使用 Hive UDF 解压列数据

Question

背景： 使用 Hive UDF evaluate() 方法解压列数据

例外：

异常失败 java.io.IOException：org.apache.hadoop.hive.ql.metadata.HiveException： 无法执行方法 public static org.apache.hadoop.io.Text Test.UDFDecompressor.evaluate(java.lang.String) 抛出 org.apache.hadoop.hive.ql.metadata.HiveException 对象 Test.UDFDecompressor@1008df1e 类 Test.UDFDecompressor 与 论据 {x��}kw⸲�_a�����֤�\��a-B�i�@`ï¿½ï¿½ï¿½ï¿½ï¿ ½"�nc3�I����$_�E�� } 大小为 1

源代码：

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.nio.charset.Charset;
import java.util.Arrays;
import java.util.zip.DataFormatException;
import java.util.zip.InflaterInputStream;

import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.JavaStringObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;

public class Decompress extends UDF{
public static String evaluate(String data1) throws IOException, DataFormatException{
ByteArrayInputStream bao=new ByteArrayInputStream(data1.getBytes());
InflaterInputStream iis= new InflaterInputStream(bao);
String out="";
byte[] bt=new byte[1024];
int len=-1;
while ((len =iis.read(bt))!=-1){ 
out += new String(Arrays.copyOf(bt, len));
}
JavaStringObjectInspector stringInspector;
stringInspector = PrimitiveObjectInspectorFactory.javaStringObjectInspector;
String ip = stringInspector.getPrimitiveJavaObject(out);

//return new String(ip.getBytes(Charset.forName("UTF-8")));
//return new String(ip.getBytes(Charset.forName("UTF-8")));
return ip;
}
}

我尝试了多种使用 gZib、zLIb Java Api 解压缩的方法，但遇到了同样的错误。谁能帮我解决这个问题并建议正确的方法来使用 Hive UDF

解压缩列数据

提前致谢。

Answer 1

import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.io.BytesWritable;
import org.apache.hadoop.io.Text;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.InflaterInputStream;

public class Decompress extends UDF {

    private final Text r = new Text();

    public Text evaluate(BytesWritable bw) throws IOException {
        ByteArrayInputStream zipped = new ByteArrayInputStream(bw.getBytes());
        InflaterInputStream inflater = new InflaterInputStream(zipped);
        ByteArrayOutputStream unzipped = new ByteArrayOutputStream();
        byte[] bt = new byte[1024];
        int len;
        while ((len = inflater.read(bt)) != -1) {
            unzipped.write(bt, 0, len);
        }

        r.clear();
        r.set(unzipped.toByteArray());
        return r;
    }
}