org.drools.core.base.ClassFieldReader Maven / Gradle / Ivy
/*
* Copyright 2005 Red Hat, Inc. and/or its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.drools.core.base;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.lang.reflect.Method;
import java.math.BigDecimal;
import java.math.BigInteger;
import org.drools.core.common.InternalWorkingMemory;
import org.drools.core.spi.InternalReadAccessor;
import org.drools.core.util.ClassUtils;
/**
* This provides access to fields, and what their numerical index/object type is.
* This is basically a wrapper class around dynamically generated subclasses of
* BaseClassFieldExtractor,
* which allows serialization by regenerating the accessor classes
* when needed.
*/
public class ClassFieldReader
implements
Externalizable,
InternalReadAccessor {
private static final long serialVersionUID = 510l;
private String className;
private String fieldName;
private transient InternalReadAccessor reader;
/**
* Utility method to take a string and convert it to normal Java variable
* name capitalization. This normally means converting the first
* character from upper case to lower case, but in the (unusual) special
* case when there is more than one character and both the first and
* second characters are upper case, we leave it alone.
*
* Thus "FooBah" becomes "fooBah" and "X" becomes "x", but "URL" stays
* as "URL".
*
* Taken from
*
* @param name The string to be decapitalized.
* @return The decapitalized version of the string.
*/
public static String decapitalizeFieldName(String name) {
if (name == null || name.length() == 0) {
return name;
}
if (name.length() > 1 && Character.isUpperCase(name.charAt(1)) &&
Character.isUpperCase(name.charAt(0))){
return name;
}
char chars[] = name.toCharArray();
chars[0] = Character.toLowerCase(chars[0]);
return new String(chars);
}
public ClassFieldReader() {
}
public ClassFieldReader(final String className,
final String fieldName) {
this.className = className;
this.fieldName = ClassFieldReader.decapitalizeFieldName(fieldName);
}
public void writeExternal(ObjectOutput out) throws IOException {
out.writeObject( className );
out.writeObject( fieldName );
}
public void readExternal(final ObjectInput is) throws ClassNotFoundException,
IOException {
className = (String) is.readObject();
fieldName = (String) is.readObject();
}
public void setReadAccessor(InternalReadAccessor reader) {
this.reader = reader;
}
public int getIndex() {
return this.reader.getIndex();
}
public String getClassName() {
return this.className;
}
public String getFieldName() {
return this.fieldName;
}
public boolean hasReadAccessor() {
return this.reader != null;
}
public Object getValue(InternalWorkingMemory workingMemory,
final Object object) {
return this.reader.getValue( workingMemory,
object );
}
public ValueType getValueType() {
return this.reader.getValueType();
}
public Class< ? > getExtractToClass() {
return reader != null ? reader.getExtractToClass() : null;
}
public String getExtractToClassName() {
return ClassUtils.canonicalName( this.reader.getExtractToClass() );
}
public String toString() {
return "[ClassFieldExtractor class=" + this.className + " field=" + this.fieldName + "]";
}
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((className == null) ? 0 : className.hashCode());
result = prime * result + ((fieldName == null) ? 0 : fieldName.hashCode());
return result;
}
public boolean equals(Object obj) {
if ( this == obj ) return true;
if ( obj == null ) return false;
if ( !(obj instanceof ClassFieldReader) ) return false;
ClassFieldReader other = (ClassFieldReader) obj;
if ( className == null ) {
if ( other.className != null ) return false;
} else if ( !className.equals( other.className ) ) return false;
if ( fieldName == null ) {
if ( other.fieldName != null ) return false;
} else if ( !fieldName.equals( other.fieldName ) ) return false;
return true;
}
public boolean getBooleanValue(InternalWorkingMemory workingMemory,
final Object object) {
return this.reader.getBooleanValue( workingMemory,
object );
}
public byte getByteValue(InternalWorkingMemory workingMemory,
final Object object) {
return this.reader.getByteValue( workingMemory,
object );
}
public char getCharValue(InternalWorkingMemory workingMemory,
final Object object) {
return this.reader.getCharValue( workingMemory,
object );
}
public double getDoubleValue(InternalWorkingMemory workingMemory,
final Object object) {
return this.reader.getDoubleValue( workingMemory,
object );
}
public float getFloatValue(InternalWorkingMemory workingMemory,
final Object object) {
return this.reader.getFloatValue( workingMemory,
object );
}
public int getIntValue(InternalWorkingMemory workingMemory,
final Object object) {
return this.reader.getIntValue( workingMemory,
object );
}
public long getLongValue(InternalWorkingMemory workingMemory,
final Object object) {
return this.reader.getLongValue( workingMemory,
object );
}
public short getShortValue(InternalWorkingMemory workingMemory,
final Object object) {
return this.reader.getShortValue( workingMemory,
object );
}
public boolean isNullValue(InternalWorkingMemory workingMemory,
final Object object) {
return this.reader.isNullValue( workingMemory,
object );
}
public Method getNativeReadMethod() {
return this.reader.getNativeReadMethod();
}
public String getNativeReadMethodName() {
return this.reader.getNativeReadMethod().getName();
}
public int getHashCode(InternalWorkingMemory workingMemory,
final Object object) {
return this.reader.getHashCode( workingMemory,
object );
}
public boolean isGlobal() {
return false;
}
public boolean isSelfReference() {
return "this".equals( this.fieldName );
}
public boolean getBooleanValue(Object object) {
return reader.getBooleanValue( object );
}
public byte getByteValue(Object object) {
return reader.getByteValue( object );
}
public char getCharValue(Object object) {
return reader.getCharValue( object );
}
public double getDoubleValue(Object object) {
return reader.getDoubleValue( object );
}
public float getFloatValue(Object object) {
return reader.getFloatValue( object );
}
public int getHashCode(Object object) {
return reader.getHashCode( object );
}
public int getIntValue(Object object) {
return reader.getIntValue( object );
}
public long getLongValue(Object object) {
return reader.getLongValue( object );
}
public short getShortValue(Object object) {
return reader.getShortValue( object );
}
public Object getValue(Object object) {
return reader.getValue( object );
}
public boolean isNullValue(Object object) {
return reader.isNullValue( object );
}
public BigDecimal getBigDecimalValue(InternalWorkingMemory workingMemory,
Object object) {
return reader.getBigDecimalValue( workingMemory,
object );
}
public BigInteger getBigIntegerValue(InternalWorkingMemory workingMemory,
Object object) {
return reader.getBigIntegerValue( workingMemory,
object );
}
public BigDecimal getBigDecimalValue(Object object) {
return reader.getBigDecimalValue( object );
}
public BigInteger getBigIntegerValue(Object object) {
return reader.getBigIntegerValue( object );
}
public AccessorKey getAccessorKey() {
return new AccessorKey( className, fieldName, AccessorKey.AccessorType.FieldAccessor );
}
}