After we installed JDK, JDK must configure environment variables. However, this environment variable must configure it yourself? That first look at what is the environment variable.
The so-called environmental variables, in fact, is the operating system used to specify some parameters operating system environment when the system requires the user to run a program and it does not tell the full path to where the program when, first look for this program (.exe file) in the current directory If not found, the system continues to path environment variable to find the path specified value, as the value of the path parameter shown in Fig.
figure 1
Path environment variable in the above figure has been configured JDK's bin directory, enter this command in any directory (in fact executable .exe files) in any path under the DOS window, can be successful.
figure 2
Now we go back to the beginning of a doubt, JDK path to a certain configuration environment variable inside it? In actual fact, if the eclipse like this built-in JDK development tools can not configure the environment variables, with specific reference to the boot sequence essays [eclipse]
CLASSPATH role:
classpath is specified in the program you use in class (.class) file location that JAVA runtime environment JRE search .classpath to the file.
When introduced as a class: import javax.swing.JTable This sentence tells the compiler to be introduced under the JTable class javax.swing package, and the classpath is to tell the compiler where to find the class.
classpath configuration is not required, if you have a disk in the D test.java file. D into late, javac test.java test.class will be generated in the current file, it will give the corresponding Java test.class results.
If the classpath is D: / myclasspath, cut to the test.class D: / myclasspath, you execute java test path at d can still get results.