hive之java api

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.security.UserGroupInformation;

import java.io.IOException;
import java.security.PrivilegedAction;
import java.sql.*;


public class HiveUtil {
    

    private static Configuration cfg;
    private static Connection conn;
    private static Statement stmt;

    static {
        System.setProperty("java.security.krb5.realm", "krb5.realm的名稱");
        System.setProperty("java.security.krb5.kdc", "krb5機器名");


        cfg = new Configuration();
        cfg.set("fs.hdfs.impl.disable.cache", "true");
        
        cfg.set("hadoop.security.authentication", "kerberos");
        cfg.set("hadoop.rpc.protection", "authentication");
        cfg.set("hadoop.security.crypto.cipher.suite", "AES/CTR/NoPadding");
    }

    /**
     * 
     * @param principalName keytab的name
     * @param keytab keytab的所在路徑
     * @return
     */
    private static UserGroupInformation login(String principalName, String keytab) {
        try {
            UserGroupInformation.setConfiguration(cfg);
            UserGroupInformation information = UserGroupInformation.loginUserFromKeytabAndReturnUGI(principalName, keytab);
            System.out.println(information.hasKerberosCredentials());
            return information;
        } catch (IOException e) {
            System.out.println(String.format("message:%s, parameter:{\"principalName\":\"%s\",\"keytab\":\"%s\"}",
                    "login kerberos error", principalName, keytab));
            return null;
        }

    }

    public static void conn() {
        if (conn != null && stmt != null) {
            return;
        }
        UserGroupInformation ugi = login(principal, keyTab);
        ugi.doAs(new PrivilegedAction<Object>() {

            public Object run() {
                try {
                    Class.forName("org.apache.hive.jdbc.HiveDriver");
                    //url就是hive的jdbc連接信息
                    conn = DriverManager.getConnection(url);
                    stmt = conn.createStatement();
                    useDatabase();
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return null;
            }
        });
    }

    public static void useDatabase() {
        try {
            conn();
            String database = "test";
            String sql = String.format("use %s", database);
            stmt.execute(sql);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void showTables() {
        try {
            String sql = "show tables";
            ResultSet rs = stmt.executeQuery(sql);
            while (rs.next()) {
                System.out.println(rs.getString(1));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void createTable(String sql) {
        try {
            sql = String.format("CREATE  %s", sql);
            System.out.println(sql);
            stmt.execute(sql);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void loadData(String path, String table) throws Exception {
        try {
            String sql = "load data local inpath '" + path + "'  into table " + table;

            System.out.println("Running: " + sql);
            stmt.execute(sql);
            System.out.println();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void insertSelect(String insertTable, String selectTable, String selectFields, Boolean overwrite) {
        try {
            String sql = "";
            if (overwrite) {
                sql = "insert into table " + insertTable + " select " + selectFields + " from " + selectTable;
            } else {
                sql = "insert overwrite  into table  " + insertTable + " select " + selectFields + " from " + selectTable;
            }
            boolean execute = stmt.execute(sql);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }