import org.apache.hadoop.security.UserGroupInformation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.security.PrivilegedAction;
import java.sql.*;
import java.util.LinkedList;
/*** 類名： ImpalaJdbcUtils
* * 描述：impala jdbc的工具類
* * 自定義連接工具池
* * **/
public class ImpalaJdbcUtils {
private static final Logger log = LoggerFactory.getLogger(ImpalaJdbcUtils.class);
/*** 描述：驅動類 <br>*/
private static String DRIVER_CLASS = "org.apache.hive.jdbc.HiveDriver";
private static String CONNECTION_URL = "jdbc:hive2://*****/default;principal=impala/";
/*** 連接池**/
private static LinkedList<Connection> pool = new LinkedList<Connection>();//初始化10個連接
static {
try {
for (int i = 0; i < 15; i++) {
Connection conn = getImpalaConnection();
//得到一個連接
pool.add(conn);
}
} catch (Exception e) {
log.error("資料庫連接池初始化失敗，請檢查配置", e);
}
}
/*** 從連接池中獲取連接**/
public static Connection getConnection() throws SQLException {
// 取出連接池中一個連接
Connection conn = null;
// 測試連接是否超時，超時重新連接
try {
conn = pool.removeFirst();
//執行以下連接，查看是否異常
String sql = "show DATABASES";
PreparedStatement ps = conn.prepareStatement(sql);
ResultSet rs = ps.executeQuery();
rs.close();
ps.close();
}catch (Exception e){
log.warn("連接異常,嘗試重新生成連接！");
conn = getImpalaConnection();
}
// 刪除第一個連接返回
log.info("取出一個連接剩餘 " + pool.size() + "個連接！");
return conn;
}
/*** @Description 釋放連接***/
public static void releaseConnection(Connection conn) {
pool.add(conn);
log.info("將連接放回到連接池中,數量:" + pool.size());
}
/*** @Description 獲取impala連接* **/
public static Connection getImpalaConnection() {
try {
Object o = UserGroupInformation.getLoginUser().doAs((PrivilegedAction<Object>) () -> {
Connection connection = null;
try {
Class.forName(DRIVER_CLASS);
} catch (ClassNotFoundException e) {
log.error("加載impala驅動失敗", e);
}
try {
connection = DriverManager.getConnection(CONNECTION_URL);
} catch (SQLException e) {
log.error("獲取jdbc連接失敗", e);
}
return connection;
});
return (Connection) o;
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
/*** 關閉jdbc連接* **/
public static void disconnect(Connection connection, ResultSet res, PreparedStatement ps) {
try {
if (res != null){
res.close();
}
if (ps != null){
ps.close();
}
if (connection != null) {
connection.close();
ImpalaJdbcUtils.releaseConnection(connection);
}
} catch (SQLException e) {
log.error("jdbc連接關閉失敗", e);
}
}
//不使用連接池
public Connection getConnectSync(){
try {
Object o = UserGroupInformation.getLoginUser().doAs((PrivilegedAction<Object>) () -> {
Connection connection = null;
try {
Class.forName(DRIVER_CLASS);
} catch (ClassNotFoundException e) {
log.error("加載impala驅動失敗", e);
}
try {
connection = DriverManager.getConnection(CONNECTION_URL);
} catch (SQLException e) {
log.error("獲取jdbc連接失敗", e);
}
return connection;
});
return (Connection) o;
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}