Kuibu, Poly stream-------Simple configuration environment variable

Know it, better know its why, this truth is actually a lot of people understand, just get fish simple, and learn to pay the price of fishing, after all, is not so simple, it may be called growth bar.

Read a lot about Java training books, like what from the beginner to proficient, like what 21 days to learn, and so on, in fact, I also from this beginning to touch Java, like open a door, from this out of the sinking.

Remember the beginning of the book will talk about the installation of the JDK and environment variable configuration, so will copy the book method, install, then configure Java-home,classpath,path, and then I go to write their first "Hello World", but also can vaguely think of the initial success of the gratified, But each time the reinstallation is still obliged to Baidu next step, to add something specific, it is not remember, repeated installation of more times, but also slowly found some rules, but also understand some principles.

First, what is the law of discovery?

* Java_home is just a synonym, is to replace the JDK installation path

As for why to replace, vaguely feel the use of static properties is also a kind of, easy to modify is sure, on the other hand, we often use a string identifier in Java instead of a long string of characters, this reason we are more acceptable, convenient to write , Avoid the path too long need to write too many characters, resulting in a greater chance of error, think of the database to avoid redundancy, it is more clear.

Of course, during the inquiry process, also heard that a statement is convenient for third-party reference , as to how to cite specific matters, personal daoxing is a bit shallow ....

So we know the definition of java_home, and then, that is classpath and path, and what is this principle?

In fact, we can easily find out, path is the function path, specifically what meaning: we follow our configured variable path to find, it will be easy to find the bin and Jre-bin under the Javac and Java. exe executable file, remember this scene (such as)

It is not possible to understand the path, that is, where to find to execute the file, so the understanding is much simpler.

The rest is only classpath, and before we think about it, let's recall the question of how Java works, or what kind of language is Java?

Presumably, most of the time, the. java files are compiled into a. class file, and then the virtual machine converts the. class file into machine code. (In this case, always remember the first place Java files in the server embarrassing scene, Khan)

As for the path to the back, we can also know the meaning of the route, and then class can you know what that means, haha

Here to emphasize a little, the path ahead of the ".;" Do not forget, this point means to tell the JDK, from the current directory to find out, as to what it is, is said to be the security mechanism of Linux caused, temporarily or do not understand, or daoxing shallow ah, let's remember it.

So again to see the environment variable configuration, will feel trouble, it is to do what, understand some, I understand, you say.

Kuibu, Poly stream-------Simple configuration environment variable