java.io,PrintWriter可以用来创建一个文件并向本文文件写入数据

java.io,PrintWriter可以用来创建一个文件并向本文文件写入数据

PrintWriter(String filename);
PrintWriter(File file);
PrintWriter(OutoutStream out);
PrintWriter(OutoutStream out,Boolean antoflush);
PrintWriter(Writer out);
PrintWriter(Writer out，Boolean );
print(Object obj);
print(String s);
print(char[] c);
print(int i);print(long i);print(float f);print(double d);print(boolean b);打印对应的类型

例如：

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
public class WriteData {
     public static void main(String[] args) throws FileNotFoundException{
         File file=new File("num.txt");//文件对象
         if(file.exists()){
             System.out.print("文件已经存在！");
             System.exit(0);
         }
         PrintWriter out=new PrintWriter(file);//由文件对象构造一个写出器
         out.println("John,Where are you?");
         out.println("I'am here!");
         out.println("How old are you?");
         out.println(15);
         //关闭写出器
         out.close();
     }
}