JDK8/Java8源码在线阅读
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
* This code is distributed in the hope that it will be useful, but WITHOUT
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* accompanied this code).
*
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package java.beans;
import java.lang.ref.Reference;
import java.lang.reflect.Method;
/**
* An IndexedPropertyDescriptor describes a property that acts like an
* array and has an indexed read and/or indexed write method to access
* specific elements of the array.
* <p>
* An indexed property may also provide simple non-indexed read and write
* methods. If these are present, they read and write arrays of the type
* returned by the indexed read method.
*/
public class IndexedPropertyDescriptor extends PropertyDescriptor {
private Reference<? extends Class<?>> indexedPropertyTypeRef;
private final MethodRef indexedReadMethodRef = new MethodRef();
private final MethodRef indexedWriteMethodRef = new MethodRef();
private String indexedReadMethodName;
private String indexedWriteMethodName;
/**
* This constructor constructs an IndexedPropertyDescriptor for a property
* that follows the standard Java conventions by having getFoo and setFoo
* accessor methods, for both indexed access and array access.
* <p>
* Thus if the argument name is "fred", it will assume that there
* is an indexed reader method "getFred", a non-indexed (array) reader
* method also called "getFred", an indexed writer method "setFred",
* and finally a non-indexed writer method "setFred".
*
* @param propertyName The programmatic name of the property.
* @param beanClass The Class object for the target bean.
* @exception IntrospectionException if an exception occurs during
* introspection.
*/
public IndexedPropertyDescriptor(String propertyName, Class<?> beanClass)
throws IntrospectionException {
this(propertyName, beanClass,
Introspector.GET_PREFIX + NameGenerator.capitalize(propertyName),
Introspector.SET_PREFIX + NameGenerator.capitalize(propertyName),
Introspector.GET_PREFIX + NameGenerator.capitalize(propertyName),
Introspector.SET_PREFIX + NameGenerator.capitalize(propertyName));
}
/**
* This constructor takes the name of a simple property, and method
* names for reading and writing the property, both indexed
* and non-indexed.
*
* @param propertyName The programmatic name of the property.
* @param beanClass The Class object for the target bean.
* @param readMethodName The name of the method used for reading the property
* values as an array. May be null if the property is write-only
* or must be indexed.
* @param writeMethodName The name of the method used for writing the property
* values as an array. May be null if the property is read-only
* or must be indexed.
* @param indexedReadMethodName The name of the method used for reading
* an indexed property value.
* May be null if the property is write-only.
* @param indexedWriteMethodName The name of the method used for writing
* an indexed property value.
* May be null if the property is read-only.
* @exception IntrospectionException if an exception occurs during
* introspection.
*/
public IndexedPropertyDescriptor(String propertyName, Class<?> beanClass,
String readMethodName, String writeMethodName,
String indexedReadMethodName, String indexedWriteMethodName)
throws IntrospectionException {
super(propertyName, beanClass, readMethodName, writeMethodName);
this.indexedReadMethodName = indexedReadMethodName;
if (indexedReadMethodName != null && getIndexedReadMethod() == null) {
throw new IntrospectionException("Method not found: " + indexedReadMethodName);
}
this.indexedWriteMethodName = indexedWriteMethodName;
if (indexedWriteMethodName != null && getIndexedWriteMethod() == null) {
throw new IntrospectionException("Method not found: " + indexedWriteMethodName);
}
// Implemented only for type checking.
findIndexedPropertyType(getIndexedReadMethod(), getIndexedWriteMethod());
}
/**
* This constructor takes the name of a simple property, and Method
* objects for reading and writing the property.
*
* @param propertyName The programmatic name of the property.
* @param readMethod The method used for reading the property values as an array.
* May be null if the property is write-only or must be indexed.
* @param writeMethod The method used for writing the property values as an array.
* May be null if the property is read-only or must be indexed.
* @param indexedReadMethod The method used for reading an indexed property value.
* May be null if the property is write-only.
* @param indexedWriteMethod The method used for writing an indexed property value.
* May be null if the property is read-only.
* @exception IntrospectionException if an exception occurs during
* introspection.
*/
public IndexedPropertyDescriptor(String propertyName, Method readMethod, Method writeMethod,
Method indexedReadMethod, Method indexedWriteMethod)
throws IntrospectionException {
super(propertyName, readMethod, writeMethod);
setIndexedReadMethod0(indexedReadMethod);
setIndexedWriteMethod0(indexedWriteMethod);
// Type checking
setIndexedPropertyType(findIndexedPropertyType(indexedReadMethod, indexedWriteMethod));
}
/**
* Creates <code>PropertyDescriptor</code> for the specified bean
* with the specified name and methods to read/write the property value.
*
* @param bean the type of the target bean
* @param base the base name of the property (the rest of the method name)
* @param read the method used for reading the property value
* @param write the method used for writing the property value
* @param readIndexed the method used for reading an indexed property value
* @param writeIndexed the method used for writing an indexed property value
* @exception IntrospectionException if an exception occurs during introspection
*
* @since 1.7
*/
IndexedPropertyDescriptor(Class<?> bean, String base, Method read, Method write, Method readIndexed, Method writeIndexed) throws IntrospectionException {
super(bean, base, read, write);
setIndexedReadMethod0(readIndexed);
setIndexedWriteMethod0(writeIndexed);
// Type checking
setIndexedPropertyType(findIndexedPropertyType(readIndexed, writeIndexed));
}
/**
* Gets the method that should be used to read an indexed
* property value.
*
* @return The method that should be used to read an indexed
* property value.
* May return null if the property isn't indexed or is write-only.
*/
public synchronized Method getIndexedReadMethod() {
Method indexedReadMethod = this.indexedReadMethodRef.get();
if (indexedReadMethod == null) {
Class<?> cls = getClass0();
if (cls == null ||
(indexedReadMethodName == null && !this.indexedReadMethodRef.isSet())) {
// the Indexed readMethod was explicitly set to null.
return null;
}
String nextMethodName = Introspector.GET_PREFIX + getBaseName();
if (indexedReadMethodName == null) {
Class<?> type = getIndexedPropertyType0();
if (type == boolean.class || type == null) {
indexedReadMethodName = Introspector.IS_PREFIX + getBaseName();
} else {
indexedReadMethodName = nextMethodName;
}
}
Class<?>[] args = { int.class };
indexedReadMethod = Introspector.findMethod(cls, indexedReadMethodName, 1, args);
if ((indexedReadMethod == null) && !indexedReadMethodName.equals(nextMethodName)) {
// no "is" method, so look for a "get" method.
indexedReadMethodName = nextMethodName;
indexedReadMethod = Introspector.findMethod(cls, indexedReadMethodName, 1, args);
}
setIndexedReadMethod0(indexedReadMethod);
}
return indexedReadMethod;
}
/**
* Sets the method that should be used to read an indexed property value.
*
* @param readMethod The new indexed read method.
* @throws IntrospectionException if an exception occurs during
* introspection.
*/
public synchronized void setIndexedReadMethod(Method readMethod)
throws IntrospectionException {
// the indexed property type is set by the reader.
setIndexedPropertyType(findIndexedPropertyType(readMethod,
this.indexedWriteMethodRef.get()));
setIndexedReadMethod0(readMethod);
}
private void setIndexedReadMethod0(Method readMethod) {
this.indexedReadMethodRef.set(readMethod);
if (readMethod == null) {
indexedReadMethodName = null;
return;
}
setClass0(readMethod.getDeclaringClass());
indexedReadMethodName = readMethod.getName();
setTransient(readMethod.getAnnotation(Transient.class));
}
/**
* Gets the method that should be used to write an indexed property value.
*
* @return The method that should be used to write an indexed
* property value.
* May return null if the property isn't indexed or is read-only.
*/
public synchronized Method getIndexedWriteMethod() {
Method indexedWriteMethod = this.indexedWriteMethodRef.get();
if (indexedWriteMethod == null) {
Class<?> cls = getClass0();
if (cls == null ||
(indexedWriteMethodName == null && !this.indexedWriteMethodRef.isSet())) {
// the Indexed writeMethod was explicitly set to null.
return null;
}
// We need the indexed type to ensure that we get the correct method.
// Cannot use the getIndexedPropertyType method since that could
// result in an infinite loop.
Class<?> type = getIndexedPropertyType0();
if (type == null) {
try {
type = findIndexedPropertyType(getIndexedReadMethod(), null);
setIndexedPropertyType(type);
} catch (IntrospectionException ex) {
// Set iprop type to be the classic type
Class<?> propType = getPropertyType();
if (propType.isArray()) {
type = propType.getComponentType();
}
}
}
if (indexedWriteMethodName == null) {
indexedWriteMethodName = Introspector.SET_PREFIX + getBaseName();
}
Class<?>[] args = (type == null) ? null : new Class<?>[] { int.class, type };
indexedWriteMethod = Introspector.findMethod(cls, indexedWriteMethodName, 2, args);
if (indexedWriteMethod != null) {
if (!indexedWriteMethod.getReturnType().equals(void.class)) {
indexedWriteMethod = null;
}
}
setIndexedWriteMethod0(indexedWriteMethod);
}
return indexedWriteMethod;
}
/**
* Sets the method that should be used to write an indexed property value.
*
* @param writeMethod The new indexed write method.
* @throws IntrospectionException if an exception occurs during
* introspection.
*/
public synchronized void setIndexedWriteMethod(Method writeMethod)
throws IntrospectionException {
// If the indexed property type has not been set, then set it.
Class<?> type = findIndexedPropertyType(getIndexedReadMethod(),
writeMethod);
setIndexedPropertyType(type);
setIndexedWriteMethod0(writeMethod);
}
private void setIndexedWriteMethod0(Method writeMethod) {
this.indexedWriteMethodRef.set(writeMethod);
if (writeMethod == null) {
indexedWriteMethodName = null;
return;
}
setClass0(writeMethod.getDeclaringClass());
indexedWriteMethodName = writeMethod.getName();
setTransient(writeMethod.getAnnotation(Transient.class));
}
/**
* Returns the Java type info for the indexed property.
* Note that the {@code Class} object may describe
* primitive Java types such as {@code int}.
* This type is returned by the indexed read method
* or is used as the parameter type of the indexed write method.
*
* @return the {@code Class} object that represents the Java type info,
* or {@code null} if the type cannot be determined
*/
public synchronized Class<?> getIndexedPropertyType() {
Class<?> type = getIndexedPropertyType0();
if (type == null) {
try {
type = findIndexedPropertyType(getIndexedReadMethod(),
getIndexedWriteMethod());
setIndexedPropertyType(type);
} catch (IntrospectionException ex) {
// fall
}
}
return type;
}
// Private methods which set get/set the Reference objects
private void setIndexedPropertyType(Class<?> type) {
this.indexedPropertyTypeRef = getWeakReference(type);
}
private Class<?> getIndexedPropertyType0() {
return (this.indexedPropertyTypeRef != null)
? this.indexedPropertyTypeRef.get()
: null;
}
private Class<?> findIndexedPropertyType(Method indexedReadMethod,
Method indexedWriteMethod)
throws IntrospectionException {
Class<?> indexedPropertyType = null;
if (indexedReadMethod != null) {
Class params[] = getParameterTypes(getClass0(), indexedReadMethod);
if (params.length != 1) {
throw new IntrospectionException("bad indexed read method arg count");
}
if (params[0] != Integer.TYPE) {
throw new IntrospectionException("non int index to indexed read method");
}
indexedPropertyType = getReturnType(getClass0(), indexedReadMethod);
if (indexedPropertyType == Void.TYPE) {
throw new IntrospectionException("indexed read method returns void");
}
}
if (indexedWriteMethod != null) {
Class params[] = getParameterTypes(getClass0(), indexedWriteMethod);
if (params.length != 2) {
throw new IntrospectionException("bad indexed write method arg count");
}
if (params[0] != Integer.TYPE) {
throw new IntrospectionException("non int index to indexed write method");
}
if (indexedPropertyType == null || params[1].isAssignableFrom(indexedPropertyType)) {
indexedPropertyType = params[1];
} else if (!indexedPropertyType.isAssignableFrom(params[1])) {
throw new IntrospectionException(
"type mismatch between indexed read and indexed write methods: "
+ getName());
}
}
Class<?> propertyType = getPropertyType();
if (propertyType != null && (!propertyType.isArray() ||
propertyType.getComponentType() != indexedPropertyType)) {
throw new IntrospectionException("type mismatch between indexed and non-indexed methods: "
+ getName());
}
return indexedPropertyType;
}
/**
* Compares this <code>PropertyDescriptor</code> against the specified object.
* Returns true if the objects are the same. Two <code>PropertyDescriptor</code>s
* are the same if the read, write, property types, property editor and
* flags are equivalent.
*
* @since 1.4
*/
public boolean equals(Object obj) {
// Note: This would be identical to PropertyDescriptor but they don't
// share the same fields.
if (this == obj) {
return true;
}
if (obj != null && obj instanceof IndexedPropertyDescriptor) {
IndexedPropertyDescriptor other = (IndexedPropertyDescriptor)obj;
Method otherIndexedReadMethod = other.getIndexedReadMethod();
Method otherIndexedWriteMethod = other.getIndexedWriteMethod();
if (!compareMethods(getIndexedReadMethod(), otherIndexedReadMethod)) {
return false;
}
if (!compareMethods(getIndexedWriteMethod(), otherIndexedWriteMethod)) {
return false;
}
if (getIndexedPropertyType() != other.getIndexedPropertyType()) {
return false;
}
return super.equals(obj);
}
return false;
}
/**
* Package-private constructor.
* Merge two property descriptors. Where they conflict, give the
* second argument (y) priority over the first argumnnt (x).
*
* @param x The first (lower priority) PropertyDescriptor
* @param y The second (higher priority) PropertyDescriptor
*/
IndexedPropertyDescriptor(PropertyDescriptor x, PropertyDescriptor y) {
super(x,y);
if (x instanceof IndexedPropertyDescriptor) {
IndexedPropertyDescriptor ix = (IndexedPropertyDescriptor)x;
try {
Method xr = ix.getIndexedReadMethod();
if (xr != null) {
setIndexedReadMethod(xr);
}
Method xw = ix.getIndexedWriteMethod();
if (xw != null) {
setIndexedWriteMethod(xw);
}
} catch (IntrospectionException ex) {
// Should not happen
throw new AssertionError(ex);
}
}
if (y instanceof IndexedPropertyDescriptor) {
IndexedPropertyDescriptor iy = (IndexedPropertyDescriptor)y;
try {
Method yr = iy.getIndexedReadMethod();
if (yr != null && yr.getDeclaringClass() == getClass0()) {
setIndexedReadMethod(yr);
}
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