DBConn.setAutoCommit(false);
logger.info(" Connet DB success");

}

public static void main(String[] args) throws Exception {

try {
DBConnect();
}
catch(Exception ex){
ex.printStackTrace();
logger.error("........."+ex.getMessage());
logger.error("Connect DB fail");
return;
}

PreparedStatement psQueryCarID = null;

ResultSet rsQueryCarID = null;

String sqlString = loadSqlFromXml(sqlFile, "//SQLSTRING/Products");

logger.info("SQL From XML File: \n" + sqlString);

try{
psQueryCarID = DBConn.prepareStatement(sqlString);

psQueryCarID.setString(1, "Audi");
rsQueryCarID = psQueryCarID.executeQuery();

while(rsQueryCarID.next()){
logger.info("car id: " + rsQueryCarID.getString("carname"));
}
} catch (SQLException e) {
logger.info(e);
}
finally{
if (DBConn != null)
try {
//DBConn.commit();
DBConn.close();
logger.info("close conn.");
} catch (SQLException e) {
e.printStackTrace();
}

if (psQueryCarID != null) {
try {
psQueryCarID.close();
} catch (SQLException e) {
e.printStackTrace();
}
}

if (rsQueryCarID != null) {
try {
rsQueryCarID.close();
} catch (SQLException e) {
e.printStackTrace();
}
}

}

}
}

其中能夠把鏈接oracle部分和load sql部分抽取出來打包以便後續直接調用, 也能夠把DB參數放到properties經過讀取配置的方式來使用