我想在hadoop中实现多模式匹配。作为第一步，我将实现booyermoore实现。我得到一个类没有发现异常。代码如下：
package saihadoopboyer;
import saihadoopboyer.BoyerMoore;
import java.io.IOException;
import java.util.StringTokenizer;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
//import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
public class BoyerMooreImpl {
public static class TokenizerMapper
extends Mapper<Object, Text, Text, IntWritable>{
private BoyerMoore boyerMoore;
private static IntWritable offset;
private Text offsetFound = new Text("offset");
public void map(Object key, Text value, Context context
) throws IOException, InterruptedException {
StringTokenizer itr = new StringTokenizer(value.toString());
while (itr.hasMoreTokens()) {
String line = itr.nextToken();
int offset1 = boyerMoore.search(line);
if (line.length() != offset1) {
offset = new IntWritable(offset1);
context.write(offsetFound,offset);
}
}
}
@Override
public final void setup(Context context) {
if (boyerMoore == null)
boyerMoore = new BoyerMoore(context.getConfiguration().get("pattern"));
}
}
public static void main(String[] args) throws Exception {
Configuration conf = new Configuration();
conf.set("pattern","sai");
Job job = Job.getInstance(conf, "BoyerMoore");
job.setJarByClass(BoyerMooreImpl.class);
job.setMapperClass(TokenizerMapper.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
FileInputFormat.addInputPath(job, new Path(args[0]));
FileOutputFormat.setOutputPath(job, new Path(args[1]));
System.exit(job.waitForCompletion(true) ? 0 : 1);
}
}Booyermore calss的实现如下：
package saihadoopboyer;
public class BoyerMoore {
private final int R; // the radix
private int[] right; // the bad-character skip array
private char[] pattern; // store the pattern as a character array
private String pat; // or as a string
/**
* Preprocesses the pattern string.
*
* @param pat the pattern string
*/
public BoyerMoore(String pat) {
this.R = 256;
this.pat = pat;
// position of rightmost occurrence of c in the pattern
right = new int[R];
for (int c = 0; c < R; c++)
right[c] = -1;
for (int j = 0; j < pat.length(); j++)
right[pat.charAt(j)] = j;
}
/**
* Preprocesses the pattern string.
*
* @param pattern the pattern string
* @param R the alphabet size
*/
public BoyerMoore(char[] pattern, int R) {
this.R = R;
this.pattern = new char[pattern.length];
for (int j = 0; j < pattern.length; j++)
this.pattern[j] = pattern[j];
// position of rightmost occurrence of c in the pattern
right = new int[R];
for (int c = 0; c < R; c++)
right[c] = -1;
for (int j = 0; j < pattern.length; j++)
right[pattern[j]] = j;
}
/**
* Returns the index of the first occurrrence of the pattern string
* in the text string.
*
* @param txt the text string
* @return the index of the first occurrence of the pattern string
* in the text string; n if no such match
*/
public int search(String txt) {
int m = pat.length();
int n = txt.length();
int skip;
for (int i = 0; i <= n - m; i += skip) {
skip = 0;
for (int j = m-1; j >= 0; j--) {
if (pat.charAt(j) != txt.charAt(i+j)) {
skip = Math.max(1, j - right[txt.charAt(i+j)]);
break;
}
}
if (skip == 0) return i; // found
}
return n; // not found
}
/**
* Returns the index of the first occurrrence of the pattern string
* in the text string.
*
* @param text the text string
* @return the index of the first occurrence of the pattern string
* in the text string; n if no such match
*/
public int search(char[] text) {
int m = pattern.length;
int n = text.length;
int skip;
for (int i = 0; i <= n - m; i += skip) {
skip = 0;
for (int j = m-1; j >= 0; j--) {
if (pattern[j] != text[i+j]) {
skip = Math.max(1, j - right[text[i+j]]);
break;
}
}
if (skip == 0) return i; // found
}
return n; // not found
}
/**
* Takes a pattern string and an input string as command-line arguments;
* searches for the pattern string in the text string; and prints
* the first occurrence of the pattern string in the text string.
*/
/*
public static void main(String[] args) {
String pat = "sai";
String txt = "babababasaibaba";
char[] pattern = pat.toCharArray();
char[] text = txt.toCharArray();
BoyerMoore boyermoore1 = new BoyerMoore(pat);
BoyerMoore boyermoore2 = new BoyerMoore(pattern, 256);
int offset1 = boyermoore1.search(txt);
int offset2 = boyermoore2.search(text);
// print results
System.out.println("text: " + txt);
System.out.println("pattern: ");
for (int i = 0; i < offset1; i++)
System.out.println(" ");
System.out.println(pat);
System.out.println("pattern: ");
for (int i = 0; i < offset2; i++)
System.out.println(" ");
System.out.println(pat);
}*/
}我的jar-tf输出如下：
META-INF/MANIFEST.MF
.classpath
saihadoopboyer/BoyerMoore.class
saihadoopboyer/BoyerMooreImpl$TokenizerMapper.class
saihadoopboyer/BoyerMooreImpl.class
.project我运行的代码如下所示：
hduser@Ganesh:~/Documents$ hadoop jar saihadoopboyer.jar saihadoopboyer.BooyerMooreImpl Behara/saihadoop/input Behara/saihadoop/output我得到以下错误：
Exception in thread "main" java.lang.ClassNotFoundException: saihadoopboyer.BooyerMooreImpl
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:278)
at org.apache.hadoop.util.RunJar.run(RunJar.java:214)
at org.apache.hadoop.util.RunJar.main(RunJar.java:136)我正在eclipse中创建一个jar文件。提前感谢所有帮助我的人：）：）
暂无答案！
目前还没有任何答案，快来回答吧！