Question

我有一个applet类，我希望当我点击applet上的按钮时，它会运行Java Class。

它运行Java类，但是在Java类中我创建了一个.csv文件，所以它给了我错误

找不到文件

.....如果我单独运行Java Class，它会给出正确的输出....

链接applet和Java Class有什么问题？

小程序类

import java.applet.*;  
import java.awt.*;  
import java.awt.event.*;  
public class anApplet extends Applet implements ActionListener{  
Button b;  
TextField tf;  

public void init(){  
tf=new TextField();  
tf.setBounds(30,40,150,20);  

b=new Button("Click");  
b.setBounds(80,150,60,50);  

add(b);add(tf);  
b.addActionListener(this);  

setLayout(null);  
}  

 public void actionPerformed(ActionEvent e){  
 tf.setText("Welcome"); 
try {
callingClass.main(null);
} catch (Throwable e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}   
}

Java类

 public class callingClass {
 public static void main(String[] main) throws Exception, Throwable
 {
      String outputFile = "Data\\Volume.csv";

    // before we open the file check to see if it already exists
    boolean alreadyExists = new File(outputFile).exists();
    try {
        // use FileWriter constructor that specifies open for appending
        CsvWriter csvOutput = new CsvWriter(new FileWriter(outputFile, true), ',');

        // if the file didn't already exist then we need to write out the header line
        if (!alreadyExists)
        {
            csvOutput.write("date");
            csvOutput.write("value");
            csvOutput.endRecord();
        }
        // else assume that the file already has the correct header line

        // write out a few records
        csvOutput.write("Hello");
        csvOutput.write( "CSV file");
        csvOutput.endRecord();

        //csvOutput.write("2");
        //csvOutput.write("John");
    //  csvOutput.endRecord();

        csvOutput.close();
    } catch (IOException e) {
        e.printStackTrace();
    }


}
}

单击Applet按钮运行Java类错误

0 个答案: