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This commit is contained in:
Keith Donald 2011-06-03 00:51:17 +00:00
parent 6f146737f4
commit 0f6d890d97
1 changed files with 42 additions and 30 deletions
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72
org.springframework.core/src/main/java/org/springframework/core/convert/TypeDescriptor.java
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@ -32,7 +32,6 @@ import org.springframework.core.GenericCollectionTypeResolver;
import org.springframework.core.GenericTypeResolver;
import org.springframework.core.MethodParameter;
import org.springframework.util.ClassUtils;
import org.springframework.util.CollectionUtils;
import org.springframework.util.ObjectUtils;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.StringUtils;
@ -104,9 +103,10 @@ public class TypeDescriptor {
}
/**
* Create a new type descriptor for a property.
* Use this constructor when a target conversion point is a property.
* @param property the property
* Create a new type descriptor for a bean property.
* Use this constructor when a target conversion point is a property on a Java class.
* @param beanClass the class that declares the property
* @param property the property descriptor
*/
public TypeDescriptor(Class<?> beanClass, PropertyDescriptor property) {
this(new BeanPropertyDescriptor(beanClass, property));
@ -158,11 +158,14 @@ public class TypeDescriptor {
* Builds in population of nested type descriptors for collection and map objects through object introspection.
* If the object is null, returns {@link TypeDescriptor#NULL}.
* If the object is not a collection or map, simply calls {@link #valueOf(Class)}.
* If the object is a collection or map, this factory method will derive the element type(s) by introspecting the collection or map.
* If the object is a collection or map, this factory method will derive nested element or key/value types by introspecting the collection or map.
* The introspection algorithm derives nested element or key/value types by resolving the "common element type" across the collection or map.
* For example, if a Collection contained all java.lang.Integer elements, its element type would be java.lang.Integer.
* If a Collection contained several distinct number types all extending from java.lang.Number, its element type would be java.lang.Number.
* If a Collection contained a String and a java.util.Map element, its element type would be java.io.Serializable.
* @param object the source object
* @return the type descriptor
* @see ConversionService#convert(Object, Class)
* @see CollectionUtils#findCommonElementType(Collection)
*/
public static TypeDescriptor forObject(Object object) {
if (object == null) {
@ -181,12 +184,13 @@ public class TypeDescriptor {
}
/**
* Creates a type descriptor for a nested type declared by the method parameter.
* Creates a type descriptor for a nested type declared within the method parameter.
* For example, if the methodParameter is a List&lt;String&gt; and the nestingLevel is 1, the nested type descriptor will be String.class.
* If the methodParameter is a List<List<String>> and the nestingLevel is 2, the nested type descriptor will also be a String.class.
* If the methodParameter is a Map<Integer, String> and the nesting level is 1, the nested type descriptor will be String, derived from the map value.
* If the methodParameter is a List<Map<Integer, String>> and the nesting level is 2, the nested type descriptor will be String, derived from the map value.
* @param methodParameter the method parameter
* @param methodParameter the method parameter with a nestingLevel of 1
* @param nestingLevel the nesting level of the collection/array element or map key/value declaration within the method parameter.
* @return the nested type descriptor
* @throws IllegalArgumentException if the method parameter is not of a collection, array, or map type.
*/
@ -195,13 +199,13 @@ public class TypeDescriptor {
}
/**
* Creates a type descriptor for a nested type declared by the field.
* Creates a type descriptor for a nested type declared within the field.
* For example, if the field is a List&lt;String&gt; and the nestingLevel is 1, the nested type descriptor will be String.class.
* If the field is a List<List<String>> and the nestingLevel is 2, the nested type descriptor will also be a String.class.
* If the field is a Map<Integer, String> and the nestingLevel is 1, the nested type descriptor will be String, derived from the map value.
* If the field is a List<Map<Integer, String>> and the nestingLevel is 2, the nested type descriptor will be String, derived from the map value.
* @param field the field
* @param nestingLevel the nesting level
* @param nestingLevel the nesting level of the collection/array element or map key/value declaration within the field.
* @return the nested type descriptor
* @throws IllegalArgumentException if the field is not of a collection, array, or map type.
*/
@ -210,13 +214,13 @@ public class TypeDescriptor {
}
/**
* Creates a type descriptor for a nested type declared by the property.
* Creates a type descriptor for a nested type declared within the property.
* For example, if the property is a List&lt;String&gt; and the nestingLevel is 1, the nested type descriptor will be String.class.
* If the property is a List<List<String>> and the nestingLevel is 2, the nested type descriptor will also be a String.class.
* If the field is a Map<Integer, String> and the nestingLevel is 1, the nested type descriptor will be String, derived from the map value.
* If the property is a List<Map<Integer, String>> and the nestingLevel is 2, the nested type descriptor will be String, derived from the map value.
* @param property the property
* @param nestingLevel the nesting level
* @param nestingLevel the nesting level of the collection/array element or map key/value declaration within the property.
* @return the nested type descriptor
* @throws IllegalArgumentException if the property is not of a collection, array, or map type.
*/
@ -255,14 +259,16 @@ public class TypeDescriptor {
}
/**
* Obtain the annotations associated with the wrapped parameter/field, if any.
* The annotations associated with this type descriptor, if any.
* @return the annotations, or an empty array if none.
*/
public Annotation[] getAnnotations() {
return this.annotations;
}
/**
* Obtain the annotation associated with the wrapped parameter/field, if any.
* Obtain the annotation associated with this type descriptor of the specified type.
* @return the annotation, or null if no such annotation exists on this type descriptor.
*/
public Annotation getAnnotation(Class<? extends Annotation> annotationType) {
for (Annotation annotation : getAnnotations()) {
@ -298,13 +304,6 @@ public class TypeDescriptor {
// indexable type descriptor operations
/**
* Is this type an array type?
*/
public boolean isArray() {
return getType().isArray();
}
/**
* Is this type a {@link Collection} type?
*/
@ -313,9 +312,16 @@ public class TypeDescriptor {
}
/**
* If this type is an array type or {@link Collection} type, returns the underlying element type.
* Is this type an array type?
*/
public boolean isArray() {
return getType().isArray();
}
/**
* If this type is a {@link Collection} or array, returns the underlying element type.
* Returns <code>null</code> if this type is neither an array or collection.
* Returns Object.class if the element type is for a collection and was not explicitly declared.
* Returns Object.class if this type is a collection and the element type was not explicitly declared.
* @return the map element type, or <code>null</code> if not a collection or array.
*/
public Class<?> getElementType() {
@ -323,7 +329,9 @@ public class TypeDescriptor {
}
/**
* Return the element type as a type descriptor.
* The collection or array element type as a type descriptor.
* Returns {@link TypeDescriptor#NULL} if this type is not a collection or an array.
* Returns TypeDescriptor.valueOf(Object.class) if this type is a collection and the element type is not explicitly declared.
*/
public TypeDescriptor getElementTypeDescriptor() {
return this.elementType;
@ -339,9 +347,9 @@ public class TypeDescriptor {
}
/**
* Determine the generic key type of the wrapped Map parameter/field, if any.
* If this type is a {@link Map}, returns the underlying key type.
* Returns <code>null</code> if this type is not map.
* Returns Object.class if the map's key type was not explicitly declared.
* Returns Object.class if this type is a map and its key type was not explicitly declared.
* @return the map key type, or <code>null</code> if not a map.
*/
public Class<?> getMapKeyType() {
@ -349,16 +357,18 @@ public class TypeDescriptor {
}
/**
* Returns map key type as a type descriptor.
* The map key type as a type descriptor.
* Returns {@link TypeDescriptor#NULL} if this type is not a map.
* Returns TypeDescriptor.valueOf(Object.class) if this type is a map and the key type is not explicitly declared.
*/
public TypeDescriptor getMapKeyTypeDescriptor() {
return this.mapKeyType;
}
/**
* Determine the generic value type of the wrapped Map parameter/field, if any.
* If this type is a {@link Map}, returns the underlying value type.
* Returns <code>null</code> if this type is not map.
* Returns Object.class if the map's value type was not explicitly declared.
* Returns Object.class if this type is a map and its value type was not explicitly declared.
* @return the map value type, or <code>null</code> if not a map.
*/
public Class<?> getMapValueType() {
@ -366,7 +376,9 @@ public class TypeDescriptor {
}
/**
* Returns map value type as a type descriptor.
* The map value type as a type descriptor.
* Returns {@link TypeDescriptor#NULL} if this type is not a map.
* Returns TypeDescriptor.valueOf(Object.class) if this type is a map and the value type is not explicitly declared.
*/
public TypeDescriptor getMapValueTypeDescriptor() {
return this.mapValueType;