| /* $Id$ |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.commons.digester; |
| |
| |
| import org.apache.commons.beanutils.ConvertUtils; |
| import org.apache.commons.beanutils.MethodUtils; |
| import org.xml.sax.Attributes; |
| |
| |
| /** |
| * <p>Rule implementation that calls a method on an object on the stack |
| * (normally the top/parent object), passing arguments collected from |
| * subsequent <code>CallParamRule</code> rules or from the body of this |
| * element. </p> |
| * |
| * <p>By using {@link #CallMethodRule(String methodName)} |
| * a method call can be made to a method which accepts no |
| * arguments.</p> |
| * |
| * <p>Incompatible method parameter types are converted |
| * using <code>org.apache.commons.beanutils.ConvertUtils</code>. |
| * </p> |
| * |
| * <p>This rule now uses {@link MethodUtils#invokeMethod} by default. |
| * This increases the kinds of methods successfully and allows primitives |
| * to be matched by passing in wrapper classes. |
| * There are rare cases when {@link MethodUtils#invokeExactMethod} |
| * (the old default) is required. |
| * This method is much stricter in it's reflection. |
| * Setting the <code>UseExactMatch</code> to true reverts to the use of this |
| * method.</p> |
| * |
| * <p>Note that the target method is invoked when the <i>end</i> of |
| * the tag the CallMethodRule fired on is encountered, <i>not</i> when the |
| * last parameter becomes available. This implies that rules which fire on |
| * tags nested within the one associated with the CallMethodRule will |
| * fire before the CallMethodRule invokes the target method. This behaviour is |
| * not configurable. </p> |
| * |
| * <p>Note also that if a CallMethodRule is expecting exactly one parameter |
| * and that parameter is not available (eg CallParamRule is used with an |
| * attribute name but the attribute does not exist) then the method will |
| * not be invoked. If a CallMethodRule is expecting more than one parameter, |
| * then it is always invoked, regardless of whether the parameters were |
| * available or not; missing parameters are converted to the appropriate target |
| * type by calling ConvertUtils.convert. Note that the default ConvertUtils |
| * converters for the String type returns a null when passed a null, meaning |
| * that CallMethodRule will passed null for all String parameters for which |
| * there is no parameter info available from the XML. However parameters of |
| * type Float and Integer will be passed a real object containing a zero value |
| * as that is the output of the default ConvertUtils converters for those |
| * types when passed a null. You can register custom converters to change |
| * this behaviour; see the beautils library documentation for more info.</p> |
| * |
| * <p>Note that when a constructor is used with paramCount=0, indicating that |
| * the body of the element is to be passed to the target method, an empty |
| * element will cause an <i>empty string</i> to be passed to the target method, |
| * not null. And if automatic type conversion is being applied (ie if the |
| * target function takes something other than a string as a parameter) then |
| * the conversion will fail if the converter class does not accept an empty |
| * string as valid input.</p> |
| * |
| * <p>CallMethodRule has a design flaw which can cause it to fail under |
| * certain rule configurations. All CallMethodRule instances share a single |
| * parameter stack, and all CallParamRule instances simply store their data |
| * into the parameter-info structure that is on the top of the stack. This |
| * means that two CallMethodRule instances cannot be associated with the |
| * same pattern without getting scrambled parameter data. This same issue |
| * also applies when a CallMethodRule matches some element X, a different |
| * CallMethodRule matches a child element Y and some of the CallParamRules |
| * associated with the first CallMethodRule match element Y or one of its |
| * child elements. This issue has been present since the very first release |
| * of Digester. Note, however, that this configuration of CallMethodRule |
| * instances is not commonly required.</p> |
| */ |
| |
| public class CallMethodRule extends Rule { |
| |
| // ----------------------------------------------------------- Constructors |
| |
| /** |
| * Construct a "call method" rule with the specified method name. The |
| * parameter types (if any) default to java.lang.String. |
| * |
| * @param digester The associated Digester |
| * @param methodName Method name of the parent method to call |
| * @param paramCount The number of parameters to collect, or |
| * zero for a single argument from the body of this element. |
| * |
| * |
| * @deprecated The digester instance is now set in the {@link Digester#addRule} method. |
| * Use {@link #CallMethodRule(String methodName,int paramCount)} instead. |
| */ |
| @Deprecated |
| public CallMethodRule(Digester digester, String methodName, |
| int paramCount) { |
| |
| this(methodName, paramCount); |
| |
| } |
| |
| |
| /** |
| * Construct a "call method" rule with the specified method name. |
| * |
| * @param digester The associated Digester |
| * @param methodName Method name of the parent method to call |
| * @param paramCount The number of parameters to collect, or |
| * zero for a single argument from the body of ths element |
| * @param paramTypes The Java class names of the arguments |
| * (if you wish to use a primitive type, specify the corresonding |
| * Java wrapper class instead, such as <code>java.lang.Boolean</code> |
| * for a <code>boolean</code> parameter) |
| * |
| * @deprecated The digester instance is now set in the {@link Digester#addRule} method. |
| * Use {@link #CallMethodRule(String methodName,int paramCount, String [] paramTypes)} instead. |
| */ |
| @Deprecated |
| public CallMethodRule(Digester digester, String methodName, |
| int paramCount, String paramTypes[]) { |
| |
| this(methodName, paramCount, paramTypes); |
| |
| } |
| |
| |
| /** |
| * Construct a "call method" rule with the specified method name. |
| * |
| * @param digester The associated Digester |
| * @param methodName Method name of the parent method to call |
| * @param paramCount The number of parameters to collect, or |
| * zero for a single argument from the body of ths element |
| * @param paramTypes The Java classes that represent the |
| * parameter types of the method arguments |
| * (if you wish to use a primitive type, specify the corresonding |
| * Java wrapper class instead, such as <code>java.lang.Boolean.TYPE</code> |
| * for a <code>boolean</code> parameter) |
| * |
| * @deprecated The digester instance is now set in the {@link Digester#addRule} method. |
| * Use {@link #CallMethodRule(String methodName,int paramCount, Class [] paramTypes)} instead. |
| */ |
| @Deprecated |
| public CallMethodRule(Digester digester, String methodName, |
| int paramCount, Class<?> paramTypes[]) { |
| |
| this(methodName, paramCount, paramTypes); |
| } |
| |
| |
| /** |
| * Construct a "call method" rule with the specified method name. The |
| * parameter types (if any) default to java.lang.String. |
| * |
| * @param methodName Method name of the parent method to call |
| * @param paramCount The number of parameters to collect, or |
| * zero for a single argument from the body of this element. |
| */ |
| public CallMethodRule(String methodName, |
| int paramCount) { |
| this(0, methodName, paramCount); |
| } |
| |
| /** |
| * Construct a "call method" rule with the specified method name. The |
| * parameter types (if any) default to java.lang.String. |
| * |
| * @param targetOffset location of the target object. Positive numbers are |
| * relative to the top of the digester object stack. Negative numbers |
| * are relative to the bottom of the stack. Zero implies the top |
| * object on the stack. |
| * @param methodName Method name of the parent method to call |
| * @param paramCount The number of parameters to collect, or |
| * zero for a single argument from the body of this element. |
| */ |
| public CallMethodRule(int targetOffset, |
| String methodName, |
| int paramCount) { |
| |
| this.targetOffset = targetOffset; |
| this.methodName = methodName; |
| this.paramCount = paramCount; |
| if (paramCount == 0) { |
| this.paramTypes = new Class[] { String.class }; |
| } else { |
| this.paramTypes = new Class[paramCount]; |
| for (int i = 0; i < this.paramTypes.length; i++) { |
| this.paramTypes[i] = String.class; |
| } |
| } |
| |
| } |
| |
| /** |
| * Construct a "call method" rule with the specified method name. |
| * The method should accept no parameters. |
| * |
| * @param methodName Method name of the parent method to call |
| */ |
| public CallMethodRule(String methodName) { |
| |
| this(0, methodName, 0, (Class[]) null); |
| |
| } |
| |
| |
| /** |
| * Construct a "call method" rule with the specified method name. |
| * The method should accept no parameters. |
| * |
| * @param targetOffset location of the target object. Positive numbers are |
| * relative to the top of the digester object stack. Negative numbers |
| * are relative to the bottom of the stack. Zero implies the top |
| * object on the stack. |
| * @param methodName Method name of the parent method to call |
| */ |
| public CallMethodRule(int targetOffset, String methodName) { |
| |
| this(targetOffset, methodName, 0, (Class[]) null); |
| |
| } |
| |
| |
| /** |
| * Construct a "call method" rule with the specified method name and |
| * parameter types. If <code>paramCount</code> is set to zero the rule |
| * will use the body of this element as the single argument of the |
| * method, unless <code>paramTypes</code> is null or empty, in this |
| * case the rule will call the specified method with no arguments. |
| * |
| * @param methodName Method name of the parent method to call |
| * @param paramCount The number of parameters to collect, or |
| * zero for a single argument from the body of ths element |
| * @param paramTypes The Java class names of the arguments |
| * (if you wish to use a primitive type, specify the corresonding |
| * Java wrapper class instead, such as <code>java.lang.Boolean</code> |
| * for a <code>boolean</code> parameter) |
| */ |
| public CallMethodRule( |
| String methodName, |
| int paramCount, |
| String paramTypes[]) { |
| this(0, methodName, paramCount, paramTypes); |
| } |
| |
| /** |
| * Construct a "call method" rule with the specified method name and |
| * parameter types. If <code>paramCount</code> is set to zero the rule |
| * will use the body of this element as the single argument of the |
| * method, unless <code>paramTypes</code> is null or empty, in this |
| * case the rule will call the specified method with no arguments. |
| * |
| * @param targetOffset location of the target object. Positive numbers are |
| * relative to the top of the digester object stack. Negative numbers |
| * are relative to the bottom of the stack. Zero implies the top |
| * object on the stack. |
| * @param methodName Method name of the parent method to call |
| * @param paramCount The number of parameters to collect, or |
| * zero for a single argument from the body of ths element |
| * @param paramTypes The Java class names of the arguments |
| * (if you wish to use a primitive type, specify the corresonding |
| * Java wrapper class instead, such as <code>java.lang.Boolean</code> |
| * for a <code>boolean</code> parameter) |
| */ |
| public CallMethodRule( int targetOffset, |
| String methodName, |
| int paramCount, |
| String paramTypes[]) { |
| |
| this.targetOffset = targetOffset; |
| this.methodName = methodName; |
| this.paramCount = paramCount; |
| if (paramTypes == null) { |
| this.paramTypes = new Class[paramCount]; |
| for (int i = 0; i < this.paramTypes.length; i++) { |
| this.paramTypes[i] = String.class; |
| } |
| } else { |
| // copy the parameter class names into an array |
| // the classes will be loaded when the digester is set |
| this.paramClassNames = new String[paramTypes.length]; |
| for (int i = 0; i < this.paramClassNames.length; i++) { |
| this.paramClassNames[i] = paramTypes[i]; |
| } |
| } |
| |
| } |
| |
| |
| /** |
| * Construct a "call method" rule with the specified method name and |
| * parameter types. If <code>paramCount</code> is set to zero the rule |
| * will use the body of this element as the single argument of the |
| * method, unless <code>paramTypes</code> is null or empty, in this |
| * case the rule will call the specified method with no arguments. |
| * |
| * @param methodName Method name of the parent method to call |
| * @param paramCount The number of parameters to collect, or |
| * zero for a single argument from the body of ths element |
| * @param paramTypes The Java classes that represent the |
| * parameter types of the method arguments |
| * (if you wish to use a primitive type, specify the corresonding |
| * Java wrapper class instead, such as <code>java.lang.Boolean.TYPE</code> |
| * for a <code>boolean</code> parameter) |
| */ |
| public CallMethodRule( |
| String methodName, |
| int paramCount, |
| Class<?> paramTypes[]) { |
| this(0, methodName, paramCount, paramTypes); |
| } |
| |
| /** |
| * Construct a "call method" rule with the specified method name and |
| * parameter types. If <code>paramCount</code> is set to zero the rule |
| * will use the body of this element as the single argument of the |
| * method, unless <code>paramTypes</code> is null or empty, in this |
| * case the rule will call the specified method with no arguments. |
| * |
| * @param targetOffset location of the target object. Positive numbers are |
| * relative to the top of the digester object stack. Negative numbers |
| * are relative to the bottom of the stack. Zero implies the top |
| * object on the stack. |
| * @param methodName Method name of the parent method to call |
| * @param paramCount The number of parameters to collect, or |
| * zero for a single argument from the body of ths element |
| * @param paramTypes The Java classes that represent the |
| * parameter types of the method arguments |
| * (if you wish to use a primitive type, specify the corresonding |
| * Java wrapper class instead, such as <code>java.lang.Boolean.TYPE</code> |
| * for a <code>boolean</code> parameter) |
| */ |
| public CallMethodRule( int targetOffset, |
| String methodName, |
| int paramCount, |
| Class<?> paramTypes[]) { |
| |
| this.targetOffset = targetOffset; |
| this.methodName = methodName; |
| this.paramCount = paramCount; |
| if (paramTypes == null) { |
| this.paramTypes = new Class[paramCount]; |
| for (int i = 0; i < this.paramTypes.length; i++) { |
| this.paramTypes[i] = String.class; |
| } |
| } else { |
| this.paramTypes = new Class[paramTypes.length]; |
| for (int i = 0; i < this.paramTypes.length; i++) { |
| this.paramTypes[i] = paramTypes[i]; |
| } |
| } |
| |
| } |
| |
| |
| // ----------------------------------------------------- Instance Variables |
| |
| |
| /** |
| * The body text collected from this element. |
| */ |
| protected String bodyText = null; |
| |
| |
| /** |
| * location of the target object for the call, relative to the |
| * top of the digester object stack. The default value of zero |
| * means the target object is the one on top of the stack. |
| */ |
| protected int targetOffset = 0; |
| |
| /** |
| * The method name to call on the parent object. |
| */ |
| protected String methodName = null; |
| |
| |
| /** |
| * The number of parameters to collect from <code>MethodParam</code> rules. |
| * If this value is zero, a single parameter will be collected from the |
| * body of this element. |
| */ |
| protected int paramCount = 0; |
| |
| |
| /** |
| * The parameter types of the parameters to be collected. |
| */ |
| protected Class<?> paramTypes[] = null; |
| |
| /** |
| * The names of the classes of the parameters to be collected. |
| * This attribute allows creation of the classes to be postponed until the digester is set. |
| */ |
| private String paramClassNames[] = null; |
| |
| /** |
| * Should <code>MethodUtils.invokeExactMethod</code> be used for reflection. |
| */ |
| protected boolean useExactMatch = false; |
| |
| // --------------------------------------------------------- Public Methods |
| |
| /** |
| * Should <code>MethodUtils.invokeExactMethod</code> |
| * be used for the reflection. |
| */ |
| public boolean getUseExactMatch() { |
| return useExactMatch; |
| } |
| |
| /** |
| * Set whether <code>MethodUtils.invokeExactMethod</code> |
| * should be used for the reflection. |
| */ |
| public void setUseExactMatch(boolean useExactMatch) |
| { |
| this.useExactMatch = useExactMatch; |
| } |
| |
| /** |
| * Set the associated digester. |
| * If needed, this class loads the parameter classes from their names. |
| */ |
| @Override |
| public void setDigester(Digester digester) |
| { |
| // call superclass |
| super.setDigester(digester); |
| // if necessary, load parameter classes |
| if (this.paramClassNames != null) { |
| this.paramTypes = new Class[paramClassNames.length]; |
| for (int i = 0; i < this.paramClassNames.length; i++) { |
| try { |
| this.paramTypes[i] = |
| digester.getClassLoader().loadClass(this.paramClassNames[i]); |
| } catch (ClassNotFoundException e) { |
| // use the digester log |
| digester.getLogger().error("(CallMethodRule) Cannot load class " + this.paramClassNames[i], e); |
| this.paramTypes[i] = null; // Will cause NPE later |
| } |
| } |
| } |
| } |
| |
| /** |
| * Process the start of this element. |
| * |
| * @param attributes The attribute list for this element |
| */ |
| @Override |
| public void begin(Attributes attributes) throws Exception { |
| |
| // Push an array to capture the parameter values if necessary |
| if (paramCount > 0) { |
| Object parameters[] = new Object[paramCount]; |
| for (int i = 0; i < parameters.length; i++) { |
| parameters[i] = null; |
| } |
| digester.pushParams(parameters); |
| } |
| |
| } |
| |
| |
| /** |
| * Process the body text of this element. |
| * |
| * @param bodyText The body text of this element |
| */ |
| @Override |
| public void body(String bodyText) throws Exception { |
| |
| if (paramCount == 0) { |
| this.bodyText = bodyText.trim(); |
| } |
| |
| } |
| |
| |
| /** |
| * Process the end of this element. |
| */ |
| @Override |
| public void end() throws Exception { |
| |
| // Retrieve or construct the parameter values array |
| Object parameters[] = null; |
| if (paramCount > 0) { |
| |
| parameters = (Object[]) digester.popParams(); |
| |
| if (digester.log.isTraceEnabled()) { |
| for (int i=0,size=parameters.length;i<size;i++) { |
| digester.log.trace("[CallMethodRule](" + i + ")" + parameters[i]) ; |
| } |
| } |
| |
| // In the case where the target method takes a single parameter |
| // and that parameter does not exist (the CallParamRule never |
| // executed or the CallParamRule was intended to set the parameter |
| // from an attribute but the attribute wasn't present etc) then |
| // skip the method call. |
| // |
| // This is useful when a class has a "default" value that should |
| // only be overridden if data is present in the XML. I don't |
| // know why this should only apply to methods taking *one* |
| // parameter, but it always has been so we can't change it now. |
| if (paramCount == 1 && parameters[0] == null) { |
| return; |
| } |
| |
| } else if (paramTypes != null && paramTypes.length != 0) { |
| // Having paramCount == 0 and paramTypes.length == 1 indicates |
| // that we have the special case where the target method has one |
| // parameter being the body text of the current element. |
| |
| // There is no body text included in the source XML file, |
| // so skip the method call |
| if (bodyText == null) { |
| return; |
| } |
| |
| parameters = new Object[1]; |
| parameters[0] = bodyText; |
| if (paramTypes.length == 0) { |
| paramTypes = new Class[1]; |
| paramTypes[0] = String.class; |
| } |
| |
| } else { |
| // When paramCount is zero and paramTypes.length is zero it |
| // means that we truly are calling a method with no parameters. |
| // Nothing special needs to be done here. |
| } |
| |
| // Construct the parameter values array we will need |
| // We only do the conversion if the param value is a String and |
| // the specified paramType is not String. |
| Object paramValues[] = new Object[paramTypes.length]; |
| for (int i = 0; i < paramTypes.length; i++) { |
| // convert nulls and convert stringy parameters |
| // for non-stringy param types |
| if( |
| parameters[i] == null || |
| (parameters[i] instanceof String && |
| !String.class.isAssignableFrom(paramTypes[i]))) { |
| |
| paramValues[i] = |
| ConvertUtils.convert((String) parameters[i], paramTypes[i]); |
| } else { |
| paramValues[i] = parameters[i]; |
| } |
| } |
| |
| // Determine the target object for the method call |
| Object target; |
| if (targetOffset >= 0) { |
| target = digester.peek(targetOffset); |
| } else { |
| target = digester.peek( digester.getCount() + targetOffset ); |
| } |
| |
| if (target == null) { |
| StringBuffer sb = new StringBuffer(); |
| sb.append("[CallMethodRule]{"); |
| sb.append(digester.match); |
| sb.append("} Call target is null ("); |
| sb.append("targetOffset="); |
| sb.append(targetOffset); |
| sb.append(",stackdepth="); |
| sb.append(digester.getCount()); |
| sb.append(")"); |
| throw new org.xml.sax.SAXException(sb.toString()); |
| } |
| |
| // Invoke the required method on the top object |
| if (digester.log.isDebugEnabled()) { |
| StringBuffer sb = new StringBuffer("[CallMethodRule]{"); |
| sb.append(digester.match); |
| sb.append("} Call "); |
| sb.append(target.getClass().getName()); |
| sb.append("."); |
| sb.append(methodName); |
| sb.append("("); |
| for (int i = 0; i < paramValues.length; i++) { |
| if (i > 0) { |
| sb.append(","); |
| } |
| if (paramValues[i] == null) { |
| sb.append("null"); |
| } else { |
| sb.append(paramValues[i].toString()); |
| } |
| sb.append("/"); |
| if (paramTypes[i] == null) { |
| sb.append("null"); |
| } else { |
| sb.append(paramTypes[i].getName()); |
| } |
| } |
| sb.append(")"); |
| digester.log.debug(sb.toString()); |
| } |
| |
| Object result = null; |
| if (useExactMatch) { |
| // invoke using exact match |
| result = MethodUtils.invokeExactMethod(target, methodName, |
| paramValues, paramTypes); |
| |
| } else { |
| // invoke using fuzzier match |
| result = MethodUtils.invokeMethod(target, methodName, |
| paramValues, paramTypes); |
| } |
| |
| processMethodCallResult(result); |
| } |
| |
| |
| /** |
| * Clean up after parsing is complete. |
| */ |
| @Override |
| public void finish() throws Exception { |
| |
| bodyText = null; |
| |
| } |
| |
| /** |
| * Subclasses may override this method to perform additional processing of the |
| * invoked method's result. |
| * |
| * @param result the Object returned by the method invoked, possibly null |
| */ |
| protected void processMethodCallResult(Object result) { |
| // do nothing |
| } |
| |
| /** |
| * Render a printable version of this Rule. |
| */ |
| @Override |
| public String toString() { |
| |
| StringBuffer sb = new StringBuffer("CallMethodRule["); |
| sb.append("methodName="); |
| sb.append(methodName); |
| sb.append(", paramCount="); |
| sb.append(paramCount); |
| sb.append(", paramTypes={"); |
| if (paramTypes != null) { |
| for (int i = 0; i < paramTypes.length; i++) { |
| if (i > 0) { |
| sb.append(", "); |
| } |
| sb.append(paramTypes[i].getName()); |
| } |
| } |
| sb.append("}"); |
| sb.append("]"); |
| return (sb.toString()); |
| |
| } |
| |
| |
| } |
