package com.xxj;
import java.io.*;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicLong;
/**
* ClassName:BigFileReader
* Package:com.xxj
* Description:描述信息
*
* @Date:2022/9/18 12:49
* @author:alpha_Joker
*/
public class BigFileReader {
private int threadSize;
private String charset;
private int bufferSize;
private IHandle handle;
private ExecutorService executorService;
private long fileLength;
private RandomAccessFile randomAccessFile;
private Set<StartEndPair> startEndPairs;
private CyclicBarrier cyclicBarrier;
private AtomicLong counter = new AtomicLong(0);
private BigFileReader(File file, IHandle handle, String charset, int bufferSize, int threadSize) {
this.fileLength = file.length();
this.handle = handle;
this.charset = charset;
this.bufferSize = bufferSize;
this.threadSize = threadSize;
try {
this.randomAccessFile = new RandomAccessFile(file, "r");
} catch (FileNotFoundException e) {
e.printStackTrace();
}
this.executorService = Executors.newFixedThreadPool(threadSize);
startEndPairs = new HashSet<BigFileReader.StartEndPair>();
}
private void calculateStartEnd(long start, long size) throws IOException {
if (start > fileLength - 1) {
return;
}
StartEndPair pair = new StartEndPair();
pair.start = start;
long endPosition = start + size - 1;
if (endPosition >= fileLength - 1) {
pair.end = fileLength - 1;
startEndPairs.add(pair);
return;
}
randomAccessFile.seek(endPosition);
byte tmp = (byte) randomAccessFile.read();
while (tmp != '\n' && tmp != '\r') {
endPosition++;
if (endPosition >= fileLength - 1) {
endPosition = fileLength - 1;
break;
}
randomAccessFile.seek(endPosition);
tmp = (byte) randomAccessFile.read();
}
pair.end = endPosition;
startEndPairs.add(pair);
calculateStartEnd(endPosition + 1, size);
}
public void shutdown() {
try {
this.randomAccessFile.close();
} catch (IOException e) {
e.printStackTrace();
}
this.executorService.shutdown();
}
private void handle(byte[] bytes) throws UnsupportedEncodingException {
String line = null;
if (this.charset == null) {
line = new String(bytes);
} else {
line = new String(bytes, charset);
}
if (line != null && !"".equals(line)) {
this.handle.handle(line);
counter.incrementAndGet();
}
}
//切片
private static class StartEndPair {
public long start;
public long end;
@Override
public String toString() {
return "star=" + start + "end=" + end;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + (int) (end ^ (end >>> 32));
result = prime * result + (int) (start ^ (start >>> 32));
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
StartEndPair other = (StartEndPair) obj;
if (end != other.end)
return false;
if (start != other.start)
return false;
return true;
}
}
//读取
private class SliceReaderTask implements Runnable {
private long start;
private long sliceSize;
private byte[] readBuff;
public SliceReaderTask(StartEndPair pair) {
this.start = pair.start;
this.sliceSize = pair.end - pair.start + 1;
this.readBuff = new byte[bufferSize];
}
@Override
public void run() {
try {
MappedByteBuffer mapBuffer = randomAccessFile.getChannel().map(FileChannel.MapMode.READ_ONLY, start, this.sliceSize);
ByteArrayOutputStream bos = new ByteArrayOutputStream();
for (int offset = 0; offset < sliceSize; offset += bufferSize) {
int readLength;
if (offset + bufferSize <= sliceSize) {
readLength = bufferSize;
} else {
readLength = (int) (sliceSize);
}
mapBuffer.get(readBuff, 0, readLength);
for (int i = 0; i < readLength; i++) {
byte tmp = readBuff[i];
if (tmp == '\n' || tmp == '\r') {
handle(bos.toByteArray());
bos.reset();
} else {
bos.write(tmp);
}
}
}
if (bos.size() > 0) {
handle(bos.toByteArray());
}
cyclicBarrier.await();
} catch (Exception e) {
e.printStackTrace();
}
}
}
public static class Builder {
private int threadSize = 1;
private String charset = null;
private int bufferSize = 1024 * 1024;
private IHandle handle;
private File file;
public Builder(String file, IHandle handle) {
this.file = new File(file);
if (!this.file.exists())
throw new IllegalArgumentException("文件不存在");
this.handle = handle;
}
public Builder withTreadSize(int size) {
this.threadSize = size;
return this;
}
public Builder withCharset(String charset) {
this.charset = charset;
return this;
}
public Builder withBufferSize(int bufferSize) {
this.bufferSize = bufferSize;
return this;
}
public BigFileReader build() {
return new BigFileReader(this.file, this.handle, this.charset, this.bufferSize, this.threadSize);
}
}
public void start() {
long everySize = this.fileLength / this.threadSize;
try {
calculateStartEnd(0, everySize);
} catch (Exception e) {
e.printStackTrace();
return;
}
final long startTime = System.currentTimeMillis();
cyclicBarrier = new CyclicBarrier(startEndPairs.size(), new Runnable() {
@Override
public void run() {
long time = System.currentTimeMillis() - startTime;
System.out.println("time:"+time);
System.out.println("line:"+counter.get());
}
});
for (StartEndPair pair : startEndPairs) {
System.out.println(pair);
this.executorService.execute(new SliceReaderTask(pair));
}
}
}
package com.xxj;
/**
* ClassName:IHandle
* Package:com.xxj
* Description:描述信息
*
* @Date:2022/9/18 12:48
* @author:alpha_Joker
*/
public interface IHandle {
void handle(String line);
}
package com.xxj;
import cn.hutool.json.JSONArray;
import cn.hutool.json.JSONObject;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
/**
* ClassName:Test
* Package:com.xxj
* Description:描述信息
*
* @Date:2022/9/18 15:11
* @author:alpha_Joker
*/
public class Test {
public static void main(String[] args) {
// fre
BigFileReader.Builder builder =new BigFileReader.Builder("C:\\Users\\Administrator\\Desktop\\fre.txt", new IHandle() {
@Override
public void handle(String line) {
// System.out.println(line);
JSONObject jsonObject = new JSONObject();
String [] str = line.split("\\s+");
String[] _str = reverseArray(str);
// System.out.println("数据："+Arrays.toString(_str));
if (str.length ==1 && str[0].length() == 14) {
jsonObject.putOpt("time", str[0]);
System.out.println(jsonObject.toJSONString(0));
}
if (_str.length == 11) {
// jsonObject.putOpt("Iteam", str[0]);
jsonObject.putOpt("Dtail", str[1]+" "+str[2]+" "+str[3]+" "+str[4]);
jsonObject.putOpt("F", _str[5]);
jsonObject.putOpt("max", _str[4]);
jsonObject.putOpt("mem", _str[3]);
jsonObject.putOpt("nem", _str[2]);
jsonObject.putOpt("csf", _str[1]);
jsonObject.putOpt("asd", _str[0]);
System.out.println(jsonObject.toJSONString(0));
}
if (_str.length == 10 || _str.length == 9) {
// jsonObject.putOpt("Iteam", str[0]);
if (_str.length == 10)
jsonObject.putOpt("Dtail", str[1]+" "+str[2]+" "+str[3]);
if (_str.length == 9)
jsonObject.putOpt("Dtail", str[1]+" "+str[2]);
jsonObject.putOpt("F", _str[5]);
jsonObject.putOpt("max", _str[4]);
jsonObject.putOpt("mem", _str[3]);
jsonObject.putOpt("nem", _str[2]);
jsonObject.putOpt("csf", _str[1]);
jsonObject.putOpt("asd", _str[0]);
System.out.println(jsonObject.toJSONString(0));
}
// System.out.println(str.length+"--"+line.startsWith(" "));
}
});
// builder.withThreadSize(10).withCharset("gbk").withBufferSize("1024*1024");
builder.withTreadSize(1).withCharset("utf-8").withBufferSize(1024*1024);
BigFileReader bigFileReader = builder.build();
bigFileReader.start();
}
/**
* 使用Collections.reverse来倒置数组
*
* @param strArray 原来的字符串数组
* @return
*/
public static String[] reverseArray(String[] strArray) {
//定一个新的数组
String[] newArray = new String[strArray.length];
List<String> list = new ArrayList<>();
Collections.addAll(list, strArray);
Collections.reverse(list);
list.toArray(newArray);
return newArray;
}
}
标签：文件,读取,jsonObject,putOpt,private,str,分片,new,public From： https://www.cnblogs.com/joyny/p/16705567.html