I installed an installation-free version of jdk1.7;
does not have administrator privileges and cannot configure system environment variables, only user environment variables;
but why, after I have configured, execute java-version and javac-version, can correctly prompt version information;
but after compiling the java file, execute javac Puppy does prompt the following error Error: Could not find or load main class Puppy;
compiled code has no syntax errors and can be executed correctly in eclipse.