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Oracle9i Business Components for Java API Reference Oracle9i Jdeveloper (9.0.4) B10391-01 | ||||||||||
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java.lang.Object
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+--java.lang.Throwable
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+--java.lang.Exception
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+--java.lang.RuntimeException
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+--oracle.jbo.JboException
Top level exception for the JBO package.
All exceptions thrown from the Business Components for Java framework should be subclasses of this exception.
This class provides a single point for the localization and formatting of Exception messages.
Translation of a message's text occurs at the time the client calls getLocalizedMessage() rather than at creation time since the client may need to present the message in one of a number of different languages (refer to DAC for details).
The Business Components for Java framework provides many exception classes, for example, ValidationException and NameClashException. These classes extend oracle.jbo.JboException, which extends java.lang.RuntimeException. Therefore, a Business Component method can throw a Business Components for Java exception without a throws clause in the signature.
Most subclasses of JboException will provide a value for the error code in a specialized constructor.
Business Components for Java exceptions have an attribute that stores an error message, and they support NLS translation and message formatting. JboException uses java.util.ListResourceBundle to format its messages. A resource bundle class defines constants and strings to use as error messages. The default format is:
{productCode}-{errorCode}: {messageBody}
For example,
ORA-10234: You cannot do that.
The components of a Business Component exception messages are derived from the following generalized set of parameters:
|
Parameter |
Description |
|
Product code |
A non-translated product code string, such as FRM, ORA, or OBCJ |
|
Error code |
A non-translated error code string, such as 10234 or 03101 |
|
ResourceBundle |
Un-translated message text such as contained in |
|
an optional set of parameters |
These can be message parameters, equal in number to the number of "%" symbols in the message text. Possible message parameter examples are: Vendor and Oracle. |
|
details |
A "details" list containing background information. This can be any exception thrown in low-level code that is transformed into a Business Component exception. |
Additional components may be introduced in future.
Messages may need to include information known only when the exception is thrown, so error message strings can include placeholders that refer to values in an array of Objects passed to the exception when it's thrown. When the message is formatted for display, these parameters are placed into slots in the message (the first slot is 0) using the standard formatting capabilities provided by java.text.MessageFormat. Following is a an entry from CSMessageBundle.java.
public static final String EXC_VAL_ATTR_SET_FAILED = "03101";
...
// Description: Generic Attribute validation failure.
// set<Attribute> method failed to set the value.
// Parameter 0: Ignored.
// Parameter 1: Entity Object/View Object name.
// Parameter 2: Attribute name.
// Parameter 3: New value
{EXC_VAL_ATTR_SET_FAILED, "Attribute set with value {3} for {2} in {1} failed."},
Applications may define subclasses of most JBO exceptions. To do this the application should override the following methods to provide the correct set of values for the messaging services:
Other methods may be overridden to modify the message format.
You can use Business Component for Java exception classes in your own code to indicate errors, and you can create custom exception classes. For example, you can extend JboException and override the getProductCode method, making it return values appropriate for your exception.
You can throw a JboException by using a statement like this:
throw new JboException("Don't do that.", "101", null );
The drawback to this approach is that the hard-coded error message is not easy to localize.
To make an exception localizable into different national languages, use the NLS framework. First, create a resource bundle for your error messages. The following code example defines a bundle named MyMsgBundle that stores three error messages.
import oracle.jbo.common.util.CheckedListResourceBundle;
public class MyMsgBundle extends CheckedListResourceBundle
// String Constants
public static final String BAD_EMPNO = "101";
public static final String DEPT_NOT_FOUND = "102";
public static final String NOT_IN_DEPT = "103";
...
//Private 2-D array of key-value pairs
private static final Object[][] sMessageStrings = {
...
{ BAD_EMPNO, "Invalid employee number." },
{ DEPT_NOT_FOUND, "Department {0} does not exist." }
{ NOT_IN_DEPT, "Employee {0} not found in Department {1}." }
...
}
}
Then you can use the resource bundle class to define a value to pass to the constructor for your exception class or JboException:
throw new JboException(MyMsgBundle.class // Class of Bundle
MyMsgBundle.DEPT_NOT_FOUND // String Constant
new Object[1] { localVar1 } //Arguments to message
);
JboException provides a getLocalizedMessage method which returns the message formatted for the specified locale.
The NLS framework translates the message text when the client calls getLocalizedMessage rather than at creation time because the client may need to present the message in a number of different languages. This mechanism provides a single point for localizing and formatting messages.
JboException can marshal itself across a network. It handles NLS issues for the middle tier, enabling one instance of a middle-tier component to serve (for example) French users and English users at the same time.
If your exception contains member data that must be marshalled, extend JboException. If you need to provide more control over the serialized stream, implement the readObject and writeObject methods. The Java serialization mechanism uses these methods to serialize/deserialize an object. You might want implement these methods if you want to:
exclude some members from being serialized
For example, suppose you have the class MyException (shown below), and you want to carry memberA and memberB across tiers:
public class MyException extends JboException
{
int memberA;
String memberB;
...
}
Write code like the following in MyException:
private void writeObject(ObjectOutputStream out) throws IOException {
out.writeInt(memberA);
out.writeUTF(mEntityRowHandle);
}
private void readObject(ObjectInputStream in) throws IOException,
ClassNotFoundException {
memberA = in.readInt();
memberB = in.readUTF();
}
| Field Summary | |
protected boolean |
mHasPeerException |
| Constructor Summary | |
JboException(java.lang.Class resBundleClass, java.lang.String errorCode, java.lang.Object[] params)Creates a translatable exception. | |
JboException(java.lang.Class resBundleClass, java.lang.String errorCode, java.lang.Object[] params, java.lang.Exception[] excs)Creates a translatable exception. | |
JboException(java.lang.Class resBundleClass, java.lang.String errorCode, java.lang.Object[] params, JboException[] exceptions)Creates a translatable exception. | |
JboException(java.lang.String message)Create a non-formattable exception. | |
JboException(java.lang.String message, java.lang.String errorCode, java.lang.Object[] params)Creates a formattable but non-localizable exception. | |
JboException(java.lang.Throwable ex)Converts an exception into a non-formattable JboException. | |
| Method Summary | |
void |
addToDetails(java.lang.Object obj)Adds to the list of details. |
void |
addToExceptions(java.lang.Throwable exception) |
void |
doEntityToVOMapping(ApplicationModule rootAm, ViewObject[] vos) |
java.lang.String |
getBaseMessage()Gets the message without localizing it or inserting parameters. |
java.lang.String |
getDetailMessage()Constructs a message incorporating the list of details. |
java.lang.Object[] |
getDetails()Gets the list of objects and exceptions that spawned this message. |
java.lang.String |
getErrorCode()Returns the message's error code. |
java.lang.Object[] |
getErrorParameters()Returns the error message parameters. |
java.lang.Throwable[] |
getExceptions()Gets the list of exceptions that spawned this message. |
protected JboExceptionHelper |
getJboExceptionHelper()Get the Helper object for this exception. |
java.lang.String |
getLocalizedBaseMessage(java.util.Locale l)Localizes the message text for a specific Locale, but without inserting parameters. |
java.lang.String |
getLocalizedMessage(java.util.Locale l)Formats the message text for a specific Locale. |
java.lang.String |
getMessage()Formats the message text for the default locale. |
java.lang.String |
getProductCode()Returns a message's product code. |
java.lang.Class |
getResourceClass()Gets the class of the resource bundle used to localize messages. |
java.lang.String |
getResourceName()Returns the name of the ResourceBundle used to localize or resolve messages. |
static java.lang.String |
getTypeNameFromId(int id) |
boolean |
hasPeerExceptions() |
boolean |
isAppendCodes()Returns true if this exception has to prefix the error message with Product and Message Ids. |
boolean |
isLocalizable()Tests this message's localizability. |
boolean |
needsEntityToVOMapping() |
void |
printStackTrace()Prints this Throwable and its backtrace to the standard error stream. |
void |
printStackTrace(java.io.PrintStream s)Prints this Throwable and its backtrace to the specified print stream. |
void |
printStackTrace(java.io.PrintWriter s)Prints this Throwable and its backtrace to the specified print writer. |
void |
setAppendCodes(boolean flag)Set false if this exception should not prefix the error message with Product and Message Ids. |
void |
setApplicationModule(ApplicationModule am) |
void |
setDetails(java.lang.Object[] details)Sets the list of details. |
protected void |
setErrorParameters(java.lang.Object[] params)Resets the error parameters. |
void |
setExceptions(java.lang.Throwable[] details)Sets the list of details. |
void |
setNeedsEntityToVOMapping(boolean flag) |
| Methods inherited from class java.lang.Throwable |
fillInStackTrace, getCause, getLocalizedMessage, getStackTrace, initCause, setStackTrace, toString |
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
| Field Detail |
protected boolean mHasPeerException
| Constructor Detail |
public JboException(java.lang.String message,
java.lang.String errorCode,
java.lang.Object[] params)
If a localizable exception is desired, use the JboException(Class, String, Object[]) constructor.
message - the unformatted text of the message.errorCode - an error code.params - the error message's parameters.ResourceBundlepublic JboException(java.lang.String message)
message - the text of the message.public JboException(java.lang.Throwable ex)
JboException.ex - an excpetion to be added to the details list.
public JboException(java.lang.Class resBundleClass,
java.lang.String errorCode,
java.lang.Object[] params)
resBundleClass - the base class of the ResourceBundle that will supply the message text.errorCode - error code; a key associated with a message in the resource bundle.params - the error message's parameters.ResourceBundle
public JboException(java.lang.Class resBundleClass,
java.lang.String errorCode,
java.lang.Object[] params,
JboException[] exceptions)
resBundleClass - the base class of the ResourceBundle that will supply the message text.errorCode - error code; a key associated with a message in the resource bundle.params - the error message's parameters.ResourceBundle
public JboException(java.lang.Class resBundleClass,
java.lang.String errorCode,
java.lang.Object[] params,
java.lang.Exception[] excs)
**Primarily for use by Oracle Applications.** BC4J framework does not use this exception nor throws such an exception.
resBundleClass - the base class of the ResourceBundle that will supply the message text.errorCode - error code; a key associated with a message in the resource bundle.params - the error message's parameters.excs - An array if exceptions that this exception bundles as peer exceptions.ResourceBundle| Method Detail |
public final boolean hasPeerExceptions()
public java.lang.String getMessage()
getMessage in interface JboMessagegetMessage in class java.lang.Throwablepublic java.lang.String getLocalizedMessage(java.util.Locale l)
Locale.getLocalizedMessage in interface JboMessagel - a locale.public java.lang.String getBaseMessage()
getBaseMessage in interface JboMessagepublic java.lang.Class getResourceClass()
getResourceClass in interface JboMessageResourceBundle.public java.lang.String getLocalizedBaseMessage(java.util.Locale l)
Locale, but without inserting parameters.getLocalizedBaseMessage in interface JboMessagel - a locale.public java.lang.String getResourceName()
ResourceBundle used to localize or resolve messages.getResourceName in interface JboMessagepublic java.lang.Object[] getErrorParameters()
getErrorParameters in interface JboMessageprotected void setErrorParameters(java.lang.Object[] params)
public java.lang.String getErrorCode()
getErrorCode in interface JboMessagepublic java.lang.String getProductCode()
getProductCode in interface JboMessageJBO_PRODUCT_CODE.public java.lang.Object[] getDetails()
Details are usually used to accommodate lower-level exceptions. For example, if a SQLException is thrown in some low-level code, the Business Components for Java framework can catch it and represent it as one of the Business Component exceptions. The original SQLException becomes the first entry in the detail.
getDetails in interface JboMessagepublic java.lang.Throwable[] getExceptions()
Details are usually used to accommodate lower-level exceptions. For example, if a SQLException is thrown in some low-level code, the Business Components for Java framework can catch it and represent it as one of the Business Component exceptions. The original SQLException becomes the first entry in the detail.
public java.lang.String getDetailMessage()
getDetailMessage in interface JboMessagepublic void setDetails(java.lang.Object[] details)
setDetails in interface JboMessagedetails - an array which replaces the current list of details. array in this exception object.public void setExceptions(java.lang.Throwable[] details)
details - a list of Throwable exception objects array in this exception object.public void addToDetails(java.lang.Object obj)
addToDetails in interface JboMessageobj - an object to add to the details list.public void addToExceptions(java.lang.Throwable exception)
public boolean isLocalizable()
isLocalizable in interface JboMessagetrue if this message can be localized.protected JboExceptionHelper getJboExceptionHelper()
JboExceptionHelperpublic static java.lang.String getTypeNameFromId(int id)
public void setApplicationModule(ApplicationModule am)
public void printStackTrace()
Throwable and its backtrace to the standard error stream. This method prints a stack trace for this Throwable object on the error output stream that is the value of the field System.err. The first line of output contains the result of the Throwable.toString() method for this object. Remaining lines represent data previously recorded by the method Throwable.fillInStackTrace(). The format of this information depends on the implementation, but the following example may be regarded as typical:
java.lang.NullPointerException
at MyClass.mash(MyClass.java:9)
at MyClass.crunch(MyClass.java:6)
at MyClass.main(MyClass.java:3)
This example was produced by running the program:
class MyClass {
public static void main(String[] argv) {
crunch(null);
}
static void crunch(int[] a) {
mash(a);
}
static void mash(int[] b) {
System.out.println(b[0]);
}
}
printStackTrace in class java.lang.Throwablepublic void printStackTrace(java.io.PrintStream s)
Throwable and its backtrace to the specified print stream.printStackTrace in class java.lang.Throwablepublic void printStackTrace(java.io.PrintWriter s)
Throwable and its backtrace to the specified print writer.printStackTrace in class java.lang.Throwablepublic final void setNeedsEntityToVOMapping(boolean flag)
public final boolean needsEntityToVOMapping()
public void doEntityToVOMapping(ApplicationModule rootAm, ViewObject[] vos)
public boolean isAppendCodes()
public void setAppendCodes(boolean flag)
|
Oracle9i Business Components for Java API Reference Oracle9i Jdeveloper (9.0.4) B10391-01 | ||||||||||
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