org.minimalj.util.IdUtils Maven / Gradle / Ivy
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package org.minimalj.util;
import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.logging.Logger;
/**
* Every main entity in a minimal-j model must have a public field named id.
*
* This class provides get and set for this special field. It caches the
* reflection calls. Mostly it's used for minimal-j internal stuff.
*/
public class IdUtils {
private static final Logger logger = Logger.getLogger(IdUtils.class.getName());
private static final Map, Field> idFieldOfClass = new HashMap<>(200);
private static Field getIdField(Class clazz) {
if (idFieldOfClass.containsKey(clazz)) {
return idFieldOfClass.get(clazz);
}
try {
Field idField = clazz.getField("id");
idFieldOfClass.put(clazz, idField);
return idField;
} catch (NoSuchFieldException e) {
idFieldOfClass.put(clazz, null);
return null;
} catch (SecurityException e) {
throw new LoggingRuntimeException(e, logger, "getting Id failed");
}
}
/**
* Check if a class has an id field
*
* @param clazz class to check. Must not be null
* @return true if the given class has a field named id
*/
public static boolean hasId(Class clazz) {
return getIdField(clazz) != null;
}
/**
* Get the value of the id field. The id is converted to
* 'plain' if it is a ReadOnly id
*
* @param object object containing the id. Must not be null
* @return the value of the id field
*/
public static Object getId(Object object) {
Objects.requireNonNull(object);
try {
Field idField = getIdField(object.getClass());
if (idField == null) throw new IllegalArgumentException(object.getClass().getName() + " has no id field to get");
Object id = idField.get(object);
return id;
} catch (SecurityException | IllegalAccessException e) {
throw new LoggingRuntimeException(e, logger, "getting Id failed");
}
}
/**
* @param modelClass
* the model class for which an id should be pars (used to
* determine the class of the id - remember code classes could
* have string id)
* @param idString
* the id as string
* @return the id object usable for persistence
*/
public static Object parseId(Class modelClass, String idString) {
Field idField = getIdField(modelClass);
if (idField == null) throw new IllegalArgumentException(modelClass.getName() + " has no id field");
Class idFieldType = idField.getType();
if (idFieldType == Object.class || idFieldType == String.class) {
return idString;
} else if (idFieldType == Integer.class) {
return Integer.parseInt(idString);
} else if (idFieldType == Long.class) {
return Long.parseLong(idString);
} else {
throw new IllegalArgumentException();
}
}
public static boolean equals(Object a, Object b) {
if (a != null && hasId(a.getClass())) {
a = getId(a);
}
if (b != null && hasId(b.getClass())) {
b = getId(b);
}
return Objects.equals(a, b);
}
/**
* Set the value of the id in the given object
*
* @param object object containing a public id field. Must not be null
* @param id the new value. Can be null.
*/
public static void setId(Object object, Object id) {
try {
Field idField = getIdField(object.getClass());
if (idField != null) {
idField.set(object, id);
}
} catch (IllegalAccessException | IllegalArgumentException e) {
throw new LoggingRuntimeException(e, logger, "setting Id failed");
}
}
/**
* Set the value of the version in the given object
*
* @param object object containing a public version field. Must not be null
* @param version the new value.
*/
public static void setVersion(Object object, int version) {
try {
Field versionField = object.getClass().getField("version");
versionField.set(object, version);
} catch (NoSuchFieldException | SecurityException | IllegalAccessException e) {
throw new RuntimeException(e);
}
}
public static int getVersion(Object object) {
try {
Field versionField = object.getClass().getField("version");
return (Integer) versionField.get(object);
} catch (NoSuchFieldException | SecurityException | IllegalAccessException e) {
throw new RuntimeException(e);
}
}
public static void setHistorized(Object object, int historized) {
try {
Field historizedField = object.getClass().getField("historized");
historizedField.set(object, historized > 0);
} catch (NoSuchFieldException | SecurityException | IllegalAccessException e) {
throw new RuntimeException(e);
}
}
/**
* Get the value of the id field as String
*
* @param object object containing the id. Must not be null
* @return the value of the id field as String
*/
public static String getIdString(Object object) {
if (object == null) {
throw new NullPointerException();
}
return String.valueOf(getId(object));
}
}