Scanner input = new Scanner(new File("temp.txt"));
System.out.print(input.nextLine());		
		
		

		
package cn.netkiller.io;

import java.io.File;
import java.io.FileNotFoundException;
//import java.io.PrintWriter;
import java.util.Scanner;

public class PrintWriterTest {

	private static Scanner input;

	public PrintWriterTest() {
		// TODO Auto-generated constructor stub
	}

	public static void main(String[] args) throws FileNotFoundException {
		// TODO Auto-generated method stub
		// PrintWriter output = new PrintWriter("temp.txt");
		// output.print("Welcome to Java!");
		// output.close();

		input = new Scanner(new File("temp.txt"));
		System.out.print(input.nextLine());
	}

}
		
		

		
@Test
void testReadFile1() throws IOException {

   String fileName = "D:\\test\\netkiller\\neo.txt";

   try (Scanner sc = new Scanner(new FileReader(fileName))) {
      while (sc.hasNextLine()) {  //按行读取字符串
         String line = sc.nextLine();
         System.out.println(line);
      }
   }

   try (Scanner sc = new Scanner(new FileReader(fileName))) {
      sc.useDelimiter("\\|");  //分隔符
      while (sc.hasNext()) {   //按分隔符读取字符串
         String str = sc.next();
         System.out.println(str);
      }
   }

   //sc.hasNextInt() 、hasNextFloat() 、基础数据类型等等等等。
   fileName = "D:\\netkiller\\test\\neo.txt";
   try (Scanner sc = new Scanner(new FileReader(fileName))) {
      sc.useDelimiter("\\|");  //分隔符
      while (sc.hasNextInt()) {   //按分隔符读取Int
          int intValue = sc.nextInt();
         System.out.println(intValue);
      }
   }
}