import java.io.*; public class Ttt { public static void main(String[] args) { BufferedReader fileIn = null;
PrintWriter fileOut = null;
int length = 0;
if (args.length != 2) {
System.err.println("please input two arguments");
} try { fileIn = new BufferedReader(new FileReader(args[0]));
fileOut = new PrintWriter(new FileWriter(args[1]), true); String line = fileIn.readLine();
while (line != null) {
System.out.println(line);
fileOut.println(line);
length += line.length(); line = fileIn.readLine();
}
} catch (IOException e) {
System.err.println("file not found");
} System.out.println("total characters are: " + length);
}
}
我先javac Ttt.java 编译成功
然后带两个文件名为参数运行java Ttt 1.txt to.txt,这两个文件我都放在和class文件相同的目录中了
运行结果出错,不知道是何原因
PrintWriter fileOut = null;
int length = 0;
if (args.length != 2) {
System.err.println("please input two arguments");
} try { fileIn = new BufferedReader(new FileReader(args[0]));
fileOut = new PrintWriter(new FileWriter(args[1]), true); String line = fileIn.readLine();
while (line != null) {
System.out.println(line);
fileOut.println(line);
length += line.length(); line = fileIn.readLine();
}
} catch (IOException e) {
System.err.println("file not found");
} System.out.println("total characters are: " + length);
}
}
我先javac Ttt.java 编译成功
然后带两个文件名为参数运行java Ttt 1.txt to.txt,这两个文件我都放在和class文件相同的目录中了
运行结果出错,不知道是何原因
Exception in thread "main" java.lang.UnsupportedClassVersionError: Ttt (Unsupported major.minor vers
ion 49.0)
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
你装了2个JDK版本对吧!