爪哇 - 了解静态{}

Question

我碰到这个代码进来，我不明白静态{}表示：

public class BookProvider extends ContentProvider 
{ 

private static final String TAG = "BookProvider"; 

private static HashMap<String, String> sBooksProjectionMap; 
static 
{ 
sBooksProjectionMap = new HashMap<String, String>(); 
sBooksProjectionMap.put(BookTableMetaData._ID, 
BookTableMetaData._ID); 

sBooksProjectionMap.put(BookTableMetaData.BOOK_NAME, 

} 

Answer 1

这是一个静态初始化。它在类加载（或初始化）时执行。

欲了解更多详情，请阅读http://docs.oracle.com/javase/tutorial/java/javaOO/initial.html