package java;
import java.io.*;
public class demo {
// TODO Auto-generated method stub
public static void main(String[] args) {
try{
writFileTest();
}catch (Exception e){
}
}
private static void writFileTest() throws FileNotFoundException,
IOException {
// 创建文件对象
File file = new File("c:\a.txt");
// 创建文件输出流
FileOutputStream fos = new FileOutputStream(file);
fos.write('j');
fos.write('d');
fos.close();
}
}
Exception in thread "main" java.lang.SecurityException: Prohibited package name: java
at java.lang.ClassLoader.preDefineClass(ClassLoader.java:659)
at java.lang.ClassLoader.defineClass(ClassLoader.java:758)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:495)
Error: A JNl error has occurred, please check your installation and try again
A Java Exception has occurred.
把java与javac运行版本调到一致
还是一样
Exception in thread "main" java.lang.SecurityException: Prohibited package name: java
根据异常提示 包名问题。
要慢慢学会看异常，如果看不懂英文一般将caused by：后边的或者其他提示后的英文复制到百度翻译中翻译一下就知道报错的原因了。这是java入门的基础。
包名不能用java，类名包名的命名要避免使用java的保留字
package java;