blob: a163636b701b6f2f610b25c619f1585007cb5787 [file] [log] [blame]
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<!-- NewPage -->
<html lang="en">
<head>
<!-- Generated by javadoc (1.8.0_292) on Tue Jun 15 06:00:54 GMT 2021 -->
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>FieldSelectionMapper (Apache Hadoop Main 3.3.1 API)</title>
<meta name="date" content="2021-06-15">
<link rel="stylesheet" type="text/css" href="../../../../../../stylesheet.css" title="Style">
<script type="text/javascript" src="../../../../../../script.js"></script>
</head>
<body>
<script type="text/javascript"><!--
try {
if (location.href.indexOf('is-external=true') == -1) {
parent.document.title="FieldSelectionMapper (Apache Hadoop Main 3.3.1 API)";
}
}
catch(err) {
}
//-->
var methods = {"i0":10,"i1":10};
var tabs = {65535:["t0","All Methods"],2:["t2","Instance Methods"],8:["t4","Concrete Methods"]};
var altColor = "altColor";
var rowColor = "rowColor";
var tableTab = "tableTab";
var activeTableTab = "activeTableTab";
</script>
<noscript>
<div>JavaScript is disabled on your browser.</div>
</noscript>
<!-- ========= START OF TOP NAVBAR ======= -->
<div class="topNav"><a name="navbar.top">
<!-- -->
</a>
<div class="skipNav"><a href="#skip.navbar.top" title="Skip navigation links">Skip navigation links</a></div>
<a name="navbar.top.firstrow">
<!-- -->
</a>
<ul class="navList" title="Navigation">
<li><a href="../../../../../../overview-summary.html">Overview</a></li>
<li><a href="package-summary.html">Package</a></li>
<li class="navBarCell1Rev">Class</li>
<li><a href="class-use/FieldSelectionMapper.html">Use</a></li>
<li><a href="package-tree.html">Tree</a></li>
<li><a href="../../../../../../deprecated-list.html">Deprecated</a></li>
<li><a href="../../../../../../index-all.html">Index</a></li>
<li><a href="../../../../../../help-doc.html">Help</a></li>
</ul>
</div>
<div class="subNav">
<ul class="navList">
<li><a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionHelper.html" title="class in org.apache.hadoop.mapreduce.lib.fieldsel"><span class="typeNameLink">Prev&nbsp;Class</span></a></li>
<li><a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionReducer.html" title="class in org.apache.hadoop.mapreduce.lib.fieldsel"><span class="typeNameLink">Next&nbsp;Class</span></a></li>
</ul>
<ul class="navList">
<li><a href="../../../../../../index.html?org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html" target="_top">Frames</a></li>
<li><a href="FieldSelectionMapper.html" target="_top">No&nbsp;Frames</a></li>
</ul>
<ul class="navList" id="allclasses_navbar_top">
<li><a href="../../../../../../allclasses-noframe.html">All&nbsp;Classes</a></li>
</ul>
<div>
<script type="text/javascript"><!--
allClassesLink = document.getElementById("allclasses_navbar_top");
if(window==top) {
allClassesLink.style.display = "block";
}
else {
allClassesLink.style.display = "none";
}
//-->
</script>
</div>
<div>
<ul class="subNavList">
<li>Summary:&nbsp;</li>
<li>Nested&nbsp;|&nbsp;</li>
<li><a href="#field.summary">Field</a>&nbsp;|&nbsp;</li>
<li><a href="#constructor.summary">Constr</a>&nbsp;|&nbsp;</li>
<li><a href="#method.summary">Method</a></li>
</ul>
<ul class="subNavList">
<li>Detail:&nbsp;</li>
<li><a href="#field.detail">Field</a>&nbsp;|&nbsp;</li>
<li><a href="#constructor.detail">Constr</a>&nbsp;|&nbsp;</li>
<li><a href="#method.detail">Method</a></li>
</ul>
</div>
<a name="skip.navbar.top">
<!-- -->
</a></div>
<!-- ========= END OF TOP NAVBAR ========= -->
<!-- ======== START OF CLASS DATA ======== -->
<div class="header">
<div class="subTitle">org.apache.hadoop.mapreduce.lib.fieldsel</div>
<h2 title="Class FieldSelectionMapper" class="title">Class FieldSelectionMapper&lt;K,V&gt;</h2>
</div>
<div class="contentContainer">
<ul class="inheritance">
<li><a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">java.lang.Object</a></li>
<li>
<ul class="inheritance">
<li><a href="../../../../../../org/apache/hadoop/mapreduce/Mapper.html" title="class in org.apache.hadoop.mapreduce">org.apache.hadoop.mapreduce.Mapper</a>&lt;K,V,<a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a>,<a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a>&gt;</li>
<li>
<ul class="inheritance">
<li>org.apache.hadoop.mapreduce.lib.fieldsel.FieldSelectionMapper&lt;K,V&gt;</li>
</ul>
</li>
</ul>
</li>
</ul>
<div class="description">
<ul class="blockList">
<li class="blockList">
<hr>
<br>
<pre>@InterfaceAudience.Public
@InterfaceStability.Stable
public class <span class="typeNameLabel">FieldSelectionMapper&lt;K,V&gt;</span>
extends <a href="../../../../../../org/apache/hadoop/mapreduce/Mapper.html" title="class in org.apache.hadoop.mapreduce">Mapper</a>&lt;K,V,<a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a>,<a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a>&gt;</pre>
<div class="block">This class implements a mapper class that can be used to perform
field selections in a manner similar to unix cut. The input data is treated
as fields separated by a user specified separator (the default value is
"\t"). The user can specify a list of fields that form the map output keys,
and a list of fields that form the map output values. If the inputformat is
TextInputFormat, the mapper will ignore the key to the map function. and the
fields are from the value only. Otherwise, the fields are the union of those
from the key and those from the value.
The field separator is under attribute "mapreduce.fieldsel.data.field.separator"
The map output field list spec is under attribute
"mapreduce.fieldsel.map.output.key.value.fields.spec".
The value is expected to be like
"keyFieldsSpec:valueFieldsSpec" key/valueFieldsSpec are comma (,) separated
field spec: fieldSpec,fieldSpec,fieldSpec ... Each field spec can be a
simple number (e.g. 5) specifying a specific field, or a range (like 2-5)
to specify a range of fields, or an open range (like 3-) specifying all
the fields starting from field 3. The open range field spec applies value
fields only. They have no effect on the key fields.
Here is an example: "4,3,0,1:6,5,1-3,7-". It specifies to use fields
4,3,0 and 1 for keys, and use fields 6,5,1,2,3,7 and above for values.</div>
</li>
</ul>
</div>
<div class="summary">
<ul class="blockList">
<li class="blockList">
<!-- =========== FIELD SUMMARY =========== -->
<ul class="blockList">
<li class="blockList"><a name="field.summary">
<!-- -->
</a>
<h3>Field Summary</h3>
<table class="memberSummary" border="0" cellpadding="3" cellspacing="0" summary="Field Summary table, listing fields, and an explanation">
<caption><span>Fields</span><span class="tabEnd">&nbsp;</span></caption>
<tr>
<th class="colFirst" scope="col">Modifier and Type</th>
<th class="colLast" scope="col">Field and Description</th>
</tr>
<tr class="altColor">
<td class="colFirst"><code>static org.slf4j.Logger</code></td>
<td class="colLast"><code><span class="memberNameLink"><a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html#LOG">LOG</a></span></code>&nbsp;</td>
</tr>
</table>
</li>
</ul>
<!-- ======== CONSTRUCTOR SUMMARY ======== -->
<ul class="blockList">
<li class="blockList"><a name="constructor.summary">
<!-- -->
</a>
<h3>Constructor Summary</h3>
<table class="memberSummary" border="0" cellpadding="3" cellspacing="0" summary="Constructor Summary table, listing constructors, and an explanation">
<caption><span>Constructors</span><span class="tabEnd">&nbsp;</span></caption>
<tr>
<th class="colOne" scope="col">Constructor and Description</th>
</tr>
<tr class="altColor">
<td class="colOne"><code><span class="memberNameLink"><a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html#FieldSelectionMapper--">FieldSelectionMapper</a></span>()</code>&nbsp;</td>
</tr>
</table>
</li>
</ul>
<!-- ========== METHOD SUMMARY =========== -->
<ul class="blockList">
<li class="blockList"><a name="method.summary">
<!-- -->
</a>
<h3>Method Summary</h3>
<table class="memberSummary" border="0" cellpadding="3" cellspacing="0" summary="Method Summary table, listing methods, and an explanation">
<caption><span id="t0" class="activeTableTab"><span>All Methods</span><span class="tabEnd">&nbsp;</span></span><span id="t2" class="tableTab"><span><a href="javascript:show(2);">Instance Methods</a></span><span class="tabEnd">&nbsp;</span></span><span id="t4" class="tableTab"><span><a href="javascript:show(8);">Concrete Methods</a></span><span class="tabEnd">&nbsp;</span></span></caption>
<tr>
<th class="colFirst" scope="col">Modifier and Type</th>
<th class="colLast" scope="col">Method and Description</th>
</tr>
<tr id="i0" class="altColor">
<td class="colFirst"><code>void</code></td>
<td class="colLast"><code><span class="memberNameLink"><a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html#map-K-V-org.apache.hadoop.mapreduce.Mapper.Context-">map</a></span>(<a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html" title="type parameter in FieldSelectionMapper">K</a>&nbsp;key,
<a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html" title="type parameter in FieldSelectionMapper">V</a>&nbsp;val,
org.apache.hadoop.mapreduce.Mapper.Context&nbsp;context)</code>
<div class="block">The identify function.</div>
</td>
</tr>
<tr id="i1" class="rowColor">
<td class="colFirst"><code>void</code></td>
<td class="colLast"><code><span class="memberNameLink"><a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html#setup-org.apache.hadoop.mapreduce.Mapper.Context-">setup</a></span>(org.apache.hadoop.mapreduce.Mapper.Context&nbsp;context)</code>
<div class="block">Called once at the beginning of the task.</div>
</td>
</tr>
</table>
<ul class="blockList">
<li class="blockList"><a name="methods.inherited.from.class.org.apache.hadoop.mapreduce.Mapper">
<!-- -->
</a>
<h3>Methods inherited from class&nbsp;org.apache.hadoop.mapreduce.<a href="../../../../../../org/apache/hadoop/mapreduce/Mapper.html" title="class in org.apache.hadoop.mapreduce">Mapper</a></h3>
<code><a href="../../../../../../org/apache/hadoop/mapreduce/Mapper.html#cleanup-org.apache.hadoop.mapreduce.Mapper.Context-">cleanup</a>, <a href="../../../../../../org/apache/hadoop/mapreduce/Mapper.html#run-org.apache.hadoop.mapreduce.Mapper.Context-">run</a></code></li>
</ul>
<ul class="blockList">
<li class="blockList"><a name="methods.inherited.from.class.java.lang.Object">
<!-- -->
</a>
<h3>Methods inherited from class&nbsp;java.lang.<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</a></h3>
<code><a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#clone--" title="class or interface in java.lang">clone</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#equals-java.lang.Object-" title="class or interface in java.lang">equals</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#finalize--" title="class or interface in java.lang">finalize</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#getClass--" title="class or interface in java.lang">getClass</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#hashCode--" title="class or interface in java.lang">hashCode</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#notify--" title="class or interface in java.lang">notify</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#notifyAll--" title="class or interface in java.lang">notifyAll</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#toString--" title="class or interface in java.lang">toString</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#wait--" title="class or interface in java.lang">wait</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#wait-long-" title="class or interface in java.lang">wait</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#wait-long-int-" title="class or interface in java.lang">wait</a></code></li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
<div class="details">
<ul class="blockList">
<li class="blockList">
<!-- ============ FIELD DETAIL =========== -->
<ul class="blockList">
<li class="blockList"><a name="field.detail">
<!-- -->
</a>
<h3>Field Detail</h3>
<a name="LOG">
<!-- -->
</a>
<ul class="blockListLast">
<li class="blockList">
<h4>LOG</h4>
<pre>public static final&nbsp;org.slf4j.Logger LOG</pre>
</li>
</ul>
</li>
</ul>
<!-- ========= CONSTRUCTOR DETAIL ======== -->
<ul class="blockList">
<li class="blockList"><a name="constructor.detail">
<!-- -->
</a>
<h3>Constructor Detail</h3>
<a name="FieldSelectionMapper--">
<!-- -->
</a>
<ul class="blockListLast">
<li class="blockList">
<h4>FieldSelectionMapper</h4>
<pre>public&nbsp;FieldSelectionMapper()</pre>
</li>
</ul>
</li>
</ul>
<!-- ============ METHOD DETAIL ========== -->
<ul class="blockList">
<li class="blockList"><a name="method.detail">
<!-- -->
</a>
<h3>Method Detail</h3>
<a name="setup-org.apache.hadoop.mapreduce.Mapper.Context-">
<!-- -->
</a>
<ul class="blockList">
<li class="blockList">
<h4>setup</h4>
<pre>public&nbsp;void&nbsp;setup(org.apache.hadoop.mapreduce.Mapper.Context&nbsp;context)
throws <a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a>,
<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/InterruptedException.html?is-external=true" title="class or interface in java.lang">InterruptedException</a></pre>
<div class="block"><span class="descfrmTypeLabel">Description copied from class:&nbsp;<code><a href="../../../../../../org/apache/hadoop/mapreduce/Mapper.html#setup-org.apache.hadoop.mapreduce.Mapper.Context-">Mapper</a></code></span></div>
<div class="block">Called once at the beginning of the task.</div>
<dl>
<dt><span class="overrideSpecifyLabel">Overrides:</span></dt>
<dd><code><a href="../../../../../../org/apache/hadoop/mapreduce/Mapper.html#setup-org.apache.hadoop.mapreduce.Mapper.Context-">setup</a></code>&nbsp;in class&nbsp;<code><a href="../../../../../../org/apache/hadoop/mapreduce/Mapper.html" title="class in org.apache.hadoop.mapreduce">Mapper</a>&lt;<a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html" title="type parameter in FieldSelectionMapper">K</a>,<a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html" title="type parameter in FieldSelectionMapper">V</a>,<a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a>,<a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a>&gt;</code></dd>
<dt><span class="throwsLabel">Throws:</span></dt>
<dd><code><a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a></code></dd>
<dd><code><a href="https://docs.oracle.com/javase/8/docs/api/java/lang/InterruptedException.html?is-external=true" title="class or interface in java.lang">InterruptedException</a></code></dd>
</dl>
</li>
</ul>
<a name="map-java.lang.Object-java.lang.Object-org.apache.hadoop.mapreduce.Mapper.Context-">
<!-- -->
</a><a name="map-K-V-org.apache.hadoop.mapreduce.Mapper.Context-">
<!-- -->
</a>
<ul class="blockListLast">
<li class="blockList">
<h4>map</h4>
<pre>public&nbsp;void&nbsp;map(<a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html" title="type parameter in FieldSelectionMapper">K</a>&nbsp;key,
<a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html" title="type parameter in FieldSelectionMapper">V</a>&nbsp;val,
org.apache.hadoop.mapreduce.Mapper.Context&nbsp;context)
throws <a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a>,
<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/InterruptedException.html?is-external=true" title="class or interface in java.lang">InterruptedException</a></pre>
<div class="block">The identify function. Input key/value pair is written directly to output.</div>
<dl>
<dt><span class="overrideSpecifyLabel">Overrides:</span></dt>
<dd><code><a href="../../../../../../org/apache/hadoop/mapreduce/Mapper.html#map-KEYIN-VALUEIN-org.apache.hadoop.mapreduce.Mapper.Context-">map</a></code>&nbsp;in class&nbsp;<code><a href="../../../../../../org/apache/hadoop/mapreduce/Mapper.html" title="class in org.apache.hadoop.mapreduce">Mapper</a>&lt;<a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html" title="type parameter in FieldSelectionMapper">K</a>,<a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html" title="type parameter in FieldSelectionMapper">V</a>,<a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a>,<a href="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</a>&gt;</code></dd>
<dt><span class="throwsLabel">Throws:</span></dt>
<dd><code><a href="https://docs.oracle.com/javase/8/docs/api/java/io/IOException.html?is-external=true" title="class or interface in java.io">IOException</a></code></dd>
<dd><code><a href="https://docs.oracle.com/javase/8/docs/api/java/lang/InterruptedException.html?is-external=true" title="class or interface in java.lang">InterruptedException</a></code></dd>
</dl>
</li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
</div>
<!-- ========= END OF CLASS DATA ========= -->
<!-- ======= START OF BOTTOM NAVBAR ====== -->
<div class="bottomNav"><a name="navbar.bottom">
<!-- -->
</a>
<div class="skipNav"><a href="#skip.navbar.bottom" title="Skip navigation links">Skip navigation links</a></div>
<a name="navbar.bottom.firstrow">
<!-- -->
</a>
<ul class="navList" title="Navigation">
<li><a href="../../../../../../overview-summary.html">Overview</a></li>
<li><a href="package-summary.html">Package</a></li>
<li class="navBarCell1Rev">Class</li>
<li><a href="class-use/FieldSelectionMapper.html">Use</a></li>
<li><a href="package-tree.html">Tree</a></li>
<li><a href="../../../../../../deprecated-list.html">Deprecated</a></li>
<li><a href="../../../../../../index-all.html">Index</a></li>
<li><a href="../../../../../../help-doc.html">Help</a></li>
</ul>
</div>
<div class="subNav">
<ul class="navList">
<li><a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionHelper.html" title="class in org.apache.hadoop.mapreduce.lib.fieldsel"><span class="typeNameLink">Prev&nbsp;Class</span></a></li>
<li><a href="../../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionReducer.html" title="class in org.apache.hadoop.mapreduce.lib.fieldsel"><span class="typeNameLink">Next&nbsp;Class</span></a></li>
</ul>
<ul class="navList">
<li><a href="../../../../../../index.html?org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionMapper.html" target="_top">Frames</a></li>
<li><a href="FieldSelectionMapper.html" target="_top">No&nbsp;Frames</a></li>
</ul>
<ul class="navList" id="allclasses_navbar_bottom">
<li><a href="../../../../../../allclasses-noframe.html">All&nbsp;Classes</a></li>
</ul>
<div>
<script type="text/javascript"><!--
allClassesLink = document.getElementById("allclasses_navbar_bottom");
if(window==top) {
allClassesLink.style.display = "block";
}
else {
allClassesLink.style.display = "none";
}
//-->
</script>
</div>
<div>
<ul class="subNavList">
<li>Summary:&nbsp;</li>
<li>Nested&nbsp;|&nbsp;</li>
<li><a href="#field.summary">Field</a>&nbsp;|&nbsp;</li>
<li><a href="#constructor.summary">Constr</a>&nbsp;|&nbsp;</li>
<li><a href="#method.summary">Method</a></li>
</ul>
<ul class="subNavList">
<li>Detail:&nbsp;</li>
<li><a href="#field.detail">Field</a>&nbsp;|&nbsp;</li>
<li><a href="#constructor.detail">Constr</a>&nbsp;|&nbsp;</li>
<li><a href="#method.detail">Method</a></li>
</ul>
</div>
<a name="skip.navbar.bottom">
<!-- -->
</a></div>
<!-- ======== END OF BOTTOM NAVBAR ======= -->
<p class="legalCopy"><small>Copyright &#169; 2021 <a href="https://www.apache.org">Apache Software Foundation</a>. All rights reserved.</small></p>
</body>
</html>