Hello, i have the following testCase (inspired by some code found online):
what it does is to read the xml from string, create a digester, and load the
object: very simple stuff, but i get the following stacktrace:
28-dic-2005 14.59.26 org.apache.commons.digester.Digester startElement
GRAVE: Begin event threw exception
java.lang.InstantiationException: jfrr.mapping.StudentDigester$Student
at java.lang.Class.newInstance0(Class.java:335)
at java.lang.Class.newInstance(Class.java:303)
at org.apache.commons.digester.ObjectCreateRule.begin(
ObjectCreateRule.java:205)
at org.apache.commons.digester.Rule.begin(Rule.java:152)
at org.apache.commons.digester.Digester.startElement(Digester.java:1361)
at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown
Source)
at
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown
Source)
at
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown
Source)
at
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown
Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown
Source)
at org.apache.commons.digester.Digester.parse(Digester.java:1685)
at jfrr.mapping.StudentDigester$DigestStudents.digest(
StudentDigester.java:53)
at jfrr.mapping.StudentDigester$DigestStudents.access$0(
StudentDigester.java:32)
at jfrr.mapping.StudentDigester.testAddBeanPropertySetter(
StudentDigester.java:21)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(
NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(
DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at junit.framework.TestSuite.runTest(TestSuite.java:208)
at junit.framework.TestSuite.run(TestSuite.java:203)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(
RemoteTestRunner.java:478)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(
RemoteTestRunner.java:344)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(
RemoteTestRunner.java:196)
java.lang.InstantiationException: jfrr.mapping.StudentDigester$Student
at org.apache.commons.digester.Digester.createSAXException(Digester.java
:2919)
at org.apache.commons.digester.Digester.createSAXException(Digester.java
:2945)
at org.apache.commons.digester.Digester.startElement(Digester.java:1364)
at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown
Source)
at
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown
Source)
at
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown
Source)
at
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown
Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown
Source)
at org.apache.commons.digester.Digester.parse(Digester.java:1685)
at jfrr.mapping.StudentDigester$DigestStudents.digest(
StudentDigester.java:53)
at jfrr.mapping.StudentDigester$DigestStudents.access$0(
StudentDigester.java:32)
at jfrr.mapping.StudentDigester.testAddBeanPropertySetter(
StudentDigester.java:21)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(
NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(
DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at junit.framework.TestSuite.runTest(TestSuite.java:208)
at junit.framework.TestSuite.run(TestSuite.java:203)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(
RemoteTestRunner.java:478)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(
RemoteTestRunner.java:344)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(
RemoteTestRunner.java:196)
The code I used is the following:
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;
import junit.framework.TestCase;
import org.apache.commons.digester.Digester;
import org.apache.commons.digester.ExtendedBaseRules;
public class StudentDigester extends TestCase {
protected String studentsXML = "<?xml version=\"1.0\"?>"
+ "<students><student>" + "<name>Java Boy</name>"
+ "<course>JSP</course>" + "<age>10</age>" + "</student>" +
"</students>";
public void testAddBeanPropertySetter() {
DigestStudents ds = new DigestStudents();
ds.digest();
}
private class DigestStudents {
List<Student> students;
public DigestStudents() {
students = new ArrayList<Student>();
}
private void digest() {
try {
Digester digester = new Digester();
digester.setRules(new ExtendedBaseRules());
//Push the current object onto the stack
digester.push(this);
//Creates a new instance of the Student class
digester.addObjectCreate("students/student", Student.class);
//Uses setName method of the Student instance
//Uses tag name as the property name
digester.addBeanPropertySetter("students/student/?");
//Uses setCourse method of the Student instance
//Explicitly specify property name as 'course'
//digester.addBeanPropertySetter( "students/student/course",
"course" );
//Move to next student
digester.addSetNext("students/student", "addStudent");
DigestStudents ds = (DigestStudents) digester.parse(new
StringReader(
studentsXML));
//Print the contents of the Vector
System.out.println("Students List " + ds.students);
} catch (Exception ex) {
ex.printStackTrace();
}
}
public void addStudent(Student stud) {
//Add a new Student instance to the Vector
students.add(stud);
}
}
public class Student {
private String name;
private String course;
private int age;
public Student() {
}
public String getName() {
return name;
}
public void setName(String newName) {
name = newName;
}
public String getCourse() {
return course;
}
public void setCourse(String newCourse) {
course = newCourse;
}
public String toString() {
return("Name="+this.name + " & Course=" + this.course +" &
Age="+this.age);
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
}
If i move the public internal class Student outside the testcase class, it
works as supposed. IS this normal behaviour ?
thanks,
valerio
--
To Iterate is Human, to Recurse, Divine
James O. Coplien, Bell Labs
