类 BeanUtils

构造器详细资料

• BeanUtils

  public BeanUtils()

方法详细资料

• instantiate

  @Deprecated
  public static <T> T instantiate​(Class<T> clazz)
                           throws BeanInstantiationException

  已过时。

  as of Spring 5.0, following the deprecation of Class.newInstance() in JDK 9
  Convenience method to instantiate a class using its no-arg constructor.

  参数:

  clazz - class to instantiate

  返回:

  the new instance

  抛出:

  BeanInstantiationException - if the bean cannot be instantiated

  另请参阅:

  Class.newInstance()

• instantiateClass

  public static <T> T instantiateClass​(Class<T> clazz)
                                throws BeanInstantiationException

  Instantiate a class using its 'primary' constructor (for Kotlin classes, potentially having default arguments declared) or its default constructor (for regular Java classes, expecting a standard no-arg setup).

  Note that this method tries to set the constructor accessible if given a non-accessible (that is, non-public) constructor.

  参数:

  clazz - the class to instantiate

  返回:

  the new instance

  抛出:

  BeanInstantiationException - if the bean cannot be instantiated. The cause may notably indicate a NoSuchMethodException if no primary/default constructor was found, a NoClassDefFoundError or other LinkageError in case of an unresolvable class definition (e.g. due to a missing dependency at runtime), or an exception thrown from the constructor invocation itself.

  另请参阅:

  Constructor.newInstance(java.lang.Object...)

• instantiateClass

  public static <T> T instantiateClass​(Class<?> clazz,
                                       Class<T> assignableTo)
                                throws BeanInstantiationException

  Instantiate a class using its no-arg constructor and return the new instance as the specified assignable type.

  Useful in cases where the type of the class to instantiate (clazz) is not available, but the type desired (assignableTo) is known.

  Note that this method tries to set the constructor accessible if given a non-accessible (that is, non-public) constructor.

  参数:

  clazz - class to instantiate

  assignableTo - type that clazz must be assignableTo

  返回:

  the new instance

  抛出:

  BeanInstantiationException - if the bean cannot be instantiated

  另请参阅:

  Constructor.newInstance(java.lang.Object...)

• instantiateClass

  public static <T> T instantiateClass​(Constructor<T> ctor,
                                       Object... args)
                                throws BeanInstantiationException

  Convenience method to instantiate a class using the given constructor.

  Note that this method tries to set the constructor accessible if given a non-accessible (that is, non-public) constructor, and supports Kotlin classes with optional parameters and default values.

  参数:

  ctor - the constructor to instantiate

  args - the constructor arguments to apply (use null for an unspecified parameter, Kotlin optional parameters and Java primitive types are supported)

  返回:

  the new instance

  抛出:

  BeanInstantiationException - if the bean cannot be instantiated

  另请参阅:

  Constructor.newInstance(java.lang.Object...)

• findPrimaryConstructor

  @Nullable
  public static <T> Constructor<T> findPrimaryConstructor​(Class<T> clazz)

  Return the primary constructor of the provided class. For Kotlin classes, this returns the Java constructor corresponding to the Kotlin primary constructor (as defined in the Kotlin specification). Otherwise, in particular for non-Kotlin classes, this simply returns null.

  参数:

  clazz - the class to check

  从以下版本开始:

  5.0

  另请参阅:

  Kotlin docs

• findMethod

  @Nullable
  public static Method findMethod​(Class<?> clazz,
                                  String methodName,
                                  Class<?>... paramTypes)

  Find a method with the given method name and the given parameter types, declared on the given class or one of its superclasses. Prefers public methods, but will return a protected, package access, or private method too.

  Checks Class.getMethod first, falling back to findDeclaredMethod. This allows to find public methods without issues even in environments with restricted Java security settings.

  参数:

  clazz - the class to check

  methodName - the name of the method to find

  paramTypes - the parameter types of the method to find

  返回:

  the Method object, or null if not found

  另请参阅:

  Class.getMethod(java.lang.String, java.lang.Class<?>...), findDeclaredMethod(java.lang.Class<?>, java.lang.String, java.lang.Class<?>...)

• findDeclaredMethod

  @Nullable
  public static Method findDeclaredMethod​(Class<?> clazz,
                                          String methodName,
                                          Class<?>... paramTypes)

  Find a method with the given method name and the given parameter types, declared on the given class or one of its superclasses. Will return a public, protected, package access, or private method.

  Checks Class.getDeclaredMethod, cascading upwards to all superclasses.

  参数:

  clazz - the class to check

  methodName - the name of the method to find

  paramTypes - the parameter types of the method to find

  返回:

  the Method object, or null if not found

  另请参阅:

  Class.getDeclaredMethod(java.lang.String, java.lang.Class<?>...)

• findMethodWithMinimalParameters

  @Nullable
  public static Method findMethodWithMinimalParameters​(Class<?> clazz,
                                                       String methodName)
                                                throws IllegalArgumentException

  Find a method with the given method name and minimal parameters (best case: none), declared on the given class or one of its superclasses. Prefers public methods, but will return a protected, package access, or private method too.

  Checks Class.getMethods first, falling back to findDeclaredMethodWithMinimalParameters. This allows for finding public methods without issues even in environments with restricted Java security settings.

  参数:

  clazz - the class to check

  methodName - the name of the method to find

  返回:

  the Method object, or null if not found

  抛出:

  IllegalArgumentException - if methods of the given name were found but could not be resolved to a unique method with minimal parameters

  另请参阅:

  Class.getMethods(), findDeclaredMethodWithMinimalParameters(java.lang.Class<?>, java.lang.String)

• findDeclaredMethodWithMinimalParameters

  @Nullable
  public static Method findDeclaredMethodWithMinimalParameters​(Class<?> clazz,
                                                               String methodName)
                                                        throws IllegalArgumentException

  Find a method with the given method name and minimal parameters (best case: none), declared on the given class or one of its superclasses. Will return a public, protected, package access, or private method.

  Checks Class.getDeclaredMethods, cascading upwards to all superclasses.

  参数:

  clazz - the class to check

  methodName - the name of the method to find

  返回:

  the Method object, or null if not found

  抛出:

  IllegalArgumentException - if methods of the given name were found but could not be resolved to a unique method with minimal parameters

  另请参阅:

  Class.getDeclaredMethods()

• findMethodWithMinimalParameters

  @Nullable
  public static Method findMethodWithMinimalParameters​(Method[] methods,
                                                       String methodName)
                                                throws IllegalArgumentException

  Find a method with the given method name and minimal parameters (best case: none) in the given list of methods.

  参数:

  methods - the methods to check

  methodName - the name of the method to find

  返回:

  the Method object, or null if not found

  抛出:

  IllegalArgumentException - if methods of the given name were found but could not be resolved to a unique method with minimal parameters

• resolveSignature

  @Nullable
  public static Method resolveSignature​(String signature,
                                        Class<?> clazz)

  Parse a method signature in the form methodName[([arg_list])], where arg_list is an optional, comma-separated list of fully-qualified type names, and attempts to resolve that signature against the supplied Class.

  When not supplying an argument list (methodName) the method whose name matches and has the least number of parameters will be returned. When supplying an argument type list, only the method whose name and argument types match will be returned.

  Note then that methodName and methodName() are not resolved in the same way. The signature methodName means the method called methodName with the least number of arguments, whereas methodName() means the method called methodName with exactly 0 arguments.

  If no method can be found, then null is returned.

  参数:

  signature - the method signature as String representation

  clazz - the class to resolve the method signature against

  返回:

  the resolved Method

  另请参阅:

  findMethod(java.lang.Class<?>, java.lang.String, java.lang.Class<?>...), findMethodWithMinimalParameters(java.lang.Class<?>, java.lang.String)

• getPropertyDescriptors

  public static PropertyDescriptor[] getPropertyDescriptors​(Class<?> clazz)
                                                     throws BeansException

  Retrieve the JavaBeans PropertyDescriptors of a given class.

  参数:

  clazz - the Class to retrieve the PropertyDescriptors for

  返回:

  an array of PropertyDescriptors for the given class

  抛出:

  BeansException - if PropertyDescriptor look fails

• getPropertyDescriptor

  @Nullable
  public static PropertyDescriptor getPropertyDescriptor​(Class<?> clazz,
                                                         String propertyName)
                                                  throws BeansException

  Retrieve the JavaBeans PropertyDescriptors for the given property.

  参数:

  clazz - the Class to retrieve the PropertyDescriptor for

  propertyName - the name of the property

  返回:

  the corresponding PropertyDescriptor, or null if none

  抛出:

  BeansException - if PropertyDescriptor lookup fails

• findPropertyForMethod

  @Nullable
  public static PropertyDescriptor findPropertyForMethod​(Method method)
                                                  throws BeansException

  Find a JavaBeans PropertyDescriptor for the given method, with the method either being the read method or the write method for that bean property.

  参数:

  method - the method to find a corresponding PropertyDescriptor for, introspecting its declaring class

  返回:

  the corresponding PropertyDescriptor, or null if none

  抛出:

  BeansException - if PropertyDescriptor lookup fails

• findPropertyForMethod

  @Nullable
  public static PropertyDescriptor findPropertyForMethod​(Method method,
                                                         Class<?> clazz)
                                                  throws BeansException

  Find a JavaBeans PropertyDescriptor for the given method, with the method either being the read method or the write method for that bean property.

  参数:

  method - the method to find a corresponding PropertyDescriptor for

  clazz - the (most specific) class to introspect for descriptors

  返回:

  the corresponding PropertyDescriptor, or null if none

  抛出:

  BeansException - if PropertyDescriptor lookup fails

  从以下版本开始:

  3.2.13

• findEditorByConvention

  @Nullable
  public static PropertyEditor findEditorByConvention​(@Nullable
                                                      Class<?> targetType)

  Find a JavaBeans PropertyEditor following the 'Editor' suffix convention (e.g. "mypackage.MyDomainClass" -> "mypackage.MyDomainClassEditor").

  Compatible to the standard JavaBeans convention as implemented by PropertyEditorManager but isolated from the latter's registered default editors for primitive types.

  参数:

  targetType - the type to find an editor for

  返回:

  the corresponding editor, or null if none found

• findPropertyType

  public static Class<?> findPropertyType​(String propertyName,
                                          @Nullable
                                          Class<?>... beanClasses)

  Determine the bean property type for the given property from the given classes/interfaces, if possible.

  参数:

  propertyName - the name of the bean property

  beanClasses - the classes to check against

  返回:

  the property type, or Object.class as fallback

• getWriteMethodParameter

  public static MethodParameter getWriteMethodParameter​(PropertyDescriptor pd)

  Obtain a new MethodParameter object for the write method of the specified property.

  参数:

  pd - the PropertyDescriptor for the property

  返回:

  a corresponding MethodParameter object

• isSimpleProperty

  public static boolean isSimpleProperty​(Class<?> type)

  Check if the given type represents a "simple" property: a simple value type or an array of simple value types.

  See isSimpleValueType(Class) for the definition of simple value type.

  Used to determine properties to check for a "simple" dependency-check.

  参数:

  type - the type to check

  返回:

  whether the given type represents a "simple" property

  另请参阅:

  AbstractBeanDefinition.DEPENDENCY_CHECK_SIMPLE, AbstractAutowireCapableBeanFactory.checkDependencies(java.lang.String, org.springframework.beans.factory.support.AbstractBeanDefinition, java.beans.PropertyDescriptor[], org.springframework.beans.PropertyValues), isSimpleValueType(Class)

• isSimpleValueType

  public static boolean isSimpleValueType​(Class<?> type)

  Check if the given type represents a "simple" value type: a primitive or primitive wrapper, an enum, a String or other CharSequence, a Number, a Date, a Temporal, a URI, a URL, a Locale, or a Class.

  Void and void are not considered simple value types.

  参数:

  type - the type to check

  返回:

  whether the given type represents a "simple" value type

  另请参阅:

  isSimpleProperty(Class)

• copyProperties

  public static void copyProperties​(Object source,
                                    Object target)
                             throws BeansException

  Copy the property values of the given source bean into the target bean.

  Note: The source and target classes do not have to match or even be derived from each other, as long as the properties match. Any bean properties that the source bean exposes but the target bean does not will silently be ignored.

  This is just a convenience method. For more complex transfer needs, consider using a full BeanWrapper.

  参数:

  source - the source bean

  target - the target bean

  抛出:

  BeansException - if the copying failed

  另请参阅:

  BeanWrapper

• copyProperties

  public static void copyProperties​(Object source,
                                    Object target,
                                    Class<?> editable)
                             throws BeansException

  Copy the property values of the given source bean into the given target bean, only setting properties defined in the given "editable" class (or interface).

  Note: The source and target classes do not have to match or even be derived from each other, as long as the properties match. Any bean properties that the source bean exposes but the target bean does not will silently be ignored.

  This is just a convenience method. For more complex transfer needs, consider using a full BeanWrapper.

  参数:

  source - the source bean

  target - the target bean

  editable - the class (or interface) to restrict property setting to

  抛出:

  BeansException - if the copying failed

  另请参阅:

  BeanWrapper

• copyProperties

  public static void copyProperties​(Object source,
                                    Object target,
                                    String... ignoreProperties)
                             throws BeansException

  Copy the property values of the given source bean into the given target bean, ignoring the given "ignoreProperties".

  Note: The source and target classes do not have to match or even be derived from each other, as long as the properties match. Any bean properties that the source bean exposes but the target bean does not will silently be ignored.

  This is just a convenience method. For more complex transfer needs, consider using a full BeanWrapper.

  参数:

  source - the source bean

  target - the target bean

  ignoreProperties - array of property names to ignore

  抛出:

  BeansException - if the copying failed

  另请参阅:

  BeanWrapper