想通过applet,在网页上显示某个文件的内容,感觉应该可以,可无法实现,惭愧贴下我的代码,只有几行:import java.applet .*;
import java.awt.*;
import java.sql.*;
import java.util.*;
import java.io.*;public class Applet1 extends Applet
{
String line;
public void start()
{
try{
File MyFi1e= new File("c:\\" ,"date1.txt");//从这读取内容,其实就是几个数字
BufferedReader read = new BufferedReader(new InputStreamReader(new FileInputStream(MyFi1e)));
line = read.readLine();
}catch(Exception e){
System.out.print(e.getMessage());
}
} public void paint(Graphics g)
{
g.drawString (line,50,50);
}}运行后一点都没有显示出来,控制台报错如下:
Exception in thread "AWT-EventQueue-56" java.lang.NullPointerException: String is null
at sun.java2d.SunGraphics2D.drawString(Unknown Source)
at TemperatureApplet.paint(TemperatureApplet.java:26)
at sun.awt.RepaintArea.paintComponent(Unknown Source)
at sun.awt.RepaintArea.paint(Unknown Source)
at sun.awt.windows.WComponentPeer.handleEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
还请各位高手多多指教!
import java.awt.*;
import java.sql.*;
import java.util.*;
import java.io.*;public class Applet1 extends Applet
{
String line;
public void start()
{
try{
File MyFi1e= new File("c:\\" ,"date1.txt");//从这读取内容,其实就是几个数字
BufferedReader read = new BufferedReader(new InputStreamReader(new FileInputStream(MyFi1e)));
line = read.readLine();
}catch(Exception e){
System.out.print(e.getMessage());
}
} public void paint(Graphics g)
{
g.drawString (line,50,50);
}}运行后一点都没有显示出来,控制台报错如下:
Exception in thread "AWT-EventQueue-56" java.lang.NullPointerException: String is null
at sun.java2d.SunGraphics2D.drawString(Unknown Source)
at TemperatureApplet.paint(TemperatureApplet.java:26)
at sun.awt.RepaintArea.paintComponent(Unknown Source)
at sun.awt.RepaintArea.paint(Unknown Source)
at sun.awt.windows.WComponentPeer.handleEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
还请各位高手多多指教!
所以,你要不就不要使用APPLET,要不就改写permission文件,让它可以允许APPLET操作本地文件系统
楼主,我很欣赏你的import 太完美了
若是读服务器端的文件,又该如何了?
applet在服务器上运行,也不可以读本地(即服务器)的文件啊