我编写了一个测试用户链接速度的 java 小程序。我收集了一些系统信息 prom 用户的计算机：CPU 负载、在 eth0 接口上下载的数据量以及使用 SIGAR API 的 NIC 卡最大速度。我将它部署在 Web 服务器上，但是当我尝试运行它时，我在 java 控制台中收到以下错误信息：
java.lang.reflect.InvocationTargetException
at java.awt.EventQueue.invokeAndWait(Unknown Source)
at speedtester_pkg.AppletMain.init(AppletMain.java:80)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ExceptionInInitializerError
at speedtester_pkg.Test.<init>(Test.java:54)
at speedtester_pkg.AppletMain.createGUI(AppletMain.java:282)
at speedtester_pkg.AppletMain$1.run(AppletMain.java:82)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(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)
Caused by: java.security.AccessControlException: access denied (java.util.PropertyPermission sigar.nativeLogging 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.checkPropertyAccess(Unknown Source)
at java.lang.System.getProperty(Unknown Source)
at org.hyperic.sigar.Sigar.<clinit>(Sigar.java:78)
... 17 more
我不确定这是否由于小程序安全限制而被阻止，但是从 SIGAR 用户论坛（http://forums.hyperic.com/jiveforums/forum.jspa?forumID=2）我有印象，它是可以将它与 Web 应用程序一起使用。
这是我使用 Sigar API 的课程：
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package speedtester_pkg;
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.hyperic.sigar.CpuPerc;
import org.hyperic.sigar.NetInterfaceStat;
import org.hyperic.sigar.Sigar;
import org.hyperic.sigar.SigarException;
/**
* The logic of the speed test. Starts downloading threads and performs measurements.
*
* @author Karol Abramczyk
*/
public class Test implements Runnable{
private ArrayList <String> urlsValues;
private URL[] urls;
private File[] files;
private int stabilizationTimeSeconds, threadNo, allThreadsNo;
private boolean continueDownload;
public AppletMain applet;
private Sigar sigar;
private NetInterfaceStat nis;
private long downloadedDataOld, downloadedDataNew, uploadedDataOld, uploadedDataNew, dataDownloaded,
downloadingTime;
private long startTime, stopTime;
private double speed;
// private String dir = "D:\\StraTJ_THD\\Abramczyk\\TestySpeedtestera\\";
/**
* Creates new instance of the Test object
* @param gui the calling AppletGUI object
* @param urlsVal the list of urls to files to download
* @param time the time of the delay for line stabilization
*/
public Test(AppletMain applet, ArrayList<String> urlsVal, int time){
try {
this.applet = applet;
this.urlsValues = urlsVal;
stabilizationTimeSeconds = time;
allThreadsNo = urlsVal.size();
AccessController.doPrivileged(new PrivilegedAction()
{ public Object run()
{
try {
sigar = new Sigar();
nis = sigar.getNetInterfaceStat("eth0");
} catch (SigarException ex) {
Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
}
return null;
}
});
urls = new URL[allThreadsNo];
for (int j = 0; j < allThreadsNo; j++) {
urls[j] = new URL(urlsValues.get(j));
}
} catch (MalformedURLException ex) {
Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
}
}
/**
* returns number of bytes downloaded so far
* @return number of bytes downloaded
*/
private long getDownloadedDataSize()
{
return nis.getRxBytes()*8;
}
/**
* returns number of bytes uploaded so far
* @return number of bytes uploaded
*/
private long getUploadedDataSize()
{
return nis.getTxBytes()*8;
}
/**
* saves data on the test start: time, downloaded and uploaded number of bytes
*/
private void getStartData()
{
downloadedDataOld = getDownloadedDataSize();
uploadedDataOld = getUploadedDataSize();
startTime = System.currentTimeMillis();
System.out.println(nis.getRxBytes());
System.out.println(downloadedDataOld);
}
/**
* saves dataon the test stop: time, downloaded and uploaded number of bytes
*/
private void getStopData()
{
stopTime = System.currentTimeMillis();
downloadedDataNew = getDownloadedDataSize();
uploadedDataNew = getUploadedDataSize();
}
/**
* starts downloading all the files specified in input file
* @throws java.io.IOException
* @throws java.lang.InterruptedException
*/
public void startDownload() throws IOException, InterruptedException{
continueDownload = true;
files = new File[allThreadsNo];
for (int g = 0; g < allThreadsNo; g++) {
String name = "speedTest" + g + "_";
files[g] = File.createTempFile(name, null);
}
Thread[] threads = new Thread[allThreadsNo];
for(int i=0; i<allThreadsNo;i++)
{
threadNo = i;
threads[threadNo] = new Thread(new Download(this, threadNo));
threads[threadNo].start();
}
}
/**
* preforms mesurements of speed ralated values as speed, cpu load, nic card speed
* @throws org.hyperic.sigar.SigarException
* @throws java.lang.InterruptedException
*/
private void measure() throws SigarException, InterruptedException {
measureCPUload();
measureLinkSpeed();
System.out.println(dataDownloaded);
System.out.println(downloadingTime);
System.out.println(speed);
measureNICspeed();
}
/**
* measures system CPU load and displays it in applet GUI
* @throws org.hyperic.sigar.SigarException
*/
private void measureCPUload() throws SigarException
{
CpuPerc cpuPerc = sigar.getCpuPerc();
applet.setLabelProcessorLoad(CpuPerc.format(cpuPerc.getCombined()));
applet.setCpuLoad(CpuPerc.format(cpuPerc.getCombined()));
}
/**
* measures link speed as:
* (number_of_bytes_downloaded_at_the_end - number_of_bytes_downloaded_at_the_beginning)/test_time
* @throws org.hyperic.sigar.SigarException
*/
private void measureLinkSpeed() throws SigarException
{
nis = sigar.getNetInterfaceStat("eth0");
getStopData();
dataDownloaded = downloadedDataNew-downloadedDataOld;
downloadingTime = (stopTime - startTime)/1000;
speed = dataDownloaded/downloadingTime;
applet.setLabelLinkSpeed(formatSpeed(speed));
applet.setSpeed(formatSpeed(speed));
}
/**
* measures Network Card Interface speed
* @throws org.hyperic.sigar.SigarException
*/
private void measureNICspeed() throws SigarException
{
nis = sigar.getNetInterfaceStat("eth0");
long nicSpeed = nis.getSpeed();
applet.setLabelNIC(formatSpeed(nicSpeed));
applet.setNICspeed(formatSpeed(nicSpeed));
}
/**
* stops file download
*/
private void stopDownload()
{
continueDownload = false;
}
/**
* formats link speed to more readable format with units. For example "3.54324E7"
* would be formatted to "35.0 Mb/s"
* @param speed the link speed
* @return the more readable link speed with units
*/
public String formatSpeed(double speed)
{
double speedD;
int speedI;
if(speed>=1000000)
{
speedI = (int)speed/10000;
speedD = speedI/100;
return new String(speedD + " Mb/s");
}
else if(speed<1000000 && speed>=1000)
{
speedI = (int)speed/10;
speedD = speedI/100;
return new String(speedD + " Kb/s");
}
else
{
speedI = (int)speed*100;
speedD = speedI/100;
return new String(speedD + " b/s");
}
}
/**
* starts the test thread
*/
public void run() {
try {
startDownload();
getStartData();
System.out.println("Sleep for " + stabilizationTimeSeconds + " seconds");
Thread.sleep(stabilizationTimeSeconds * 1000);
System.out.println("Sleep finished");
measure();
stopDownload();
Thread.sleep(1000 * files.length / 2);
// removeDownloadedFiles();
} catch (SigarException ex) {
Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
} catch (InterruptedException ex) {
Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
}
}
public URL[] getUrls() {
return urls;
}
public boolean isContinueDownload() {
return continueDownload;
}
public File[] getFiles() {
return files;
}
public int getStabilizationTimeSeconds() {
return stabilizationTimeSeconds;
}
}
这是我的第一个小程序，我对网络解决方案不是很熟悉，所以如果有人可以帮助我，我将不胜感激。我有许多类似主题的搜索者，但没有找到解决方案。我尝试使用 AccessCONtroller.do Priviliged() 方法，但效果不佳。我用小程序类签署了我的 jar 文件。我不确定是否应该签署这些 jar 库，应该吗？我的html文件如下：
<HTML>
<HEAD>
<TITLE>Speed Test</TITLE>
</HEAD>
<BODY>
<P>
<APPLET
code="speedtester_pkg.AppletMain"
archive="SpeedTester.jar,activation.jar,mail.jar,mailapi.jar,sigar.jar,smtp.jar"
width=440
height=600>
</APPLET>
</P>
</BODY>
</HTML>