The difference between environment variables in Java configuration

1, see "Crazy Java Handout" in the third edition of the configuration environment variables, 1.4 and 1.5, only the path is configured, and run successfully;

Question: Do I need to configure path only?

2, Baidu found the following link to explain the above problems: if only in the DOS console to compile execution, configure the PATH environment variable is enough;

Java environment Variables Java_home, CLASSPATH, path settings detailed

3, "Crazy Java Handout" The third edition of 1.5.4 section, if you use more than 1.5 version of the JDK, even if you do not set classpath, you can normally compile the Java program;

After 1.5, it will automatically search for class files under the current path, and automatically load Dt.jar and Tools.jar;

Using the JDK of the previous version of 1.4, you need to add (.) in the CLASSPATH environment variable to make it easier for the JRE to search for Java classes under the current path;

In addition, the Dt.jar and Tools.jar two jar packages in the Lib folder in the JDK are also required to be added to the classpath

4, the role of environmental variables java_home, equivalent to a reference variable, generally set to the JDK installation directory

The difference between environment variables in Java configuration