Compact API Profiles - Java

Compact API Profiles

JDK 8 adds a feature that organizes subsets of the API library into what are called compact profiles. These are called compact1, compact2, and compact3. Each profile contains a subset of the library. Furthermore, compact2 includes all of compact1, and compact3 includes all of compact2. Thus, each profile builds on the previous one. The advantage of the compact profiles is that an application that does not require the full library need not download it. Using a compact profile reduces the size of the library, thus enabling some types of Java applications to run on devices that could not otherwise support the entire Java API. The use of a compact profile can also reduce the time it takes to load a program. The Java API documentation indicates to which (if any) profile each API element belongs.

When compiling a program, you can determine if a program uses only APIs defined by a compact profile by using the -profile option. Here is its general form:

javac -profile profileName programName

Here, profileName specifies the profile, which must be compact1, compact2, or compact3. For example:

javac -profile compact2 Test.java

Here, the compact2 profile is specified. If Test.java contains an API that is not part of compact2, then a compilation error will result.