零拷贝java_java arraycopy方法

import com.fasterxml.jackson.databind.JsonNode; //导入方法依赖的package包/类

/**

* Applies this schema rule to take the required code generation steps.

*

* A Java {@link Enum} is created, with constants for each of the enum

* values present in the schema. The enum name is derived from the nodeName,

* and the enum type itself is created as an inner class of the owning type.

* In the rare case that no owning type exists (the enum is the root of the

* schema), then the enum becomes a public class in its own right.

*

* The actual JSON value for each enum constant is held in a property called

* “value” in the generated type. A static factory method

* fromValue(String) is added to the generated enum, and the

* methods are annotated to allow Jackson to marshal/unmarshal values

* correctly.

*

* @param nodeName

* the name of the property which is an “enum”

* @param node

* the enum node

* @param container

* the class container (class or package) to which this enum

* should be added

* @return the newly generated Java type that was created to represent the

* given enum

*/

@Override

public JType apply(String nodeName, JsonNode node, JClassContainer container, Schema schema) {

JDefinedClass _enum;

try {

_enum = createEnum(node, nodeName, container);

} catch (ClassAlreadyExistsException e) {

return e.getExistingClass();

}

schema.setJavaTypeIfEmpty(_enum);

if (node.has(“javaInterfaces”)) {

addInterfaces(_enum, node.get(“javaInterfaces”));

}

// copy our node; remove the javaType as it will throw off the TypeRule for our case

ObjectNode typeNode = (ObjectNode)node.deepCopy();

typeNode.remove(“javaType”);

// If type is specified on the enum, get a type rule for it. Otherwise, we’re a string.

// (This is different from the default of Object, which is why we don’t do this for every case.)

JType backingType = node.has(“type”) ?

ruleFactory.getTypeRule().apply(nodeName, typeNode, container, schema) :

container.owner().ref(String.class);

JFieldVar valueField = addValueField(_enum, backingType);

// override toString only if we have a sensible string to return

if(isString(backingType)){

addToString(_enum, valueField);

}

addValueMethod(_enum, valueField);

addEnumConstants(node.path(“enum”), _enum, node.path(“javaEnumNames”), backingType);

addFactoryMethod(_enum, backingType);

return _enum;

}