将1000到1100的素数输入到文件data.txt中，并且读出来

二进制形式输出：

import java.io.*;
public class Outputsushu
{
public static int panduansushu(int a)
{
for(int i=2;i <Math.sqrt(a);i++)
{
if(a%i==0)
{
return 1;
}
}

return 0;
}
public static void main(String args[])
{
int b;
try
{
FileOutputStream t=new FileOutputStream("data.txt");
DataOutputStream f=new DataOutputStream(t);
for(b=1000;b <=1100;b++)
{
if(panduansushu(b)==0)
{
//System.out.println(b);
f.writeInt(b);

}
}
f.close( );
}
catch(Exception e)
{
System.out.println(e);
}
int n;
try
{
FileInputStream p=new FileInputStream("data.txt");
DataInputStream q=new DataInputStream(p);
while(true)
{
try
{
n=q.readInt();
System.out.println(n);
}
catch (EOFException ex)
{
System.out.println();
break;
}
}
q.close();
}
catch(Exception e)
{
System.out.println(e);
}
}

}

正常显示：

public static void main(String args[]) {
int b;
String temp = new String();
for (b = 1000; b <= 1100; b++) {
if (panduansushu(b) == 0) {
// System.out.println(b);
temp += String.valueOf(b) + "/n";
}
}
try {
FileWriter fw = new FileWriter("C://data.txt");
PrintWriter out = new PrintWriter(fw);
out.write(temp);
out.println();
fw.close();
out.close();
} catch (Exception e) {
System.out.println(e);
}
try {
File fr = new File("c://data.txt");
BufferedReader reader = null;
// System.out.println("以行为单位读取文件内容，一次读一整行：");
reader = new BufferedReader(new FileReader(fr));
String tempString = null;
System.out.println(reader.readLine());
int line = 1;
// 一次读入一行，直到读入null为文件结束
while ((tempString = reader.readLine()) != null) {
// 显示行号
System.out.println("line " + line + ": " + tempString);
line++;
}
reader.close();
} catch (IOException e) {
e.printStackTrace();
}

}