Develop Reference

jsp checkbox value not binding

I have a problem in getting checkbox's value from JSP.
I used SpringMVC, and my related class as follows:
Form:
#Getter #Setter
public class Sample3Form extends AbstractForm {<
private List<Sample1Bean> sampleList; //all data
private ValidPagedListHolder<Sample1Bean> samplePagedList;//1 page data
}
the class to control changing page:
ValidPagedListHolder:
#SuppressWarnings("serial")
public class ValidPagedListHolder<E> extends PagedListHolder<E> implements
Serializable {
...
...
/**
* Return a sub-list representing the current page.
*/
#Override
#Valid
public List<E> getPageList() {
return super.getPageList();
}
/**
* コンストラクタ生成時の初期化処理を行うメソッド
*/
protected void init() {
setPageSize(DEFAULT_PAGE_SIZE);
}
}
Sample1Bean:
#Getter #Setter
public class Sample1Bean extends AbstractOnlineDataBean {
private String keiyakuno;
private String keiyakunm;
private String torisakino;
}
Parent Bean Class:
#Getter
#Setter
public abstract class AbstractOnlineDataBean extends AbstractDataBean {
private Integer selectedIndex;
private String maskPattern;
}
Controller:
#Controller
#RequestMapping(value = "app/sample3")
#SessionAttributes(value = "sample3Form")
#NotCheckToken
public class SampleController3 extends AbstractController {
private static Logger logger = LoggerFactory.getLogger(UserUtil.class);
#ModelAttribute(value = "sample3Form")
public Sample3Form getForm() {
return new Sample3Form();
}
......
......
#RequestMapping(value = "delete")
public String delete(Model model, #Validated Sample3Form form, BindingResult result, HttpServletRequest request) throws GdcSystemException {
List<Sample1Bean> list = new ArrayList<Sample1Bean>();
int size = form.getSampleList().size();
ValidPagedListHolder<Sample1Bean> plist = form.getSamplePagedList();
list = plist.getPageList();
for (int i = 0 ; i < size; i ++) {
if (form.getSampleList().get(i).getSelectedIndex() == null ) {
} else {
//I cannot arrive here even though I checked in JSP
list.add(form.getSampleList().get(i));
}
}
...
...
}
JSP:
<ab:form id="sample3" action="submit" modelAttribute="sample3Form">
<table width="100%" class="tableborder" cellpadding="0" cellspacing="0">
...
...
<ab:tr index="${row.index}">
<td width="2%" class="data_list_area">
<ab:checkbox path="${sample3Form.samplePagedList.pageList[row.index].selectedIndex}" fwformat='NONE'
value="${sample3Form.samplePagedList.page * sample3Form.samplePagedList.pageSize + row.index }" name="checkedids"/>
</td>
<td width="5%" class="data_list_area">
<!--ab:out value="${sample3Form.samplePagedList.pageList[row.index].keiyakuno}" /-->
<ab:label path="" fwformat='NONE'>${sample3Form.samplePagedList.pageList[row.index].keiyakuno}</ab:label>
</td>
...
...
In above JSP, I set checkboxes and bind the checkboxes to selectedIndex property for for every row data.but i cannot get selected row in controller as follows:
form.getSampleList().get(i).getSelectedIndex()
The return value is always null.
why? Could who please tell me how i can get the selectedIndex in controller?
By the way, I can get checked row in controller like below:
String[] arr = request.getParameterValues("checkedids");
Remarks: in JSP, These added checkboxes is defined by name "checkedids".
and <ab:checkbox> is a tag class extends AbstractSingleCheckedElementTag.
the src for CheckboxTagImpl is here:
public class CheckboxTagImpl extends AbstractSingleCheckedElementTag {
private String maskPatterns = null;
private boolean escapeMaskFlg = false;
/**
*
* #return
*/
public String getMaskPatterns() {
return maskPatterns;
}
/**
*
* #param maskPatterns
*/
public void setMaskPatterns(String maskPatterns) {
this.maskPatterns = maskPatterns;
}
/**
* #return
*/
public Boolean isEscapeMaskFlg() {
return escapeMaskFlg;
}
/**
* #param escapeMaskFlg
*/
public void setEscapeMaskFlg (Boolean escapeMaskFlg) {
this.escapeMaskFlg = escapeMaskFlg;
}
#Override
protected int writeTagContent(TagWriter tagWriter) throws JspException {
if (maskPatterns != null) {
FormTagImpl formTag = TagUtil.getFormTag(this);
String formClassName = formTag.getModelAttribute();
String maskPattern = TagUtil.getMaskPattern(formClassName, pageContext);
if (maskPattern != null) {
String[] maskPatternArray = maskPatterns.split(",");
for (int i = 0; i < maskPatternArray.length; i++) {
if (maskPattern.equals(maskPatternArray[i])) {
setDisabled(true);
break;
}
}
}
}
FormTagImpl formTag = TagUtil.getFormTag(this);
String formClassName = formTag.getModelAttribute();
Boolean maskFlg = TagUtil.getMaskFlg(formClassName, pageContext);
if (maskFlg == true && escapeMaskFlg == false) {
setDisabled(true);
}
if (!isDisabled()) {
// Write out the 'field was present' marker.
tagWriter.startTag("input");
tagWriter.writeAttribute("type", "hidden");
String name = WebDataBinder.DEFAULT_FIELD_MARKER_PREFIX + getName();
tagWriter.writeAttribute("id", getId());
tagWriter.writeAttribute("name", name);
tagWriter.writeAttribute("value", processFieldValue(name, SystemConstant.FLAG_OFF, getInputType()));
tagWriter.endTag();
}
super.writeTagContent(tagWriter);
return SKIP_BODY;
}
#Override
protected void writeTagDetails(TagWriter tagWriter) throws JspException {
tagWriter.writeAttribute("type", getInputType());
Object boundValue = getBoundValue();
Class<?> valueType = getBindStatus().getValueType();
if (Boolean.class.equals(valueType) || boolean.class.equals(valueType)) {
// the concrete type may not be a Boolean - can be String
if (boundValue instanceof String) {
boundValue = Boolean.valueOf((String) boundValue);
}
Boolean booleanValue = (boundValue != null ? (Boolean) boundValue : Boolean.FALSE);
renderFromBoolean(booleanValue, tagWriter);
} else if (String.class.equals(valueType) && getValue() == null) {
renderFromValue(SystemConstant.FLAG_ON, tagWriter);
}
else {
Object value = getValue();
if (value == null) {
throw new IllegalArgumentException("Attribute 'value' is required when binding to non-boolean values");
}
Object resolvedValue = (value instanceof String ? evaluate("value", value) : value);
renderFromValue(resolvedValue, tagWriter);
}
}
#Override
public void doFinally() {
if (PropertiesUtil.getProperty("cleanAtDoFinally").equals("true")) {
super.doFinally();
this.maskPatterns = null;
this.escapeMaskFlg = false;
setDisabled(false);
}
}
#Override
protected String getInputType() {
return "checkbox";
}
#Override
protected String getName() throws JspException {
if (getPath()==null) {
return super.getName();
} else {
return getPath();
}
}
#Override
protected BindStatus getBindStatus() throws JspException {
BindStatus bindStatus = null;
if (bindStatus == null) {
// HTML escaping in tags is performed by the ValueFormatter class.
String nestedPath = getNestedPath();
String pathToUse = (nestedPath != null ? nestedPath + getPath() : getPath());
if (pathToUse.endsWith(PropertyAccessor.NESTED_PROPERTY_SEPARATOR)) {
pathToUse = pathToUse.substring(0, pathToUse.length() - 1);
}
bindStatus = new BindStatus(getRequestContext(), pathToUse, false);
}
return bindStatus;
}
}
Thanks.

(identifier expected) getter/setter and objects

I've got a problem with my programm. When i try to compile following i just receive the message:
Tutorium.java:15: error: <identifier> expected
public void settName(vorlesung.lectureName) {
^
So my Code:
Tutorium.java
public class Tutorium {
private Vorlesung vorlesung;
public String tName;
private int tNumber;
public int gettNumber() {
return this.tNumber;
}
public String gettName() {
return this.tName;
}
public void settName(vorlesung.lectureName) {
this.tName = vorlesung.lectureName;
}
public String toString() {
return (this.tName + ", " + this.tNumber);
}
public Tutorium(int tNumber){
this.tNumber = tNumber; } }
Vorlesung.java
public class Vorlesung {
public String lectureName;
private int lectureNumber;
private int lecture;
private Dozent dozent;
private String lecturerlName;
public String getlectureName(){
return this.lectureName;
}
public int lectureNumber(){
return this.lectureNumber;
}
public int lecture(){
return this.lecture;
}
public String getlecturer(){
this.lecturerlName = dozent.lecturerlName;
return this.lecturerlName;
}
public String toString() {
return (this.lectureName + ", " + this.lectureNumber);
}
public Vorlesung(String lectureName, int lecture) {
this.lectureName = lectureName;
this.lecture = lecture +1;
this.lectureNumber = this.lecture -1;
this.lecturerlName = lecturerlName;
}}
My Main-Method:
public class MainVorlesung {
public static void main(String[] args) {
Student student = new Student("STUDENTNAME", "STUDENTLASTNAME", 178, 1);
Vorlesung vorlesung = new Vorlesung("Programmieren", 13341);
Tutorium tutorium = new Tutorium(3);
Dozent dozent = new Dozent("LECTURERFIRSTNAME", "LECTURERLASTNAME", 815);
System.out.println(student.toString());
System.out.println(vorlesung.toString());
System.out.println(tutorium.toString());
System.out.println(dozent.toString());
}}
My goal is to set the value of tName equal the value of vorlesung.lectureName.
Why can't i do this that way?
I appreciate every help. :)
Thanks

For methods, the arguments that you pass in must have a declared value.
In this case, a String. So you need to change your method to this:
public void settName(String newLectureName) {
this.tName = newLectureName;
}
Read more about what a java method is and how to create one here: http://www.tutorialspoint.com/java/java_methods.htm

Change settName to
public void settName(String name) {
this.tName = name;
}

Since your goal is:
My goal is to set the value of tName equal the value of vorlesung.lectureName.
You should get rid of the setName method entirely since it will depend entirely on the vorlesung field and so should not be changeable. You should also get rid of the tName field, and instead change getName() to:
public class Tutorium {
private Vorlesung vorlesung;
// public String tName; // get rid of
private int tNumber;
public String gettName() {
if (vorlesung != null) {
return vorlesung.getlecturer();
}
return null; // or throw exception
}
// *** get rid of this since you won't be setting names
// public void settName(Vorlesung vorlesung) {
// this.tName = vorlesung.lectureName;
// }
I have just now noticed that your Tutorium class does not have and absolutely needs a setVorlesung(...) method.
public void setVorlesung(Vorlesung vorlesung) {
this.vorlesung = vorlesung;
}

static factory builder trouble

Needing to create an unspecified number of objects, I tried to create a builder that do that. All was well until I realized that my builder creates all objects with their properties having the same values.
So when I call the builder:
ValidationHelper v = new ValidationHelper.HelperBuilder()
.addHelper("ICAO Identifier", icaoIdentifier, rulesICAO)
.addHelper("Long Name", longName, rulesLongName)
.build();
... I'll have 2 objects and their properties will have values of the last object the builder was asked to create.
To start with, is factory builder the prudent approach to this? Secondly, is my builder salvageable?
Builder:
public class ValidationHelper {
private static ArrayList<HelperBuilder> validatorHelpers = new ArrayList();
public static class HelperBuilder {
private String txtFieldName;
private String txtFieldValue;
private List<Integer> valCodes = new ArrayList<Integer>();
private ArrayList<HelperBuilder> innerValidatorHelpers = new ArrayList<HelperBuilder>();
public HelperBuilder() {}
public final HelperBuilder addHelper(String txtFieldName, String txtFieldValue, int[] validationCodes) {
this.txtFieldName = txtFieldName;
this.txtFieldValue = txtFieldValue;
for( int i = 0; i < validationCodes.length; i++ ){
getValCodes().add((Integer) validationCodes[i]);
}
innerValidatorHelpers.add(this);
return this;
}
public final ValidationHelper build() {
return new ValidationHelper(this);
}
public String getTxtFieldName() {
return txtFieldName;
}
public String getTxtFieldValue() {
return txtFieldValue;
}
public List<Integer> getValCodes() {
return valCodes;
}
}//end HelperBuilder
private ValidationHelper(HelperBuilder helperBuilder) {
validatorHelpers = helperBuilder.innerValidatorHelpers;
}
public void setHelpers(ArrayList validatorHelpers) {
validatorHelpers = validatorHelpers;
}
public ArrayList getHelpers() {
return validatorHelpers;
}
}
EDIT/FIXED:
So for what it's worth, here's the revised builder. It needed another constructor that could properly initialize an instance of what it's supposed to build.
public class ValidationHelper {
private static ArrayList<HelperBuilder> validatorHelpers = new ArrayList();
public static class HelperBuilder {
private String txtFieldName;
private String txtFieldValue;
private List<Integer> valCodes = new ArrayList<Integer>();
private ArrayList<HelperBuilder> innerValidatorHelpers = new ArrayList<HelperBuilder>();
public HelperBuilder() {}
public HelperBuilder(String txtFieldName, String txtFieldValue, int[] validationCodes) {
this.txtFieldName = txtFieldName;
this.txtFieldValue = txtFieldValue;
for (int i = 0; i < validationCodes.length; i++) {
valCodes.add((Integer) validationCodes[i]);
}
}
public final HelperBuilder addHelper(String txtFieldName, String txtFieldValue, int[] validationCodes) {
innerValidatorHelpers.add( new HelperBuilder(txtFieldName, txtFieldValue, validationCodes) );
return this;
}
public final ValidationHelper build() {
return new ValidationHelper(this);
}
public String getTxtFieldName() {
return txtFieldName;
}
public String getTxtFieldValue() {
return txtFieldValue;
}
public List getValCodes() {
return valCodes;
}
}//end HelperBuilder
private ValidationHelper(HelperBuilder helperBuilder) {
validatorHelpers = helperBuilder.innerValidatorHelpers;
}
public ArrayList getHelpers() {
return validatorHelpers;
}
}

Each time you just overwrite the values in
private String txtFieldName;
private String txtFieldValue;
and the last one winns. So you create only 1 HelperInstance here
ValidationHelper v = new ValidationHelper.HelperBuilder()
and the fields name and value are overwritten each time you call addHelper(). But you need to create an instance for each "configuration". So addHelper should create a new Instance and add it into
private ArrayList<HelperBuilder> innerValidatorHelpers = ...;

If you want to build objects with different values you have to either
alter the builder between creating the objects so it will build something different.
instruct the builder to change the values automatically e.g. use a counter, or filename based on the date, or provide a list of values.

Travesring through an object in java

I have a method that return an object of a class.The object sets the properties of class and returns.
I have to traverse the object and get the value of the properties which the object has set before.
I tried to use for-each loop,iterator but failed to traverse.
Can someone please help me to get through this.Thanks in advance.
code:
public class ConsumerTool {
public MessageBean getMessages() {
MessageBean msgBean = new MessageBean();
msgBean.setAtmId(atmId.trim());
msgBean.setEventText(eventText.trim());
msgBean.setEventNumber(eventNumber.trim());
msgBean.setSeverity(severity.trim());
msgBean.setSubsystemID(subsystemID.trim());
msgBean.setUniqueEventID(uniqueEventID.trim());
msgBean.setTaskID(taskID.trim());
msgBean.setGenerator(generator.trim());
msgBean.setGeneratorBuildVsn(generatorBuildVsn.trim());
msgBean.setDateTime(dateTime.trim());
this.msgBean = msgBean;
return msgBean;
}
}
JavaBean class:
public class MessageBean implements java.io.Serializable {
public String dateTime;
public String severity;
public String eventText;
public String eventNumber;
public String generator;
public String generatorBuildVsn;
public String atmId;
public String uniqueEventID;
public String subsystemID;
public String taskID;
//System.out.println("dateTime2222222"+dateTime);
public String getAtmId() {
return this.atmId;
}
public void setAtmId(String n) {
this.atmId = n;
}
public String getDateTime() {
return this.dateTime;
}
public void setDateTime(String n) {
this.dateTime = n.trim();
}
public String getEventNumber() {
return this.eventNumber;
}
public void setEventNumber(String n) {
this.eventNumber = n;
}
public String getEventText() {
return this.eventText;
}
public void setEventText(String n) {
this.eventText = n;
}
public String getGenerator() {
return this.generator;
}
public void setGenerator(String n) {
this.generator = n;
}
public String getGeneratorBuildVsn() {
return this.generatorBuildVsn;
}
public void setGeneratorBuildVsn(String n) {
this.generatorBuildVsn = n;
}
public String getSeverity() {
return this.severity;
}
public void setSeverity(String n) {
this.severity = n;
}
public String getSubsystemID() {
return this.subsystemID;
}
public void setSubsystemID(String n) {
this.subsystemID = n;
}
public String getTaskID() {
return this.taskID;
}
public void setTaskID(String n) {
this.taskID = n;
}
public String getUniqueEventID() {
return this.uniqueEventID;
}
public void setUniqueEventID(String n) {
this.uniqueEventID = n;
}
}
The theme is the object sets the properties of javabean class and I have to get those values from UI.
In Jsp
<%
MessageBean consumer = msg.getMessages();
//Now here i want to iterate that consumer object
%>

As the MessagesBean seems to comply the javabeans specification, you can just use java.beans.Introspector for this.
MessageBean messageBean = consumerTool.getMessages();
// ...
BeanInfo beanInfo = Introspector.getBeanInfo(MessageBean.class);
for (PropertyDescriptor property : beanInfo.getPropertyDescriptors()) {
String name = property.getName();
Object value = property.getReadMethod().invoke(messageBean);
System.out.println(name + "=" + value);
}
This all is under the covers using the reflection API.
Update your edit reveals that you're intending to use this to present the data in JSP. This is then not really the right approach. Bite the bullet and specify every property separately. This way you've full control over the ordering.

Inner Class. What is its purpose?

Can someone tell me what the purpose of having inner classes? I can think of a few but may be they are not good reasons for using inner classes. My reasoning is that inner class is helpful when you want to use a class that no other classes can use. What else?

When I was learning Java we used inner classes for GUI event handling classes. It is sort of a "one time use" class that need not be available to other classes, and only is relevant to the class in which it resides.

Inner classes can be used to simulate closures: http://en.wikipedia.org/wiki/Closure_(computer_science)#Java

I use inner classes to define a structure that is best represented by the containing class, but doesn't necessarily make sense to use a separate external class to represent the structure.
To give an example I have a class that represents a particular type of network device, and the class has certain types of tests that can be run on that device. For each test there is also a potential set of errors that can be found. Each type of device may have a different structure for the errors.
With this you could do things like
List<Error> errors = RemoteDeviceA.getErrors();
With methods being available from the inner class, like
for ( Error error : errors ) {
System.out.println("MOnitor Type: " + error.getMonType());
...
}
Of course there are other ways to do this, this is just an inner class approach.
Simplified (aka incomplete) code for above:
public class RemoteDeviceA {
private String host;
private String user;
private String password;
private static List<Error> errors;
public RemoteDeviceA(String user, String host, String password) {
this.host = host;
this.user = user;
this.password = password;
login();
}
private void login() {
// Logs in
}
public void runTestA() {
List<Error> errorList = new ArrayList<Error>();
//loop through test results
if (!value.equals("0")) {
Error error = new Error(node, rackNum, shelfNum, slotNum, monType, value);
if (error.isError()) {
errorList.add(error);
}
}
setErrors(errorList);
}
private static void setErrors(List<Error> errors) {
RemoteDeviceA.errors = errors;
}
public List<Error> getErrors() {
return errors;
}
public class Error {
private String monType;
private String node;
private String rack;
private String shelf;
private String slot;
private String value;
private boolean error = false;
private boolean historyError = false;
private boolean critical = false;
private boolean criticalHistory = false;
Error(String node, String rack, String shelf, String slot,
String monType, String value) {
parseAlarm(node, rack, shelf, slot, monType, value);
}
private void parseAlarm(String node, String rack, String shelf,
String slot, String monType, String value) {
String modType = "";
if (monType.startsWith("ES_15") && !value.equals("0")) {
setMonType("ES_15");
setError(true);
} else if (monType.startsWith("SES_15") && !value.equals("0")) {
setMonType("SES_15");
setError(true);
} else if (monType.startsWith("BBE_15") && !value.equals("0")) {
setMonType("BBE_15");
setError(true);
} else if (monType.startsWith("UT_15") && !value.equals("0")) {
setMonType("UT_15");
setError(true);
setCritial(critical);
} else if (monType.startsWith("ES_24") && !value.equals("0")) {
setMonType("ES_24");
setHistoryError(true);
setError(true);
} else if (monType.startsWith("SES_24") && !value.equals("0")) {
setMonType("SES_24");
setHistoryError(true);
setError(true);
} else if (monType.startsWith("BBE_24") && !value.equals("0")) {
setMonType("BBE_24");
setHistoryError(true);
setError(true);
} else if (monType.startsWith("UT_24") && !value.equals("0")) {
setMonType("UT_24");
setHistoryError(true);
setError(true);
setCriticalHistory(true);
} else if (monType.startsWith("UT_15") && !value.equals("0")) {
setMonType("UT_15");
setError(true);
setCritial(true);
} else if (monType.startsWith("LASPWR")) {
float laserPwr = Float.valueOf(value);
if (node.startsWith("LEM_EM")) {
if ((laserPwr < 8.0) || (laserPwr > 12.0)) {
setMonType("LASERPWR");
setError(true);
}
} else if (node.startsWith("LEM10")) {
if ((laserPwr < 18.0) || (laserPwr > 22.0)) {
setMonType("LASERPWR");
setError(true);
}
}
}
if (isError()) {
setNode(node);
setRack(rack);
setShelf(shelf);
setSlot(slot);
setValue(value);
setError(true);
}
}
private void setMonType(String monType) {
this.monType = monType;
}
public String getMonType() {
return monType;
}
private void setNode(String node) {
this.node = node;
}
public String getNode() {
return node;
}
public void setRack(String rack) {
this.rack = rack;
}
public String getRack() {
return rack;
}
public void setShelf(String shelf) {
this.shelf = shelf;
}
public String getShelf() {
return shelf;
}
public void setSlot(String slot) {
this.slot = slot;
}
public String getSlot() {
return slot;
}
private void setValue(String value) {
this.value = value;
}
public String getValue() {
return value;
}
private void setError(boolean error) {
this.error = error;
}
public boolean isError() {
return error;
}
public void setCritial(boolean critical) {
this.critical = critical;
}
public boolean isCritical() {
return critical;
}
public void setCriticalHistory(boolean criticalHistory) {
this.criticalHistory = criticalHistory;
}
public boolean isCriticalHistory() {
return criticalHistory;
}
public void setHistoryError(boolean historyError) {
this.historyError = historyError;
}
public boolean isHistoryError() {
return historyError;
}
}
}

A list implementation that internally uses a linked list to store the elements could make good use of an inner class to represent the nodes within the list. I think you've hit the nail on the head by saying that you'd use such a class where you want to use it internally to a class but don't want it exposed - a 'one off' class that is only really useful 'here'.

I use inner classes (in C++) in situations where multiple classes, unrelated through inheritance, have conceptually similar implementation details, which form an implicit part of the public interface and ought to be named similarly.
class lib::Identifier { ... };
class lib::Person {
public:
class Identifier : public lib::Identifier { ... };
};
class lib::File {
public:
class Identifier : public lib::Identifier { ... };
};
This makes it convenient to refer to Identifier, Person::Identifier, and File::Identifier as simply Identifier, in the appropriate scopes.