FindJava¶
尋找 Java
此模組會尋找是否已安裝 Java，並決定標頭檔和程式庫的位置。呼叫者可以設定變數 JAVA_HOME 來明確指定 Java 安裝前綴。
另請參閱 FindJNI 模組以尋找 Java 原生介面 (JNI)。
新增於 3.10 版本: 新增對 Java 9+ 版本解析的支援。
在呼叫此尋找模組時，指定以下一個或多個組件。請參閱以下範例。
Runtime = Java Runtime Environment used to execute Java byte-compiled applications
Development = Development tools (java, javac, javah, jar and javadoc), includes Runtime component
IdlJ = Interface Description Language (IDL) to Java compiler
JarSigner = Signer and verifier tool for Java Archive (JAR) files
此模組會設定以下結果變數
Java_JAVA_EXECUTABLE = the full path to the Java runtime
Java_JAVAC_EXECUTABLE = the full path to the Java compiler
Java_JAVAH_EXECUTABLE = the full path to the Java header generator
Java_JAVADOC_EXECUTABLE = the full path to the Java documentation generator
Java_IDLJ_EXECUTABLE = the full path to the Java idl compiler
Java_JAR_EXECUTABLE = the full path to the Java archiver
Java_JARSIGNER_EXECUTABLE = the full path to the Java jar signer
Java_VERSION_STRING = Version of java found, eg. 1.6.0_12
Java_VERSION_MAJOR = The major version of the package found.
Java_VERSION_MINOR = The minor version of the package found.
Java_VERSION_PATCH = The patch version of the package found.
Java_VERSION_TWEAK = The tweak version of the package found (after '_')
Java_VERSION = This is set to: $major[.$minor[.$patch[.$tweak]]]
新增於 3.4 版本: 新增 Java_IDLJ_EXECUTABLE 和 Java_JARSIGNER_EXECUTABLE 變數。
可以使用 find_package() 語法指定所需的最低 Java 版本，例如
find_package(Java 1.8)
注意： ${Java_VERSION} 和 ${Java_VERSION_STRING} 並不保證完全相同。例如，某些 Java 版本可能會回傳： Java_VERSION_STRING = 1.8.0_17 和 Java_VERSION = 1.8.0.17
另一個例子是 Java OEM，其回傳： Java_VERSION_STRING = 1.8.0-oem 和 Java_VERSION = 1.8.0
對於這些組件，將會設定以下變數
Java_FOUND - TRUE if all components are found.
Java_<component>_FOUND - TRUE if <component> is found.
使用範例
find_package(Java)
find_package(Java 1.8 REQUIRED)
find_package(Java COMPONENTS Runtime)
find_package(Java COMPONENTS Development)