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EclipseLink/Examples/SDO/BasicAPI
Contents
HelperContext
The helper context is the access point for all the SDO helpers and factories. If a type is defined in the TypeHelper for a HelperContext, then the DataFactory from that HelperContext can be used to create a DataObject of that Type.
Default HelperContext
SDO provides a default helper context. The helpers and factories obtained from the default helper context are the same ones available from the static INSTANCE variables on each of the helpers and factory classes. De-serialization is always performed in the scope of the default HelperContext.
HelperContext helperContext = HelperProvider.getDefaultContext();
Local HelperContext
SDO also allows for HelperContexts other than the default
HelperContext helperContext = new SDOHelperContext();
If you are using type safe DataObjects then you can provide the ClassLoader that contains the generated interfaces.
HelperContext helperContext = new SDOHelperContext(aClassLoader);
TypeHelper - Access Metadata
TypeHelper provides a convenient means of handling SDO metadata.
TypeHelper typeHelper = helperContext.getTypeHelper();
Get Types
You can lookup the SDO type by name and uri.
typeHelper.getType("http://www.example.org/customer-example", "customer-type");
You can also use the type safe interface classes to look up the corresponding SDO type.
typeHelper.getType(Customer.class);
Get Open Content Properties
You can lookup open content properties by name and uri.
typeHelper.getOpenContentProperty("http://www.example.org/customer-example", "phone-number");
XSDHelper - Access XML Schema Metadata
XSDHelper provides a convenient means of handling XML Schema metadata.
XSDHelper xsdHelper = helperContext.getXSDHelper();
Define
The XSDHelper contains a number of define methods for generating SDO types from an XML Schema.
URL xsdURL = new URL("http://www.example.org/customer-example/customer.xsd"); List types = xsdHelper.define(xsdUrl.openStream(), xsdUrl.toExternalForm());
Generate
The XSDHelper contains a number of generate methods to generate an XML Schema from SDO types.
String xmlSchema = xsdHelper.generate(types);
DataFactory - Create DataObjects
DataFactory provides a convenient means of creating SDO DataObjects.
DataFactory dataFactory = helperContext.getDataFactory();
Create
DataHelper - Convert Simple Values
DataHelper provides a convenient means of converting SDO data type values.
DataHelper dataHelper = helperContext.getDataHelper();
XMLHelper - Handle XML Data as DataObjects
XMLHelper provides a convenient means of handling XML data as DataObjects.
XMLHelper xmlHelper = helperContext.getXMLHelper();
Load
Load methods are used to unmarshal XML into DataObjects.
FileInputStream xmlInputStream = new FileInputStream("customer.xml"); XMLDocument xmlDocument = xmlHelper.load(xmlInputStream); DataObject customerDO = xmlDocument.getRootObject;
Save
Save methods are used to convert DataObjects to XML.
xmlHelper.save(customerDO, "http://www.example.org/customer-example", "customer", System.out);
The XML root information can also be encapsulated in an XMLDocument object.
XMLDocument xmlDocument = xmlHelper.createDocument(customerDO, "http://www.example.org/customer-example", "customer"); xmlHelper.save(xmlDocument, System.out, null);
CopyHelper - Create Copies of DataObjects
CopyHelper provides a convenient means of copying DataObjects.
CopyHelper copyHelper = helperContext.getCopyHelper();
Shallow Copy
Create a new DataObject containing the values of all dataType=true properties (excluding the ChangeSummary property).
DataObject shallowCopy = copyHelper.copyShallow(dataObject);
Deep Copy
Create a copy of the entire tree.
DataObject deepCopy = copyHelper.copy(dataObject);
EqualityHelper - Compare DataObjects
EqualityHelper provides a convenient means of comparing DataObjects.
EqualityHelper equalityHelper = helperContext.getEqualityHelper();
Shallow Equal
Two DataObjects are considered shallow equal if the data objects are of the same type and all the values of all dataType=true properties (excluding the ChangeSummary property) are equal.
boolean isShallowEqual = equalityHelper.equalShallow(dataObject1, dataObject2);
Deep Equal
Two DataObjects are considered deep equal if the data objects and the trees that they belong to are both equal.
boolean isDeepEqual = equalityHelper.equal(dataObject1, dataObject2);