Valid @suppresswarnings warning name

1. Introduce

understand And @SuppressWarnings Java Different warning names used with annotations , It allows the compiler to suppress warnings . These warning names allow specific warnings to be suppressed . The available warning names depend on our IDE or Java compiler

2. Warning name

Here are @SuppressWarnings A list of valid warning names available in the annotation ：

• all: This is a wildcard that prohibits all warnings
• boxing: Suppression and packing / Warnings related to unpacking operation
• unused: Warning against unused code
• cast: Suppress warnings related to object conversion operations
• deprecation: Suppress discard related warnings , For example, deprecated classes or methods
• restriction: Suppress warnings related to the use of discouraged or prohibited references
• dep-ann: Suppress warnings related to deprecated comments
• fallthrough: Inhibition and switch Missing in statement break sentence
• finally: Inhibition and finally Block related warnings , These blocks do not return
• hiding: Suppress and hide Warnings about locals of variables
• incomplete-switch: Inhibition and switch Missing entry related warning in statement *（ enumeration * situation ）
• nls: Inhibition and non nls String text related warnings
• null: Prohibition and null analysis
• serial: Inhibition and lack serialVersionUID Field related warnings , This field is usually in Serializable class
• static-access: Suppress warnings related to incorrect static variable access
• synthetic-access: Suppress warnings related to unoptimized access from inner classes
• unchecked: Warnings related to unchecked operations are prohibited
• unqualified-field-access: Suppress warnings related to unqualified field access
• javadoc: Inhibition and Javadoc Related warnings
• rawtypes: Suppress warnings related to using primitive types
• resource: Prohibition and use Closeable
• super: Super call In case of overriding method related warnings
• sync-override: In the cover Sync Method Suppression due to lack of Sync

3. Use warning name

Examples of using different warning names .

3.1.@SuppressWarnings(“unused”)

In the following example , Warning name suppresses Method Warnings for unused values in ：

@SuppressWarnings("unused")
void suppressUnusedWarning() {
    
    int usedVal = 5;
    int unusedVal = 10;  // no warning here
    List<Integer> list = new ArrayList<>();
    list.add(usedVal);
}

3.2. @SuppressWarnings（“deprecated）

In the following example , Warning name prohibited *@deprecated* Method warning ：

@SuppressWarnings("deprecated")
void suppressDeprecatedWarning() {
    
    ClassWithSuppressWarningsNames cls = new ClassWithSuppressWarningsNames();
    cls.deprecatedMethod(); // no warning here
}

@Deprecated
String deprecatedMethod() {
    
    return "deprecated method";
}

3.3. @SuppressWarnings（“fallthrough”）

In the following example , The warning name suppresses the lack of break Warning for statement —— Include them here , Comment out , To display a warning ：

@SuppressWarnings("fallthrough")
String suppressFallthroughWarning() {
    
    int day = 5;
    switch (day) {
    
        case 5:
            return "This is day 5";
// break; // no warning here
        case 10:
            return "This is day 10";
// break; // no warning here 
        default:
            return "This default day";
    }
}

3.4. @SuppressWarnings（“serial”）

This warning name is at the class level . In the following example , Warning name suppresses Serializable Missing from class serialVersionUID（ It has been commented out ） Warning of ：

@SuppressWarnings("serial")
public class ClassWithSuppressWarningsNames implements Serializable {
    
// private static final long serialVersionUID = -1166032307853492833L; // no warning even though this is commented

4. Combine multiple warning names

@SuppressWarnings Comments need a String Array , So you can combine multiple warning names ：

@SuppressWarnings({
    "serial", "unchecked"})