JAVA构造MAP并初始化MAP

第一种方法：static块初始化

public class Demo{
private static final Map<String, String> myMap;
static
{
myMap = new HashMap<String, String>();
myMap.put("a", "b");
myMap.put("c", "d");
}
}

第二种方法：双括号初始化 （匿名内部类）

HashMap<String, String > h = new HashMap<String, String>(){{
put("a","b");
}};

第三种方法：Guava

Map<String, Integer> left = ImmutableMap.of("a", 1, "b", 2, "c", 3);
//或者
Map<String, String> test = ImmutableMap.<String, String>builder()
.put("k1", "v1")
.put("k2", "v2")
...
.build();