@SuppressWarnings注解主要用在取消一些编译器产生的警告对代码左侧行列的遮挡,有时候这会挡住我们断点调试时打的断点。 如图所示:
这时候我们在方法上加上@SuppressWarnings注解就可以消除这些警告的产生,注解的使用有三种: 1. @SuppressWarnings("unchecked") [^ 抑制单类型的警告] 2. @SuppressWarnings("unchecked","rawtypes") [^ 抑制多类型的警告] 3. @SuppressWarnings("unchecked") [^ 抑制所有类型的警告] *** > 通过源码分析可知@SuppressWarnings其注解目标为类、字段、函数、函数入参、构造函数和函数的局部变量。建议把注解放在最近进警告发生的位置。 下面列举警告关键字:
关键字 | 用途 |
---|---|
all | to suppress all warnings (抑制所有警告) |
boxing | to suppress warnings relative to boxing/unboxing operations (抑制装箱、拆箱操作时候的警告) |
cast | to suppress warnings relative to cast operations (抑制映射相关的警告) |
dep-ann | to suppress warnings relative to deprecated annotation (抑制启用注释的警告) |
deprecation | to suppress warnings relative to deprecation (抑制过期方法警告) |
fallthrough | to suppress warnings relative to missing breaks in switch statements (抑制确在switch中缺失breaks的警告) |
finally | to suppress warnings relative to finally block that don’t return (抑制finally模块没有返回的警告) |
hiding | to suppress warnings relative to locals that hide variable(抑制相对于隐藏变量的局部变量的警告) |
incomplete-switch | to suppress warnings relative to missing entries in a switch statement (enum case)(忽略没有完整的switch语句) |
nls | to suppress warnings relative to non-nls string literals( 忽略非nls格式的字符) |
null | to suppress warnings relative to null analysis( 忽略对null的操作) |
rawtypes | to suppress warnings relative to un-specific types when using generics on class params( 使用generics时忽略没有指定相应的类型) |
restriction | to suppress warnings relative to usage of discouraged or forbidden references( 抑制禁止使用劝阻或禁止引用的警告) |
serial | to suppress warnings relative to missing serialVersionUID field for a serializable class( 忽略在serializable类中没有声明serialVersionUID变量) |
static-access | to suppress warnings relative to incorrect static access( 抑制不正确的静态访问方式警告) |
synthetic-access | to suppress warnings relative to unoptimized access from inner classes( 抑制子类没有按最优方法访问内部类的警告) |
unchecked | to suppress warnings relative to unchecked operations( 抑制没有进行类型检查操作的警告) |
unqualified-field-access | to suppress warnings relative to field access unqualified( 抑制没有权限访问的域的警告) |
unused | to suppress warnings relative to unused code( 抑制没被使用过的代码的警告) |