当我使用Java程序在Ubuntu中创建文件时，我收到此错误：
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at actions.create.actionPerformed(create.java:18)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3312)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:729)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:688)
at java.awt.EventQueue$3.run(EventQueue.java:686)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:702)
at java.awt.EventQueue$4.run(EventQueue.java:700)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:699)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
显然文件没有创建，甚至尝试以root身份运行，但仍然没有。这是我的代码：
File shortcut;
shortcut = new File(global.location + "/" + global.name + ".desktop");
try {
FileWriter fWrite = new FileWriter(shortcut.getAbsoluteFile());
BufferedWriter bWrite = new BufferedWriter(fWrite);
shortcut.createNewFile();
bWrite.write("[Desktop Entry]\nType=" + global.type + "\nTerminal=" + global.term + "\nIcon=" + global.icon + "\nExec=" + global.exec + "\nName=" + global.name);
bWrite.close();
} catch (IOException e1) {}
有人可以帮忙解决这个问题吗？在使用java创建文件时，我总是遇到这个问题。
答案 0 :(得分：0)
你应该做
System.out.println(shortcut.getAbsoluteFile());
并仔细检查目录是否真的存在。我有一种感觉，shortcut.createNewFile();因此而抛出了NPE。
答案 1 :(得分：0)
尝试输入父文件夹和文件名的文件创建者：
File subFolder=new File(folderName,subFolder);
File f=new File(folderName,filename;)
System.out.println(f.getAbsolutePath()); //this to see the actual path of the file
subFolder.mkdirs();
BufferedWriter writer=new BufferedWriter(new FileWriter(f));
答案 2 :(得分：0)
我会说实话，我不知道你在这里做了什么，好像你在黑暗中试图制作文件。我想向你展示一个可以帮助你的课程（我创建的）：
package your.package;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
public class FileHelper
{
public static boolean createFile(String dir)
{
return FileHelper.createFile(dir, false);
}
public static boolean createFile(String dir, boolean isDirectory)
{
boolean returning = false;
boolean created = false;
Path p = Paths.get(dir);
try
{
if (Files.exists(p))
{
returning = true;
}
else if (isDirectory)
{
Files.createDirectory(p);
created = true;
returning = true;
}
else
{
Files.createFile(p);
created = true;
returning = true;
}
}
catch (IOException e)
{
e.printStackTrace();
}
if (returning)
{
Util.println((created ? "Created New " : "") + (isDirectory ? "Directory" : "File") + (created ? "" : " Already Exists") + " In: " + p.toString());
}
return returning;
}
public static boolean writeToFile(String fileName, String stuff)
{
return FileHelper.writeToFile(fileName, stuff, true);
}
public static boolean writeToFile(String fileName, String stuff, boolean newLine)
{
try (BufferedWriter writer = new BufferedWriter(new FileWriter(fileName, true)))
{
writer.write(stuff);
if (newLine) writer.newLine();
return true;
}
catch (IOException x)
{
System.err.format("IOException: %s%n", x);
x.printStackTrace();
return false;
}
}
public static BufferedReader getFileReader(String fileName)
{
Charset c = Charset.forName("US-ASCII");
Path p = Paths.get(fileName);
try
{
return Files.newBufferedReader(p, c);
}
catch (IOException e)
{
e.printStackTrace();
}
return null;
}
public static boolean deleteDirectory(File dir)
{
Util.requireNonNull(dir);
if (!dir.exists() || !dir.isDirectory())
{
throw new IllegalArgumentException("\"dir\" Must exist!");
}
String[] files = dir.list();
for (int i = 0, len = files.length; i < len; i++)
{
File f = new File(dir, files[i]);
if (f.isDirectory())
{
deleteDirectory(f);
Util.println("Found new directory to delete: " + f.getPath() + " Deleting now...");
}
else
{
f.delete();
Util.println("Deleted File: " + f.getPath());
}
}
Util.println("Deleted Directory: " + dir.getPath());
return dir.delete();
}
}
让我知道这是否有助于解决您的问题！顺便说一句，你不需要为这个文件给我任何功劳。现在是公众！好运和快乐的编码！