1, concepts: native method: That is a java method calls a non-java code interface.
2, Usage: defining native method, does not provide implementations body (which does not mean body not achieved), because its implementation thereof is non java language on the outside. native and any modifiers can be used in conjunction with, but the abstract exception (because this implies that when the native method is modified to achieve the body, while the display indicates the abstract but this method does not achieve the body).
3, the return type: a java native method can return any type, including a non-basic types. Abnormal and can be controlled.
4. Impact: native method does not have any impact on other classes to call these native methods. Actually call these methods of other classes do not even know what it is calling a local method. Because jvm control all the details of the native method call.