请问java如何生成大量数字英文单词的13位随机数大概5.5亿条只求不重复

请问java如何生成大量数字英文单词的13位随机数大概5.5亿条只求不重复
请问java如何生成大量数字英文单词的13位随机数大概5.5亿条只求不重复

请问java如何生成大量数字英文单词的13位随机数大概5.5亿条只求不重复

5.5亿条 13个字符 保存成文件都要700-800M,要计算的话很花时间的.试着写了一下,你参考下

由于用了并行框架fork join所以cup越多运行越快,不过生成的文件太大,打开会很慢.

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.HashMap;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.ForkJoinTask;
import java.util.concurrent.RecursiveAction;
import java.util.concurrent.TimeUnit;
public class TestForkJoin extends RecursiveAction{
static int ll=0;
static int ai=5;
FileWriter fwr=null;
int[][] s=null;
static String[] array={"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
public TestForkJoin(int[][] s,FileWriter fwr){
this.s=s;
this.fwr=fwr;
}
protected void compute() {
if(test()){
ddd(s,fwr);
}else{
for(int i=0;i<s[0].length;i++){
if(s[1][i]-s[0][i]>ai){
int[][] a=new int[2][s[0].length];
int[][] b=new int[2][s[0].length];
for(int p=0;p<a.length;p++){
for(int q=0;q<a[p].length;q++){
a[p][q]=s[p][q];
b[p][q]=s[p][q];
}
}
a[0][i]=s[0][i];
a[1][i]=(s[0][i]+s[1][i])/2;
b[0][i]=(s[0][i]+s[1][i])/2+1;
b[1][i]=s[1][i];
invokeAll(new TestForkJoin(a,fwr),new TestForkJoin(b,fwr));
break;
}
}
}
}
private boolean test(){
for(int i=0;i<s[0].length;i++){
if(s[1][i]-s[0][i]>ai){
return false;
}
}
return true;
}
private void ddd(int[][] s,FileWriter fwr){
HashMap<Integer,String> map=new HashMap<Integer,String>();
StringBuilder sb=null;
int n=0;
int tm=0;
String sss=null;
while(map.entrySet().size()<270){
n=0;
tm=0;
sb=new StringBuilder();
for(int m=0;m<13;m++){
if(m%2==1){
tm=(int)(Math.random()*(s[1][n]-s[0][n]))+s[0][n];
sb.append(array[tm]);
}else{
tm=(int)(Math.random()*array.length);
sb.append(array[tm]);
}
}
sss=sb.toString();
if(map.get(sss.hashCode())==null){
map.put(sss.hashCode(), sss);
try {
fwr.write(sss+"\r\n");
fwr.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
@SuppressWarnings("unchecked")
public static void main(String[] args) throws IOException, InterruptedException{
FileWriter fw=new FileWriter(new File("F://111.txt"),true);
int[][] k={{0,0,0,0,0,0},{array.length,array.length,array.length,array.length,array.length,array.length}};
ForkJoinTask sort = new TestForkJoin(k,fw);
ForkJoinPool fjpool = new ForkJoinPool();
fjpool.submit(sort);
fjpool.shutdown();
fjpool.awaitTermination(12000,TimeUnit.SECONDS);
fw.close();
}
}