hive不支持多個字符做爲分隔符的解決方案

題記：

　　近期在作某個大型銀行的大數據項目，當在處理非結構化數據時，卻發現他們給的數據並不符合hive和pig的處理要求，數據每行必須須要多個分割符才能完美處理，一下午也沒有想到完美的辦法解決，今天從新審視了一下整個過程。看來hive的命令行無法搞定了。因而乎，只能經過代碼來搞定。

一、從新實現hive的InputFormat了，別急放碼過來

package hiveStream;

import java.io.IOException;

import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileSplit;
import org.apache.hadoop.mapred.InputSplit;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.JobConfigurable;
import org.apache.hadoop.mapred.RecordReader;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.TextInputFormat;

public class MyHiveInputFormat  extends TextInputFormat implements JobConfigurable{

	@Override
	public RecordReader<LongWritable, Text> getRecordReader(
			InputSplit genericSplit, JobConf job, Reporter reporter)
			throws IOException {
		 reporter.setStatus(genericSplit.toString());
	       return new MyRecordReader((FileSplit) genericSplit, job);
	}
	
}

二、仔細看看下面的方法，不解釋，本身領悟。

package hiveStream;

import java.io.IOException;
import java.io.InputStream;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.compress.CompressionCodec;
import org.apache.hadoop.io.compress.CompressionCodecFactory;
import org.apache.hadoop.mapred.FileSplit;
import org.apache.hadoop.mapred.RecordReader;
import org.apache.hadoop.util.LineReader;


public class MyRecordReader implements RecordReader<LongWritable, Text>{
	
	private CompressionCodecFactory compressionCodecs = null;
    private long start;
    private long pos;
    private long end;
    private LineReader lineReader;
    int maxLineLength;
	
    public MyRecordReader(InputStream in, long offset, long endOffset,
            int maxLineLength) {
        this.maxLineLength = maxLineLength;
        this.start = offset;
        this.lineReader = new LineReader(in);
        this.pos = offset;
        this.end = endOffset;
    }
    
    public MyRecordReader(InputStream in, long offset, long endOffset,
            Configuration job) throws IOException {
        this.maxLineLength = job.getInt(
                "mapred.mutilCharRecordReader.maxlength", Integer.MAX_VALUE);
        this.lineReader = new LineReader(in, job);
        this.start = offset;
        this.end = endOffset;
    }
    
    // 構造方法
    public MyRecordReader(FileSplit inputSplit, Configuration job)
            throws IOException {
        maxLineLength = job.getInt("mapred.mutilCharRecordReader.maxlength",
                Integer.MAX_VALUE);
        start = inputSplit.getStart();
        end = start + inputSplit.getLength();
        final Path file = inputSplit.getPath();
        // 建立壓縮器
        compressionCodecs = new CompressionCodecFactory(job);
        final CompressionCodec codec = compressionCodecs.getCodec(file);
        // 打開文件系統
        FileSystem fs = file.getFileSystem(job);
        FSDataInputStream fileIn = fs.open(file);
        boolean skipFirstLine = false;
 
        if (codec != null) {
            lineReader = new LineReader(codec.createInputStream(fileIn), job);
            end = Long.MAX_VALUE;
        } else {
            if (start != 0) {
                skipFirstLine = true;
                --start;
                fileIn.seek(start);
            }
            lineReader = new LineReader(fileIn, job);
        }
 
        if (skipFirstLine) {
            start += lineReader.readLine(new Text(), 0,
                    (int) Math.min((long) Integer.MAX_VALUE, end - start));
        }
        this.pos = start;
    }
	
    @Override
	public void close() throws IOException {
    	if (lineReader != null)
            lineReader.close();
	}

	@Override
	public LongWritable createKey() {
		return new LongWritable();
	}

	@Override
	public Text createValue() {
		 return new Text();
	}

	@Override
	public long getPos() throws IOException {
		  return pos;
	}

	@Override
	public float getProgress() throws IOException {
	   if (start == end) {
            return 0.0f;
        } else {
            return Math.min(1.0f, (pos - start) / (float) (end - start));
        }
	}

	@Override
	public boolean next(LongWritable key, Text value) throws IOException {
		 while (pos < end) {
	            key.set(pos);
	            int newSize = lineReader.readLine(value, maxLineLength,
	                    Math.max((int) Math.min(Integer.MAX_VALUE, end - pos),
	                            maxLineLength));
	            // 把字符串中的"##"轉變爲"#"
	            String strReplace = value.toString().replaceAll("\\s+", "\001");
	            Text txtReplace = new Text();
	            txtReplace.set(strReplace);
	            value.set(txtReplace.getBytes(), 0, txtReplace.getLength());
	            if (newSize == 0)
	                return false;
	            pos += newSize;
	            if (newSize < maxLineLength)
	                return true;
	        }
	        return false;
	    }
	}

三、處理實例：以下

     

數據處理要求：
    
    12 afd   fewf	fewfe  we
    76 vee   ppt	wfew  wefw
    83 tyutr   ppt	wfew  wefw
    45 vbe   ppt	wfew  wefw
    565 wee   ppt	wfew  wefw
    12 sde   ppt	wfew  wefw
注意：字段之間的空格不一致

一、建表：
    create table micmiu_blog(author int, category string, url string,town string,oop string) stored as inputformat 'hiveStream.MyHiveInputFormat' outputformat  'org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat';
注意：輸出咱可沒有重寫哦

二、加載數據：
    LOAD DATA LOCAL INPATH'/mnt/test' OVERWRITE INTO TABLE micmiu_blog;

三、看看的成果：
    select * from micmiu_blog;

本身去試試，不解釋