如何用Java

Question

File Name = new File("G:/Java/lesson25_1/Name.txt"); 

if(Name==null){ 

    JOptionPane.showMessageDialog(this, "Details are missing"); 
} 

try{ 

    FileReader fr1 = new FileReader("Name.txt"); 

    BufferedReader br1=new BufferedReader(fr1); 

    String str=br1.readLine(); 

    br1.close(); 

创建文件时，我这样做的方法，它不到风度工作时，我按一下按钮

Answer 1

有名为exists检查给定文件是否存在，或者没有文件的方法。

String path = "G:/Java/lesson25_1/Name.txt"; 
File file = new File(path); 

if(!file.isFile() || !file.canRead()){ 
    JOptionPane.showMessageDialog(this, "Details are missing"); 
} else { 
    try { 

     FileReader fr1 = new FileReader("Name.txt"); 
     BufferedReader br1=new BufferedReader(fr1); 

     String str=br1.readLine(); 

     br1.close(); 
    } catch (Exception e){ 
     e.printStackTrace(); 
    } 
}