小弟很着急~ 大哥看这里~ (关于:applet 在浏览器中读取文件时的错误)
先把程序贴出来~
import java.io.*;
import java.net.*;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.JOptionPane;
public class Pc extends Applet implements ActionListener
{ TextField text;
Button buttonEnter;
public void init()
{
text = new TextField("0",10);
add(text);
buttonEnter = new Button("确定");
add(buttonEnter);
buttonEnter.addActionListener(this);
}
public void paint(Graphics g)
{
g.drawString("请输入正确的密码",5,80);
}
public void actionPerformed(ActionEvent e)
{
if (e.getSource() == buttonEnter)
{
String psw = new String("");
String inp = new String("");
int psw_len,len=0,l,temp;
byte pp[] = new byte[100];
try{
File f = new File("psw"); // psw为密码文件名
FileInputStream readfile = new FileInputStream(f);
psw_len = readfile.read(); // 读取密码文件的第一字节(密码位数)
// 此密码位数其实无用,掩人耳目而已
while( (l = readfile.read(pp,1,psw_len + 1)) != -1)
{
len = l; // 读取密码按字节 并计数
}
for (l = 1; l <= len; l++) // 密码转换
{
temp = (int)pp[l];
temp = temp + 3;
if (temp > 255) temp = temp - 255;
pp[l] = (byte)temp;
}
psw = new String (pp,1,len); // 创建密码串
System.out.println(psw); // 密码测试输出
text.setText(psw); // 测试输出（当applet在浏览器中运行，不能读出密码!!!!!!!!!!!!!!）
readfile.close(); // 关闭
}
catch (IOException exp_file){
System.out.println("File read error:"+exp_file);
text.setText(exp_file);
}
inp = text.getText();
System.out.println(inp);
System.out.println(inp.length());
System.out.println(psw.length());
// 得到窗口句柄
Container c = text.getParent();
c = c.getParent();
System.out.println(c); // 测试输出
if (psw.equals(inp)) // 密码判断逻辑
{
try{
System.out.println("open the URL ");
getAppletContext().showDocument(new URL("http://www.gtsoft.com.cn/newgt/index.htm"));
}
catch (MalformedURLException e_url){
JOptionPane.showMessageDialog(c,"不能打此页面","警告",
JOptionPane.WARNING_MESSAGE);
}
}
else{
JOptionPane.showMessageDialog(c,"error psw","警告",
JOptionPane.WARNING_MESSAGE);
}
}
}
}
问题点数：100、回复次数：4Top
1 楼thomaslw（void）回复于 2005-12-14 11:30:18 得分 0
这个applet 中有读取磁盘文件的内容.文件里放的密码.
当这个 APPLET 使用 appletviewer 时,一切正常~
(当然这里还有个页面跳转没有反映的问题:getAppletContext().showDocument(new URL("http://www.gtsoft.com.cn/newgt/index.htm")); )
但是将此applet 放在浏览器中运行时就会在JAVA控制台中出现文件读取异常提示:
java.security.AccessControlException: access denied (java.io.FilePermission psw read)
at java.security.AccessControlContext.checkPermission(Unknown Source)
at java.security.AccessController.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkRead(Unknown Source)
at java.io.FileInputStream.<init>(Unknown Source)
at Pc.actionPerformed(Pc.java:34)
at java.awt.Button.processActionEvent(Unknown Source)
at java.awt.Button.processEvent(Unknown Source)
at java.awt.Component.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)
程序排版不好~ 真是不好意思~ 看着麻烦了点~
谢谢~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Top
2 楼hendy（hendy）回复于 2005-12-14 13:40:06 得分 100
applet是不能存取本地文件系统的，这是安全设置，
你可以通过https+数字签名解决这个问题Top
3 楼thomaslw（void）回复于 2005-12-14 14:52:44 得分 0
谢谢楼上~
还有为什么我的这一句不起作用啊~~~~~~~
getAppletContext().showDocument(new URL("http://www.gtsoft.com.cn/newgt/index.htm"));Top
4 楼thomaslw（void）回复于 2005-12-16 20:50:40 得分 0
顶一下~~Top
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