# 对象工具类 **类名:** `ObjectUtil` ## isNotEmpty ```java /** * 判断元素不为空 * @param obj object * @return boolean */ ObjectUtil.isNotEmpty(Object obj); ``` ## isCheckedException ```java /** * Return whether the given throwable is a checked exception: * that is, neither a RuntimeException nor an Error. * @param ex the throwable to check * @return whether the throwable is a checked exception * @see java.lang.Exception * @see java.lang.RuntimeException * @see java.lang.Error */ ObjectUtil.isCheckedException(Throwable ex); ``` ## isCompatibleWithThrowsClause ```java /** * Check whether the given exception is compatible with the specified * exception types, as declared in a throws clause. * @param ex the exception to check * @param declaredExceptions the exception types declared in the throws clause * @return whether the given exception is compatible */ ObjectUtil.isCompatibleWithThrowsClause(Throwable ex, Class> declaredExceptions); ``` ## isArray ```java /** * Determine whether the given object is an array: * either an Object array or a primitive array. * @param obj the object to check */ ObjectUtil.isArray(Object obj); ``` ## isEmpty ```java /** * Determine whether the given array is empty: * i.e. {@code null} or of zero length. * @param array the array to check * @see #isEmpty(Object) */ ObjectUtil.isEmpty(Object[] array); ``` ## isEmpty ```java /** * Determine whether the given object is empty. *
This method supports the following object types. *
If the given object is non-null and not one of the aforementioned
* supported types, this method returns {@code false}.
* @param obj the object to check
* @return {@code true} if the object is {@code null} or empty
* @since 4.2
* @see Optional#isPresent()
* @see ObjectUtils#isEmpty(Object[])
* @see StringUtils#hasLength(CharSequence)
* @see StringUtils#isEmpty(Object)
* @see CollectionUtils#isEmpty(java.util.Collection)
* @see CollectionUtils#isEmpty(java.util.Map)
*/
ObjectUtil.isEmpty(Object obj);
```
## unwrapOptional
```java
/**
* Unwrap the given object which is potentially a {@link java.util.Optional}.
* @param obj the candidate object
* @return either the value held within the {@code Optional}, {@code null}
* if the {@code Optional} is empty, or simply the given object as-is
* @since 5.0
*/
ObjectUtil.unwrapOptional(Object obj);
```
## containsElement
```java
/**
* Check whether the given array contains the given element.
* @param array the array to check (may be {@code null},
* in which case the return value will always be {@code false})
* @param element the element to check for
* @return whether the element has been found in the given array
*/
ObjectUtil.containsElement(Object[] array, Object element);
```
## containsConstant
```java
/**
* Check whether the given array of enum constants contains a constant with the given name,
* ignoring case when determining a match.
* @param enumValues the enum values to check, typically obtained via {@code MyEnum.values()}
* @param constant the constant name to find (must not be null or empty string)
* @return whether the constant has been found in the given array
*/
ObjectUtil.containsConstant(Enum>[] enumValues, String constant);
```
## containsConstant
```java
/**
* Check whether the given array of enum constants contains a constant with the given name.
* @param enumValues the enum values to check, typically obtained via {@code MyEnum.values()}
* @param constant the constant name to find (must not be null or empty string)
* @param caseSensitive whether case is significant in determining a match
* @return whether the constant has been found in the given array
*/
ObjectUtil.containsConstant(Enum>[] enumValues, String constant, boolean caseSensitive);
```
## caseInsensitiveValueOf
```java
/**
* Case insensitive alternative to {@link Enum#valueOf(Class, String)}.
* @param A {@code null} source value will be converted to an
* empty Object array.
* @param source the (potentially primitive) array
* @return the corresponding object array (never {@code null})
* @throws IllegalArgumentException if the parameter is not an array
*/
ObjectUtil.toObjectArray(Object source);
```
## nullSafeEquals
```java
/**
* Determine if the given objects are equal, returning {@code true} if
* both are {@code null} or {@code false} if only one is {@code null}.
* Compares arrays with {@code Arrays.equals}, performing an equality
* check based on the array elements rather than the array reference.
* @param o1 first Object to compare
* @param o2 second Object to compare
* @return whether the given objects are equal
* @see Object#equals(Object)
* @see java.util.Arrays#equals
*/
ObjectUtil.nullSafeEquals(Object o1, Object o2);
```
## nullSafeHashCode
```java
/**
* Return as hash code for the given object; typically the value of
* {@code Object#hashCode()}}. If the object is an array,
* this method will delegate to any of the {@code nullSafeHashCode}
* methods for arrays in this class. If the object is {@code null},
* this method returns 0.
* @see Object#hashCode()
* @see #nullSafeHashCode(Object[])
* @see #nullSafeHashCode(boolean[])
* @see #nullSafeHashCode(byte[])
* @see #nullSafeHashCode(char[])
* @see #nullSafeHashCode(double[])
* @see #nullSafeHashCode(float[])
* @see #nullSafeHashCode(int[])
* @see #nullSafeHashCode(long[])
* @see #nullSafeHashCode(short[])
*/
ObjectUtil.nullSafeHashCode(Object obj);
```
## nullSafeHashCode
```java
/**
* Return a hash code based on the contents of the specified array.
* If {@code array} is {@code null}, this method returns 0.
*/
ObjectUtil.nullSafeHashCode(Object[] array);
```
## nullSafeHashCode
```java
/**
* Return a hash code based on the contents of the specified array.
* If {@code array} is {@code null}, this method returns 0.
*/
ObjectUtil.nullSafeHashCode(boolean[] array);
```
## nullSafeHashCode
```java
/**
* Return a hash code based on the contents of the specified array.
* If {@code array} is {@code null}, this method returns 0.
*/
ObjectUtil.nullSafeHashCode(byte[] array);
```
## nullSafeHashCode
```java
/**
* Return a hash code based on the contents of the specified array.
* If {@code array} is {@code null}, this method returns 0.
*/
ObjectUtil.nullSafeHashCode(char[] array);
```
## nullSafeHashCode
```java
/**
* Return a hash code based on the contents of the specified array.
* If {@code array} is {@code null}, this method returns 0.
*/
ObjectUtil.nullSafeHashCode(double[] array);
```
## nullSafeHashCode
```java
/**
* Return a hash code based on the contents of the specified array.
* If {@code array} is {@code null}, this method returns 0.
*/
ObjectUtil.nullSafeHashCode(float[] array);
```
## nullSafeHashCode
```java
/**
* Return a hash code based on the contents of the specified array.
* If {@code array} is {@code null}, this method returns 0.
*/
ObjectUtil.nullSafeHashCode(int[] array);
```
## nullSafeHashCode
```java
/**
* Return a hash code based on the contents of the specified array.
* If {@code array} is {@code null}, this method returns 0.
*/
ObjectUtil.nullSafeHashCode(long[] array);
```
## nullSafeHashCode
```java
/**
* Return a hash code based on the contents of the specified array.
* If {@code array} is {@code null}, this method returns 0.
*/
ObjectUtil.nullSafeHashCode(short[] array);
```
## hashCode
```java
/**
* Return the same value as {@link Boolean#hashCode(boolean)}}.
* @deprecated as of Spring Framework 5.0, in favor of the native JDK 8 variant
*/
ObjectUtil.hashCode(boolean bool);
```
## hashCode
```java
/**
* Return the same value as {@link Double#hashCode(double)}}.
* @deprecated as of Spring Framework 5.0, in favor of the native JDK 8 variant
*/
ObjectUtil.hashCode(double dbl);
```
## hashCode
```java
/**
* Return the same value as {@link Float#hashCode(float)}}.
* @deprecated as of Spring Framework 5.0, in favor of the native JDK 8 variant
*/
ObjectUtil.hashCode(float flt);
```
## hashCode
```java
/**
* Return the same value as {@link Long#hashCode(long)}}.
* @deprecated as of Spring Framework 5.0, in favor of the native JDK 8 variant
*/
ObjectUtil.hashCode(long lng);
```
## identityToString
```java
/**
* Return a String representation of an object's overall identity.
* @param obj the object (may be {@code null})
* @return the object's identity as String representation,
* or an empty String if the object was {@code null}
*/
ObjectUtil.identityToString(Object obj);
```
## getIdentityHexString
```java
/**
* Return a hex String form of an object's identity hash code.
* @param obj the object
* @return the object's identity code in hex notation
*/
ObjectUtil.getIdentityHexString(Object obj);
```
## getDisplayString
```java
/**
* Return a content-based String representation if {@code obj} is
* not {@code null}; otherwise returns an empty String.
* Differs from {@link #nullSafeToString(Object)} in that it returns
* an empty String rather than "null" for a {@code null} value.
* @param obj the object to build a display String for
* @return a display String representation of {@code obj}
* @see #nullSafeToString(Object)
*/
ObjectUtil.getDisplayString(Object obj);
```
## nullSafeClassName
```java
/**
* Determine the class name for the given object.
* Returns a {@code "null"} String if {@code obj} is {@code null}.
* @param obj the object to introspect (may be {@code null})
* @return the corresponding class name
*/
ObjectUtil.nullSafeClassName(Object obj);
```
## nullSafeToString
```java
/**
* Return a String representation of the specified Object.
* Builds a String representation of the contents in case of an array.
* Returns a {@code "null"} String if {@code obj} is {@code null}.
* @param obj the object to build a String representation for
* @return a String representation of {@code obj}
*/
ObjectUtil.nullSafeToString(Object obj);
```
## nullSafeToString
```java
/**
* Return a String representation of the contents of the specified array.
* The String representation consists of a list of the array's elements,
* enclosed in curly braces ({@code "{}"}). Adjacent elements are separated
* by the characters {@code ", "} (a comma followed by a space).
* Returns a {@code "null"} String if {@code array} is {@code null}.
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
ObjectUtil.nullSafeToString(Object[] array);
```
## nullSafeToString
```java
/**
* Return a String representation of the contents of the specified array.
* The String representation consists of a list of the array's elements,
* enclosed in curly braces ({@code "{}"}). Adjacent elements are separated
* by the characters {@code ", "} (a comma followed by a space).
* Returns a {@code "null"} String if {@code array} is {@code null}.
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
ObjectUtil.nullSafeToString(boolean[] array);
```
## nullSafeToString
```java
/**
* Return a String representation of the contents of the specified array.
* The String representation consists of a list of the array's elements,
* enclosed in curly braces ({@code "{}"}). Adjacent elements are separated
* by the characters {@code ", "} (a comma followed by a space).
* Returns a {@code "null"} String if {@code array} is {@code null}.
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
ObjectUtil.nullSafeToString(byte[] array);
```
## nullSafeToString
```java
/**
* Return a String representation of the contents of the specified array.
* The String representation consists of a list of the array's elements,
* enclosed in curly braces ({@code "{}"}). Adjacent elements are separated
* by the characters {@code ", "} (a comma followed by a space).
* Returns a {@code "null"} String if {@code array} is {@code null}.
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
ObjectUtil.nullSafeToString(char[] array);
```
## nullSafeToString
```java
/**
* Return a String representation of the contents of the specified array.
* The String representation consists of a list of the array's elements,
* enclosed in curly braces ({@code "{}"}). Adjacent elements are separated
* by the characters {@code ", "} (a comma followed by a space).
* Returns a {@code "null"} String if {@code array} is {@code null}.
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
ObjectUtil.nullSafeToString(double[] array);
```
## nullSafeToString
```java
/**
* Return a String representation of the contents of the specified array.
* The String representation consists of a list of the array's elements,
* enclosed in curly braces ({@code "{}"}). Adjacent elements are separated
* by the characters {@code ", "} (a comma followed by a space).
* Returns a {@code "null"} String if {@code array} is {@code null}.
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
ObjectUtil.nullSafeToString(float[] array);
```
## nullSafeToString
```java
/**
* Return a String representation of the contents of the specified array.
* The String representation consists of a list of the array's elements,
* enclosed in curly braces ({@code "{}"}). Adjacent elements are separated
* by the characters {@code ", "} (a comma followed by a space).
* Returns a {@code "null"} String if {@code array} is {@code null}.
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
ObjectUtil.nullSafeToString(int[] array);
```
## nullSafeToString
```java
/**
* Return a String representation of the contents of the specified array.
* The String representation consists of a list of the array's elements,
* enclosed in curly braces ({@code "{}"}). Adjacent elements are separated
* by the characters {@code ", "} (a comma followed by a space).
* Returns a {@code "null"} String if {@code array} is {@code null}.
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
ObjectUtil.nullSafeToString(long[] array);
```
## nullSafeToString
```java
/**
* Return a String representation of the contents of the specified array.
* The String representation consists of a list of the array's elements,
* enclosed in curly braces ({@code "{}"}). Adjacent elements are separated
* by the characters {@code ", "} (a comma followed by a space).
* Returns a {@code "null"} String if {@code array} is {@code null}.
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
ObjectUtil.nullSafeToString(short[] array);
```