Joshua Bloch の「ビルダー パターン」[ Effective Java Second Editionの項目 2 ] をリフレクションで使用しようとすると [ object = constructors[index].newInstance(constructorParameterValues); ] 次の例外が発生します。
java.lang.IllegalAccessException: クラス info.soaj.core.util.SjUtilReflection は、クラス info.soaj.core.attribute.SjAttributesForThrowable のメンバーに修飾子 "private" でアクセスできません
注: これは解決済みです。アクセス可能な (プライベート) コンストラクターが破棄され、アクセス不可 (オーバーライド = false) が試行されました。結論: プログラマー エラー
Builder クラスの例は次のとおりです。
package info.soaj.core.attribute;
import info.soaj.core.attribute.internal.SjAttributesForStronglyTypedWrappers;
import info.soaj.core.internal.string.SjPopulatedClassName;
import info.soaj.core.internal.string.SjPopulatedMethodName;
import info.soaj.core.util.internal.SjUtilThrowable;
import java.io.Serializable;
/**
* <p>
* The "Builder" pattern as documented by Joshua Bloch ("Effective Java" -
* Second Edition) is utilized to handle the variable number of required and
* optional parameters.
* </p>
*
* <p style="font-family:Verdana; font-size:10px; font-style:italic"> Copyright
* (c) 2006 - 2008 by Global Technology Consulting Group, Inc. at <a
* href="http://gtcGroup.com">gtcGroup.com </a>. </p>
*
* @author MarvinToll@gtcGroup.com
* @since v. 1.0
*/
public class SjAttributesExample implements Serializable {
/** UID */
private static final long serialVersionUID = 1L;
/** The name of class throwing the exception. */
protected final SjPopulatedClassName classname;
/** The name of method throwing the exception. */
protected final SjPopulatedMethodName methodname;
/**
* Suppresses logging; default is <code>false</code>.
*/
protected final boolean suppressLoggingOnly;
/**
* Constructor - private
*
* @param builderThrowable
*/
private SjAttributesExample(final BuilderThrowable builderThrowable) {
this.classname = builderThrowable.classname;
this.methodname = builderThrowable.methodname;
this.suppressLoggingOnly = builderThrowable.suppressLoggingOnly;
}
/**
* This static member immutable class is used to implement the builder
* pattern.
*
* @author MarvinToll@gtcGroup.com
* @since v. 1.0
*/
public static class BuilderThrowable {
/** Class name. */
private static final String CLASS_NAME = BuilderThrowable.class
.getName();
// Required attributes.
/** The name of class throwing the exception. */
protected final SjPopulatedClassName classname;
/** The name of method throwing the exception. */
protected final SjPopulatedMethodName methodname;
// Optional attributes.
/** Prevents action from occurring. Default is false. */
protected boolean suppressLoggingOnly = false;
/**
* Constructor
*
* @param classname
* @param methodname
*/
public BuilderThrowable(final String classname, final String methodname) {
super();
final String Method_Name = "BuilderThrowable";
// What happens when handling an exception throws an exception?
try {
this.classname = new SjPopulatedClassName(classname,
new SjAttributesForStronglyTypedWrappers(CLASS_NAME,
Method_Name));
this.methodname = new SjPopulatedMethodName(methodname,
new SjAttributesForStronglyTypedWrappers(CLASS_NAME,
Method_Name));
} catch (final RuntimeException e) {
// Log the contextual details.
SjUtilThrowable.logExceptionOccuredWhileThrowingException(
CLASS_NAME, Method_Name, e);
throw e;
}
return;
}
/**
* This method sets a flag to suppress logging.
*
* @param isLoggingSuppressed
* @return BuilderThrowable
*/
public BuilderThrowable suppressLoggingOnly(
final boolean isLoggingSuppressed) {
this.suppressLoggingOnly = isLoggingSuppressed;
return this;
}
/**
* This method is used for instantiating this class.
*
* @return SjAttributesForThrowable
*/
@SuppressWarnings("synthetic-access")
public SjAttributesExample build() {
return new SjAttributesExample(this);
}
}
/**
* This method returns an attribute.
*
* @return String - Returns the <code>classname</code> attribute.
*/
public String getClassname() {
return this.classname.getString();
}
/**
* This method returns an attribute.
*
* @return String - Returns the <code>methodname</code> attribute.
*/
public String getMethodname() {
return this.methodname.getString();
}
/**
* This method returns an attribute.
*
* @return boolean - Returns the <code>suppressLoggingOnly</code> attribute.
*/
public boolean isLoggingSuppressed() {
return this.suppressLoggingOnly;
}
}