- 浏览: 47710 次
文章分类
最新评论
[hadoop2.7.1]I/O之一步一步解析Text(实例)
通过上一篇的讲述,我们知道hadoop中的Text类,跟java中的String类很相似,在其定义的方法上,也多有相近之处,当然,由于用途、UTF编码的不同,两者之间还是有很大的区别。下面要讲实例除了测试Text的方法之外,着重跟java.lang.String进行比较。
1、首先,我们来看生成String串的方法:
源码如下:
// 生成java字符串 private static String getTestString(int len) throws Exception { StringBuilder buffer = new StringBuilder(); int length = (len==RAND_LEN) ? RANDOM.nextInt(1000) : len; while (buffer.length()<length) { int codePoint = RANDOM.nextInt(Character.MAX_CODE_POINT); char tmpStr[] = new char[2]; if (Character.isDefined(codePoint)) { //unpaired surrogate if (codePoint < Character.MIN_SUPPLEMENTARY_CODE_POINT && !Character.isHighSurrogate((char)codePoint) && !Character.isLowSurrogate((char)codePoint)) { Character.toChars(codePoint, tmpStr, 0); buffer.append(tmpStr); } } } return buffer.toString(); } //默认情况下生成随机String串 public static String getTestString() throws Exception { return getTestString(RAND_LEN); } //长串 public static String getLongString() throws Exception { String str = getTestString(); int length = Short.MAX_VALUE+str.length(); StringBuilder buffer = new StringBuilder(); while(buffer.length()<length) buffer.append(str); return buffer.toString(); }
2、测试编码方法:
public void testCoding() throws Exception { String before = "Bad \t encoding \t testcase"; Text text = new Text(before); String after = text.toString(); assertTrue(before.equals(after)); for (int i = 0; i < NUM_ITERATIONS; i++) { // generate a random string if (i == 0) before = getLongString(); else before = getTestString(); // test string to utf8 ByteBuffer bb = Text.encode(before); byte[] utf8Text = bb.array(); byte[] utf8Java = before.getBytes("UTF-8");//注意:这里指定用UTF-8标准charset,java语言的本机字符编码方案是UTF-16 assertEquals(0, WritableComparator.compareBytes( utf8Text, 0, bb.limit(), utf8Java, 0, utf8Java.length)); // test utf8 to string after = Text.decode(utf8Java); assertTrue(before.equals(after)); } }
注意:默认的equals方法是直接返回==的结果,所以也是比较数组是否是同一个,等同于使用==比较,是两个数组是否是同一个,而不是是否相等。
3、测试Text的输入\输出方法:
主要有:
读:
void |
readFields(DataInputin)
deserialize
|
void |
readFields(DataInputin,
intmaxLength)
|
static
String |
readString(DataInputin)
Read a UTF8 encoded string from in
|
static
String |
readString(DataInputin,
intmaxLength)
Read a UTF8 encoded string with a maximum size
|
void |
readWithKnownLength(DataInputin,
intlen)
Read a Text object whose length is already known.
|
写:
void |
write(DataOutputout)
serialize write this object to out length uses zero-compressed encoding
|
void |
write(DataOutputout,
intmaxLength)
|
static int |
writeString(DataOutputout,Strings)
Write a UTF8 encoded string to out
|
static int |
writeString(DataOutputout,Strings,
intmaxLength)
Write a UTF8 encoded string with a maximum size to out
|
测试源码:
public void testIO() throws Exception { DataOutputBuffer out = new DataOutputBuffer(); DataInputBuffer in = new DataInputBuffer(); for (int i = 0; i < NUM_ITERATIONS; i++) { // generate a random string String before; if (i == 0) before = getLongString(); else before = getTestString(); // write it out.reset(); Text.writeString(out, before); // test that it reads correctly in.reset(out.getData(), out.getLength()); String after = Text.readString(in); assertTrue(before.equals(after)); // Test compatibility with Java's other decoder int strLenSize = WritableUtils.getVIntSize(Text.utf8Length(before)); String after2 = new String(out.getData(), strLenSize, out.getLength()-strLenSize, "UTF-8"); assertTrue(before.equals(after2)); } } public void doTestLimitedIO(String str, int len) throws IOException { DataOutputBuffer out = new DataOutputBuffer(); DataInputBuffer in = new DataInputBuffer(); out.reset(); try { Text.writeString(out, str, len); fail("expected writeString to fail when told to write a string " + "that was too long! The string was '" + str + "'"); } catch (IOException e) { } Text.writeString(out, str, len + 1); // test that it reads correctly in.reset(out.getData(), out.getLength()); in.mark(len); String after; try { after = Text.readString(in, len); fail("expected readString to fail when told to read a string " + "that was too long! The string was '" + str + "'"); } catch (IOException e) { } in.reset(); after = Text.readString(in, len + 1); assertTrue(str.equals(after)); } public void testLimitedIO() throws Exception { doTestLimitedIO("汉", 2);//注意:汉字“汉”占用3个字节 doTestLimitedIO("abcd", 3); doTestLimitedIO("foo bar baz", 10); doTestLimitedIO("1", 0); }
4、Text专门优化重写了compare方法:
/** A WritableComparator optimized for Text keys. */ public static class Comparator extends WritableComparator { public Comparator() { super(Text.class); } @Override public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) { int n1 = WritableUtils.decodeVIntSize(b1[s1]); int n2 = WritableUtils.decodeVIntSize(b2[s2]); return compareBytes(b1, s1+n1, l1-n1, b2, s2+n2, l2-n2); } }
测试实例:
public void testCompare() throws Exception { DataOutputBuffer out1 = new DataOutputBuffer(); DataOutputBuffer out2 = new DataOutputBuffer(); DataOutputBuffer out3 = new DataOutputBuffer(); Text.Comparator comparator = new Text.Comparator(); for (int i=0; i<NUM_ITERATIONS; i++) { // reset output buffer out1.reset(); out2.reset(); out3.reset(); // generate two random strings String str1 = getTestString(); String str2 = getTestString(); if (i == 0) { str1 = getLongString(); str2 = getLongString(); } else { str1 = getTestString(); str2 = getTestString(); } // convert to texts Text txt1 = new Text(str1); Text txt2 = new Text(str2); Text txt3 = new Text(str1); // serialize them txt1.write(out1); txt2.write(out2); txt3.write(out3); // compare two strings by looking at their binary formats int ret1 = comparator.compare(out1.getData(), 0, out1.getLength(), out2.getData(), 0, out2.getLength()); // compare two strings int ret2 = txt1.compareTo(txt2); assertEquals(ret1, ret2); assertEquals("Equivalence of different txt objects, same content" , 0, txt1.compareTo(txt3)); assertEquals("Equvalence of data output buffers", 0, comparator.compare(out1.getData(), 0, out3.getLength(), out3.getData(), 0, out3.getLength())); } }
5、find()方法:
注:只带一个String参数的,默认为从头开始查找字串,而带两个参数的表示从start位置往后变开始查找字串,如果找到了,则返回值为字串第一次出现的位置,没找到,则返回-1
实例源码:
public void testFind() throws Exception { Text text = new Text("abcd\u20acbdcd\u20ac"); assertTrue(text.getLength()==14); assertTrue(text.find("abd")==-1); assertTrue(text.find("ac")==-1); assertTrue(text.find("\u20ac")==4); assertTrue(text.find("\u20ac", 5)==11); byte [] b1 = new byte[]{97, 98, 99, 100, -30, -126, -84, 98, 100, 99, 100, -30, -126, -84}; byte [] b2 = text.copyBytes(); assertTrue(Arrays.equals(b1, b2)); } public void testFindAfterUpdatingContents() throws Exception { Text text = new Text("abcd"); text.set("a".getBytes()); assertEquals(text.getLength(),1); assertEquals(text.find("a"), 0); assertEquals(text.find("b"), -1); }
注:这里比较数组里的值是否相等,使用arrays.equals(a,b)。
6、validateUTF8,有效地UTF-8编码检查
static void |
validateUTF8(byte[]utf8)
Check if a byte array contains valid utf-8
|
static void |
validateUTF8(byte[]utf8, intstart, intlen)
Check to see if a byte array is valid utf-8
|
实例源码:
public void testValidate() throws Exception { Text text = new Text("abcd\u20acbdcd\u20ac"); byte [] utf8 = text.getBytes(); int length = text.getLength(); Text.validateUTF8(utf8, 0, length); }
7、清空Text的clear()方法:
实例源码:
public void testClear() throws Exception { // Test lengths on an empty text object Text text = new Text(); assertEquals( "Actual string on an empty text object must be an empty string", "", text.toString()); assertEquals("Underlying byte array length must be zero", 0, text.getBytes().length); assertEquals("String's length must be zero", 0, text.getLength()); // Test if clear works as intended text = new Text("abcd\u20acbdcd\u20ac"); int len = text.getLength(); text.clear(); assertEquals("String must be empty after clear()", "", text.toString()); assertTrue( "Length of the byte array must not decrease after clear()", text.getBytes().length >= len); assertEquals("Length of the string must be reset to 0 after clear()", 0, text.getLength()); }
8、Text的append方法:
void |
append(byte[]utf8, intstart, intlen)
Append a range of bytes to the end of the given text
|
|
测试源码:
public void testTextText() throws CharacterCodingException { Text a=new Text("abc"); Text b=new Text("a"); b.set(a); assertEquals("abc", b.toString()); a.append("xdefgxxx".getBytes(), 1, 4); assertEquals("modified aliased string", "abc", b.toString()); assertEquals("appended string incorrectly", "abcdefg", a.toString()); // add an extra byte so that capacity = 14 and length = 8 a.append(new byte[]{'d'}, 0, 1); assertEquals("abcdefgd",a.toString()); byte[] b1= new byte[]{97, 98, 99, 100, 101, 102, 103, 100, 0, 0, 0, 0, 0, 0}; byte[] b2= new byte[]{97, 98, 99, 100, 101, 102, 103, 100}; assertEquals(8, a.getLength()); assertEquals(14, a.getBytes().length); assertEquals(8, a.copyBytes().length); assertTrue(Arrays.equals(b1, a.getBytes())); assertTrue(Arrays.equals(b2, a.copyBytes())); a.set(new Text("abc")); assertEquals(14, a.getBytes().length);//byte长度没变小! assertEquals(3, a.getLength()); }
完整的实例源码如下:
package org.apache.hadoop.io; import junit.framework.TestCase; import java.io.IOException; import java.nio.BufferUnderflowException; import java.nio.ByteBuffer; import java.nio.charset.CharacterCodingException; import java.util.Arrays; import java.util.Random; import com.google.common.base.Charsets; import com.google.common.primitives.Bytes; /** Unit tests for LargeUTF8. */ public class THT_TestText extends TestCase { private static final int NUM_ITERATIONS = 100; public THT_TestText(String name) { super(name); } private static final Random RANDOM = new Random(1); private static final int RAND_LEN = -1; // generate a valid java String private static String getTestString(int len) throws Exception { StringBuilder buffer = new StringBuilder(); int length = (len==RAND_LEN) ? RANDOM.nextInt(1000) : len; while (buffer.length()<length) { int codePoint = RANDOM.nextInt(Character.MAX_CODE_POINT); char tmpStr[] = new char[2]; if (Character.isDefined(codePoint)) { //unpaired surrogate if (codePoint < Character.MIN_SUPPLEMENTARY_CODE_POINT && !Character.isHighSurrogate((char)codePoint) && !Character.isLowSurrogate((char)codePoint)) { Character.toChars(codePoint, tmpStr, 0); buffer.append(tmpStr); } } } return buffer.toString(); } public static String getTestString() throws Exception { return getTestString(RAND_LEN); } public static String getLongString() throws Exception { String str = getTestString(); int length = Short.MAX_VALUE+str.length(); StringBuilder buffer = new StringBuilder(); while(buffer.length()<length) buffer.append(str); return buffer.toString(); } public void testWritable() throws Exception { for (int i = 0; i < NUM_ITERATIONS; i++) { String str; if (i == 0) str = getLongString(); else str = getTestString(); TestWritable.testWritable(new Text(str)); } } public void testCoding() throws Exception { String before = "Bad \t encoding \t testcase"; Text text = new Text(before); String after = text.toString(); assertTrue(before.equals(after)); for (int i = 0; i < NUM_ITERATIONS; i++) { // generate a random string if (i == 0) before = getLongString(); else before = getTestString(); // test string to utf8 ByteBuffer bb = Text.encode(before); byte[] utf8Text = bb.array(); byte[] utf8Java = before.getBytes("UTF-8"); assertEquals(0, WritableComparator.compareBytes( utf8Text, 0, bb.limit(), utf8Java, 0, utf8Java.length)); // test utf8 to string after = Text.decode(utf8Java); assertTrue(before.equals(after)); } } public void testIO() throws Exception { DataOutputBuffer out = new DataOutputBuffer(); DataInputBuffer in = new DataInputBuffer(); for (int i = 0; i < NUM_ITERATIONS; i++) { // generate a random string String before; if (i == 0) before = getLongString(); else before = getTestString(); // write it out.reset(); Text.writeString(out, before); // test that it reads correctly in.reset(out.getData(), out.getLength()); String after = Text.readString(in); assertTrue(before.equals(after)); // Test compatibility with Java's other decoder int strLenSize = WritableUtils.getVIntSize(Text.utf8Length(before)); String after2 = new String(out.getData(), strLenSize, out.getLength()-strLenSize, "UTF-8"); assertTrue(before.equals(after2)); } } public void doTestLimitedIO(String str, int len) throws IOException { DataOutputBuffer out = new DataOutputBuffer(); DataInputBuffer in = new DataInputBuffer(); out.reset(); try { Text.writeString(out, str, len); fail("expected writeString to fail when told to write a string " + "that was too long! The string was '" + str + "'"); } catch (IOException e) { } Text.writeString(out, str, len + 1); // test that it reads correctly in.reset(out.getData(), out.getLength()); in.mark(len); String after; try { after = Text.readString(in, len); fail("expected readString to fail when told to read a string " + "that was too long! The string was '" + str + "'"); } catch (IOException e) { } in.reset(); after = Text.readString(in, len + 1); assertTrue(str.equals(after)); } public void testLimitedIO() throws Exception { doTestLimitedIO("汉", 2); doTestLimitedIO("abcd", 3); doTestLimitedIO("foo bar baz", 10); doTestLimitedIO("1", 0); } public void testCompare() throws Exception { DataOutputBuffer out1 = new DataOutputBuffer(); DataOutputBuffer out2 = new DataOutputBuffer(); DataOutputBuffer out3 = new DataOutputBuffer(); Text.Comparator comparator = new Text.Comparator(); for (int i=0; i<NUM_ITERATIONS; i++) { // reset output buffer out1.reset(); out2.reset(); out3.reset(); // generate two random strings String str1 = getTestString(); String str2 = getTestString(); if (i == 0) { str1 = getLongString(); str2 = getLongString(); } else { str1 = getTestString(); str2 = getTestString(); } // convert to texts Text txt1 = new Text(str1); Text txt2 = new Text(str2); Text txt3 = new Text(str1); // serialize them txt1.write(out1); txt2.write(out2); txt3.write(out3); // compare two strings by looking at their binary formats int ret1 = comparator.compare(out1.getData(), 0, out1.getLength(), out2.getData(), 0, out2.getLength()); // compare two strings int ret2 = txt1.compareTo(txt2); assertEquals(ret1, ret2); assertEquals("Equivalence of different txt objects, same content" , 0, txt1.compareTo(txt3)); assertEquals("Equvalence of data output buffers", 0, comparator.compare(out1.getData(), 0, out3.getLength(), out3.getData(), 0, out3.getLength())); } } public void testFind() throws Exception { Text text = new Text("abcd\u20acbdcd\u20ac"); assertTrue(text.getLength()==14); assertTrue(text.find("abd")==-1); assertTrue(text.find("ac")==-1); assertTrue(text.find("\u20ac")==4); assertTrue(text.find("\u20ac", 5)==11); byte [] b1 = new byte[]{97, 98, 99, 100, -30, -126, -84, 98, 100, 99, 100, -30, -126, -84}; byte [] b2 = text.copyBytes(); assertTrue(Arrays.equals(b1, b2)); } public void testFindAfterUpdatingContents() throws Exception { Text text = new Text("abcd"); text.set("a".getBytes()); assertEquals(text.getLength(),1); assertEquals(text.find("a"), 0); assertEquals(text.find("b"), -1); } public void testValidate() throws Exception { Text text = new Text("abcd\u20acbdcd\u20ac"); byte [] utf8 = text.getBytes(); int length = text.getLength(); Text.validateUTF8(utf8, 0, length); } public void testClear() throws Exception { // Test lengths on an empty text object Text text = new Text(); assertEquals( "Actual string on an empty text object must be an empty string", "", text.toString()); assertEquals("Underlying byte array length must be zero", 0, text.getBytes().length); assertEquals("String's length must be zero", 0, text.getLength()); // Test if clear works as intended text = new Text("abcd\u20acbdcd\u20ac"); int len = text.getLength(); text.clear(); assertEquals("String must be empty after clear()", "", text.toString()); assertTrue( "Length of the byte array must not decrease after clear()", text.getBytes().length >= len); assertEquals("Length of the string must be reset to 0 after clear()", 0, text.getLength()); } public void testTextText() throws CharacterCodingException { Text a=new Text("abc"); Text b=new Text("a"); b.set(a); assertEquals("abc", b.toString()); a.append("xdefgxxx".getBytes(), 1, 4); assertEquals("modified aliased string", "abc", b.toString()); assertEquals("appended string incorrectly", "abcdefg", a.toString()); // add an extra byte so that capacity = 14 and length = 8 a.append(new byte[]{'d'}, 0, 1); assertEquals("abcdefgd",a.toString()); byte[] b1= new byte[]{97, 98, 99, 100, 101, 102, 103, 100, 0, 0, 0, 0, 0, 0}; byte[] b2= new byte[]{97, 98, 99, 100, 101, 102, 103, 100}; assertEquals(8, a.getLength()); assertEquals(14, a.getBytes().length); assertEquals(8, a.copyBytes().length); assertTrue(Arrays.equals(b1, a.getBytes())); assertTrue(Arrays.equals(b2, a.copyBytes())); a.set(new Text("abc")); assertEquals(14, a.getBytes().length);//byte长度没变小! assertEquals(3, a.getLength()); } private class ConcurrentEncodeDecodeThread extends Thread { public ConcurrentEncodeDecodeThread(String name) { super(name); } @Override public void run() { final String name = this.getName(); DataOutputBuffer out = new DataOutputBuffer(); DataInputBuffer in = new DataInputBuffer(); for (int i=0; i < 1000; ++i) { try { out.reset(); WritableUtils.writeString(out, name); in.reset(out.getData(), out.getLength()); String s = WritableUtils.readString(in); assertEquals("input buffer reset contents = " + name, name, s); } catch (Exception ioe) { throw new RuntimeException(ioe); } } } } public void testConcurrentEncodeDecode() throws Exception{ Thread thread1 = new ConcurrentEncodeDecodeThread("apache"); Thread thread2 = new ConcurrentEncodeDecodeThread("hadoop"); thread1.start(); thread2.start(); thread2.join(); thread2.join(); } public void testAvroReflect() throws Exception { AvroTestUtil.testReflect (new Text("foo"), "{\"type\":\"string\",\"java-class\":\"org.apache.hadoop.io.Text\"}"); } /** * */ public void testCharAt() { String line = "adsawseeeeegqewgasddga"; Text text = new Text(line); for (int i = 0; i < line.length(); i++) { assertTrue("testCharAt error1 !!!", text.charAt(i) == line.charAt(i)); } assertEquals("testCharAt error2 !!!", -1, text.charAt(-1)); assertEquals("testCharAt error3 !!!", -1, text.charAt(100)); } /** * test {@code Text} readFields/write operations */ public void testReadWriteOperations() { String line = "adsawseeeeegqewgasddga"; byte[] inputBytes = line.getBytes(); inputBytes = Bytes.concat(new byte[] {(byte)22}, inputBytes); DataInputBuffer in = new DataInputBuffer(); DataOutputBuffer out = new DataOutputBuffer(); Text text = new Text(line); try { in.reset(inputBytes, inputBytes.length); text.readFields(in); } catch(Exception ex) { fail("testReadFields error !!!"); } try { text.write(out); } catch(IOException ex) { } catch(Exception ex) { fail("testReadWriteOperations error !!!"); } } public void testReadWithKnownLength() throws IOException { String line = "hello world"; byte[] inputBytes = line.getBytes(Charsets.UTF_8); DataInputBuffer in = new DataInputBuffer(); Text text = new Text(); in.reset(inputBytes, inputBytes.length); text.readWithKnownLength(in, 5); assertEquals("hello", text.toString()); // Read longer length, make sure it lengthens in.reset(inputBytes, inputBytes.length); text.readWithKnownLength(in, 7); assertEquals("hello w", text.toString()); // Read shorter length, make sure it shortens in.reset(inputBytes, inputBytes.length); text.readWithKnownLength(in, 2); assertEquals("he", text.toString()); } /** * test {@code Text.bytesToCodePoint(bytes) } * with {@code BufferUnderflowException} * */ public void testBytesToCodePoint() { try { ByteBuffer bytes = ByteBuffer.wrap(new byte[] {-2, 45, 23, 12, 76, 89}); Text.bytesToCodePoint(bytes); assertTrue("testBytesToCodePoint error !!!", bytes.position() == 6 ); } catch (BufferUnderflowException ex) { fail("testBytesToCodePoint unexp exception"); } catch (Exception e) { fail("testBytesToCodePoint unexp exception"); } } public void testbytesToCodePointWithInvalidUTF() { try { Text.bytesToCodePoint(ByteBuffer.wrap(new byte[] {-2})); fail("testbytesToCodePointWithInvalidUTF error unexp exception !!!"); } catch (BufferUnderflowException ex) { } catch(Exception e) { fail("testbytesToCodePointWithInvalidUTF error unexp exception !!!"); } } public void testUtf8Length() { assertEquals("testUtf8Length1 error !!!", 1, Text.utf8Length(new String(new char[]{(char)1}))); assertEquals("testUtf8Length127 error !!!", 1, Text.utf8Length(new String(new char[]{(char)127}))); assertEquals("testUtf8Length128 error !!!", 2, Text.utf8Length(new String(new char[]{(char)128}))); assertEquals("testUtf8Length193 error !!!", 2, Text.utf8Length(new String(new char[]{(char)193}))); assertEquals("testUtf8Length225 error !!!", 2, Text.utf8Length(new String(new char[]{(char)225}))); assertEquals("testUtf8Length254 error !!!", 2, Text.utf8Length(new String(new char[]{(char)254}))); } }
运行结果如下:
相关推荐
Hadoop安装教程_单机/伪分布式配置_Hadoop2.7.1/Ubuntu 16.04 本教程主要讲述了在 Ubuntu 16.04 环境下安装 Hadoop 2.7.1 的步骤,包括单机模式、伪分布式模式和分布式模式三种安装方式。以下是本教程的知识点总结...
hadoop2.7.1的eclipse插件,编译环境,eclipse 4.4(luna) ,jdk1.7,ant1.9.6,maven3.3,hadoop2.7.1,centos6.7,jdk1.7 要注意的是开发黄金下jdk版本必须是jdk1.7及以上,否则无法使用
eclipse hadoop2.7.1 plugin 配置,包括操作步骤说明,eclipse hadoop2.7.1的插件,还有hadoop.dll和winutils.exe等文件。
Hadoop2.7.1中文文档
hadoop2.7.1的linux下eclipse支持插件。已经经过检查,安装后在eclipse下,可以正常上传,下载,删除hdfs文件,以及跑mapreduce程序。 编译环境:ant1.9.6 jdk1.8 hadoop2.7.1
hadoop-2.7.1 + hive-1.2.1 稳定
hadoop2.7.1平台搭建
Spark所需的hadoop2.7.1相关资源 hadoop2.7.1版本的hadoop.dll,winutils.exe 适用Spark2.0.0+版本
hadoop2.7.1版本的hadoop.dll,winutils.exe hadoop2.7.1版本的hadoop.dll,winutils.exe
在网上下了好多2.6版本的hadoop.dll,但是都不好使,昨天有个好心网友给我发了一份,实际测试通过。开发环境是64位win7+hadoop2.7.1+redhat版本的linux。
本人用7个多小时成功编译 hadoop 2.7.1 64位编译包(JDK1.8 64),由于文件太大,分3卷压缩。 hadoop 2.7.1 相对于2.7.0修复了上百个Bug,是可用于生产环境的版本了。
hadoop2.7.1 windows 64位 相关 dll文件
Hadoop-2.7.1-Windows-64-binaries, 预先编译,非官方的Hadoop 2.7.1的Win64二进制文件 用于 Windows 64位 平台的 2.7.1二进制文件这是针对 Windows 64位 平台的非官方预先编译的Apache Hadoop 2.7.1. 这里的tar.gz ...
Windows 7 or 10 eclipse hadoop2.7.1 配置需要文件和工具
Hadoop 2.7.1 中文文档 Hadoop 2.7.1 中文文档 Hadoop 2.7.1 中文文档
hadoop.dll winutils.exe for hadoop2.7.1 下载版本,
hadoop2.7.1运行Wordcount错误 at java.lang.ProcessBuilder.start(ProcessBuilder.java:1012) Exception in thread "main" java.lang.UnsatisfiedLinkError
win32平台winutils,hadoop win32 native code
hadoop2.7.1 windows7 32 位 hadoop.dll winutils.exe.在window7 32位下,编译的源码。
hadoop-2.7.1-64位编译包,本人亲测,绝对有用。