前期准备

1.下载Impala JDBC驱动包

https://downloads.cloudera.com/connectors/impala_jdbc_2.5.41.1061.zip

2.创建maven工程

<dependency>
    <groupId>org.apache.hadoop</groupId>
    <artifactId>hadoop-client</artifactId>
    <version>2.6.5</version>
</dependency>

将下载的Impala驱动包添加到工程lib目录下，并加载到环境变量

非kerberos环境

private static String JDBC_DRIVER = "com.cloudera.impala.jdbc41.Driver";
private static String CONNECTION_URL ="jdbc:impala://hadoop1:21050/";

static {
    try {
        Class.forName(JDBC_DRIVER);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public static void main(String[] args) {
    Connection connection = null;
    ResultSet rs = null;
    PreparedStatement ps = null;
    try {
        connection = DriverManager.getConnection(CONNECTION_URL);
        ps = connection.prepareStatement("select * from test_table");
        rs = ps.executeQuery();
        while (rs.next()) {
            System.out.println(rs.getInt(1) + "-------" + rs.getString(2));
        }

    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        JDBCUtils.disconnect(connection, rs, ps);
    }
}

Kerberos

在Kerberos环境下的Impala需要准备Kerberos的krb5.conf文件及keytab文件。

private static String JDBC_DRIVER = "com.cloudera.impala.jdbc41.Driver";
private static String CONNECTION_URL = "jdbc:impala://haodop1:21050/default;AuthMech=1;KrbRealm=HADOOP.COM;KrbHostFQDN=hadoop1;KrbServiceName=impala";

static {
    try {
        Class.forName(JDBC_DRIVER);
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }
}

public static void main(String[] args) {
    //登录Kerberos账号
    try {
        System.setProperty("java.security.krb5.conf", "/home/xiet/keytab/krb5.conf");
        Configuration configuration = new Configuration();
        configuration.set("hadoop.security.authentication" , "Kerberos");
        UserGroupInformation. setConfiguration(configuration);
        UserGroupInformation.loginUserFromKeytab("xiet@HADOOP.COM", "/home/xiet/keytab/fayson.keytab");
        System.out.println(UserGroupInformation.getCurrentUser() + "------" + UserGroupInformation.getLoginUser());

        UserGroupInformation loginUser = UserGroupInformation.getLoginUser();

        loginUser.doAs(new PrivilegedAction<Object>(){

            public Object run() {
                Connection connection = null;
                ResultSet rs = null;
                PreparedStatement ps = null;
                try {
                    Class.forName(JDBC_DRIVER);
                    connection = DriverManager.getConnection(CONNECTION_URL);
                    ps = connection.prepareStatement("select * from test_table");
                    rs = ps.executeQuery();
                    rs = ps.executeQuery();
                    while (rs.next()) {
                        System.out.println(rs.getInt(1));
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    JDBCUtils.disconnect(connection, rs, ps);
                }
                return null;
            }
        });
    } catch (IOException e) {
        e.printStackTrace();
    }
}

Sentry

 private static String JDBC_DRIVER = "com.cloudera.impala.jdbc41.Driver";
private static String CONNECTION_URL =" jdbc:impala://hadoop1:21050/default;AuthMech=3;UID=hive;PWD=;UseSasl=0";
    static {
        try {
            Class.forName(JDBC_DRIVER);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public static void main(String[] args) {
        System.out.println("集群中只启用了Sentry服务通过JDBC访问Impala");
        Connection connection = null;
        ResultSet rs = null;
        PreparedStatement ps = null;
        try {
            connection = DriverManager.getConnection(CONNECTION_URL);
            ps = connection.prepareStatement("show databases");
            rs = ps.executeQuery();
            while (rs.next()) {
                System.out.println(rs.getString(1));
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCUtils.disconnect(connection, rs, ps);
        }
    }

LDAP和Sentry

private static String JDBC_DRIVER = "com.cloudera.impala.jdbc41.Driver";
    private static String CONNECTION_URL ="jdbc:impala://hadoop1:21050/;AuthMech=3;UID=hive;PWD=123456";
    static {
        try {
            Class.forName(JDBC_DRIVER);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public static void main(String[] args) {
        System.out.println("通过JDBC连接LDAP和Sentry环境下的Impala");
        Connection connection = null;
        ResultSet rs = null;
        PreparedStatement ps = null;
        try {
            connection = DriverManager.getConnection(CONNECTION_URL);
            ps = connection.prepareStatement("show databases");
            rs = ps.executeQuery();
            while (rs.next()) {
                System.out.println(rs.getString(1));
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCUtils.disconnect(connection, rs, ps);
        }
    }